Photoelectric conversion device and method of making the same

A photoelectric conversion device has a non-single-crystal semiconductor laminate member formed on a substrate having a conductive surface, and a conductive layer formed on the non-single-crystal semiconductor laminate member. The non-single-crystal semiconductor laminate member has such a structure that a first non-single-crystal semiconductor layer having a P or N first conductivity type, an I-type second non-single-crystal semiconductor layer and a third non-single-crystal semiconductor layer having a second conductivity type opposite the first conductivity type are laminated in this order. The first (or third) non-single-crystal semiconductor layer is disposed on the side on which light is incident, and is P-type. The I-type non-single-crystal semiconductor layer has introduced thereinto a P-type impurity, such as boron which is distributed so that its concentration decreases towards the third (or first) non-single-crystal semiconductor layer in the thickwise direction of the I-type layer.

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Description

This application is a continuation of Ser. No. 06/785,586, filed Oct. 8, 1985, which itself was a division of application Ser. No. 06/564,213 filed Dec. 22, 1983, both now abandoned.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of Ser. No. 08/408,781, filed Mar. 22, 1995, now abandoned; which is a reissue application for U.S. Pat. No. 5,077,223, which issued from Ser. No. 07/443,015, filed Nov. 29, 1989; which is a continuation of Ser. No. 06/785,586, filed Oct. 8, 1985, now abandoned; which is a divisional of Ser. No. 06/564,213 filed Dec. 22, 1983, now U.S. Pat. No. 4,581,476; which is a continuation-in-part of Ser. No. 06/525,459, filed Aug. 22, 1983, now U.S. Pat. No. 4,591,892.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a photoelectric conversion device which has a non-single-crystal semiconductor laminate member having formed therein at least one PIN junction, and a method for the manufacture of such a photoelectric conversion device.

2. Description of the Prior Art

A photoelectric conversion device of the type including a non-single-crystal semiconductor laminate member having formed therein at least one PIN junction usually has the non-single-crystal semiconductor laminate member formed on a substrate having a conductive surface and a conductive layer formed on the non-single-crystal semiconductor laminate member. The non-single-crystal semiconductor laminate member has at least a first non-single-crystal semiconductor layer of a P or N first conductivity type, an I type second non-single-crystal semiconductor layer formed on the first non-single-crystal semiconductor layer and a third non-single-crystal semiconductor layer formed on the second non-single-crystal semiconductor layer and having a second conductivity type opposite from the first conductivity type. The first, second and third non-single-crystal semiconductor layers form one PIN junction.

In this case, for example, the substrate has such a structure that a light-transparent conductive layer is formed as a first conductive layer on a light-transparent insulating substrate body. The first and third non-single-crystal semiconductor layers of the non-single-crystal semiconductor laminate member are P- and N-type, respectively. Further, the conductive layer on the non-single-crystal semiconductor laminate member is formed as a second conductive layer on the N-type third non-single-crystal semiconductor layer.

With the photoelectric conversion device of such a structure as described above, when light is incident on the side of the light-transparent substrate towards the non-single-crystal semiconductor laminate member, electron-hole pairs are created by the light in the I-type second non-single-crystal semiconductor layer. Holes of the electron-hole pairs thus created pass through the P-type first non-single-crystal semiconductor layer to reach the first conductive layer, and electrons flow through the N-type third non-single-crystal semiconductor layer into the second conductive layer. Therefore, photocurrent is supplied to a load which is connected between the first and second conductive layers, thus providing a photoelectric conversion function.

In conventional photoelectric conversion devices of the type described above, however, since the I-type second non-single-crystal semiconductor layer is formed to contain oxygen with a concentration above 1020 atoms/cm3, and/or carbon with a concentration above 1020 atoms/cm3, and/or phosphorus with a concentration as high as above 5×1017 atoms/cm3, the I-type non-single-crystal semiconductor layer inevitably contains impurities imparting N conductivity type, with far lower concentrations than in the P-type first non-single-crystal semiconductor layer and the N-type third non-single-crystal semiconductor layer.

In addition, the impurity concentration has such a distribution that it undergoes substantially no variations in the thickness direction of the layer.

On account of this, in the case where the second non-single-crystal semiconductor layer is formed thick with a view to creating therein a large quantity of electron-hole pairs in response to the incidence of light, a depletion layer, which spreads into the second non-single-crystal semiconductor layer from the PI junction defined between the P-type first and the I-type second non-single-crystal semiconductor layers, and a depletion layer, which spreads into the second non-single-crystal semiconductor layer from the NI junction defined between the N-type third and the I-type second non-single-crystal semiconductor layers, are not linked together. In consequence, the second non-single-crystal semiconductor layer has, over a relatively wide range thickwise thereof at the central region in that direction, a region in which the bottom of the conduction band and the top of the valence band of its energy band are not inclined in the directions, necessary for the holes and electrons to drift towards the first and third non-single-crystal semiconductor layers, respectively. Therefore, the holes and electrons of the electron-hole pairs created by the incident light in the second non-single-crystal semiconductor layer, in particular, the electrons and holes generated in, the central region of the second layer in its thickness direction, are not effectively directed to the first and third non-single-crystal semiconductor layers, respectively.

Accordingly, the prior art photoelectric conversion devices of the above-described structure have the defect that even if the second non-single-crystal semiconductor layer is formed thick for creating a large quantity of electron-hole pairs in response to incident light, a high photoelectric conversion efficiency cannot be obtained.

Further, even if the I-type second non-single-crystal semiconductor layer is thick enough to permit the depletion layer extending into the second non-single-crystal semiconductor layer from the PI junction between the P-type first non-single-crystal semiconductor layer on the side on which light is incident and the I-type second non-single-crystal semiconductor layer formed on the first semiconductor layer and the depletion layer extending into the second non-single-crystal semiconductor layer from the NI junction between the N-type third non-single-crystal semiconductor layer on the side opposite from the side of the incidence of light and the I-type second non-single-crystal semiconductor layer to be linked together, the expansion of the former depletion layer diminishes with the lapse of time for light irradiation by virtue of a known light irradiation effect commonly referred to as the Staebler-Wronsky effect, because the I-type non-single-crystal semiconductor layer forming the PI junction contains impurities which impart N conductivity type as mentioned previously. Finally, the abovesaid depletion layers are disconnected from each other. In consequence, there is formed in the central region of the second non-single-crystal semiconductor layer in the thickness direction thereof a region in which the bottom of the conduction band and the top of the valence band of the energy band are not inclined in the directions in which the holes and electrons of the electron-hole pairs created by the incidence of light are drifted towards the first and third non-single-crystal semiconductor layers, respectively.

Accordingly, the conventional photoelectric conversion devices of the abovesaid construction have the defect that the photoelectric conversion efficiency is impaired by the long-term use of the devices.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a novel photoelectric conversion device which is able to achieve a far higher photoelectric conversion efficiency than that obtainable with the conventional devices described above.

Another object of the present invention is to provide a novel photoelectric conversion device the photoelectric conversion efficiency of which is hardly or only slightly lowered by the Staebler-Wronski effect even if it is used for a long period of time.

Yet another object of the present invention is to provide a novel method which permits easy manufature of the photoelectric conversion device having the abovesaid excellent features.

In accordance with an aspect of the present invention, the first (or third) non-single-crystal semiconductor layer of the non-single-crystal laminate member is a layer on the side on which light is incident and is of P conductivity type, and the I-type second non-single-crystal semiconductor layer has introduced therein an impurity for imparting thereto P type conductivity, which is distributed so that the impurity concentration continuously decreases towards the third (or first) non-single-crystal semiconductor layer in the thickness direction of the I-type layer.

In this case, for example, the substrate is light-transparent and, accordingly, the first non-single-crystal semiconductor layer is disposed on the side where light is incident. The first and third non-single-crystal semiconductor layers are P- and N-type, respectively, and the I-type second non-single-crystal semiconductor layer has introduced therein an impurity for imparting thereto P-type conductivity, such as boron, so that its concentration in the region adjacent the first non-single-crystal semiconductor layuer is higher than the concentration in the region adjacent the third non-single-crystal semiconductor layer.

On account of this, even if the I-type second non-single-crystal semiconductor layer is formed relatively thick for creating therein a large quantity of electron-hole pairs in response to the incidence of light, the depletion layer extending into the second non-single-crystal semiconductor layer from the PI junction between the first and second non-single-crystal semiconductor layers and the depletion layer extending into the second non-single-crystal layer from the NI junction between the third and second non-single-crystal semiconductor layers are joined together. Accordingly, the holes and electrons which are produced in the central region of the second non-single crystal semicondutor layer in its thickwise direction are also effectively drifted towards the first and third non-sinlge-crystal semiconductor layers, respectively.

Moreover, even if the I-type second non-single-crystal semiconductor layer contains impurities which impart thereto N-type conductivity, because it is formed to contain oxygen and/or carbon and phosphorus in large quantities as described previously, boron, which imparts P-type conductivity and is introduced into the second non-single-crystal semiconductor layer, combines with oxygen, and/or carbon, and/or phosphorus. Besides, the P-type impurity introduced into the second non-single-crystal semiconductor layer has a high concentration in the region thereof adjacent the P-type first non-single-crystal semiconductor layer, that is, on the side of the PI junction. Therefore, the expansion of the depletion layer spreading into the second non-single-crystal semiconductor layer from the PI junction between the first and second non-single-crystal semiconductor layers is scarcely or only slightly diminished by the light irradiation effect (the Staeabler-Wronski effect).

Accordingly, the photoelectric conversion device of the present invention retains a high photoelectric conversion efficiency, even if used for a long period of time.

In accordance with another aspect of the present invention, the second non-single-crystal semiconductor layer, which has introduced thereinto an impurity which imparts P-type conductivity, with such a distribution that its concentration continuously decreases towards the N-type third (or first) non-single-crystal semiconductor layer in the thickness direction of the second layer, can easily be formed, through a CVD (Chemical Vapor Deposition) method using a semiconductor material gas and an impurity material gas for imparting P-type conductivity, merely by continuously decreasing (or increasing) the concentration of the depart material gas relative to the semiconductor material gas with the lapse of time.

Accordingly, the manufacturing method of the present invention allows ease in the fabrication of the photoelectric conversion device of the present invention which possesses the aforementioned advantages.

Other objects, features and advantages of the present invention will become more fully apparent from the detailed description take in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to D are sectional views schematically illustrating a sequence of steps involved in the manufacture of a photoelectric conversion device in accordance with an embodiment of the present invention;

FIG. 2A is a sectional view schematically illustrating a first embodiment of the photoelectric conversion device by the manufacturing method shown in FIG. 1;

FIG. 2B is a graph showing the concentration distributions of impurities introduced into first, second, and third non-single-crystal semiconductor layers of the photoelectric conversion device depicted in FIG. 2A;

FIG. 2C is a graph showing the energy band of the photoelectric conversion device shown in FIG. 2A;

FIG. 3 is a graph showing the voltage V (volt)current density I (mA/cm2) characteristic of the photoelectric conversion device of FIG. 2, in comparison with the characteristric of a conventional photoelectric conversion device;

FIG. 4 is a graph showing variations (%) in the photoelectric conversion efficiency of the photoelectric conversion device of the present invention, shown in FIG. 2, in comparison with a conventional photoelectric conversion device;

FIG. 5A is a sectional view schematically illustrating a second embodiment of the photoelectic conversion device of the present invention;

FIG. 5B is a graph showing concentration distributions of impurities introduced into first second, and third non-single-crystal semiconductor layers of the second embodiment of the present invention;

FIG. 6A is a sectional view sechematically illustrating a third embodiment of the photoelectric conversion device of the present invention; and

FIG. 6B is a graph showing the concentration distributions of impurities introduced into first, second, and third non-single-crystal semiconductor layers of the photoelectric conversion device shown in FIG. 6A.

 DESCRIPTION OF THE PREFERRED EMBODIMENTS

A description will be given of, with reference to FIGS. 1 and 2, of a first embodiment of the photoelectric conversion device of the present invention, along with the manufacturing method of the present invention.

The manufacture of the photoelectric conversion device starts with the preparation of an insulating, light transparent substrate 1 as of glass (FIG. 1).

A light-transparent conductive layer 2 is formed on the substrate 1 (FIG. 1B).

The conductive layer 2 is formed of, for example, a tin oxide, or a light-transparent conductive material consisting principally of a tin oxide. The conductive layer 2 is formed by, for example, a known vacuum evaporation method to a thickness of, for instance, 0.1 to 0.2 μm.

Next, a non-single-crystal semiconductor laminate member 3 is formed on the conductive layer 2 (FIG. 1C).

The non-single-crystal semiconductor laminate member 3 has such a stucture that a P-type non-single-crystal semiconductor layer 4, an I-type non-single-crystal semiconductor layer 5 and an N-type non-single-crystal semiconductor layer 6 are sequentially formed in this order. These non-single-crystal semiconductor layers 4, 5 and 6 form a PIN junction.

The non-single-crystal semiconductor layer 4 of the non-single-crystal semiconductor laminate member 3 is formed of, for example, Si, SixC1-x (where 0<×<1, for instance, ×=0.8) or Ge in an amorphous, semiamorphous, or microcrystalline form. The non-single-crystal semiconductor layer 4 is, for example, 100 angstroms thick. Moreover, the energy band gap of layer 4 is preferably larger than that of layer 5.

The non-single-crystal semiconductor layer 4 is formed by a CVD method which employs a semiconductor material gas composed of a hydride or halide of a semiconductor, such as Si, Si,Ge1-x (where oxl), or Ge, and an impurity material gas composed of a hydride or halide of a P-type impurity, for instance, diborane (B2H6), The CVD method may or may not employ a glow discharge (plasma), or light. In this case non-single-crystal semiconductor layer 4 has a p-type impurity introduced therein (boron) in a concentration above about 1×1018 and as high as 1×1019 to 6×1020 atoms/cm3, as shown in FIG. 2B.

The non-single-crystal semiconductor Iayer 5 is formed of, for instance, amorphous or semi-amorphous silicon, and has a thickness of, for example, 3 to 0.8 μm, in particular, 0.5 μm.

The non-single-crystal semiconductor layer 5 is formed by a CVD method which uses a semiconductor raw material gas composed of a hydride or halide of silicon, for example, SinH2n+2 (where n is greater than or equal to 1), or SiFm (where m is greater than or equal to 2), and a deposit material gas composed of a hydride or halide of a P-type impurity, for instance, diborane (B2H6), the CVD method may or may not employ a glow discharge (plasma), or light. In this case, by decreasing the concentration of the deposit material gas relative to the concentation of the semiconductor material gas within a range of less than 5 ppm with the lapse of time, the non-single-crystal semiconductor layer 5 is formed having introduced thereinto a P-type impurity (boron) the concentration of which linearly and continuously decreases in the thickness direction of the layer towards the non-single-crystal semiconductor layer 6 as shown in FIG. 2B. The concentration of the P-type impurity in the non-single-crystal semiconductor layer 5 is high on the side of the non-single-crystal semiconductor layer 4 as compared with the impurity concentration on the side of the non-single-crystal semiconductor layer 6. The ratio of the impurity concentration in the layer 5 at one end thereof adjacent the layer 6 to the concentration at the other end adjacent the layer 4 is 1/10 to 1/100, preferably, 1/20 to 1/40. In practice, the P-type impurity (boron) has a concentration of 2×1015 to 2×1017 atoms/cm3 at the end of the layer 5 adjacent the layer 4 and a concentration below 1×1015 atoms/cm3 at the end of the layer 5 adjacent the layer 6.

The non-single-crystal semiconductor layer 5 is formed by the abovesaid above said CVD method. In this case, the semiconductor raw material gas is one that is obtained by passing a semiconductor raw material gas through a molecular sieve or zeolite which adsorbs oxygen, and/or carbon and/or phosphorus. Accordingly, the non-single-crystal semiconductor layer 5 is formed to contain oxygen at a concentration less than 5×1019 atoms/cm3 as low as 5×1018 atoms/cm3, and/or carbon at a concentration level less than 4×1019 4×1018 atoms/cm3 as low as 4×1015 atoms/cm3, and/or phosphorus at a concentration at least as low as 5×1015 atoms/cm3.

The non-single-crystal semiconductor layer 6 is formed of, for instance, microcrystalline silicon, and has a thickness of, for example, 100 to 300 angstroms. Moreover, the energy band gap of layer 6 is preferably larger than that of layer 5.

The non-single-crystal semiconductor layer 6 is formed by a CVD method which employs a semiconductor raw material gas composed of a hydride or halide of silicon, for example, SinH2n+2 (where n is greater than or equal to 1) or SiFm (where m is greater than or equal to 2), and an impurity material gas composed of a hydride or halide of an N-type impurity, for instance, phosphine (PH3), the CVD method may or may not employ a glow discharge (plasma) or light. In this case, the non-single-crystal semiconductor layer 6 has an N-type impurity (phosphorus) introduced thereinto with a concentration of 1×1019 to 6×1020 atoms/cm3, as shown in FIG. 2.

Next, a conductive layer 7 is formed on the non-single-crystal semiconductor laminate member 3 made up of the non-single-crystal semiconductor layers 4, 5. Moreover, the energy band gap of layer 6 is, preferably larger than that of layer 5. and 6, that is, on the non-single-crystal semiconductor layer 6 (FIG. 1D).

The conductive layer 7 has such a structure that a light-transparent conductive layer 8 formed of, for example, a tin oxide or a light-transparent conductive material consisting principally of tin oxide, and a reflective conductive layer 9 formed of a metal, such as aluminum, silver or the like, are formed in this order. In this case, the conductive layer 8 is formed to a thickness of 900 to 1300 angstroms by means of, for example, vacuum evaporation, and the conductive layer 9 is also formed by vacuum evaporation.

In the manner described above, the first embodiment of the photoelectric conversion device of the present invention shown in FIG. 2A is manufactured.

With the photoelectric conversion device shown in FIG. 2A, when light 10 is incident on the side of the substate 1 towards the non-single-crystal semiconductor laminate member 3, electron-hole pairs are created in the I-type non-single-crystal semiconductor layer 5 in response to the light 10. The holes of the electron-hole pairs thus produced flow through the P-type non-single-crystal semiconductor layer 4 into the light-transparent conductive layer 2, and the electrons flow through the N-type non-single-crystal semiconductor layer 6 into the conductive layer 7. Therefore, photocurrent is supplied to a load which is connected between the conductive layers 2 and 7, thus providing the photoelectric conversion function.

In this case, the I-type non-single-crystal semiconductor layer 5 has a P-type impurity (boron) introduced thereinto which is distributed so that the impurity concentration continuously decreases towards the non-single-crystal semiconductor layer 6 in the thickness direction of the layer 5, as shown in FIG. 2B. On account of this, even if the I-type non-single-crystal semiconductor layer 5 is formed thick for generating therein a large quantity of electraonhole pairs in response to the incident of light, a depletion layer (not shown) which extends into the non-single-crystal semiconductor layer 5 from the PI junction 11 between the P-type non-single-crystal semiconductor layer 4 and the I-type non-single-crystal semiconductor layer 5 and a depletion (not shown) layer which extends into the non-single-crystal semiconductor layer 5 from the NI junction 12 between the N-type non-single-crystal semiconductor layer 6 and the non-single-crystal semiconductor layer 5 are joined together. Therefore, the I-type non-single-crystal semiconductor layer 5, as viewed from the bottom of the conduction band and the top of the valence bands of its enegy band, has a gradient that effectively causes holes and electrons drift towards the non-single-crystal semiconductor layers 4 and 6, respectively.

Accordingly, the photoelectric conversion device of the present invention, shown in FIG. 2A, achieves a higher photoelectric conversion efficiency than do the conventional photoelectric conversion devices.

A photoelectric conversion device corresponding to the conventional one and which is identical in construction with the photoelectric conversion device of the present invention shown in FIG. 2A, except that the concentration of the N-type impurity in the I-type non-single-crystal semiconductor layer 5 is about 1016 atoms/cm3 which is far lower than the impurity concentrations in the P-type and I-type non-single-crystal semiconductor layers 4 and 6 because the I-type non-single-crystal semiconductor layer 5 is formed to contain oxygen, and/or carbon, and/or phosphorus in large quantities, as referred to previously, provided a voltage V (volt)-current density I (mA/cm2) characteristic as indicated by curve 30 in FIG. 3. Accordingly, the open-circuit voltage was 0.89 V, the short-circuit current density I 16.0 mA/cm2, the fill factor was 61%, and the photoelectric conversion efficiency about 8.7%. In contrast thereto, the photoelectric conversion device of the present invention shown in FIG. 2A, provided the voltage V -current density I characteristic as indicated by curve 31 in FIG. 3, obtained. Accordingly, the open-circuit voltage V was 0.92 V, which is higher than was with the abovesaid device corresponding to the prior art device; the current density I was 19.5 mA/cm2; the fill factor was 68%; and the photoelectric conversion efficiency was about 12.2%. Incidentally, these results were obtained under the conditions wherein the photoelectric conversion devices, each having the non-single-crystal semiconductor laminate member 3 of a 1.05 cm2 area, were exposed to irradiation by light with an intensity of AM1 (100 mW/cm2).

In the case of the photoelectric conversion device of a present invention shown in FIG. 2A, since the I-type non-single-crystal semiconductor layer 5 has boron introduced thereinto as a P-type impurity the boron, combines with the oxygen and/or carbon and/or phosphorus contained in the non-single-crystal semiconductor layer 5. In addition, the concentration of the P-type impurity (boron) is high on the side of the PI junction 11, that is, on the side of the P-type non-single-crystal semiconductor layer 4. Accordingly, the expansion of the depletion layer extending into the I-type non-single-crystal semiconductor layer 5 from the PI junction 11 between the P-type non-single-crystal semiconductor layer 4 and the I-type non-single-crystal semiconductor layer 5 is hardly or only slightly diminished by the light irradiation effect (the Staebler-Wronski effect).

For this reason, according to the photoelectric conversion device of the present invention, the aforesaid high photoelectric conversion efficiency is hardly impaired by long-term use.

In addition the aforesaid photoelectric conversion device corresponding to the prior art one which provided the voltage V-current density I characteristeristic indicated by the curve 30 in FIG. 3, exhibited variations (%) in the photoelectric conversion efficiency relative to the light irradiation time T (hr) as indicated by curve 40 in FIG. 4. In contrast thereto, in the case of the photoelectric conversion device of the present invention, the photoelectric conversion efficiency varied with the light irradiation time T as indicated by curve 41 in FIG. 4. That is, the photoelectric conversion efficiency slightly increased in an early stage and, thereafter, it decreased only very slightly with time. These result were also obtained under the same conditions mentioned previously in connection with FIG. 3.

As described above, the first embodiment of the photoelectric conversion device of the present invention possesses the advantage that it provides a higher photoelectric conversion efficiency than do the conventional photoelectric conversion devices, even when used for a long period of time.

Further, the manufacturing method of the present invention shown in FIG. 1 employs a series of simple steps such as forming the conductive layer 2 on the substrate 1, forming the non-single-crystal semiconductor layers 4, 5 and 6 on the conductive layer 2 through the CVD method to provide the non-single-crystal semiconductor laminate member 3 and forming the conductor layer 7 on the non-single-crystal semiconductor laminate member 3, The I-type non-single-crystal semiconductor layer 5 is formed by a CVD method using a semiconductor raw material gas and a P-type deposit (boron) gas and, in this case, simply by continuously changing the concentration of the deposit material gas relative to the concentration of the semiconductor raw material gas as a function of time, the P-type impurity is introduced into the layer 5 with such a concentration distribution that its concentration continuously decreases towards the non-single-crystal semiconductor layer 6 in the thickness direction of the layer 5.

Accordingly, the manufacturing method of the present invention allows ease in the fabrication of the photoelectric conversion device of the present invention which has the aforementioned advantages.

Incidentally, the first embodiment illustrated in FIG. 2 shows the case in which the impurity contained in the I-type non-single-crystal semiconductor layer 5 has such a concentration distribution as shown in FIG. 2B in which the concentration linearly and continuously drops towards the non-single-crystal semiconductor layer 6.

As will be appreciated from the above, however, even if the impurity introduced in the I-type non-single-crystal semiconductor layer 5 has a concentration profile such that the impurity concentration drops stepwise and continuously towards the non-single-crystal semiconductor layer 6 as shown in FIG. 5 which illustrates a second embodiment of the present invention, and even if the impurity in the layer 5 has such a concentration distribution that the impurity concentration decreases non-linearily and continuously towards the layer 6 in a manner to obtain a concentration distribution such that the impurity concentration abruptly drops in the end portion of the layer 5 adjacent the layer 6 as shown in FIG. 6 which illustates a third embodiment of the present invention, the photoelectric conversion device of the present invention produces the same excellent operation and effects as are obtainable with the photoelectric conversion device shown in FIG. 2.

Further, the foregoing description has been given of the case where light is incident on the photoelectric conversion device from the side of the substrate 1 and, accordingly, the non-single-crytal semiconductor layer 4 of the non-single-crystal semiconductor laminate member 3 on the side on which the light is incident is P-type.

But, also in case where the photoelectric conversion device is arranged to be exposed to light on the side opposite from the substrate 1, the non-single-crystal semiconductor layer 6 of the non-single-crystal semiconductor laminate member 3 on the side of the incidence of light is P-type, the non-single-crystal semiconductor layer 4 on the side of the substrate 1 is N-type and the non-single-crystal semiconductor layer 5 has introduced thereinto a P-type impurity (boron) which is distributed so that the impurity concentration continuously decreases towards the non-single-crystal semiconductor layer 4 in the thickness direction of the layer 5, the same excellent operation and effects as described previously can be obtained, as will be understood from the foregoing description. In this case, however, the conductive layer 7 must be substituted with a light-transparent one. The substrate 1 and the conductive layer 2 need not be light-transparent.

While in the foregoing the non-single-crystal semiconductor laminate member 3 has one PIN junction, it is also possible to make the laminate member 3 have two or more PIN junctions and to form each of the two or more I-type non-single-crystal semiconductor layers so that the P-type impurity introduced therein may have the aforesaid concentration distribution.

It will be apparent that many modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

Claims

1. A method for manufacturing a photoelectric conversion device comprising the steps of:

forming a first impurity, non-single crystalline semiconductor layer of a first conductivity type on a substrate in a reaction chamber;
depositing a substantially intrinsic semiconductor layer on said first impurity layer by introducing process gas into said reaction chamber together with a dopant gas comprising boron, the introducing ratio of said dopant gas to said process gas being monotonically decreased throughout the deposition of the intrinsic semiconductor layer in order that the impurity concentration in said intrinsic semiconductor layer is monotonically decreased from the interface between said first impurity and intrinsic semiconductor layers;
forming a second impurity, non-single crystalline semiconductor layer of a second conductivity type opposite to said first conductivity type, the impurity semiconductor layer adjacent to the heavier doping side of said intrinsic layer having the same conductivity type as that corresponding to the dopant gas for said intrinsic semiconductor layer;
forming an electrode arrangement for said conversion device; and
reducing the oxygen concentration in said substantially intrinsic layer to a level less than 5×1019 atoms/cm3.

2. A manufacturing method according to claim 1 5, wherein the process gas is a hydride or halide of silicon and the dopant gas is a hydride or halide of boron.

3. A manufacturing method according to claim 2 5, wherein the concentration of the dopant gas relative to the concentration of the process gas is continuously decreased with time within a range of less than 5 ppm.

4. A method as in claim 3 where 5, wherein said level is as low as 5×1018 atoms/cm3.

5. A manufacturing method as in claim 1 where for manufacturing a photoelectric conversion device comprising the steps of:

forming a first impurity, non-single crystalline semiconductor layer of a first conductivity type on a substrate in a reaction chamber;
depositing a substantially intrinsic semiconductor layer on said first impurity layer by introducing process gas into said reaction chamber together with a dopant gas comprising boron, the introducing ratio of said dopant gas to said process gas being monotonically decreased throughout the deposition of the intrinsic semiconductor layer in order that the impurity concentration in said intrinsic semiconductor layer is monotonically decreased from the interface between said first impurity and intrinsic semiconductor layers;
forming a second impurity, non-single crystalline semiconductor layer of a second conductivity type opposite to said first conductivity type, the impurity semiconductor layer adjacent to the heavier doping side of said intrinsic layer having the same conductivity type as that corresponding to the dopant gas for said intrinsic semiconductor layer;
forming an electrode arrangement for said conversion device; and
reducing the oxygen concentration in said substantially intrinsic layer to a level less than 5×1019 atoms/cm3,
wherein the reduction of the oxygen concentration is effected by passing said process gas through a molecular sieve or zeolite which adsorbs oxygen.

6. A method of claim 1 5, wherein said semiconductor layer is made of amorphous semiconductor.

7. A method of claim 6 5, wherein said process gas is filtered in advance of introduction into said reaction chamber.

8. A method for manufacturing a photoelectric conversion device comprising the steps of:

forming a first impurity, non-single crystalline semiconductor layer of a first conductivity type on a substrate in a reaction chamber;
depositing a substantially intrinsic semiconductor layer on said first impurity layer by introducing process gas into said reaction chamber together with a dopant gas comprising boron, the introducing ratio of said dopant gas to said process gas being monotonically decreased throughout the deposition of the intrinsic semiconductor layer in order that the impurity concentration in said intrinsic semiconductor layer is monotonically decreased from the interface between said first impurity and intrinsic semiconductor layers;
forming a second impurity, non-single crystalline semiconductor layer of a second conductivity type opposite to said first conductivity type, the impurity semiconductor layer adjacent to the heavier doping side of said intrinsic layer having the same conductivity type as that corresponding to the dopant gas for said intrinsic semiconductor layer;
forming an electrode arrangement for said conversion device; and
reducing the carbon concentration in said substantially intrinsic layer to a level less than 4×1019 atoms/cm3.

9. A method as in claim 8 where 10, wherein said level is as low as 4×1015 atoms/cm3.

10. A manufacturing method as in claim 8 method for manufacturing a photoelectric conversion device comprising the steps of:

forming a first impurity, non-single crystalline semiconductor layer of a first conductivity type on a substrate in a reaction chamber;
depositing a substantially intrinsic semiconductor layer on said first impurity layer by introducing process gas into said reaction chamber together with a dopant gas comprising boron, the introducing ratio of said dopant gas to said process gas being monotonically decreased throughout the deposition of the intrinsic semiconductor layer in order that the impurity concentration in said intrinsic semiconductor layer is monotonically decreased from the interface between said first impurity and intrinsic semiconductor layers;
forming a second impurity, non-single crystalline semiconductor layer of a second conductivity type opposite to said first conductivity type, the impurity semiconductor layer adjacent to the heavier doping side of said intrinsic layer having the same conductivity type as that corresponding to the dopant gas for said intrinsic semiconductor layer;
forming an electrode arrangement for said conversion device; and
reducing the carbon concentration in said substantially intrinsic layer to a level less than 4×1018 atoms/cm3;
wherein the reduction of the carbon concentration is effected by passing said process gas through a molecular sieve or zeolite which adsorbs carbon.

11. A method for manufacturing a photoelectric conversion device comprising the steps of:

forming a first impurity, non-single crystalline semiconductor layer of a first conductivity type on a substrate in a reaction chamber;
depositing a substantially intrinsic semiconductor layer on said first impurity layer by introducing process gas into said reaction chamber together with a dopant gas comprising boron, the introducing ratio of said dopant gas to said process gas being monotonically decreased throughout the deposition of the intrinsic semiconductor layer in order that the impurity concentration in said intrinsic semiconductor layer is monotonically decreased from the interface between said first impurity and intrinsic semiconductor layers;
forming a second impurity, non-single crystalline semiconductor layer of a second conductivity type opposite to said first conductivity type, the impurity semiconductor layer adjacent to the heavier doping side of said intrinsic layer having the same conductivity type as that corresponding to the dopant gas for said intrinsic semiconductor layer;
forming an electrode arrangement for said conversion device; and
reducing the phosphorus concentration in said substantially intrinsic layer to a level less than 5×1015 atoms/cm3.

12. A method as in claim 11 where said level is as low as 5×1015 atoms/cm3.

13. A manufacturing method as in claim 11 where the reduction of the phosphorus concentration is effected by passing said process gas through a molecular sieve or zeolite which adsorbs phosphorus.

14. A method as in claims 1, 8, or 11 where 5 or 10, wherein said first conductivity type is n-type and said second conductivity type is p-type.

15. A method as in claims 1, 8, or 11 where 5 or 10, wherein said first conductivity type is p-type and said second conductivity type is n-type.

16. A method as in claims 1, 8, or 11 where 5 or 10, wherein the ratio of said impurity concentration at the interface between said second impurity and intrinsic semiconductor layers to that at said interface between said first impurity and the intrinsic semiconductor layers is 1/10 to 1/100.

17. A method as in claim 16 where wherein said ratio is 1/20 to 1/40.

18. A method as in claims 1, 8, or 11 where 5 or 10, wherein said impurity is boron and the boron concentration at said interface between the p-type and intrinsic layers is 2×1015 to 2×1017 atoms/cm3.

19. A method as in claims 1, 8, or 11 where 5 or 10, wherein said first layer comprises p-type, non-single crystalline SixC1-x (0<x<1) and said impurity comprises boron.

Referenced Cited
U.S. Patent Documents
2882243 April 1959 Milton
2971607 February 1961 Caswell
3155621 November 1964 Cowlard
3462422 February 1969 Deal
3492175 January 1970 Conrad et al.
3785122 January 1974 Yatsurugi et al.
3892606 July 1975 Chappelow et al.
3982912 September 28, 1976 Yatsurugi et al.
4064521 December 20, 1977 Carlson
4109271 August 22, 1978 Pankove
4117506 September 26, 1978 Carlson et al.
4226898 October 7, 1980 Ovshinsky et al.
4239554 December 16, 1980 Yamazaki
4409311 October 11, 1983 Kawamura et al.
4409805 October 18, 1983 Wang
4418132 November 29, 1983 Yamazaki
4425143 January 10, 1984 Nishizawa et al.
4459163 July 10, 1984 MacDiarmid et al.
4460670 July 17, 1984 Ogawa
4461820 July 24, 1984 Shirai et al.
4464521 August 7, 1984 Gruber
4469527 September 4, 1984 Sugano et al.
4471042 September 11, 1984 Komatsu et al.
4485146 November 27, 1984 Mizuhashi
4489782 December 25, 1984 Yamazaki
4490208 December 25, 1984 Tanaka et al.
4520380 May 28, 1985 Ovshinsky et al.
4549889 October 29, 1985 Yamazaki
4581476 April 8, 1986 Yamazaki
4582395 April 15, 1986 Morozumi
4591892 May 27, 1986 Yamazaki
4681984 July 21, 1987 Moeller
4710786 December 1, 1987 Ovshinsky et al.
4742012 May 3, 1988 Matsumura et al.
4758527 July 19, 1988 Yamazaki
4766477 August 23, 1988 Nakagawa et al.
4843451 June 27, 1989 Watanabe et al.
4888305 December 19, 1989 Yamazaki et al.
4889783 December 26, 1989 Yamazaki
5043772 August 27, 1991 Yamazaki
5077223 December 31, 1991 Yamazaki
5294555 March 15, 1994 Mano et al.
5315132 May 24, 1994 Yamazaki
5349204 September 20, 1994 Yamazaki
5391893 February 21, 1995 Yamazaki
5521400 May 28, 1996 Yamazaki
5543636 August 6, 1996 Yamazaki
Foreign Patent Documents
0180781 May 1986 EP
2130008 September 1985 GB
51-1389 January 1976 JP
54-136274 October 1979 JP
54-158190 December 1979 JP
55-11329 January 1980 JP
55-13939 January 1980 JP
55-29154 March 1980 JP
55-78524 June 1980 JP
53-152887 June 1980 JP
56-135968 October 1981 JP
57-40940 March 1982 JP
57-110356 July 1982 JP
57-146561 August 1982 JP
57-146562 August 1982 JP
57-182546 October 1982 JP
57187972 November 1982 JP
57-187972 November 1982 JP
58-28873 February 1983 JP
58-92218 June 1983 JP
58-155774 September 1983 JP
59-35423 February 1984 JP
59-35488 February 1984 JP
57-211078 July 1984 JP
59-115574 July 1984 JP
60-96391 September 1994 JP
Other references
  • Fifth E.C., Photovoltaic Solar Energy Conference, Oct. 1983, Kavouri (Athens), Greece.*
  • Moller et al., low level baron doping and tight induced effects in amorphous silicon. IEEE photovoltaic specialist conference, San Diego, CA Sep. 27-30, 1982, Published Jan. 1983.
  • Amorphous Semiconductor, Technologies and Devices, 1982, Editor Y. Hamakawa, et al., pp. 194-198 North Holland Publishing Corporation [QC 611.8 A5J3].
  • Declaration Of Robert Cote In Support of SEL's Motion For Summary Judgment Dismissing Samsung's Inequitable Conduct Defense To The '636 Patent.
  • Japanese Patent No. 55-29155 issued Mar. 1, 1980 to Yamazaki.
  • Japanese Patent No. 57-40940 issued Mar. 6, 1982 to Shibamata et al.
  • Japanese Patent No. 54-136274 issued Oct. 23, 1979 to Hayafuji et al.
  • Uchida et al., “Large Area Amorphous Silicon Solar Cell”, Denshi Zairyou, Jan. 1980, pp. 75-81.
  • Hirose, “Amorphous Silicon Material”, Denshi Zairyou, Jan. 1981, pp. 56-58.
  • Japanese Patent No. 56-4287 issued Jan. 17, 1981 to Carlson.
  • Japanese Patent No. 56-45083 issued Apr. 24, 1981 to Carlson.
  • Japanese Patent No. 58-92218 issued Jun. 1, 1983 to Yamazaki.
  • Scilla et al., Determination of Metallic Impurities in a-Si:H by SIMS, Surface and Interface Analysis, vol. 4, No. 6, 1982, pp. 253-254.
  • Japanese Patent No. 57-187972 isued Nov. 18, 1982 to Uchida et al.
  • Japanese Patent No. 56-64476 issued Jun. 1, 1981 to Allen et al.
  • Japanese Patent No. 57-1272 issued Jan. 6, 1982 to Uchida et al.
  • Japanese Patent Document 57-13777 with English translation published Jan. 23, 1982, Japan.
  • Szydlo et al., “High Current Post-Hydrogenated Chemical Vapor Deposited Amorphous Silicon PIN Diodes”, pp. 988-990, Jun. 1, 1992.
  • Kamei et al., “Deposition and Extensive Light Soaking of Highly Pure Hydrogenated Amorphous Silicon”, pp. 2380-2382, Apr. 22, 1996.
  • D. Carlson, “The Effects of Impurities and Temperature on Amorphous Silicon Solar Cells”, IEEE Technical Digest for the 1977 IEDM in Washington, D.C., pp. 214-217 (IEEE New York, 1977).
  • A. Delahoy and R. Griffith, “Impurities Effects In a-Si:H Solar Cells Due to Air, Oxygen, Nitrogen, Phosphine, or Monochlorosilane in the Plasma”, Journal of Applied Physics, vol. 52, No. 10, pp. 6337-6346 (1981).
  • P. Vanier, et al., “Study of Gap States in a-Si:H Alloys By Measurements of Photoconductivity and Spectral Response of MIS Solar Cells”, American Institute of Physics, Proceedings of the International Conference on Tetrahedrally Bonded Amorphous Semicondutors, Carefree, Arizona, pp. 237-232 (1981).
  • P. Vanier, et al., “New Features of the Temperature Dependence of Photoconductivity in Plasma-Deposited Hydrogenated Amorphous Silicon Alloys”, Journal of Applied Physics, vol. 52, No. 8, pp. 5235-5242 (1981).
  • A. Delahoy, et al., “Impurity Effects in a-Si:H Solar Cells”, IEEE Proceedings of the 15th Photovoltaic Specialists Conference, Kissimmee, Florida, pp. 704-712 (1981).
  • R. Corderman, et al., “Mass Spectrometric Studies of Impurities in Silane and Their Effects on the Electronic Properties of Hydrogenated Amorphous Silicon”, Journal of Applied Phyusics, vol. 54, No. 7, pp. 3987-3992 (1983), submitted Sep., 1982.
  • The prior work of C.C. Tsai as evidenced by the document: C.C. Tsai, et al., “Amorphous Si Prepared in a UHV Plasma Deposition System”, Journal on Non-Crystalline Solids, Proceedings of the Tenth International Conference on Amorphous and Liquid Semiconductors in Tokyo, vols. 59&60, pp. 731-734 (1983).
  • Z. Hirose, “Amorphous Silicon”, Nikkei Electronics—Special Issue, pp. 163-179 (Dec. 20, 1982).
  • Yusa, et al., “Ultrahigh Purification of Silane for Semiconductor Silicon”, Journal of the Electrochemical Society: Solid-State Science and Technology, vol. 122, No. 12, pp. 1700-1705 (1975).
  • T. Takaishi, et al., “Changes in the Sieving Action and Thermal Stability of Zeolite a Produced by Ion-Exchange”, Journal of the Chemical Society: Faraday Transactions I, part. 1, pp. 97-105 (1975).
  • D. Carlson, “Amorphous Thin Films for Terrestrial Solar Cells”, D.E. Carlson, Journal of Vacuum Science Technology, vol. 20, No. 3, pp. 290-295 (Mar. 1982).
  • C. Magee and D. Carlson, “Investigation of the Hydrogen and Impurity Contents of Amorphous Silicon by Secondary Ion Mass Spectrometry”, Solar Cells, vol. 2, pp. 365-376 (1980).
  • A. Delahoy and R. Griffity, “Impurities Effects In a-Si:H Solar Cells Due to Air, Oxygen, Nitrogen, Phosphine, or Monochlorosilane in the Plasma”, Journal of Applied Physics, vol. 52, No. 10, pp. 6337-6346 (1981).
  • W. Spear, et al., “Doping of Amorphous Silicon By Alkali Ion Implantations”, Philosophical Magazine B, vol. 39, No. 2, pp. 159-165 (1979).
  • R. Kriegler, et al., “The Effect of HCl and Cl2 on the Thermal Oxidation of Silicon”, Journal of Electrochemical Society: Solid-State Science and Technology, p. 388-392 (1972).
  • S. Sze, “Physics of Semiconductor Devices”, John Wiley & Sons, pp. 567-571 (1969).
  • H. Tuan, “Amorphous Silicon Thin Film Transistor and its Applications to Large-Area Electronics”, Materials Research Society Symposia Proceedings, vol. 33, pp. 247-257 (1984).
  • K. Harii et al., “Self-Alignment Type a-Si:H TFT”, 27p-L-16, Extended Abstract of the Japanese Applied Physics Society (Sep. 27, 1983).
  • C.C. Tsai, “Impurities in Bulk a-Si:H, Silicon Nitride, and at the a-Si:H/Silicon Nitride Interface”, Material Research Society Symposia Proceedings, vol. 33, pp. 297-300 (1984).
  • Tsai et al., “Amorphous Si Prepared in a UHV Plasma Deposition System”, Journal of Non-Crystalline Solids, Proceedings of the Tenth International Conference on Amorphous and Liquid Semiconductors in Tokyo, vols. 59 & 60, p. 731-734 (1983).
  • E.H. Snow, A.S. Grove, B.E. Deal; J. Appl. Phys., vol. 36, No. 5, pp. 1664-1673, Published 1965, “Ion Transport Phenomena in Insulating Films”.
  • A.S. Grove, P. Lamond, et al.; Electro-Technology, p. 40-43, Published 1965; “Stable MOS Transistors”.
  • B. Yurash and B.E. Deal; J. Electrochem. Soc., 15, 1191, Published 1968; “A Method for Determining Sodium Content of Semiconductor Processing Materials”.
  • E.H. Nicollian and J.R. Brews, MOS (Metal-Oxide-Semiconductor) Physics and Technology, Chap. 5, “Control of Oxide Charges”, pp. 754-775, 1982.
  • P.F. Schmidt, Solid-State Tech., 26(6), 147, 1983; “Furnace Contamination and its Remedies”.
  • S. Mayo, J. Appl. Phys., 47, 4012, 1976.
  • J.R. Davis, Instabilities in MOS Devices, Chap. 4, “Mobile Ions”, pp. 65-81, 1981.
  • P.F. Schmidt and C.W. Pearce, J. Electrochem. Soc., 128, pp. 630-636, 1981; “A Neutron Activation Analysis Study of the Sources of Transition Group Metal Contamination in the Silicon Device Manufacturing Process”.
  • R.W. Lee, J. Chem. Phys., vol. 38, No. 2, pp. 448-455, 1963; “Diffusin of Hydrogen in Natural and Synthetic Fused Quartz”.
  • G. Hetherington and L.W. Bell, Phys. Chem. Glasses, vol. 8, No. 5, pp. 206-208, Oct. 1967; “Letter to the Editor”.
  • R.J. Kriegler et al., J. Electrochem. Soc., 119, 388, 1972; “The Effect of HCL and CL2 on the Thermal Oxidation of Silicon”.
  • R.J. Kriegler, Proc. Semiconductor Silicon 1973, The Electrochemical Society, Princeton, N.J., p. 363, 1973.
  • S. Mayo and W.H. Evans, J. Electrochem. Soc., 124, pp. 780-785, 1977; “Development of Sodium Contamination in Semiconductor Oxidation Atmospheres at 1000° C.”.
  • B.E. Deal, Jap. J. Appl. Phys., 16(Suppl. 16-1), pp. 29-35, 1977; “ Invited: New Developments in Materials and Processing Aspects of Silicon Device Technology”.
  • H. Dersch, J. Stuke and J. Beichler; Phys. Stat. Sol. (b)105,265, 1981 “ Electron Spin Resonance of Doped Glow-Discharge Amorphous Silicon”.
  • M. Stutzmann, et al., Phy. Rev. 32, pp 23, 1985, “Light-induced Metastable Defects In Hydrogenated Amorphous Silicon—A Systematic Study”.
  • J. Knights, et al., “Phys. Rev. Lett., 39, 712, 1977” pp 279-284 (1980) “Electronic and Structural Properties of Plasma-Deposited a-Si:O:H— The Story of O2”.
  • W. Beyer and R. Fisher, Appl. Phys. Lett., 31, 850, 1977.
  • J. Knights, R. Street, and G. Lucovski, Journal of Non-Crystalline Solids, 35&36, 279-284, 1980.
  • R. B. Swaroop, “Advances in Silicon Technology for the Semiconductor Industry”, Solid State Technology, 1983, pp. 111-114.
  • R. Crandall, D. Carlson, and H. Weakleam, Applied Physics Letters., vol. 44, pp. 200-201, 1984 “ Role of Carbon in Hydrogenated Amorphous Silicon Solar Cell Degradation”.
  • G. Scilla and G. Ceaser, Xerox Corporation Reported, “Determination on Metallic Impurities in a-Si:H by SIMS” Surface and Interface Analysis, vol. 4, No. 6, 1982.
  • R. Colclaser, Wiley, “Microelectronics: Processing and Device Design”, 1980.
  • A. Delahoy and R. Griffith, Proceeding of the 15th IEEE Photovoltaics Specialists Conference, IEEE Press, pp. 704-712, 1981, “Impurity Effects In a-Si:H Solar Cells”.
  • S. Sze, “Physics of Semiconductor Devices”, Div. of John Wiley & Sons, 1981.
  • M. Hirose, In Hydrogenated Amorphous Silicon, Semiconductors and Semimetals Series, vol. 21, 1984.
  • Paesler et al., Phys. Rev. Lett., 41, 1492, 1978, “New Development in the Study of Amorphous Silicon Hydrogen Alloys: The Story of O”.
  • Y. Matsushita et al., Jap. J. Appl. Phys. 19. L101, 1980, “A Study on Thermally Induced Microdefects in Czochralski-Grown Silicon Crystals: Dependence on Annealing Temperature and Starting Materials”.
  • J. Leroueille, Physics Stat. Sol. (A)67, 177, 1981, “Influence of Carbon on Oxygen Behavior in Silicon”.
  • D. Staebler, R. Crandall, and R. Williams, “Stability Test on p-i-n Amorphous Silicon Solar Cells”, Conference Record of the 15th IEEE Photovoltaic Specialists Conference, 249-250, 1981.
  • H. Branz, “Hydrogen Collision Model of Light-Induced Metastability in Hydrogenated Amorphous Silicon”, Solid State Communications, in Press, 9/97.
  • S. Guha, Conference Record of the 25th Photovoltaics Specialists Conference, pp. 1017-1022, IEEE Press, 1996, “Amorphous Silicon Alloy Solar Cells and Modules—Opportunities and Challenges”.
  • D. Neamen, Semiconductor Physics and Devices, Irwin Press, 1992.
  • J. Pankove, Hydrogenated Amorphous Silicon, vol. 21 A,B,C,D Semiconductors and Semimetals Series, Academic Press, 1984.
  • B. Ali Khan and R. Pandya, “Activation Energy of Source-Drain Current in Hydrogenated and Unhydrogenated Polysilicon Thin-Film Transistors” IEEE Transactions on Electron Devices, vol. 37, No. 7, Jul. 1990.
  • A. Pecora et al., “Off-Current in Polycrystalline Silicon Thin Film Transistors: An Analysis of the Thermally Generated Component”, Solid-State Electronics, vol. 38, No. 4, pp. 845-850, (1995).
  • D. Passoja et al., Some Aspects of the Structure-Properties Relationships Associated With Haze in SOS, Journal of Crystal Growth, vol. 58, 1982, pp. 44-52.
  • Silicon on Sapphire, Update II, Union Carbide, Bulletin 1980, F-EMG-5801-4M, 4 pages.
  • T.J. Donahue et al., PECVD of Silicon Epitaxial Layers, Semiconductor International, Aug. 1985, pp. 142-146.
  • R.P. Roberge et al., Gaseous Impurity Effects in Silicon Epitaxy, Semiconductor International, Jan. 1987, pp. 77-81.
  • S.K. Iya, Production of Ultra-High-Purity Polycrystalline Silicon, Journal of Crystal Growth, vol. 75, 1986, pp. 88-90.
  • P.A. Taylor, Purification Techniques and Analytical Methods for Gaseous and Metallic Impurities in High-Purity Silane, Journal Crystal Growth, vol. 89, 1988, pp. 28-38.
  • A. Yusa et al., Ultrahigh Purification of Silane for Semiconductor Silicon, Journal of the Electrochemical Society, vol. 122, No. 12, Dec. 1975, pp. 1700-1705.
  • G. Robertson, et al., Boron -Free Silicon Detectors, Final Report of Sep. 1984 to Jun. 1988, Wright Research and Development Center, Materials Laboratory, WRDC-TR-90-4079, Sep. 1990, pp. 121-131.
  • J. Maurits et al., Abstracts of the Electrochemical Society, 90-2, 1990.
  • Silicon Source Gases for Chemical Vapor Deposition, Solid State Technology, May 1989, pp. 143-147.
  • R. Coderman et al., Mass Spectrometric Studies of Impurities in Silane and Their Effects on the Electronic Properties of Hydrogenated Amorphous Silicon, J. Appl. Phys., vol. 54, No. 7, Jul. 1983, pp. 3987-3992.
  • C. Magee et al., Investigation of the Hydrogen and Impurity Contents of Amorphous Silicon by Secondary Ion Mass Spectrometry, Solar Cells, vol. 2, 1980, pp. 365-376.
  • T. Takahashi et al., Instrumentation, 47, 3, 1976.
  • Metheson Gases and Equipment Catalogue, 1992.
  • J. Maurits, Advanced Silicon Materials Inc. 1997.
  • P. Schmidt, Contamination-Free High Temperature Treatment of Silicon or Other Materials, J. Electrochem. Soc.: Solid-State Science and Technology, Jan. 1983, pp. 186-189.
  • J. Maurits et al., The Effect of Polysilicon Impurities on Minority Carrier Lifetime in CZ Silicon Crystals, 22nd IEEE Photovoltaic Specialists Conference, Oct. 1991, pp. 309-314.
  • Silane—Ultraplus ™ II SiH4, Linde Union Carbide Specialty Gases Product Information, May 10, 1990, 2 pages.
  • J.E.A. Maurits, SOS Wafers—Some Comparisons to Silicon Wafers, IEEE Transactions on Electron Devices, vol. ED-25, No. 8, Aug. 1978, pp. 359-363.
  • J.E.A. Maurits, Problems and Solutions in the Preparation of SOS Wafers, Solid State Technoloty, Apr. 1977, 6 pages.
  • T. Deacon, Silicon Epitaxy: An Overview, Microelectronic Manufacturing and Testing, Sep. 1984, pp. 89-92.
  • H. Boyd, Non-Contaminating Gas Containment, Control, and Delivery Systems for VLSI-Class Wafer Fabrication, Microelectronic Manufacturing and Testing, Mar. 1984, pp. 1-6.
  • J.L. Briesacher et al., Gas Purification and Measurement at the PPT Level, J. Electrochem. Soc., vol. 138, No. 12, Dec. 1991, pp. 3717-3718 and 3723.
  • A. Homyak et al., Delivering Hydrogen to Meet < 1 ppb Impurity Levels Without the use of Purifiers, Solid State Technology, Gas Handling and Delivery, Oct. 1995, 4 pages.
  • Friedel and Ladenburg, Annalen 143,124, 1967.
  • A. Stock and C, Ber. 55, 3961, 1922.
  • H.J. Emeleus et al., The Oxidation of the Silicon Hydrides.Part I, Imperial College, S.W. 7., Jun. 27, 1935, pp. 1182-1189.
  • H.J. Emeleus and K. Stewart, J. Chem. Soc. pp 1182, 1936.
  • W. Shockley, Transistor Electronics: Imperfections, Unipolar and Analog Transisters*,Proceedings of the I.R.E. , Nov. 1952, pp. 1289-1313.
  • R.S. Crandall et al., Appl. Phys. Letters, 44(2), pp. 200-201, 1984.
  • K.A. Dumas et al., Characterization of HEM Silicon for Solar Cells, Conference Record of the 15th IEEE Photovoltaic Specialists Conference, 1981, pp. 954-958.
  • T. Saito et al., A New Directional Solidification Technique for Polycrystalline Solar Grade Silicon, Conference Record of the 15th IEEE Photovoltaic Specialists Conference, 1981, pp. 576-580.
  • T. Nozaki, Concentration and Behavior of Carbon in Semiconductor Silicon, J. Electrochemical Soc. Solid State Science, vol. 117, No. 12, Dec. 1970, pp. 1566-1568.
  • D.E. Carlson et al., The Effect of Flourine on the Performance of Amprphous Silicon Solar Cells, Conference Record of the 15th IEEE Photovoltaic Specialists Conference, 1981, pp. 694-697.
  • T.F. Ciszek et al., Growth of Silicon Sheets From Metallurgical-Grade Silicon, Conference Record of the 15th IEEE Photovoltaic Specialists Conference, 1981, pp. 581-588.
  • A.E. Delahoy et al., Impurity Effects in α-SI:H Solar Cells Due to Air, Oxygen, Nitrogen, Phosphine, or Monochlorosllane in the Plasma, Journal of Applied Physics, vol. 52, No. 10, Oct. 1981, pp. 6337-6347.
  • R.E. Griffith et al., Advanced Amorphous Materials for Photovoltaic Conversion, Semiannual Report, Oct. 1, 1979-Mar. 31, 1980, Department of Energy and Environment, Brookhaven National Laboratory, pp. 1-33.
  • A.E. Delahoy et al., Impurity Effects in α-Si:H Solar Cells, Conference Record of the 15th IEEE Photovoltaic Specialists Conference, 1981, pp. 704-712.
  • P.G. LeComber et al., Electrical and Photoconductive Properties of Ion Implanted Amorphous Silicon, Journal of Non-Crystalline Solids, 35 & 36, 1980, pp. 327-332.
  • Charles Feldman et al., Vacuum Deposited Polycrystalline Silicon Solar Cells for Terrestrial Use, The Conference Record of the 14th IEEE Photovoltaic Specialists Conference, 1980, pp. 391-396.
  • J.I. Hanoka et al., A Combined Quantitative Ebic and Ion Microprobe Analysis of SiC Particles in EFG Ribbon, The Conference Record of the 14th IEEE Photovoltaic Specialists Conference, 1980, pp. 478-483.
  • J.I. Hanoka, et al., Efficient Polycrystalline Solar Cells Made From Low-Cost Refined Metallurgical Silicon, The Conference Record of the 13th IEEE Photovoltaic Specialists Conference, 1978, pp. 485-489.
  • W.E. Spear et al., Doping of Amorphous Silicon by Alkali-Ion Implantations, Philosophical Magazine B, vol. 39, No. 2, 1979, pp. 159-165.
  • R.A. Gibson et al., J. Non-Crystalline Solids, 35 & 36, pp. 725-730, 1980.
  • T.I. Kamins et al., Mosfets in Laser-RecrystallizedPoly-Silicon on Quartz, IEEE Electron Device Letters, vol. EDL-1, No. 10, Oct. 1980, pp. 214-216.
  • R.S. Sussmann et al., Laser Annealing of Glow Discharge Amorphous Silicon, J. Non-Crystalline Solids, 35 & 36, 1980, pp. 249-254.
  • S. Onga et al., Characterization of Polycrystalline Silicon MOS Transistors, Japanese Journal of Applied Phyusics, vol. 21, No. 10, Oct. 1982, pp. 1472-1478.
  • S. Yamazaki et al., An Amorphous Silicon Solar Cell Having a Converstion Efficiency of 10.50 Percent, IEEE Electron Device Letters, vol. EDL-5, No. 8, Aug. 1984, pp. 315-318.
  • C.C. Tsai et al.,Clean α-Si:H Prepared in a UHV System, Journal of Non-Crystalline Solids, 66 1984, pp. 45-50.
  • M. Ohnishi et al., Preparation and Photovoltaic Characteristics of α-Si Solar Cells Produced by a Consecutive, Separated Reaction Chamber Method, Japanese Journal of Applied Physics, Vo. 21, 1982, Supplement 21-2, pp. 231-237.
  • O. Tsuji et al., Proceedings of the 6th International Symposium on Plasma Chemistry, vol. 3, pp. 782-786, 1983.
  • Y. Kuwano, et al., Preparation and Properties of Amorphous Silicon Produced by a Consecutive, Separated Reaction Chamber Method, Japanese Journal of Applied Physics, vol. 21, No. 3, Mar. 1982, pp. 413-417.
  • P.A. Iles et al., Effect of Impurity Doping Concentration on Solar Cell Output, 11th IEEE Photovoltaic Spec. Conf., 1982, pp. 19-24.
  • P. Sichanugrist et al., Amorphous Silicon Solar Cells With Graded Boron-Doped Active Layers, Journal of Applied Physics, vol. 54, No. 11, Nov. 1983, pp. 6705-6707.
  • N. Szydlo et al., High Current Post-Hydrogenated Chemical Vapor Deposited Amorphous Silicon P-I-N Diodes, Applied Physics Letters, vol. 40, No. 11, Jun. 1982, pp. 988-990.
  • K. Katoh et al., Amorphous-Silicon Silicon-Nitride Field-Effect Transistors, Electronics Letters, vol. 18, No. 14, May 26, 1982, pp. 599-600.
  • M. Matsumura, (Invited) Amorphous Silicon Transistors and Integrated Circuits, Japanese Journal of Applied Physics, vol. 22, Supplement 22-1, 1983, pp. 487-491.
  • P.G. LeComber et al., Amorphous-Silicon Field-Effect Device and Possible Application, Electronics Letters, vol. 15, No. 6, Mar. 15, 1979, pp. 179-181.
  • H.C. Tuan, Amorphous Silicon Thin Film Transistor and Its Applications to Large Area Electronics, Materials Research, Society, Symp. Proc. vol. 33, 1984, pp. 247-257.
  • C.C. Tsai et al., Impurities in Bulk α-Si:H, Silicon Nitride, and at the α-Si:H/Silicon Nitride Interface, Mat. Res. Soc. Symp. Proc. vol. 33, 1984, pp. 297-300.
  • H. Fritzsche, Characterization of Glow-Discharge Deposited α-Sil:H, Soler Energy Materials 3 1980, pp. 447-501.
  • R.S. Sussmann et al., J. Non-Crystalline Solids, 35 & 36, pp. 249-254, 1980.
  • M. Hirose et al., Defect Compensation in Doped CVD Amorphous Silicon, Journal of Non-Crystalline Solids, 35 & 36, 1980, pp. 297-302.
  • J. Ishikawa et al., The Effects of Oxygen, Hydrogen and Fluorine on the Conductivity of High Purity Evaporated Amorphous Silicon Films, Journal of Non-Crystalline Solids, 45, 1981, pp. 271-281.
  • N. Sol et al., J. Non-Crystalline Solids, 35 & 36, pp. 291, 1980.
  • R.G. Wolfson et al., Ion-Implanted Thin-Film Solar Cells on Sheet Silicon, IEEE Photovoltaic Specialists Conference, 1981, pp. 595-597.
  • D.E. Carlson, Recent Developments in Amorphous Silicon Solar Cells, Solar Energy Materials, 3, 1980, pp. 503-518.
  • D.E. Carlson, Amorphous Thin Films for Terrestrial Solar Cells, Journal of Vacuum Science & echnology, vol. 20, No. 3, Mar. 1982, pp. 290-295.
  • D.E. Carlson et al., Amorphous Silicon Solar Cells, Quarterly Report No. 4, for the period Jul. 1, 1981 to Sep. 30, 1981, Nov. 1981, pp. 1-33.
  • S.J. Solomon, Silicon From Silane Through Plasma Deposition, Conference Record of the 15th IEEE Photovoltaic Specialists Conference, 1981, pp. 569-571.
  • P.E. Vanier et al., New Features of the Temperature Dependence of Photoconductivity in Plasma-Deposited Hydrogenated Amorphous Silicon Alloys, J.Appl. Phys. vol. 52, No. 8, Aug. 1981, pp. 5235-5242.
  • J.R. Davis et al., Silicon Solar Cells From Transition Metal Doped Czochralski and Web Crystals, Conference Record of the 12th IEEE Photovoltaic Specialists Conference, 1976, pp. 106-111.
  • M. Wolf et al., Silicon Fluoride Transport: Summary of Current Results and Interim Assessment, Conference Record of the 12th IEEE Photovoltaic Specialists Conference, 1976, pp. 137-145.
  • W.E. Spear, Doped Amorphous Semiconductors,Advances in Physics, vol. 26, No. 6, Nov. 1977, pp. 811-845.
  • P. Viktorovitch et al., Determination of the Electronic Density of States in Hydrogenated Amorphous Silicon (α-SiH) From Schottky Diode Capacitance-Voltage and Conductance-Voltage Measurements,Journal of Non-Crystalline Solids, 35 & 36, 1980, pp. 569-574.
  • C.H. Hyun et al., DLTS Response Due to Localized States in Hydrogenated Amorphous Silicon, Journal of Non-Crystalline Solids, 46, 1981, pp. 221-234.
  • W.E. Spear et al., Electronic Properties of Substitutionally Doped Amorphous SI, Philosophical Magazine, vol. 33, No. 6, 1976, pp. 935-949.
  • J.R. McCormick, Preparation and Characterization of Low Cost Silicon Substrates for Epitaxial Solar Cell Applications, Proceedings of the 14th IEEE Photovoltaic Specialists Conference, 1980, pp. 298-302.
  • J.M. McBain, Sorption by Chabasite, Other Zeolites and Permeable Crystals, The Sorption of Gases and Vapours by Solids, Rutledge & Sons, Ltd., London, 1932, pp. 167-176.
  • A. Yusa et al., Ultrahigh Purification of Silane for Semiconductor Silicon, J. Electrochem. Soc.: Solid-State Science and Technology, vol. 122, No. 12, Nov. 1975, pp. 1700-1705.
  • T. Takahashi et al., Changes in the Sieving Action and Thermal Stability of Zeolite A Produced by Ion-Exchange, Faraday Transactions I, Journal of Physical Chemistry pt. 1, 1975, pp. 97-105.
  • T. Ohgushi et al., The Molecular Sieving Action of Ion-Exchanged Zeolites A, Bulletin of the Chemical Society of Japan, vol. 51, No. 2, 1978, pp. 419-421.
  • D.E. Carlson et al., Amorphous Silicon Solar Cell, Applied Physics Letters, vol. 28, No. 11, Jun. 1, 1976, pp. 671-673.
  • D.L. Staebler et al., Reversible Conductivity Changes in Discharge-Produced Amorphous, Applied Physics Letters,vol. 31, No. 4, Aug. 15, 1977, pp. 292-294.
  • T. Kamei et al., Deposition and Extensive Light Soaking of Highly Pure Hyarogenated Amorphous Silicon, Applied Physics Letters, vol. 68, No. 17, Apr. 22, 1996, pp. 2380-2382.
  • M. Stutzmann et al., Light-Induced Metastable Defects in Hydrogenated Amorphous Silicon: A Systematic Study, Phyusical Review B, The American Physical Society, vol. 32, No. 1, Jul. 1, 1985, pp. 23-47.
  • C.C. Tsai et al., Amorphous Si Prepared in a UHV Plasma Deposition System, Journal of Non-Crystalline Solids, vols. 59 & 60, 1983, pp. 731-734.
  • C.C. Tsai et al., The Staebler-Wronskieffect in Undoped α-Si:H: Its Intrinsic Nature and the Influence of Imprurities, American Institute of Physics, 1984, pp. 242-249.
  • B.R. Weinberger et al., AM-1 Short Circuit Currents in Small Area Pin a-SiHX Solar Cells, 16th IEEE Photovoltaic Specialists Conference, 1982, pp. 1316-1320.
  • R. Plattner et al., Influence of Impurities and Doping Residues on the Stability Behavior of a-Si:H and a-SIGE:H-Pin Cells, 18th IEEE Photovoltaic Specialists Conference, 1985, pp. 1598-1603.
  • C.R. Wronski et al., Recombination Centers in Phosphorous Doped Hydrogenated Amorphous Silicon, Solid State Communications, vol. 44, No. 10, 1982, pp. 1423-1426.
  • C.C. Tsai, M.J. Thompson and H.C. Tuan, Mat. Res. Symp. Proc. 33, 297, 1984.
  • C.W. Magee, J.C. Bean, G. Foti and J.M. Poate, Thin Solid Films 81, 1, 1981.
  • J.C. Bean, J.M. Poate, Appl. Phys. Letters, 36, 59, 1980.
  • G. Foti, J.C. Bean, J.M. Poate and C.W. Magee, Appl. Phys. Letters, 36, 840, 1980.
  • T. Yamamoto, S. Yamamoto, S. Tomita, K. Okuno, F. Soeda, Y. Murata and A. Isitani, SIMS X, ed. by A. Benninghoven, B. Hagendorf and H.W. Werner, John Wiley & Sons, Chichester, 1997.
  • Magee, “Investigations of the Hydrogen and Impurity Contents of Amorphous Silicon by Secondary Ion Mass Spetrometry”, Solar Cells, vol. 2 (1980) 365-376.
  • M. Moller et al. Conference Record, 16th IEEE Photovoltaic Specialist Conf. (Sep. 1982) pp. 1376-1380.
  • Ohrishi et al., The annual meeting of applied physics in Japan (1980) 3p-T-12.
  • Sakai et al., The 28th annual meeting of Japan Society of Appl. Phys. (Spring 1981) 29p-T-2.
  • Ishiwata et al., The 28th annual meeting of Japan, Society of Appl. Phys. (Spring 1981) 1a-5-9.
  • Nikkei Electronics, Zenko Hirose, Dec. 20, 1982, p. 168 (English translation herewith).
  • Journal of Non-Crystalline Solids (vol. 68, 1984) Magee & Carlson, “Investigation of the Hydrogen and Impurity Contents of Amorphous Silicon by Secondary Ion Mass Spectrometry”, Solar Cells, vol. 2, pp. 365-376 (1980).
  • M. Moller et al., Conference Record, 167th IEEE Photovoltaic Specialists Conference (Sep. 1982), pp. 1376-1380 “Low Level Boron Doping & Light-Induced Effects in Amorphous Silicon Pin Solar Cells”.
  • Y. Hamakawa, Amorphous Semiconductor Technologies and Devices, pp. 194, 198 (1982).
  • Matsumura, Japanese Journal of Applied Physics, (Invited) Amorphous Silicon Transistors and Integrated Circuits, 1983.
  • P.G. LeComber, Electronics Letters, Amorphous-Silicon Field-Effect Device and Possible Application, Mar. 15, 1979.
  • K. Roy, IEEE Electron Device Letters 1980.
  • C.C. Tsai, Tenth International Conference on Amorphous and Liquid Semiconductors, Glow Discharge a-Si:H Produced in a UHV System, Tokyo, Aug. 22-26, 1983 (Abstract).
  • C.C. Tsai, Journal of Non-Crystalline Solids, Amorphous Si Prepared in a Uhv Plasma Deposition System, (1983), published, Jan. 16, 1984.
  • T.I. Kamins, IEEE Electron Device Letters, MOSFETs in Laser-Recrystallized Poly-Silicon on Quartz, Oct. 1980.
  • A.E. Delahoy et al., Conf. Record, 15th IEEE Photovoltare Specialists Conf. (1981), pp. 704-712.
Patent History
Patent number: RE38727
Type: Grant
Filed: Oct 8, 1997
Date of Patent: Apr 19, 2005
Assignee: Semiconductor Energy Laboratory Co., Ltd. (Kanagawa-ken)
Inventor: Shunpei Yamazaki (Tokyo)
Primary Examiner: Amir Zarabian
Assistant Examiner: Jeff Vockrodt
Attorney: Robinson Intellectual Property Law Office, P.C.
Application Number: 08/999,682