Abstract: A thermal processing operation is performed for a silicon wafer W (silicon single-crystal layer) in an atmosphere gas which is formed by a hydrogen gas or an inert gas or a mixture gas of these gases at a temperature in a range of 600° C. to 950° C. (here, the temperature should not be greater than 950° C.). By doing this, a quality of a surface of the silicon single-crystal layer is improved.

Abstract: A method for growing a silicon single crystal ingot by a Czochralski method, which is capable of providing silicon wafers having very uniform in-plane quality and which results in improvement of semiconductor device yield. A method is provided for producing a silicon single crystal ingot by a Czochralski method, wherein when convection distribution of a silicon melt is divided into a core cell and an outer cell, the silicon single crystal ingot is grown under the condition that the maximal horizontal direction width of the core cell is 30 to 60% of a surface radius of the silicon melt. In one embodiment the silicon single crystal ingot is grown under the condition that the maximal vertical direction depth of the core cell is equal to or more than 50% of the maximal depth of the silicon melt.

Abstract: A high resistivity p type silicon wafer with a resistivity of 100 ?cm or more, in the vicinity of the surface being formed denuded zone, wherein when a heat treatment in the device fabrication process is performed, a p/n type conversion layer due to thermal donor generation is located at a depth to be brought into contact with neither any device active region nor depletion layer region formed in contact therewith or at a depth more than 8 ?m from the surface, and a method for fabricating the same. The high resistivity silicon wafer can cause the influence of thermal donors to disappear without reducing the soluble oxygen concentration in the wafer, whereby even if various heat treatments are performed in the device fabrication process, devices such as CMOS that offer superior characteristics can be fabricated. The wafer has wide application as a substrate for a high-frequency integrated circuit device.

Abstract: The present invention is a method for producing a single crystal of which a whole plane in a radial direction is a defect-free region with pulling the single crystal from a raw material melt in a chamber by Czochralski method, wherein a pulling condition is changed in a direction of the crystal growth axis during pulling the single crystal so that a margin of a pulling rate is always a predetermined value or more that the single crystal of which the whole plane in a radial direction is a defect-free region can be pulled. Thereby, there can be provided a method for producing a single crystal in which when a single crystal is produced by CZ method, the single crystal of which a whole plane in a radial direction is a defect-free region entirely in a direction of the crystal growth axis can be produced with stability.

Abstract: A method for eliminating defects in single crystal silicon, which comprises subjecting single crystal silicon prepared by the CZ method to an oxidation treatment and then to an ultra high temperature heat treatment at a temperature of at least 1300° C., or comprises subjecting single crystal silicon which is prepared by the CZ method and is not subjected to an oxidation treatment (a bare wafer) to an ultra high temperature heat treatment in an oxygen atmosphere and at a temperature of higher than 1200° C. and lower than 1310° C. The method allows the elimination of void defects present in single crystal silicon with reliability.

Abstract: A known quartz glass crucible for crystal pulling consists of a crucible wall, having an outer layer which is provided in an external area thereof with a crystallisation promoter which results in crystallisation of quartz glass, forming cristobalite when the quartz glass crucible is heated according to specified use in crystal pulling. The aim of the invention is to provide a quartz glass crucible which has a long service life. As a result, the crystallisation promoter contains, in addition to a silicon, a first component which acts as a reticulating agent in quartz glass and a second component which is free of alkali metals and which acts as an agent forming separating points in quartz glass. The above mentioned components are contained and incorporated into a doping area (8) of the outer layer (6) having a layer thickness of more than 0.2 mm.

Abstract: The present invention relates to a process for preparing a single crystal silicon ingot, as well as to the ingot or wafer resulting therefrom. The process comprises controlling (i) a growth velocity, v, (ii) an average axial temperature gradient, G0, and (iii) a cooling rate of the crystal from solidification to about 750° C., in order to cause the formation of a segment having a first axially symmetric region extending radially inward from the lateral surface of the ingot wherein silicon self-interstitials are the predominant intrinsic point defect, and a second axially symmetric region extending radially inward from the first and toward the central axis of the ingot.

Abstract: The present invention is a method of producing a P(phosphorus)-doped silicon single crystal by Czochralski method, wherein, at least, a growth of the single crystal is performed so that an Al (aluminum) concentration is 2×1012 atoms/cc or more. Thereby, there can be provided a method of easily and inexpensively producing a P(phosphorus)-doped silicon single crystal of defect-free region having an excellent capability of electrical characteristics to be high breakdown voltage, which contains neither, for example, V region, OSF region, nor large dislocation cluster (LSEPD, LFPD) region.

Abstract: The present invention is a method for producing a wafer comprising, at least, a BMD forming step of subjecting a silicon single crystal in a state of an ingot to heat treatment thereby to form bulk micro defects (BMDs) inside, and a wafer processing step of processing the ingot in which the bulk micro defects (BMDs) was formed into wafers. Thereby, there can be provided a method for producing a wafer, wherein heat treatment for providing IG capability in production of wafer can be shortened and wafers with high IG capability can be produced in large quantity. Also, the present invention can further comprise a wafer heat-treating step of subjecting the processed wafer to heat treatment, or an epitaxial growth step of forming an epitaxial layer on the wafer. Thereby, there is improved productivity of annealed wafers or epitaxial wafers that are excellent in gettering capability.

Abstract: A silicon semiconductor substrate has a structure possessing oxygen precipitate defects fated to form gettering sites in a high density directly below the defect-free region of void type crystals. The silicon semiconductor substrate is formed by heat-treating a silicon semiconductor substrate derived from a silicon single crystal grown by the Czochralski method or the magnetic field-applied Czochralski method and characterized by satisfying the relational expression (Oi DZ)?(COP DZ)?10 ?m wherein Oi DZ denotes a defect-free zone of oxygen precipitate crystal defects and COP DZ denotes a region devoid of a void type defect measuring not less than 0.11 ?m in size, and having not less than 5×108 oxygen precipitate crystal defects per cm3.

Abstract: A silicon single crystal ingot is pulled at a pull rate so that the interior of the ingot results in a perfect region in which agglomerates of interstitial silicon-type point defects and agglomerates of vacancy-type point defects are absent, while rotating a quartz crucible for storing a silicon melt at a predetermined rotation speed and rotating the ingot pulled from the silicon melt in the opposite direction to the rotation of the quartz crucible at a predetermined rotation speed. An average rotation speed CRTAV of the quartz crucible during the pulling of a top ingot portion is set to be faster than an average rotation speed CRTAV of the quartz crucible during the pulling of a bottom ingot portion of the silicon single crystal ingot.

Abstract: There are disclosed a silicon wafer for epitaxial growth wherein the wafer is produced by slicing a silicon single crystal grown with doping nitrogen according to the Czochralski method (CZ method) in the region where at least the center of the wafer becomes V region in which the void type defects are generated, and wherein the number of defects having an opening size of 20 nm or less among the void type defects appearing on the surface of the wafer is 0.02/cm2 or less, and an epitalial wafer wherein an epitaxial layer is formed on the silicon wafer for epitaxial growth. Thereby, there can be produced an epitaxial wafer having a high gettering capability wherein very few SF exist in the epitaxial layer easily at high productivity and at low cost.

Abstract: A process for imparting controlled oxygen precipitation behavior to a single crystal silicon wafer. Specifically, prior to formation of the oxygen precipitates, the wafer bulk comprises dopant stabilized oxygen precipitate nucleation centers. The dopant is selected from a group consisting of nitrogen and carbon, and the concentration of the dopant is sufficient to allow the oxygen precipitate nucleation centers to withstand thermal processing, such as an epitaxial deposition process, while maintaining the ability to dissolve any grown-in nucleation centers.

Abstract: A silicon single crystal rod (24) is pulled from a silicon melt (13) made molten by a heater (17), and a change in diameter of the silicon single crystal rod every predetermined time is fed back to a pulling speed of the silicon single crystal rod and a temperature of the heater, thereby controlling a diameter of the silicon single crystal rod. A PID control in which a PID constant is changed on a plurality of stages is applied to a method which controls the pulling speed of the silicon single crystal rod so that the silicon single crystal rod has a target diameter and a method which controls a heater temperature so that the silicon single crystal rod has the target temperature. A set pulling speed for the silicon single crystal rod is set so that V/G becomes constant, and an actual pulling speed is accurately controlled so as to match with the set pulling speed, thereby suppressing a fluctuation in diameter of the single crystal rod.

Abstract: A single crystal silicon, ingot or wafer form, which contains an axially symmetric region in which vacancies are the predominant intrinsic point defect, is substantially free of oxidation induced stacking faults and is nitrogen doped to stabilize oxygen precipitation nuclei therein, and a process for the preparation thereof.

Abstract: A single crystal semiconductor manufacturing apparatus in which the concentration of oxygen in a single crystal semiconductor is controlled while pulling up a single crystal semiconductor such as single crystal silicon by the CZ method, a single crystal semiconductor manufacturing method, and a single crystal ingot manufactured by the method are disclosed. The natural convection (20) in the melt (5) in a quartz crucible (3) is controlled by regulating the temperatures at a plurality of parts of the melt (5). A single crystal semiconductor (6) can have a desired diameter by regulating the amount of heat produced by heating means (9a) on the upper side. Further the ratio between the amount of heat produced by the upper-side heating means (9a) and that by the lower-side heating means (9b) is adjusted to vary the process condition. In the adjustment, the amount of heat produced by the lower-side heating means (9b) is controlled to a relatively large proportion.

Abstract: An inexpensive method of coating silicon shot with boron atoms comprises (1) immersing silicon shot in an aqueous solution comprising a boric acid and polyvinyl alcohol, and (2) heating the solution so as to evaporate water and form a polymerized polyvinyl alcohol coating containing boron on the shot. A precise amount of this coated shot may then be mixed with a measured quantity of intrinsic silicon pellets and the resulting mixture may then be melted to provide a boron-doped silicon melt for use in growing p-type silicon bodies that can be converted to substrates for photovoltaic solar cells.

Abstract: A single crystal silicon ingot having a constant diameter portion that contains arsenic dopant atoms at a concentration which results in the silicon having a resistivity that is less than about 0.003 ?·cm.

Abstract: A process for the preparation of a silicon single ingot in accordance with the Czochralski method. The process for growing the single crystal silicon ingot comprises controlling (i) a growth velocity, v, (ii) an average axial temperature gradient, G0, during the growth of a constant diameter portion of the crystal over a temperature range from solidification to a temperature of no less than about 1325° C. to initially produce in the constant diameter portion of the ingot a series of predominant intrinsic point defects including vacancy dominated regions and silicon self interstitial dominated regions, alternating along the axis, and cooling the regions from the temperature of solidification at a rate which allows silicon self-interstitial atoms to diffuse radially to the lateral surface and to diffuse axially to vacancy dominated regions to reduce the concentration intrinsic point defects in each region.

Abstract: Using a seed crystal comprising a silicon single crystal not including a vacancy excess region, a neck comprising a silicon single crystal not including a vacancy excess region is grown with a diameter contracted smaller than, or equal to that of the contact surface of the silicon seed crystal in contact with a raw material silicon melt, and necking is performed so that the length L of the neck satisfies L?d·(cot ?), where d denotes the length of the diameter or the diagonal of the contact surface of the silicon seed crystal in contact with the raw material silicon melt, and ? denotes the angle formed between the propagation direction of dislocations and the growth direction of the neck, and then the silicon single crystal is grown with the diameter expanded.

Abstract: Techniques for predicting the behavior of dopant and defect components in a substrate lattice formed from a substrate material can be implemented in hardware or software. Fundamental data for a set of microscopic processes that can occur during one or more material processing operations is obtained. Such data can include data representing the kinetics of processes in the set of microscopic processes and the energetics and structure of possible states in the material processing operations. From the fundamental data and a set of external conditions, distributions of dopant and defect components in the substrate lattice are predicted.

Abstract: A process for producing a doped silicon single crystal, comprising after-doping the melt during the pulling process with a quantity of volatile dopant ?N(t), calculated according to the equation ?N(t)=N0?N(t)=N0·(1?e??a·t) or according to the approximation equation ?N(t)=N0·?a·t where ?a is an evaporation coefficient which describes process-specific evaporation behavior of the foreign substance and which is obtained after a resistance profile R(t) of a further single crystal has been measured and calculated according to the equation R(t)=R0·e?a·t, where R0 is a starting resistivity and the further single crystal is pulled under the same process conditions without being after-doped with the foreign substance.

Abstract: Process for the production of semiconductor crystals with high resistivity of the CdXTe type, wherein X=Zn, Se, ZnSe or 0, characterized in that it consists in carrying out a multiple doping with iron and with at least one second doping element selected from the group formed by the elements of group III of the periodic chart of the elements.

Abstract: At the time of fabricating a silicon single crystal wafer from a nitrogen-doped silicon single crystal grown according to the Czochralski method, a silicon single crystal wafer covered with a region in which an oxygen precipitation bulk micro defect and an oxidation induced stacking fault mixedly exist is subjected to heat treatment at a temperature of 1100 to 1300° C. in a reducing gas or inert gas atmosphere. In such a manner, a method of fabricating a high-quality silicon single crystal wafer and a silicon single crystal wafer in which no grown-in crystal defects exist in the whole surface and oxygen precipitation bulk micro defects (BMD) are formed at a sufficiently high density to display the IG effect on the inner side can be provided. The single crystal wafer can be suitably used to form an operation region of a semiconductor device.

Abstract: The present invention is directed to a single crystal Czochralski-type silicon wafer, and a process for the preparation thereof, which has a non-uniform distribution of stabilized oxygen precipitate nucleation centers therein. Specifically, the peak concentration is located in the wafer bulk and a precipitate-free zone extends inward from a surface.

Abstract: The present invention relates to a method to control the nucleation and transverse motion of 180° inverted domains in ferroelectric nonlinear crystals. It includes a process composing of a high temperature oxidation of the first metal layer and a pulsed field poling of the second electrodes. The main object of present invention is to provide domain inversion of ferroelectric nonlinear crystals with field control the nucleation and transverse motion of inverted domains and two-dimension nonlinear photonic crystals for time-domain multiple-wave simultaneous lasers and space filter function. Another object of present invention is to provide space-charge effect for screened edge field beneath the metal electrode, The other object of present invention is to provide the constraint of inverted domain nucleation in the oxidized electrode for arbitrarily geometrical form of 2D ferroelectric lattice structure.

Abstract: The present invention provides a silicon single crystal wafer having a diameter of 300 mm or more and having a defect-free layer containing no COP for a depth of 3 ?m or more from a surface and a method for producing a silicon single crystal, wherein, when a silicon single crystal having a diameter of 300 mm or more is pulled with nitrogen doping by the CZ method, the crystal is grown with a value of V/G [mm2/K·min] of 0.17 or less, where V [mm/min] is a pulling rate, and G [K/mm] is an average of temperature gradient in the crystal along a pulling axis from the melting point of silicon to 1400° C. Thus, there are established conditions for pulling a silicon single crystal and conditions for heat treatment of wafer for obtaining a silicon single crystal wafer having a defect-free layer free from COP for a sufficient depth of the surface layer by pulling a silicon single crystal having a diameter of 300 mm or more, processing the crystal into wafers and subjecting the wafers to the heat treatment.

Abstract: A silicon single crystal growing apparatus supplemented with a low melting point dopant feeding instrument and a low melting point dopant feeding method thereof for producing a heavily doped silicon single crystal with a dopant of low melting point. The apparatus includes a quartz crucible containing molten silicon liquid, a heating unit supplying the quartz crucible with a radiant heat, a crystal pulling lifter pulling up a silicon single crystal from a molten silicon liquid contained in the quartz crucible, and a low melting point dopant feeding instrument. The low melting point dopant feeding instrument includes a sidewall portion, an upper portion, and an open bottom portion with net-like structure having many holes, the sidewall and upper portions being vacuum-tight sealed.

Abstract: The present invention is directed to a process for producing a silicon wafer which, during the heat treatment cycles of essentially any arbitrary electronic device manufacturing process, may form an ideal, non-uniform depth distribution of oxygen precipitates and may additionally contain an axially symmetric region which is substantially free of agglomerated intrinsic point defects. The process including growing a single crystal silicon ingot from molten silicon, and as part of the growth process, controlling (i) a growth velocity, v, (ii) an average axial temperature gradient, G0, during the growth of a constant diameter portion of the crystal over a temperature range from solidification to a temperature of no less than about 1325° C., and (iii) a cooling rate of the crystal from a solidification temperature to about 1,050° C., in order to cause the formation of an axially symmetrical segment which is substantially free of agglomerated intrinsic point defects.

Abstract: According to the present invention, there is disclosed a silicon single crystal wafer grown according to the CZ method which is a wafer having a diameter of 200 mm or more produced from a single crystal grown at a growth rate of 0.5 mm/min or more without doping except for a dopant for controlling resistance, wherein neither an octahedral void defect due to vacancies nor a dislocation cluster due to interstitial silicons exists as a grown-in defect, and a method for producing it.

Abstract: A semiconductor wafer made from silicon which is doped with hydrogen. The hydrogen concentration is less than 5*1016 atcm?3 and greater than 1*1012 atcm?3. A method for producing a semiconductor wafer from silicon includes separating the semiconductor wafer from a silicon single crystal, with the single silicon crystal being pulled from a melt, in the presence of hydrogen, using the Czochralski method. The hydrogen partial pressure during the pulling of the single silicon crystal is less than 3 mbar.

Abstract: A silicon single crystal wafer grown by the CZ method, which is doped with nitrogen and has an N-region for the entire plane and an interstitial oxygen concentration of 8 ppma or less, or which is doped with nitrogen and has an interstitial oxygen concentration of 8 ppma or less, and in which at least void type defects and dislocation clusters are eliminated from the entire plane, and a method for producing the same. Thus, there are provided a defect-free silicon single crystal wafer having an N-region for the entire plane, in which void type defects and dislocation clusters are eliminated, produced by the CZ method under readily controllable stable production conditions with a wide controllable range, and a method producing the same.

Abstract: The present invention provides a method for producing a solar cell comprising forming the solar cell from a CZ silicon single crystal wafer, wherein a CZ silicon single crystal wafer having an initial interstitial oxygen concentration of 15 ppma or less is used as the CZ silicon single crystal wafer; a solar cell produced from a CZ silicon single crystal wafer, wherein the CZ silicon single crystal wafer has an interstitial oxygen concentration of 15 ppma or less; and a solar cell produced from a CZ silicon single crystal wafer, wherein the CZ silicon single crystal wafer has a BMD density of 5×108/cm3 or less. Thus, there can be obtained a solar cell showing little fluctuation of characteristics.

Abstract: A method for growing a silicon single crystal used for semiconductor integrated circuit devices, wherein the single crystal is grown by the CZ method at a nitrogen concentration of 1×1013 atoms/cm3-1×1015 atoms/cm3 with a cooling rate of not less than 2.5° C./min at a crystal temperature of 1150° C.-1000° C., in which case, the pulling rate is adjusted such that the outside diameter of a circular region including oxidation-induced stacking faults generated at the center of a wafer which is subjected to the oxidation heat treatment at high temperature is not more than ⅗ of the wafer diameter, wherein the wafer is prepared by slicing the grown single crystal. In the growth method, the concentration of oxygen in the silicon single crystal is preferably not more than 9×1017 atoms/cm3 (ASTM '79).

Abstract: There can be provided according to the present invention a silicon single crystal produced according to Czochralski method to which Ga (gallium) is added as a dopant characterized in that a resistivity is 5&OHgr;.cm to 0.1&OHgr;.cm and a method for producing a silicon single crystal to which Ga (gallium) is added as a dopant according to Czochralski method characterized in that Ga is added in a silicon melt in a crucible, a seed crystal is brought into contact with the silicon melt and is pulled with rotating to grow a silicon single crystal ingot. Thereby, a silicon single crystal and silicon single crystal wafer and a method for producing them that can produce a solar cell characterized in that photo-degradation is not caused even in the single crystal having high oxygen concentration and a conversion efficiency of optical energy is very high.

Abstract: The present invention provides aluminum oxide crystalline materials including dopants and oxygen vacancy defects and methods of making such crystalline materials. The crystalline materials of the present invention have particular utility in optical data storage applications.

Abstract: Oxygen can be doped into a gallium nitride crystal by preparing a non-C-plane gallium nitride seed crystal, supplying material gases including gallium, nitrogen and oxygen to the non-C-plane gallium nitride seed crystal, growing a non-C-plane gallium nitride crystal on the non-C-plane gallium nitride seed crystal and allowing oxygen to infiltrating via a non-C-plane surface to the growing gallium nitride crystal.

Abstract: There is provided a manufacturing process for a CZ silicon single crystal wafer which is subjected to heat treatment wherein slip resistance of a portion of the CZ silicon single crystal wafer in contact with a heat treatment boat is improved with extreme simplicity, convenience and very low cost. A silicon single crystal rod is grown by means of a Czochralski method in a condition that an OSF ring region is formed in a peripheral region of the silicon single crystal rod and the grown silicon signal crystal rod is processed into silicon single crystal wafers, whereby the silicon single crystal wafer is obtained such that when the silicon single crystal wafer is subjected to heat treatment, at least a portion of the silicon single crystal wafer in contact between the wafer and the boat is formed of an OSF ring region.

Abstract: In the manufacture of a silicon single crystal by the Czochralski method, there is provided a seed crystal for use in the production of the silicon single crystal. This seed crystal is capable of preventing creation of a dislocation occurring during the immersion of the seed crystal in the molten silicon and withstanding the load of a silicon single crystal of great weight as well. There is also a method for the production of the seed crystal and a method for the production of a silicon single crystal which enables the ratio of elimination of dislocation to be increased.

Abstract: An inexpensive method of coating silicon shot with boron atoms comprises (1) immersing silicon shot in an aqueous solution comprising a boric acid and polyvinyl alcohol, and (2) heating the solution so as to evaporate water and form a polymerized polyvinyl alcohol coating containing boron on the shot. A precise amount of this coated shot may then be mixed with a measured quantity of intrinsic silicon pellets and the resulting mixture may then be melted to provide a boron-doped silicon melt for use in growing p-type silicon bodies that can be converted to substrates for photovoltaic solar cells.

Abstract: A method of fabricating a semiconductor epitaxial wafer having doped carbon includes the steps of mixing a quantity of carbon with a quantity of silicon and then melting together the quantities of carbon and silicon, growing an ingot with carbon from the melted silicon containing carbon, grinding the ingot having carbon so as to produce a flat surface and a notch, slicing the ingot having carbon into a piece of silicon wafer, polishing the silicon wafer having carbon, and growing an epitaxial silicon layer on a surface of the polished silicon wafer having carbon.

Abstract: A silicon single crystal which, over an ingot length of over 10 percent of the total ingot length, has a uniform defect picture and narrow radial dopant and oxygen variations. The process in accordance with the Czochralski method involves bringing about a temperature distribution in the melt in the region of the solidification interface which deviates from rotational symmetry.

Abstract: A method is disclosed for forming an epitaxial layer on a front side of a substrate formed of a monocrystalline material, using a chemical vapor deposition system. In this method, a plurality of gettering wafers formed of a gettering material are arranged in the CVD system, such that the front side of each substrate is facing one of the gettering wafers. Impurities present in the CVD system during formation of the epitaxial layer are gettered by the gettering wafers. Alternatively, a layer of a gettering material is deposited on a back side of each of the plurality of substrates, and the substrates are arranged such that the front side of each substrate is facing the backside of another of the substrates. In another embodiment, a layer of a gettering material is deposited on an interior surface of the CVD system. Impurities removed from the CVD system during epitaxial formation include oxygen, water vapor and other oxygen-containing contaminants.

Abstract: A method of making a fracture-resistant large-size calcium fluoride single crystal is described, which is suitable for an optical component for radiation in the far UV range. The calcium fluoride raw material for the single crystal is first melted and subsequently solidified by cooling the melt to form a single crystal. However the calcium fluoride raw material is doped with from 1 to 250, preferably 1 to 100, ppm of strontium, preferably added as strontium fluoride, and contains from 1 to 10 ppm of sodium as well as up to 100 ppm of other impurities.

Abstract: An inexpensive method of coating silicon shot with boron atoms comprises (1) immersing silicon shot in a boron dopant spin-on solution comprising a borosilicate, a polymer precursor, and a volatile solvent, and (2) removing the solvent so as to leave a polymeric coating containing borosilicate on the shot. A precise amount of this coated shot may then be mixed with a measured quantity of silicon pellets and the resulting mixture may then be melted to provide a boron-doped silicon melt for use in growing p-type silicon bodies that can be converted to substrates for photovoltaic solar cells.

Abstract: A silicon wafer is doped with boron and germanium in a range that satisfies a relational expression defined by: −0.8×10−3≦4.64×10−24×[Ge]−2.69×10−23×[B]≦1.5×10−3. This can reduce the miss-fit dislocation which might be induced when an epitaxial layer is grown over the silicon wafer that has been added with boron in high concentration. It is to be noted that in the above relational expression, the [B] denotes a boron concentration, while the [Ge] denotes a germanium concentration and a concentration unit is indicated by atoms/cm3.

Abstract: A process for producing a silicon single crystal which is doped with highly volatile foreign substance by pulling the single crystal from a melt which is held under predetermined process conditions in a crucible. A quantity of the foreign substance N0 is added in order to achieve a desired resistance of the melt, and the melt, after a time t, is after-doped at least once with a quantity &Dgr;N(t) of the foreign substance, in order to compensate for losses caused by the foreign substance evaporating out of the melt.

Abstract: An epitaxial silicon wafer which comprises a silicon wafer produced by a method characterized as comprising pulling up a silicon single crystal under a condition wherein when an oxygen concentration is 7×1017 atoms/cm3 a nitrogen concentration is about 3×1015 atoms/cm3 or less, and when an oxygen concentration is 1.6×1018 atoms/cm3 a nitrogen concentration is about 3×1014 atoms/cm3 or less, and, an epitaxial film formed on the wafer. The epitaxial film, being formed on such a wafer, has crystal defects, which are observed as LPD of 120 nm or more on the epitaxial film, in a range of 20 pieces/200-mm wafer or less. The epitaxial silicon wafer contains nitrogen atoms doped therein and also has satisfactory characteristics as that for use in a semiconductor device.

Abstract: A process for modifying the surface of a quartz glass crucible and a modified quartz glass crucible produced by the process, where the crucible has a transparent coated layer containing a crystallization accelerator on the surface. The process includes coating a mixed solution containing a metal salt and a partial hydrolyzate of alkoxysilane oligomer on the surface of the crucible and heating to obtain a quartz glass crucible having a transparent coated layer. The crystallization promoter contains a metal oxide or a metal carbonate dispersed in a silica matrix.

Abstract: A method for growing solid state laser crystal boules is disclosed that when made into laser rods do not need separate end caps attached to the laser rods. The crystal boule is grown as a single integral unit with three segments. Two segments, the end segments, are un-doped or non-laser active, and they flank a central segment of the boule that is doped with an active laser ion. A first end segment of the crystal boule is first grown from un-doped melt material in a first crucible by slowly withdrawing its growing end from the first melt. The boule is then transferred to a doped melt in a second crucible where its growing end is submersed therein to grow the doped, laser active central segment. The temperature of the melt in the second crucible is initially higher than the growing temperature of the first melt and causes the growing end of the boule to melt.