Processing apparatus and processing method
A processing apparatus according to the present invention, which conditions a substrate placed on a table equipped with a heater by radiating an electron beam onto the substrate while heating the substrate with the heater, includes at least three projecting portions for holding the substrate at a predetermined distance from the table. This structure minimizes the extent of uneven heating of the substrate, which, in turn, enables uniform processing of the surface on the substrate.
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This document claims priority to Japanese Patent Application No. 2005-024271, filed Jan. 31, 2005 and U.S. Provisional Application No. 60/653,100 filed Feb. 16, 2005, the entire contents of which are hereby incorporated by reference
FIELD OF THE INVENTIONThe present invention relates to a processing apparatus and a processing method. More specifically, it relates to a processing apparatus and a processing method with which the surface of a substrate, such as a wafer, is processed by radiating, for instance, an electron beam.
BACKGROUND OF THE INVENTIONA semiconductor device formed on a work substrate (hereafter simply referred to as a “substrate”) normally adopts a multilayer wiring structure which includes a plurality of wiring films and a plurality of insulating films insulating the individual wiring films from one another. It is crucial that the parasitic capacity at the insulating films disposed between the wiring films be minimized in order to assure higher processing speed at such a semiconductor device. The parasitic capacity at the insulating films can be kept to a low level by constituting them with a material having a lower dielectric constant (a low K material).
Such an insulating film is coated onto the surface of the substrate by employing, for instance, a spin coater and a baking furnace. Since the insulating film is usually constituted of an organic material and a low dielectric constant is sometimes achieved by raising the porosity of the material, it tends to have inferior mechanical strength.
In some processing apparatuses, an electron beam, an ultraviolet beam or the like is radiated onto the substrate having an insulating film formed thereupon so as to improve the mechanical strength of the insulating film constituted of an organic material. For instance, in a processing apparatus in which an electron beam is radiated, the insulating film on the surface of the substrate placed on a table at which a heater is disposed is conditioned by radiating the electron beam onto the substrate surface while heating the substrate with the heater, so as to assure a desired level of mechanical strength.
During this process, the electron beam must be radiated while the temperature over the surface of the substrate is controlled so as to achieve the highest possible level of temperature consistency, in order to ensure that the insulating film is uniformly processed over its entire surface. The processing apparatuses proposed in the related art by addressing this need include the following.
Japanese Laid Open Patent Publication No. 2004-207314 (reference 1) discloses an electron beam processing apparatus that monitors the intensity of electron beam radiation by utilizing a current monitor disposed in the vicinity of the substrate placed on the table.
International Publication No. 03/067636 (reference 2) discloses a surface processing apparatus that includes a table capable of moving up/down to facilitate an optimal adjustment of the distance between an electron beam radiating mechanism and the table and evenly processes the insulating film formed at the surface of the substrate by radiating an electron beam onto the substrate. In this surface processing apparatus, the energy level of the electron beam is controlled by applying a DC voltage to the table in order to process the insulating film to a uniform depth over the entire surface thereof.
However, there is a problem in the art disclosed in reference 1 in that since the substrate is placed directly on the table, thermal deformation of the substrate, which may occur during the processing of the substrate, will result in uneven contact between the substrate and the table. Such uneven contact, in turn, will lead to uneven heating at the substrate surface, which will make it very difficult to process the substrate uniformly over its entire surface. In addition, since the intensity of the electron beam radiation on the substrate is measured with the current monitor disposed near the substrate, the intensity of the electron beam radiation at the substrate surface is not directly measured.
In addition, while the insulating film is processed to a uniform depth by processing the surface of the substrate with the table moved up/down so as to set it at an optimal distance from the electron beam radiating mechanism or by controlling the energy of the electron beam with the DC voltage applied to the table in the art disclosed in reference 2, the substrate is placed directly on the table in this case, too, which gives rise to uneven heating of the substrate, as in reference 1. Also, the intensity of the electron beam radiation at the substrate surface cannot be directly measured.
Japanese Laid Open Patent Publication No. H10-261695 (reference 3) discloses a technology for achieving a high level of pattern alignment accuracy in an electron beam patterning apparatus by holding the substrate without allowing it to become deformed and also by preventing a charge buildup at the substrate. In order to prevent a charge buildup, one of the holding numbers, i.e., either an upper holding member or a lower holding member, for holding the substrate is formed by using an electrically conductive material, and the holding member constituted of the electrically conductive material is grounded. In addition, Japanese Laid Open Patent Publication No. H11-111599 (reference 4) discloses an electron beam patterning apparatus in which the potential at the substrate electrostatically held by an electrostatic holding device during substrate processing is minimized so as to reduce the extent to which the electron beam trajectory is affected by the potential. In this art, in order to minimize the potential attributable to the leak current at the wafer when electrostatically holding the wafer, a reverse potential is applied to the conducting jig which achieves electrical continuity with the wafer. Japanese Laid Open Patent Publication No. H3-011541 (reference 5) discloses a technology adopted in an ion transplanting device to prevent electrons from becoming deposited on the wafer in a large quantity by applying a DC voltage to the wafer.
However, the technologies in references 3, 4 and 5 each intended to prevent a charge buildup at the substrate by using a conductive material so as to improve the patterning accuracy of an electron beam patterning apparatus or to reduce the extent of the adverse effect of the potential at the substrate on the electron beam trajectory in the vicinity of the substrate by minimizing the potential, are not designed to condition the substrate surface. For this reason, none of these references refer to a specific technology for detecting the intensity of electron beam radiation onto the substrate.
SUMMARY OF THE INVENTIONAn object of the present invention, which has been conceived to address the problems discussed above, is to uniformly process the entire surface of the substrate by reducing the extent of uneven heating at the substrate. Another object of the present invention is to enable direct measurement of the intensity of electron beam radiation onto the substrate.
The objects described above are achieved in an aspect of the present invention by providing A processing apparatus that conditions a substrate placed on a table equipped with a heater by radiating an electron beam onto the substrate while heating the substrate with the heater, characterized in that at least three projecting portions for holding the substrate at a specific distance from the table are disposed at the table.
The projecting portions in the present invention may be constituted of, for instance, an electrically conductive material and may be electrically grounded via a current detecting means. Such an apparatus may include a current control means for controlling a current flowing through the current detecting means. In addition, the processing apparatus may include a switch capable of switching the projecting portions between an electrically grounded state and an ungrounded state. Alternatively a voltage detecting means and a DC power source may be connected with the projecting portions which may be constituted with an electrically conductive material.
The objects described above are achieved in another aspect of the present invention by providing an apparatus that conditions a substrate placed on a table by radiating an electron beam onto the substrate, comprising a ground wiring that electrically grounds the substrate and a current control means disposed at the ground wiring to control a current flowing through the ground wiring. The current control means may have, for instance, a variable resistance element with an adjustable current resistance value.
The objects described above are also achieved in yet another aspect of the present invention by providing a method for conditioning a substrate placed on a table equipped with a heater by radiating an electron beam onto the substrate while heating the substrate with the heater, characterized in that when processing the substrate, the substrate is lifted from the table by a predetermined distance via at least three projecting portions.
The projecting portions may be constituted of, for instance, an electrically conductive material and may be electrically grounded via a current detecting means. In this method a current flowing through the current detecting means may be controlled via a current control means. In addition, the projecting portions may be switched between an electrically grounded state and an ungrounded state. Alternatively, a voltage detecting means and a DC power source may be connected to the projecting portions constituted of, for instance, an electrically conductive material may be connected with a voltage detecting means and a DC power source so as to enable application of a DC voltage to the projecting portions.
The objects described above are achieved in a further aspect of the present invention by providing a processing method for conditioning a substrate placed on a table by radiating an electron beam onto the substrate, comprising steps for electrically grounding the substrate via a ground wiring when processing the substrate and controlling a current flowing through the ground wiring with a current control means. The current control means used in this method may be a variable resistance element and the method may further include a step for adjusting a current resistance value at the variable resistance element.
According to the present invention described above, the entire surface of the substrate can be processed uniformly by minimizing the extent of uneven heating of the substrate and the intensity of the electron beam radiation at the substrate can be directly measured.
BRIEF DESCRIPTION OF THE DRAWINGS
The following is a detailed explanation of the preferred embodiments of the present invention given in reference to the attached drawings. It is to be noted that in the specification and the drawings, the same reference numerals are assigned to components having substantially identical functions and structural features to preclude the necessity for a repeated explanation thereof.
First Embodiment The processing apparatus achieved in the first embodiment of the present invention is now explained in reference to drawings.
As shown in
The following processing is executed in the processing apparatus 1 under control implemented on various units thereof based upon a control program installed in, for instance, a control device 6. Namely, an inert gas is drawn into the processing chamber 2 in which a predetermined degree of vacuum is sustained, and electron beams B are radiated over the entire surface of a wafer W on the table 3 from the electron beam radiating mechanism 4. An insulating film formed on the surface of the wafer W is thus conditioned. The inert gas may be, for instance, Ar, He, Xe or the like. The insulating film may be formed by using an organic material constituted of elements such as Si, O, C and H. The insulating film may be used as a layer insulating film or a protective film.
The plurality of electron beam tubes 4A constituting the electron beam radiating mechanism 4 include an electron beam tube 4A disposed at the center of the upper surface of the processing chamber 2, six electron beam tubes 4A disposed around the central electron beam tube 4A and twelve electron beam tubes 4A disposed around the six electron beam tubes 4A, as shown in
The electron beam tubes 4A each include an electron beam transmission window and their internal spaces are disconnected from the processing space within the processing chamber 2. The transmission windows are constituted of, for instance, transparent quartz glass, and the grid electrode 5 is disposed under the transmission windows so as to face opposite the transmission windows.
An elevating mechanism 7 is linked to the lower surface of the table 3 so as to raise/lower the table 3 via a ball screw 7A of the elevating mechanism 7. The lower surface of the table 3 and the bottom surface of the processing chamber 2 are linked via a stainless steel bellows 8 that expands/contracts freely. A desired level of air tightness is maintained inside the processing chamber 2 via the bellows 8. In addition, a bellows cover 12 is disposed at the lower surface of the table 3 so as to enclose the bellows 8.
A transfer port 2A through which a wafer W is transferred is formed at the circumferential surface of the processing chamber 2, and a gate valve 9 is mounted at the transfer port 2A so as to open/close the transfer port as necessary. A gas supply port 2B is formed at the processing chamber 2 above the transfer port 2A, whereas a gas discharge port 2C is formed at the bottom surface of the processing chamber 2. A gas supply source (not shown) is connected via a gas supply pipe 10 to the gas supply port 2B, and an evacuating device (not shown) is connected via a gas discharge pipe 11 to the gas discharge port 2C.
The table 3 is formed by using a ceramic material such as quartz. A heater 13 is installed in the table 3, and a temperature sensor 14 is mounted at the heater 13. The heater 13 and the temperature sensor 14 are both connected to a temperature control device 6A, which is constituted as part of the control device 6 so that the temperature at the heater 13 is controlled to sustain a desirable level based upon the temperature detected by the temperature sensor 14 under control executed by the temperature control device 6A. Since the table 13 includes the internal heater 13, as described above, the table 3 itself functions as a heater.
At the table 3, a plurality of (seven in this example) holding pins 15 are mounted as shown in
As shown in
It is to be noted that while the holding pins 15 are disposed on a single circumference in the example presented in
The height h representing the extent by which the holding pins 15 project out from the table 3 should be set to a value that does not allow the wafer W to come in contact with the upper surface of the table 3 even if it becomes thermally deformed and also ensures that the wafer W receives the heat radiated from the table 3 within the closest possible range for efficient heating. In more specific terms, it is desirable to set the height h to approximately 0.2 mm in conjunction with a 300 mm wafer W.
The diameter d of the holding pins 15 is set to, for instance, 2˜3 mm. The holding pins 15 are mounted so that they project out of the upper surface of the table 3 by approximately 0.2 mm.
With the seven holding pins 15 structured as described above, the wafer W is supported without contacting the table 3 and, at the same time, is heated with the heat radiated from the table 3 present within a close range. As a result, the wafer W does not become contaminated through contact with the table 3, and also, even if the wafer W becomes thermally deformed, the heat radiated from the table 3 uniformly heats the entire surface of the wafer W.
In addition, as shown in
As the wafer W is processed while the holding pins 15 are grounded via the switch 18 in the substrate processing apparatus structured as described above, electrons radiation at the wafer W flow from the wafer W through the ground wiring 17 via the holding pins 15 and the electrode 16. Thus, the wafer W does not become charged and, at the same time, the intensity of the electron beam radiation at the wafer W can be directly measured with the ammeter 19.
Accordingly, prior to wafer processing, the relationship between the intensity of the electron beam radiation onto a reference wafer W (e.g., an unprocessed wafer is that has not undergone processing such as film formation) and the voltage at the electron beam tubes 4A or the like may be ascertained, and specific conditions may be set for the electron beam tubes 4A when actually processing a wafer W so as to automatically process the wafer W under optimal conditions. In addition, if there is any risk of the wafer W undergoing the processing becoming damaged by the electron beams B or the plasma generated by using the electron beams B depending upon the wafer processing conditions, the switch 18 is disconnected, to electrically isolate the wafer W from the ground potential.
Next, the operations executed in the processing apparatus are explained. The processing apparatus 1 achieved in the first embodiment is driven based upon a control program installed in the control device 6 and executes processing for conditioning the wafer W (e.g., processing for conditioning an insulating film on the wafer) through the following procedure. It is to be noted that the processing apparatuses achieved in the second and third embodiments to be detailed later, as well as the processing apparatus achieved in the first embodiment, are driven based upon a control program installed in the control device 6 to execute the specific processing characterizing the individual embodiments.
The wafer conditioning processing is executed through the following procedure. First, the inert gas is supplied through the gas supply port 2A into the processing chamber 2, a wafer W it is transferred through the transfer part 2A by opening the gate valve 9 and the wafer W is positioned above the table 3. The wafer W positioned above the table 3 is supported by the holding pins 15 over a slight distance from the table 3.
Next, the gate valve 9 is closed and the table 3 is moved up/down via the elevating mechanism 7 to set it at the optimal position. During this process, the wafer W supported by the holding pins 15 is heated to a predetermined processing temperature by the heater 13. The pressure inside the processing chamber 2 is adjusted so as to achieve a predetermined degree of vacuum and the electron beams B is radiated from the electron beam radiating mechanism 4 in the inert gas atmosphere. As a result, the insulating film at the surface all the wafer W becomes conditioned.
Electrons having entered the wafer W during the wafer processing are made to flow out to the ground wiring 17 via the holding pins 15 and the electrode 16, and thus, the wafer W does not become charged. In addition, the current flowing through the ground wiring 17 can be detected by the ammeter 19.
Even if the wafer W undergoing the processing becomes thermally deformed by the heat from the heater 13 or the radiation of the electron beams B, the entire surface of the wafer W supported by the holding pins 15 in a slightly lifted state over a small distance from the table 3 is evenly heated with the heat radiated from the table 3, which minimizes irregularities in heat distribution at the surface of the wafer W. Consequently, the entire surface of the wafer W can be uniformly processed.
Once the processing of the wafer W is completed, the wafer W is carried out of the processing chamber 2 by reversing the procedure through which it was carried into the processing chamber 2. Since the wafer W is held by the holding pins 15 maintaining a small gap from the table 3, the wafer W does not contact with the table 3 while it is carried out of the processing chamber. Thus, metal contamination or particle deposits which might otherwise occur if the wafer W contact with the table 3, are prevented.
In the processing apparatus 1 achieved in the first embodiment as described above which includes a plurality of holding pins 15 for holding the wafer W at a predetermined distance from the upper surface of the table 3, the wafer W positioned above the table 3 inside the processing chamber 2 is kept in a lifted state by the holding pins 15, thereby allowing the entire surface of the wafer W to be heated uniformly with the heat radiated from the table 3. Thus, the insulating film at the wafer W can be uniformly processed over the entire surface thereof while preventing metal contamination or particle deposits at the rear surface of the wafer W.
In addition, the holding pins 15, constituted of an electrically conductive material are electrically grounded via the ammeter 19 and the holding pins 15 electrically ground the wafer W at the ground potential. As a result, electrons having entered the wafer W are caused to flow out to the ground wiring 17 from the wafer W via the holding pins 15. This prevents a charge from developing at the wafer W and also enables direct detection of the intensity of the electron beam radiation at the wafer W via the ammeter 19.
Furthermore, the switch 18, capable of switching the holding pins 15 to an electrically grounded state or an ungrounded state, isolates the wafer W from the ground potential as the holding pins 15 are switched from the grounded state to the ungrounded state via the switch 18 whenever necessary.
Second Embodiment Next, the processing apparatus achieved in the second embodiment of the present invention is explained in reference to a drawing.
In the processing apparatus achieved in the second embodiment adopting the structure described above, as a negative voltage is applied to the wafer W from the DC power source 21, an electric field, which will reduce the energy of the electrons radiated from the electron beam radiating mechanism, is generated inside the processing chamber. As a result, the level of the energy of the electrons radiation at the wafer W is lowered. The energy of the electrons radiation at the wafer W is lowered to a greater extent when the absolute value of the negative voltage applied to the wafer W is greater, and, in such a case, the wafer W is processed to a smaller depth.
As a positive voltage is applied to the wafer W from the DC power source 21, an electric field, which will increase the energy of the electrons radiated from the electron beam radiating mechanism, is generated inside the processing chamber. As a result, the level of the energy of the electrons radiation at the wafer W is raised. The energy of the electrons radiation at the wafer W is raised to a greater extent when the absolute value of the positive voltage applied to the wafer W is greater and, in such a case, the wafer W is processed to a greater depth.
Thus, when processing the wafer W, the polarity and the absolute value of the voltage applied from the DC power source 21 are controlled in correspondence to a desired processing depth to be achieved at the wafer W, so as to provide electron beams with the correct electron energy level for the wafer processing.
In the processing apparatus achieved in the second embodiment, the holding pins 15 are constituted of an electrically conductive material and are connected with the voltmeter 20 and the DC power source 21. By applying a DC voltage with a specific polarity from the DC power source 21 to the holding pins 15 via the voltmeter 20, the energy of the electrons in the electron beams can be increased or decreased. In addition, the voltage applied to the wafer W from the DC power source 21 via the holding pins 15 can be detected with the voltmeter 20 at all times. This means that the intensity of the electron beam radiation at the wafer W can be directly monitored based upon fluctuations of the voltage value. In addition, since the voltage applied from the DC power source 21 is adjustable, the energy of the electrons in the electron beams radiated onto the wafer W can be controlled by controlling the voltage in correspondence to the type of wafer W undergoing the processing.
Third Embodiment Next, the processing apparatus achieved in the third embodiment of the present invention is explained in reference to a drawing.
The resistance at the variable resistance element 22 is controlled as appropriate in correspondence to the type of wafer W undergoing the processing in the processing apparatus in the third embodiment, so as to achieve the optimal electron beam intensity for the wafer processing.
As described above, in the processing apparatus achieved in the third embodiment, which includes the variable resistance element 22 disposed at the ground wiring 17 connected with the holding pins 15, the current flowing from the wafer W to the ground wiring 17 via the holding pins 15 and the electrode 16 is controlled through the variable resistance element 22, the resistance of which is controlled as appropriate in correspondence to the type of the specific wafer W undergoing the processing. The intensity of the electron beam radiation at the wafer W is thus controlled.
FIRST IMPLEMENTATION EXAMPLENext, a first implementation example of the present invention is explained. In the first implementation example, the extent to which the presence of the holding pins affects the wafer temperature was investigated by using a bare wafer, which had not undergone any processing. The bare wafer was delivered to the table 3 inside the processing chamber 2 and was supported with the holding pins 15 at the table 3. The processing chamber 2 was filled with Ar gas at a pressure of 10 Torr, the heater 13 at the table 3 was engaged in operation to heat the table 3 in a temperature range of 300° C. to 400° C., as shown in Table 1 below, and the temperature at the wafer surface was measured at five different positions each time the temperature of the table 3 rose by 25° C. within the range of 300° C. to 400° C.
The wafer temperature was measured by using five thermocouples. The five thermocouples were each disposed at a central point of the wafer surface (TC1), at a point −75 mm away from the central point along the X direction (TC2), at a point +75 mm away from the central point along the X direction, at a point −75 mm away from the central point along the Y direction (TC4) and at a point +75 mm away from the central point along the Y direction (TC5). Table 1 below presents the results of measurement obtained via the thermocouples disposed at these positions by measuring the wafer temperature in correspondence to various temperature levels achieved at the table.
It is to be noted that as a comparison example to be compared with the first implementation example, a wafer was heated under conditions identical to those in the first implementation example in a processing apparatus in the related art that did not include holding pins and the wafer temperature was measured at the five different positions at the wafer surface in correspondence to the various temperature levels achieved at the table. The measurement results are presented in Table 2 below.
The measurement results achieved in the first implementation example indicate that the difference Ä between the highest value and the lowest value of the surface temperature at the wafer never exceeds 10° C. regardless of the temperature at the table, and that as the temperature at the table becomes higher, the difference Ä becomes more consistent in the processing apparatus equipped with the holding (see Table 1). In contrast, in the processing apparatus without holding pins (see Table 2), the difference Ä between the highest value and the lowest value of the surface temperature at the wafer is always greater than the difference observed in the processing apparatus equipped with holding pins, regardless of the temperature at the table, and that the difference Ä gradually increases as the temperature at the table becomes higher. In other words, better temperature uniformity is achieved at the surface of a wafer that is supported with the holding pins at a slight distance from the table compared to a wafer set directly on the table.
SECOND IMPLEMENTATION EXAMPLE The second implementation example of the present invention is explained next. In the second implementation example, the effectiveness of the holding pins in preventing metal contamination in the processing apparatus 1 shown in
Also, as a comparison example to be compared with the second implementation example, a wafer was processed under conditions identical to those of the second implementation example in a processing apparatus in the related art without holding pins and the metal atoms deposited at the same positions as those in the second implementation example were counted. The tabulation results are provided in Table 4 below.
The measurement results presented in correspondence to the second implementation example above indicate that no significant metal contamination was observed at the processed wafer apart from a slight deposit of Fe and Co metal atoms at the rear surfaces of the wafers, as is obvious from the comparison with the reference in the processing apparatus with the holding pins (see Table 3). In contrast, in the processing apparatus with no holding pins (see Table 4), large numbers of K atoms, Ca atoms and stainless steel metal atoms, as well as a great number of Zn atoms, were observed at the wafer rear surfaces though hardly any metal contamination was observed at the wafer front surfaces. This means that by disposing the holding pins at the table, metal contamination at the wafer rear surface can be reliably prevented.
THIRD IMPLEMENTATION EXAMPLE Next, the third implementation example of the present invention is explained. In the third implementation example, the relationship among the type of inert gas in the processing chamber in which a wafer supported with the holding pins was being heated, the length of time over which the wafer was heated at a specific gas pressure and the wafer temperature was investigated. In the third implementation example, two different types of gas, i.e., He and Ar, were used as the inert gas, the pressure of each inert gas was changed as shown in
The measurement results in
While the invention has been particularly shown and described with respect to preferred embodiments thereof by referring to the attached drawings, the present invention is not limited to these examples and it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit, scope and teaching of the invention.
Claims
1. A processing apparatus for conditioning a substrate placed on a table equipped with a heater by radiating an electron beam onto the substrate while heating the substrate with said heater that comprising:
- at least three projecting portions that hold the substrate at a predetermined distance from said table.
2. A processing apparatus according to claim 1, wherein:
- said projecting portions are constituted of an electrically conductive material and are electrically grounded via a current detecting means.
3. A processing apparatus according to claim 2, further comprising:
- a current control means for controlling a current flowing through said current detecting means.
4. A processing apparatus according to claim 1, further comprising:
- a switch capable of switching said projecting portions between an electrically grounded state and an ungrounded state.
5. A processing apparatus according to claim 1, wherein:
- said projecting portions are constituted of an electrically conductive material, with a voltage detecting means and a DC power source connected to said projecting portions.
6. A processing apparatus for conditioning a substrate placed on a table by radiating an electron beam onto the substrate, comprising:
- a ground wiring that electrically grounds the substrate; and
- a current control means disposed at said ground wiring to control a current flowing through said ground wiring.
7. A processing apparatus according to claim 6, wherein:
- said current control means has a variable resistance element with an adjustable current resistance value.
8. A processing method for conditioning a substrate placed on a table equipped with a heater by radiating an electron beam onto the substrate while heating the substrate with said heater, wherein:
- when processing the substrate, the substrate is lifted from said table by a predetermined distance via at least three projecting portions.
9. A processing method according to claim 8, wherein:
- said projecting portions are constituted of an electrically conductive material and are electrically grounded via a current detecting means.
10. A processing method according to claim 9, wherein:
- a current control means controls a current flowing through said current detecting means.
11. A processing method according to claim 8, wherein:
- said projecting portions can be switched to an electrically grounded state or an ungrounded state.
12. A processing method according to claim 8, wherein:
- said projecting portions are constituted of an electrically conductive material, a voltage detecting means and a DC power source are connected to said projecting portions and a DC voltage is applied to said projecting portions.
13. A processing method for conditioning a substrate placed on a table by radiating an electron beam onto the substrate, comprising steps for:
- electrically grounding the substrate via a ground wiring when processing the substrate; and
- controlling a current flowing through said ground wiring with a current control means.
14. A processing method according to claim 13, wherein:
- said current control means has a variable resistance element; and
- said method further comprising a step for;
- adjusting a current resistance value at said variable resistance element.
Type: Application
Filed: Jan 31, 2006
Publication Date: Aug 31, 2006
Applicant: TOKYO ELECTRON LIMITED (Minato-ku)
Inventors: Akiko Kamigori (Hyogo), Tadashi Onishi (Yamanashi)
Application Number: 11/342,827
International Classification: B24B 7/30 (20060101); B24B 1/00 (20060101); B24B 7/19 (20060101);