JP2004119792A - Electron beam aligner and residual attraction force reducing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electron beam aligner which can reduce residual attraction force generated between a semiconductor wafer and an electrostatic chuck plate. <P>SOLUTION: The electron beam aligner exposes a semiconductor wafer 64 in an electron beam. It has a wafer stage 62 whereon the semiconductor wafer 64 is mounted in exposure treatment, an electrostatic chuck plate of a dielectric which is provided to the wafer stage 62 and holds the semiconductor wafer 64 by electrostatic force by applying a voltage, a conductor wafer standby table 212 for putting the conductive conductor wafer 214 on standby and a handler 210 which carries out the semiconductor wafer 64 from on an electrostatic chuck plate after exposure treatment of the semiconductor wafer 64 and carries the conductor wafer 214 from the conductor wafer standby stable 212 onto the electrostatic chuck plate for removing charge remaining in the electrostatic chuck plate. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electron beam exposure apparatus and a method for reducing a residual attraction force. In particular, the present invention relates to an electron beam exposure apparatus that performs an exposure process while holding a semiconductor wafer by an electrostatic chuck plate, and a method for reducing a residual attraction force that removes electric charges remaining between the electrostatic chuck plate and the semiconductor wafer.
[0002]
[Prior art]
In a conventional electron beam exposure apparatus, a semiconductor wafer is held on a wafer stage by a clone type electrostatic chuck and subjected to exposure processing. The Coulomb-type electrostatic chuck arranges a dielectric ceramic on an electrostatic chuck electrode, applies a voltage, holds a semiconductor wafer at a constant potential, and uses a Coulomb force acting on an interface between the dielectric ceramic and the semiconductor wafer. A semiconductor wafer is fixed (for example, refer to Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2000-91225
[Problems to be solved by the invention]
However, when the semiconductor wafer is irradiated with an electron beam, electron collision generates electron-hole pairs in the semiconductor wafer. Then, the electron-hole pairs generated in the semiconductor wafer are arranged in the same direction by the electric field of the dielectric ceramic to which a voltage is applied to form a polarization state, and in proportion to the polarization state of the semiconductor wafer, A polarization state is also formed in the dielectric ceramic. As a result, stable charge coupling is formed between the semiconductor wafer and the dielectric ceramic, and residual adsorption occurs. This residual adsorption is not observed as a defect in macro phenomena, but becomes a factor of trouble in semiconductor wafer transport when a wide area of the semiconductor wafer is irradiated with the electron beam for a long time. For example, when the semiconductor wafer is peeled off from the dielectric ceramic by an external force, the semiconductor wafer may be damaged or particles may be generated. In addition, a transfer trouble occurs due to a jump when the semiconductor wafer is detached, which leads to a decrease in the quality of the semiconductor wafer transfer.
[0005]
Therefore, an object of the present invention is to provide an electron beam exposure apparatus and a method for alleviating a residual attraction force capable of solving the above-mentioned problems. This object is achieved by a combination of features described in the independent claims. The dependent claims define further advantageous embodiments of the present invention.
[0006]
[Means for Solving the Problems]
That is, according to the first embodiment of the present invention, there is provided an electron beam exposure apparatus for exposing a semiconductor wafer with an electron beam, wherein a wafer stage on which the semiconductor wafer is mounted at the time of exposure processing, and a wafer stage are provided. A dielectric electrostatic chuck plate for holding the semiconductor wafer by electrostatic force when applied, a conductive wafer standby base for holding the conductive conductive wafer, and a semiconductor wafer being exposed after the semiconductor wafer is exposed to light. A handler for carrying the conductive wafer from the conductive wafer standby platform onto the electrostatic chuck plate so as to remove the electric charge remaining on the electrostatic chuck plate from the chuck plate;
[0007]
The semiconductor device may further include a conductive wafer placed on the conductive wafer stand. The conductivity of the conductor wafer may be higher than the conductivity of the semiconductor wafer. The conductor wafer may be a conductive plastic material. The semiconductor device may further include a ground contact that is electrically connected to the conductive wafer loaded on the electrostatic chuck plate and grounds the conductive wafer. The apparatus may further include a chamber for holding the wafer stage and the conductive wafer standby table in a reduced pressure space.
[0008]
After the application of the voltage to the electrostatic chuck plate is stopped, the apparatus further includes a residual suction force detection unit that detects a residual suction force between the electrostatic chuck plate and the semiconductor wafer. When the force is larger than the predetermined value, the conductor wafer may be carried from the conductor wafer stand to the electrostatic chuck plate.
[0009]
The semiconductor device further includes lift pins for pressing the semiconductor wafer held on the electrostatic chuck plate from below and detaching the semiconductor wafer from the electrostatic chuck plate. The residual suction force detection unit includes a lift pin for detaching the semiconductor wafer from the electrostatic chuck plate. May be detected as the residual suction force.
[0010]
According to a second aspect of the present invention, there is provided an electron beam exposure apparatus for exposing a semiconductor wafer with an electron beam, the method for reducing a residual adsorption force between an electrostatic chuck plate of a wafer stage and a semiconductor wafer. Loading a semiconductor wafer onto an electrostatic chuck plate, applying a voltage to the electrostatic chuck plate to apply a voltage to hold the semiconductor wafer by electrostatic force, and exposing the semiconductor wafer with an electron beam. An exposure step, a voltage stop step of stopping application of a voltage to the electrostatic chuck plate after completion of the exposure processing in the exposure step, a semiconductor wafer unloading step of unloading the semiconductor wafer from the electrostatic chuck plate, and a conductive step. By loading the conductive wafer onto the electrostatic chuck plate, the electrostatic chuck And a conductive wafer loading step of removing the charges remaining bets.
[0011]
After the voltage stopping step, the method further comprises a residual suction force detection step of detecting a residual suction force between the electrostatic chuck plate and the semiconductor wafer, and the conductive wafer loading step includes a step of detecting the residual suction force detected in the residual suction force detection step. If it is larger than the predetermined value, the method may include a step of loading the conductive wafer onto the electrostatic chuck plate.
[0012]
The semiconductor wafer unloading step includes a semiconductor wafer detaching step of pressing the semiconductor wafer held on the electrostatic chuck plate from below by lift pins and detaching the semiconductor wafer from the electrostatic chuck plate. The residual suction force detecting step includes a semiconductor wafer detaching step. And detecting a load applied to the lift pin as a residual suction force.
[0013]
Note that the above summary of the present invention does not list all of the necessary features of the present invention, and a sub-combination of these features may also be an invention.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described through embodiments of the present invention. However, the following embodiments do not limit the invention according to the claims, and all of the combinations of the features described in the embodiments are not limited thereto. It is not always essential to the solution of the invention.
[0015]
FIG. 1 shows an example of the configuration of an electron beam exposure apparatus 100 according to one embodiment of the present invention. The electron beam exposure apparatus 100 includes an exposure unit 150 for performing a predetermined exposure process on the semiconductor wafer 64 with an electron beam, and a control system 140 for controlling the operation of each component of the exposure unit 150.
[0016]
The exposure unit 150 irradiates an electron beam irradiation system 110 for irradiating a predetermined electron beam into the lens barrel 10, deflects the electron beam irradiated from the electron beam irradiation system 110, and exposes the first rectangular opening near the mask 30. A collimator lens unit 112 for forming an image on the surface, a field lens system 114 for connecting the distribution of the irradiating electron beam to the next stage, and an electron beam that has passed through the mask 30 to a predetermined position on the semiconductor wafer 64 mounted on the wafer stage 62. An electron optical system including a reduction and objective optical system 116 for deflecting the region and adjusting the direction and size of the image of the pattern irradiated on the semiconductor wafer 64 is provided.
[0017]
The exposure unit 150 includes a mask stage 72 on which a mask 30 having a plurality of blocks each having a pattern to be exposed on the semiconductor wafer 64 is formed, a mask stage driving unit 68 for driving the mask stage 72, and a main unit. Inside the chamber 202, a wafer stage 62 on which a semiconductor wafer 64 is placed during exposure processing, an electrostatic chuck unit 200 for holding the semiconductor wafer 64 by electrostatic force, and a wafer stage driving unit 70 for driving the wafer stage 62 Including stage system. Further, the exposure unit 150 detects reflected electrons scattered from the wafer stage 62 side for adjusting the electron optical system, and includes a plurality of reflected electron detectors 60 that output an electric signal corresponding to the detected amount of electrons. Having.
[0018]
The electron beam irradiation system 110 includes an electron gun 12 for generating an electron beam, a first electron lens 14 for determining a focal position of the electron beam, and a first slit portion 16 having a rectangular opening for passing the electron beam. Having. In FIG. 1, the optical axis of the electron beam when the electron beam emitted from the electron beam irradiation system 110 is not deflected by the electron optical system is represented by a chain line A.
[0019]
The collimator lens unit 112 includes a first deflector 22 and a second deflector 26 as a mask deflection system for deflecting the electron beam, and a second electron lens 20 as a mask focus system for adjusting the focus of the electron beam. Have. The first deflector 22 and the second deflector 26 deflect to irradiate a predetermined region on the mask 30 with the electron beam. For example, the predetermined area is a block having a pattern to be transferred to the semiconductor wafer 64. When the electron beam passes through the pattern, the cross-sectional shape of the electron beam becomes the same as the pattern formed on the block. The second electron lens 20 has a function of forming an image of the opening of the first slit section 16 on the mask 30 placed on the mask stage 72.
[0020]
The field lens system 114 has a third electronic lens 28 and a fourth electronic lens 32. The reduction and objective optical system 116 includes a fifth electronic lens 40, a sixth electronic lens 46, a seventh electronic lens 50, an objective lens 52, a third deflector 34, a fourth deflector 38, a main deflector 56, and a sub deflector. 58, a blanking electrode 36, and a round aperture section 48.
[0021]
The third electronic lens 28 and the fourth electronic lens 32 focus the electron beam on the semiconductor wafer 64. The fifth electron lens 40 adjusts the rotation of the electron beam so that the electron beam is irradiated on the semiconductor wafer 64 in a desired direction. The sixth electronic lens 46 and the seventh electronic lens 50 adjust the reduction ratio of the pattern image irradiated on the semiconductor wafer 64 with respect to the pattern formed on the mask 30. The third deflector 34 deflects the electron beam in the direction of the optical axis A downstream of the mask 30 with respect to the traveling direction of the electron beam. The fourth deflector 38 deflects the electron beam so as to be substantially parallel to the optical axis A. The main deflector 56 and the sub deflector 58 deflect the electron beam so that a predetermined region on the semiconductor wafer 64 is irradiated with the electron beam. In the present embodiment, the main deflector 56 is used to deflect the electron beam between subfields including a plurality of areas (shot areas) that can be irradiated with one shot of the electron beam, and the sub deflector 58 is used to deflect the subfield. Is used for deflection between shot areas.
[0022]
The round aperture section 48 has a circular opening (round aperture). The round aperture section 48 allows the electron beam emitted inside the round aperture to pass therethrough and shields the electron beam emitted outside the round aperture. The blanking electrode 36 deflects the electron beam so as to hit the outside of the round aperture. Therefore, the blanking electrode 36 can prevent the electron beam from traveling downstream from the round aperture section 48 by deflecting the electron beam.
[0023]
The control system 140 includes an overall control unit 130 and an individual control unit 120. The individual control unit 120 includes a deflection control unit 82, a mask stage control unit 84, a blanking electrode control unit 86, an electron lens control unit 88, a reflected electron processing unit 90, a wafer stage control unit 92, a residual suction force detection unit 204, and It has a handler control unit 206. The general control unit 130 is, for example, a workstation, and controls each control unit included in the individual control unit 120 collectively. The deflection controller 82 supplies deflection data indicating the amount of deflection to the first deflector 22, the second deflector 26, the third deflector 34, the fourth deflector 38, the main deflector 56, and the sub deflector 58. Then, the amount of deflection by the first deflector 22, the second deflector 26, the third deflector 34, the fourth deflector 38, the main deflector 56, and the sub deflector 58 is controlled. The mask stage controller 84 controls the mask stage driver 68 to move the mask stage 72.
[0024]
The blanking electrode control unit 86 controls the blanking electrode 36 when changing the pattern to be transferred to the semiconductor wafer 64 or changing the region of the semiconductor wafer 64 where the pattern is exposed, so that the round aperture unit 48 The electron beam is deflected so that the electron beam does not travel downstream. This prevents the semiconductor wafer 64 from being irradiated with the electron beam. The electronic lens control unit 88 includes a first electronic lens 14, a second electronic lens 20, a third electronic lens 28, a fourth electronic lens 32, a fifth electronic lens 40, a sixth electronic lens 46, a seventh electronic lens 50, and The power supplied to the objective lens 52 is controlled. The backscattered electron processing unit 90 outputs data indicating the amount of backscattered electrons detected by the backscattered electron detector 60. Wafer stage controller 92 controls wafer stage driver 70 to move wafer stage 62 to a predetermined position. The residual suction force detection unit 204 detects the residual suction force between the semiconductor wafer 64 and the electrostatic chuck unit 204 when the application of the voltage to the electrostatic chuck unit 200 is stopped. The handler control unit 206 controls the handler to carry in and carry out the semiconductor wafer 64 with respect to the main chamber 202.
[0025]
Further, the electron beam exposure apparatus 100 may be a variable rectangular exposure apparatus that exposes a pattern on the semiconductor wafer 64 with a variable rectangular beam. Further, a multi-beam exposure apparatus that exposes a pattern on the semiconductor wafer 64 with a plurality of electron beams may be used.
[0026]
FIG. 2 shows an example of a configuration around the wafer stage 62. The electron beam exposure apparatus 10 includes a sub-chamber 208 in which a semiconductor wafer 64 before or after exposure is held, a handler 210 for transporting the semiconductor wafer 64 between the main chamber 202 and the sub-chamber 208, The semiconductor device further includes a conductive wafer standby base 212 for holding the body wafer, and a conductive wafer 214 mounted on the conductive wafer standby base 212.
[0027]
The handler 210 loads the semiconductor wafer 64 held in the sub-chamber 208 into the main chamber 202 and places it on the electrostatic chuck unit 200 of the wafer stage 62 under the control of the handler control unit 206. Further, when the exposure processing of the semiconductor wafer 64 is completed, the handler 210 unloads the semiconductor wafer 64 mounted on the wafer stage 62 of the main chamber 208 to the sub-chamber 208. Further, after unloading the semiconductor wafer 64 from the electrostatic chuck section 63, the handler 210 loads the conductive wafer 214 placed on the conductive wafer standby table 212 into the main chamber 202 and sets the static state of the wafer stage 62. It is placed on the electric chuck unit 200. Then, the electric charge remaining on the electrostatic chuck unit 200 is removed by grounding the conductive wafer 214 mounted on the electrostatic chuck unit 200.
[0028]
The main chamber 202 and the sub-chamber 208 are each depressurized by a decompression pump. The main chamber 202 and the sub-chamber 208 are connected via a valve 216. After the sub-chamber 208 is sufficiently depressurized with the valve 216 closed, the valve 216 is opened to carry the semiconductor wafer 64. The main chamber 202 holds the wafer stage 62, the handler 210, and the conductor wafer standby table 212 in a decompressed space. Since the conductor wafer 212 stands by in a space at the same atmospheric pressure as the wafer stage 62, the conductor wafer 212 can be quickly transferred onto the wafer stage 62 when it is necessary to remove the residual charge of the electrostatic chuck unit 200. Can be.
[0029]
Note that the conductivity of the conductor wafer 214 is preferably higher than the conductivity of the semiconductor wafer 64. Further, the conductor wafer 214 preferably does not have a band structure like a semiconductor, has a high charge density, and has a high Fermi level. The conductor wafer 214 may be a metal-based material, but is preferably an organic material such as a conductive plastic material because of a problem of metal contamination in a semiconductor bulk process. The conductor wafer 214 may be a ceramic material having a surface coated with a conductive film.
[0030]
FIG. 3 shows an example of the configuration of the electrostatic chuck section 200. FIG. 3A is a perspective view of the electrostatic chuck unit 200. FIG. FIG. 3B is a cross-sectional view of the electrostatic chuck unit 200.
[0031]
The electrostatic chuck unit 200 is provided on the wafer stage 62, and a dielectric electrostatic chuck plate 218 that holds the semiconductor wafer 64 by electrostatic force when a voltage is applied, and the electrostatic chuck plate 218 is attached to the wafer stage 62. A chuck holder 220 for fixing, a plurality of lift pins 222 for pressing the semiconductor wafer 64 held on the electrostatic chuck plate 218 from below and detaching the semiconductor wafer 64 from the electrostatic chuck plate, and a semiconductor wafer loaded on the electrostatic chuck plate 218 A ground contact 224 electrically connected to the semiconductor wafer 64 or the conductive wafer 214 to ground the semiconductor wafer 64 or the conductive wafer 214; an electrostatic chuck electrode 226 for applying a voltage to the electrostatic chuck plate 218; Electrostatic chuck power supply 22 for applying voltage to 226 With the door.
[0032]
When the semiconductor wafer 64 is loaded on the electrostatic chuck plate 218, the electrostatic chuck power supply 228 applies a voltage to the electrostatic chuck plate 218 via the electrostatic chuck electrode 226, and the ground contact 224 The upper surface of the semiconductor wafer 64 loaded on the chuck plate 218 is contacted and grounded, and the semiconductor wafer 64 is held by electrostatic force between the semiconductor wafer 64 and the electrostatic chuck plate 214.
[0033]
When the conductive wafer 214 is carried into the electrostatic chuck plate 218, the ground contact 224 contacts the upper surface of the semiconductor wafer 64 to be grounded, and the remaining charge of the electrostatic chuck plate 218 via the conductive wafer 214. Is discharged and removed.
[0034]
When unloading the semiconductor wafer 64 from the electrostatic chuck plate 218, the electrostatic chuck power supply 228 stops applying a voltage to the electrostatic chuck plate 218, and the ground contact 224 is driven upward, and the semiconductor wafer 64 is driven upward. 64 away from the top surface. Then, the lift pins 222 press the semiconductor wafer 64 from below and separate the semiconductor wafer 64 from the electrostatic chuck plate 218. At this time, the residual suction force detecting unit 204 detects a load applied to the lift pins 222 when the lift pins 222 separate the semiconductor wafer 64 from the electrostatic chuck plate 218 as a residual suction force. Then, the overall control unit 130 determines whether or not to carry the conductive wafer 214 onto the electrostatic chuck plate 218 based on the residual suction force detected by the residual suction force detection unit 204.
[0035]
When unloading the conductive wafer 214 from the electrostatic chuck plate 218, the ground contact 224 is driven upward and separates from the upper surface of the conductive wafer 214. Then, the lift pins 222 press the conductor wafer 214 from below and separate it from the electrostatic chuck plate 218.
[0036]
FIG. 4 shows the measurement results of the residual attraction force of the semiconductor wafer and the conductor wafer. The vertical axis indicates the driving pressure (MPa) at the time of wafer detachment, that is, the load applied to the lift pins 222 when the semiconductor wafer or the conductive wafer is detached from the electrostatic chuck plate. The horizontal axis indicates the number of trials (times), that is, the number of times of measurement of the wafer separation drive pressure (MPa) for each of the semiconductor wafer and the conductor wafer. In this measurement, a silicon wafer was used as a semiconductor wafer, and a metal wafer was used as a conductor wafer.
[0037]
First, the semiconductor wafer is loaded onto the electrostatic chuck plate 218, a voltage is applied to the electrostatic chuck plate 218, the ground contact 224 is brought into contact with the semiconductor wafer and grounded, and the semiconductor wafer is held. Irradiated with electron beam for hours. Specifically, while moving the wafer stage 62 stepwise, the region having a width of 200 μm was irradiated with an electron beam every 5 seconds, and the entire region of the semiconductor wafer was irradiated with the electron beam.
[0038]
After applying the electron beam for 24 hours, the application of the voltage to the electrostatic chuck plate 218 is stopped, the arc contact 224 is separated from the semiconductor wafer, and the semiconductor wafer irradiated with the electron beam is separated from the electrostatic chuck plate 218. The driving pressure (1) at the time of wafer detachment at this time was measured. Then, the semiconductor wafer detached from the electrostatic chuck plate 218 was mounted on the electrostatic chuck plate 218 again, detached from the electrostatic chuck plate 218, and the driving pressure (2) for detaching the wafer at this time was measured. The same operation was repeated five times, and the driving pressures (3), (4), and (5) during wafer detachment were measured.
[0039]
Next, the semiconductor wafer was unloaded from the electrostatic chuck plate 218, the conductive wafer was loaded onto the electrostatic chuck 218, and the ground contact 224 was brought into contact with the conductive wafer and grounded. Then, the arc contact 224 was separated from the semiconductor wafer, the conductive wafer was separated from the electrostatic chuck plate 218, and the driving pressure (6) at the time of separating the wafer was measured. Then, the conductive wafer detached from the electrostatic chuck plate 218 is mounted again on the electrostatic chuck plate 218, detached from the electrostatic chuck plate 218, and the driving pressure (7) at the time of detaching the wafer was measured. . The same operation was repeated five times, and the driving pressures (8), (9), and (10) during wafer detachment were measured.
[0040]
As shown in FIG. 4, by carrying the conductive wafer onto the electrostatic chuck plate 218, the residual suction force generated by irradiating the semiconductor wafer with the electron beam can be reduced. In addition, since the driving pressure at the time of wafer detachment when the residual suction force is not generated is 0.18 (MPa), the conductive wafer is loaded onto the electrostatic chuck plate 218, so that the residual suction force is almost completely removed. Is eliminated, that is, the charge remaining on the electrostatic chuck plate 218 can be almost completely removed.
[0041]
FIG. 5 shows an example of a flow of a residual attraction force reducing method for reducing the residual attraction force between the semiconductor wafer 64 and the electrostatic chuck plate 218. First, the handler 210 loads the semiconductor wafer 64 onto the electrostatic chuck plate 218 of the wafer stage 62 based on the control of the handler control unit 206 (S100). Then, the electrostatic chuck power supply 228 applies a voltage to the electrostatic chuck plate 218, and the ground contact 224 contacts and grounds the semiconductor wafer 64, thereby holding the semiconductor wafer 64 by electrostatic force (S102). Then, the semiconductor wafer 64 is exposed by irradiating the semiconductor wafer 64 with an electron beam (S104).
[0042]
Next, after the end of the exposure processing in S104, the electrostatic chuck power supply 228 stops applying the voltage to the electrostatic chuck plate 218, and the ground contact 224 separates from the semiconductor wafer 64, so that the semiconductor wafer 64 is moved to the electrostatic chuck plate. 218 (S106). Then, the lift pins 222 press the semiconductor wafer 64 held on the electrostatic chuck plate 218 from below to separate the semiconductor wafer 64 from the electrostatic chuck plate 218 (S108). At this time, the residual suction force detection unit 204 detects the load applied to the lift pins in S108 as the residual suction force between the semiconductor wafer 64 and the electrostatic chuck plate 218 (S110). Then, the handler 210 unloads the semiconductor wafer 64 from above the electrostatic chuck plate 218 of the wafer stage 62 based on the control of the handler control unit 206 (S112).
[0043]
Next, the overall control unit 130 determines whether or not the residual suction force detected by the residual suction force detection unit 204 is larger than a predetermined value (S114). If the overall control unit 130 determines in S114 that the residual suction force is smaller than the predetermined value, the process returns to S100, and the handler 210 moves the semiconductor wafer 64 to be exposed next to the wafer stage 62 based on the control of the handler control unit 206. (S100). When the overall control unit 130 determines that the residual suction force is larger than the predetermined value in S114, the handler 210 loads the conductive wafer 214 onto the electrostatic chuck plate 218 based on the control of the handler control unit 206. (S116). Then, the ground contact 224 removes the electric charge remaining on the electrostatic chuck plate 218 by contacting and grounding the conductive wafer 214 (S118).
[0044]
According to the method for reducing the residual attraction force of the present embodiment, the charge remaining on the electrostatic chuck plate 218 is removed, so that the semiconductor wafer 64 does not need to be externally forcibly peeled off from the electrostatic chuck plate 218 by applying an external force. The wafer 64 is not damaged or particles are not generated. In addition, the transfer quality of the semiconductor wafer 64 can be improved without causing a transfer trouble due to a jump when the semiconductor wafer 64 is detached. Further, when the residual suction force becomes larger than a predetermined value, the conductive wafer 214 is loaded onto the electrostatic chuck plate 218, so that deterioration of the throughput of the electron beam exposure apparatus 100 can be reduced.
[0045]
As described above, the present invention has been described using the embodiment. However, the technical scope of the present invention is not limited to the scope described in the embodiment. Various changes or improvements can be added to the above embodiment. It is apparent from the description of the appended claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.
[0046]
【The invention's effect】
As is clear from the above description, according to the present invention, it is possible to provide an electron beam exposure apparatus and a method for alleviating a residual chucking force generated between a semiconductor wafer and an electrostatic chuck plate.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a configuration of an electron beam exposure apparatus 100.
FIG. 2 is a diagram showing an example of a configuration around a wafer stage 62.
FIG. 3A is a perspective view of an electrostatic chuck unit 200. FIG.
(B) is a sectional view of the electrostatic chuck unit 200.
FIG. 4 is a diagram showing a measurement result of a residual suction force of a semiconductor wafer and a conductor wafer.
FIG. 5 is a diagram showing an example of a flow of a method for alleviating residual attraction force.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... barrel, 12 ... electron gun, 14 ... 1st electron lens, 16 ... 1st slit part, 20 ... 2nd electron lens, 22 ... 1st deflector, 26: second deflector, 28: third electron lens, 30: mask, 32: fourth electron lens, 34: fourth deflector, 36: blanking electrode, 38, a fourth deflector, 40, a fifth electron lens, 46, a sixth electron lens, 48, a round aperture, 50, a seventh electron lens, 52, an objective lens, 56: main deflector, 58: sub deflector, 60: backscattered electron detector, 62: wafer stage, 64: wafer, 68: mask stage drive unit, 70 ...・ Wafer stage driving unit, 72: mask stage, 82: deflection control unit, 84: mask Tage control unit, 86: Blanking electrode control unit, 88: Electronic lens control unit, 90: Reflection electron processing unit, 92: Wafer stage control unit, 100: Electron beam exposure device, 110: electron beam irradiation system, 112: collimator lens unit, 114: field lens system, 116: reduction and objective optical system, 120: individual control unit, 130: general control unit , 140: control system, 150: exposure unit, 200: electrostatic chuck unit, 202: main chamber, 204: residual suction force detection unit, 206: handler control unit, 208 ... Sub-chamber, 210 ... Handler, 212 ... Conductive wafer stand, 214 ... Conductor wafer, 216 ... Valve, 218 ... Electrostatic chuck play , 220 ... chuck holder, 222 ... lift pins 224 ... ground contact, 226 ... electrostatic chuck electrode, 228 ... chuck electrode

Claims (11)

An electron beam exposure apparatus that exposes a semiconductor wafer with an electron beam,
A wafer stage on which the semiconductor wafer is mounted during exposure processing;
A dielectric electrostatic chuck plate that is provided on the wafer stage and holds the semiconductor wafer by electrostatic force when a voltage is applied;
A conductive wafer standby table for waiting the conductive conductive wafer,
After the exposure processing of the semiconductor wafer, the semiconductor wafer is unloaded from the electrostatic chuck plate, and the conductive wafer is removed from the conductive wafer standby table in order to remove electric charges remaining on the electrostatic chuck plate. An electron beam exposure apparatus, comprising: a handler to be carried on the electric chuck plate. 2. The electron beam exposure apparatus according to claim 1, further comprising a conductive wafer mounted on the conductive wafer waiting table. 2. The electron beam exposure apparatus according to claim 1, further comprising an earth contact electrically connected to the conductive wafer loaded on the electrostatic chuck plate and grounding the conductive wafer. After stopping the application of the voltage to the electrostatic chuck plate, further comprising a residual suction force detection unit for detecting a residual suction force between the electrostatic chuck plate and the semiconductor wafer,
The handler, when the residual suction force detected by the residual suction force detection unit is larger than a predetermined value, loads the conductive wafer from the conductive wafer standby stand onto the electrostatic chuck plate. The electron beam exposure apparatus according to claim 1. The semiconductor device further includes lift pins for pressing the semiconductor wafer held on the electrostatic chuck plate from below and detaching the semiconductor wafer from the electrostatic chuck plate,
5. The electronic device according to claim 4, wherein the residual attraction force detection unit detects, as the residual attraction force, a load applied to the lift pins when the lift pins separate the semiconductor wafer from the electrostatic chuck plate. 6. Beam exposure equipment. 2. The electron beam exposure apparatus according to claim 1, further comprising a chamber for holding the wafer stage and the conductor wafer stand in a reduced pressure space. The electron beam exposure apparatus according to claim 1, wherein the conductivity of the conductor wafer is higher than the conductivity of the semiconductor wafer. The electron beam exposure apparatus according to claim 7, wherein the conductor wafer is made of a conductive plastic material. In an electron beam exposure apparatus for exposing a semiconductor wafer with an electron beam, a method for reducing a residual chucking force between an electrostatic chuck plate of a wafer stage and the semiconductor wafer, comprising:
Loading a semiconductor wafer onto the electrostatic chuck plate to load the semiconductor wafer,
By applying a voltage to the electrostatic chuck plate, a voltage application step of holding the semiconductor wafer by electrostatic force,
An exposure step of exposing the semiconductor wafer with the electron beam,
After the end of the exposure processing in the exposure step, a voltage stop step of stopping application of a voltage to the electrostatic chuck plate,
A semiconductor wafer unloading step of unloading the semiconductor wafer from the electrostatic chuck plate,
Loading a conductive wafer onto the electrostatic chuck plate to remove charges remaining on the electrostatic chuck plate. After the voltage stopping step, the method further includes a residual suction force detecting step of detecting a residual suction force between the electrostatic chuck plate and the semiconductor wafer,
The loading of the conductive wafer may include loading the conductive wafer onto the electrostatic chuck plate when the residual suction force detected in the residual suction force detecting step is greater than a predetermined value. The method for alleviating residual adsorptive power according to claim 9. The semiconductor wafer unloading step includes a semiconductor wafer detaching step of pressing the semiconductor wafer held on the electrostatic chuck plate from below with lift pins and detaching the semiconductor wafer from the electrostatic chuck plate,
11. The method according to claim 10, wherein the detecting step includes detecting a load applied to the lift pin in the detaching step of the semiconductor wafer as the residual suction force.

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