JP2010199244A - Aligner and method of manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aligner capable of further surely reducing the degree of charging of a mask. <P>SOLUTION: The aligner which has a holding means for holding an original plate according to the voltage to be applied, and exposes a substrate through the original plate held by the holding means includes: a raising and lowering means which raises and lowers the original plate relative to the holding means; a grounding means provided on at least one of the holding means and the raising and lowering means to ground at least a part of the original plate; a detection means which detects that the original plate is grounded; and a control means which controls the voltage to be applied to the holding means according to the output of the detection means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an exposure apparatus and a device manufacturing method.

  An EUV exposure apparatus using EUV light (extreme ultraviolet light) is expected as a next-generation exposure apparatus. In an EUV exposure apparatus, a mask on which a pattern for transfer onto a wafer is formed is used. On the mask surface, charges induced by leakage current, electrostatic chuck electrodes, etc. are generated, and the mask can be charged. . When the mask is charged and exposed to an atmospheric pressure atmosphere in a load lock or the like, dust in the atmosphere may be sucked and foreign matters such as dust may adhere to the mask surface.

  However, the EUV exposure apparatus cannot use a pellicle. For this reason, the EUV exposure apparatus has a problem that foreign matters such as dust adhere to the mask surface. When the foreign matter has an electric charge, the adhesion of the foreign matter to the mask surface can be suppressed by setting the mask surface to the ground potential. Furthermore, even if the foreign matter is neutral particles, since the foreign matter can adhere to the mask surface with non-uniform potential and the edge portion of the mask surface with uniform potential due to the electric field gradient, it is adhering to grounding the mask surface. Effective in reducing foreign matter. Patent Document 1 discloses an exposure apparatus in which a conductive film is formed on a resist surface and grounded in order to prevent charging by an electrostatic chuck. Patent Document 2 discloses an exposure apparatus that sets two conductive pins on a mask and measures the resistance between the two conductive pins at the time of mask drawing with an electron beam. Patent Document 3 discloses an exposure apparatus that measures the potential of the wafer surface and applies a voltage to the wafer so as to cancel the potential in order to prevent charging during electron beam irradiation. Patent Document 4 discloses a proximity X-ray exposure apparatus mask having a structure for preventing electrification. Patent Document 5 discloses a metal film vapor deposition method in which a metal film is formed on the side wall of a mask in order to conduct between the front and back of an EUV mask.

JP-A-11-67646 JP-A-11-67647 JP 2005-129828 A JP-A-5-198482 JP 2006-324268 A

  In order to reduce foreign matter adhering to the mask, it is necessary to more reliably reduce the degree of charging of the mask. However, the above-described conventional technology has an insufficient aspect in that respect.

  An object of the present invention is to more reliably reduce the degree of charging of a mask.

  An exposure apparatus according to one aspect of the present invention is an exposure apparatus that includes a holding unit that holds an original according to an applied voltage, and that exposes a substrate through the original held by the holding unit. A raising / lowering means for raising and lowering the original with respect to the holding means; a grounding means provided on at least one of the holding means and the raising / lowering means for grounding at least a part of the original; and detecting that the original is grounded Detecting means for controlling, and control means for controlling a voltage applied to the holding means according to an output of the detecting means.

  An exposure apparatus according to another aspect of the present invention includes a first electrode to which a positive voltage is applied and a second electrode to which a negative voltage is applied, and includes the first electrode and the second electrode. An exposure apparatus having a holding means for holding the original according to the applied voltage, and exposing the substrate through the original held by the holding means, the detecting means for detecting the potential of the original; and And control means for controlling at least one of the positive voltage and the negative voltage so that the original has a ground potential based on the output of the detection means.

  An exposure apparatus according to another aspect of the present invention is an exposure apparatus that has a holding unit that holds an original according to an applied voltage, and that exposes a substrate through the original held by the holding unit, The raising and lowering means for raising and lowering the original with respect to the holding means, the detecting means for detecting the potential of the original, and the raising and lowering means after determining that the original has a ground potential based on the output of the detecting means. Control means for lowering the original.

  A device manufacturing method according to another aspect of the present invention includes a step of exposing a substrate using the exposure apparatus, and a step of developing the substrate exposed in the step.

  Other objects and features of the invention are described in the following embodiments.

  According to the present invention, for example, the degree of charging of the mask can be more reliably reduced.

FIG. 3 is an enlarged view of a main part in the exposure apparatus of Embodiment 1. FIG. 5 is an enlarged view of a main part in the exposure apparatus of Embodiment 2. It is a principal part enlarged view in the exposure apparatus of Embodiment 3. FIG. It is a principal part enlarged view in the exposure apparatus of Embodiment 4. FIG. 10 is an enlarged view of a main part in the exposure apparatus of Embodiment 5. It is a principal part enlarged view in the exposure apparatus of Embodiment 6. FIG. It is a principal part enlarged view in the exposure apparatus of Embodiment 7. FIG. It is a block diagram of the exposure apparatus of this embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same members are denoted by the same reference numerals, and redundant description is omitted.

  First, an outline of an exposure apparatus according to an embodiment of the present invention will be described. FIG. 8 is a block diagram of the exposure apparatus in the present embodiment. The exposure apparatus of this embodiment is an exposure apparatus that exposes a wafer (substrate) through a mask (original plate) pattern. In FIG. 8, 41 is a load lock chamber for a mask, 42 is a transfer chamber, 43 is an exposure chamber, and 44 is a mask storage chamber. 45 to 47 are dedicated chambers adjacent to the exposure chamber 43. The mask load lock chamber 41 is provided to transfer the mask 8 between the inside of the exposure apparatus and the outside of the exposure apparatus while maintaining a vacuum atmosphere in the exposure apparatus. In the transfer chamber 42, a mask handling device 29 (transfer unit) is arranged.

[Embodiment 1]
Next, the exposure apparatus in Embodiment 1 of the present invention will be described. FIG. 1 is an enlarged view of a main part of the exposure apparatus 100a of the present embodiment. In FIG. 1, reference numeral 1 denotes an electrostatic chuck (original plate holding means) as a mask chuck. The electrostatic chuck 1 includes an electrode 2 (first electrode) to which a positive voltage is applied, an electrode 3 (second electrode) to which a negative voltage is applied, and a semiconductor member 4 such as ceramic. . Although the semiconductor member 4 has a high resistance, when a predetermined positive voltage and a negative voltage are applied to the electrodes 2 and 3 in a state where the mask 8 is pressed against the electrostatic chuck 1, a current flows. The electrostatic chuck 1 holds or releases the mask 8 according to the voltage applied to the electrodes 2 and 3. The voltage applied to the electrodes 2 and 3 is controlled by control means (not shown).

  Reference numeral 8 denotes a mask (original plate). The mask 8 includes an electrode layer 5, a mask substrate 6, and a multilayer film 7. The multilayer film 7 is formed on the surface of the mask substrate 6 made of glass or the like. The surface of the multilayer film 7 is made of metal and reflects EUV light (extreme ultraviolet light). The electrode layer 5 is formed on the back surface of the mask substrate 6. For example, a metal film such as a CrN film is deposited on the back surface of the mask substrate 6. The support pins 9 support the mask 8, and a mask elevating mechanism 10 (original plate elevating means) including the support pins 9 is configured to elevate with respect to the electrostatic chuck 1. The direction in which the original lifting / lowering means moves the original plate is not limited to the gravitational (vertical) direction, and may be arbitrary. For example, when the chuck surface of the electrostatic chuck 1 is parallel to the gravitational direction, it can be a horizontal direction. The mask 8 can be transferred between the electrostatic chuck 1 and the mask lifting mechanism 10.

  The electrostatic chuck 1 is provided with a ground pin 12a (first ground pin). The ground pin 12 a is configured to contact the surface of the mask 8. The mask raising / lowering mechanism 10 is provided with a ground pin 12b (second ground pin). The ground pin 12 b is built in the support pin 9 of the mask lifting mechanism 10 and is configured to contact the mask 8. The ground wires 13 a and 13 b attached to the ground pins 12 a and 12 b are taken out of the vacuum chamber 11 through the feedthrough 15. Thus, the ground pins 12a and 12b and the ground lines 13a and 13b are ground means for grounding at least a part of the mask 8. An ohmmeter 14 for detecting the resistance between the ground pins 12a and 12b is provided in the middle of the ground wire 13b. The ohmmeter 14 functions as detection means for detecting that the mask 8 is grounded.

  In the exposure apparatus 100a of the present embodiment, until the electrode layer 5 on the back surface of the mask 8 (upper surface of the mask 8 in FIG. 1) contacts the surface of the electrostatic chuck 1 (lower surface of the electrostatic chuck 1 in FIG. 1). Alternatively, the mask 8 is brought close to the electrostatic chuck 1 by the mask lifting mechanism 10 until just before that. At this stage, the ground pin 12b and the multilayer film 7 on the surface of the mask 8 (the lower surface of the mask 8 in FIG. 1) are already connected, and the surface of the mask 8 (the multilayer film 7) is at the ground potential. It has become. However, detection (confirmation) as to whether or not the surface of the mask 8 is grounded has not been performed yet.

  Next, when the ground pin 12a extends from the electrostatic chuck 1 and contacts the surface of the multilayer film 7 of the mask 8, "ground line 13a-ground pin 12a-multilayer film 7-ground pin 12b-ground line 13b-earth" The closed loop is completed. At this time, if the output (resistance value) of the ohmmeter 14 is zero (including the case where it is substantially zero (below a predetermined threshold)), it is detected that the surface of the multilayer film 7 has become the ground potential. (It is confirmed. If the output of the ohmmeter 14 does not indicate zero, the surface potential of the multilayer film 7 may not be the ground potential. For this reason, the control means (not shown) does not apply a voltage to the electrodes 2 and 3 of the electrostatic chuck 1. Then, the operation of bringing at least one of the ground pins 12a and 12b into contact with the surface of the mask 8 is performed again, and the above-described detection (confirmation) step is repeated. When the output of the resistance meter 14 becomes zero, it is detected that the potential of the surface of the mask 8 (the surface of the multilayer film 7) has become the ground potential. Control means (not shown) applies positive and negative voltages to the electrodes 2 and 3 so that the electrostatic chuck 1 holds the mask 8 after the ohmmeter 14 detects the grounding of the mask 8. Thus, the control means (not shown) controls the voltage applied to the electrodes 2 and 3 based on the output of the resistance meter 14.

  When positive and negative voltages are respectively applied to the electrodes 2 and 3 of the electrostatic chuck 1 and the mask 8 is held by the electrostatic chuck 1, the mask elevating mechanism 10 is lowered. For this reason, the ground pin 12b is separated from the surface of the mask 8, and the output (resistance value) of the ohmmeter 14 becomes infinite. However, since the ground pin 12a remains in contact with the surface of the mask 8 (the surface of the multilayer film 7), the surface of the mask 8 remains grounded.

  Thus, in this embodiment, after detecting that the surface of the mask 8 is grounded, a voltage is applied to the electrodes 2 and 3 of the electrostatic chuck 1. For this reason, the degree of charging of the mask 8 can be within an allowable range, and dust, particles, and the like adhering to the surface of the multilayer film 7 can be reduced. Further, if one ground pin 12a provided on the electrostatic chuck 1 for grounding the surface of the mask 8 is used, the structure is simple and the possibility of generating foreign matter such as dust due to contact is low.

[Embodiment 2]
Next, an exposure apparatus according to Embodiment 2 of the present invention will be described. FIG. 2 is an enlarged view of a main part of the exposure apparatus 100b of the present embodiment. Since the basic configuration of the present embodiment is the same as that of the first embodiment, a description of the same components as those of the first embodiment is omitted.

  The exposure apparatus 100b is implemented in that a ground pin 12c (third ground pin) provided on the electrostatic chuck 1 so as to contact the mask is provided instead of the ground pin 12b of the first embodiment. It is different from the exposure apparatus 100a of the first embodiment. That is, the grounding means of the exposure apparatus 100b includes a ground pin 12a (first ground pin) and a ground pin 12c (third ground pin). The resistance meter 14 of the exposure apparatus 100b detects the resistance between the ground pins 12a and 12c.

In the present embodiment, when the electrode layer 5 of the mask 8 comes into contact with the surface of the electrostatic chuck 1 or comes close to just before that, the ground pins 12a and 12c extend from the electrostatic chuck 1 and the surface of the mask 8 (multilayer). The surface of the membrane 7).
When the electrode layer 5 of the mask 8 and the surface of the electrostatic chuck 1 are in reliable contact, the ground pins 12a and 12c are brought into conduction, and the output of the resistance meter 14 is reduced (the resistance value becomes substantially zero). .

  In this embodiment, after the grounding of the surface of the mask 8 is detected in this way, a voltage is applied to the electrodes 2 and 3 of the electrostatic chuck 1. For this reason, the degree to which the mask 8 is charged can be reliably reduced, and foreign matters such as dust adhering to the surface of the multilayer film 7 can be reduced.

  As described above, the information on the confirmation of the grounding of the mask was used to determine the start of voltage application to the electrostatic chuck. However, the ground information can also be used to determine whether to continue applying voltage to the electrostatic chuck. For example, the continuity between the ground pins 12a and 12b is appropriately monitored during exposure, and when the continuity cannot be obtained, the exposure is stopped, the power supply to the electrostatic chuck is shut off, the mask is recovered, and the foreign matter adhering to the mask is removed. Can be reduced.

  In this embodiment, two ground wires are used to detect the grounding of the mask surface, but three or more ground wires may be used. Moreover, although the ground pin of this embodiment is contacting the surface of a mask, it is not limited to this. For example, when a metal film is deposited on the side surface of the mask and is electrically connected to the surface, the metal film on the side surface of the mask or the electrode on the back surface of the mask is used instead of contacting the ground pin with the surface of the mask. It may be configured to contact the layer. In this embodiment, the front surface of the mask is configured to be grounded, but the back surface of the mask may be configured to be grounded.

  In this embodiment, a voltage is applied to the electrostatic chuck (electrodes 2 and 3) after detecting the grounding of the mask surface. However, it may be difficult to bring the ground pin into contact with the mask before the mask is held on the electrostatic chuck. For example, when a protective substrate for protecting the mask surface is in the vicinity of the mask surface, the mask needs to be lifted off the protective substrate. In such a case, immediately after the voltage is applied to the electrostatic chuck and the mask is held by the electrostatic chuck, the protective substrate is lowered, and the gap between the mask and the protective substrate is opened, the ground pin is brought into contact with the mask surface. You may comprise.

  The electrostatic chuck according to the present embodiment is a so-called bipolar electrostatic chuck having two electrodes to which positive and negative voltages are applied. However, the present embodiment is not limited to this, and can also be applied to a so-called monopolar electrostatic chuck having one electrode to which either positive or negative voltage is applied.

[Embodiment 3]
Next, an exposure apparatus according to Embodiment 3 of the present invention will be described. FIG. 3 is an enlarged view of a main part of the exposure apparatus 100c of the present embodiment. Since the basic configuration of the present embodiment is the same as that of the first embodiment, a description of the same components as those of the first embodiment is omitted.

  In the exposure apparatus 100c, a metal protective substrate 16 (metal substrate) for protecting the mask 8 is disposed immediately below the mask 8 separated from the mask 8 by, for example, about 1 μm to 10 mm. The protective substrate 16 is disposed on the support pins 9 of the mask lifting mechanism 10. As the protective substrate 16 having such a structure, for example, there is an inner base in an inner case of a double pod. The EUV mask is transported in an inner case within the exposure apparatus. The inner base is a metal flat substrate and protects the mask surface in the vicinity of the mask surface.

  As shown in FIG. 3, the ground pin 12 d (fourth ground pin) of this embodiment is built in one of the support pins 9. The installation means of this embodiment is provided in the mask lifting mechanism 10 so as to contact the grounding pin 12a (first grounding pin) provided on the electrostatic chuck 1 so as to contact the mask 8 and the protective substrate 16. And a ground pin 12d (fourth ground pin). Since the protective substrate 16 is in contact with the ground pin 12d, the potential of the protective substrate 16 is the ground potential. The protective substrate 16 includes support pins 19 made of a dielectric, and the surface of the mask 8 is in direct contact with the support pins 19 made of a dielectric. For this reason, the potential of the surface of the mask 8 is not the ground potential.

  In the present embodiment, when the mask 8 comes close to the electrostatic chuck 1 and the ground pin 12a comes into contact with the surface of the mask 8 (the surface of the multilayer film 7), the surface of the mask 8 becomes a ground potential. At this time, since the surface of the multilayer film 7 and the surface of the protective substrate 16 are planar metal surfaces facing each other, a capacitor structure is adopted. Therefore, the capacitance between the surface of the multilayer film 7 and the surface of the protective substrate 16 is detected (measured) by the capacitance measuring device (capacitance meter) 17, so that the surface of the multilayer film 7 is grounded. It can be determined whether or not. In other words, the capacitance measuring instrument 17 is a detecting means connected between the ground pin 12a and the ground pin 12d so as to detect the capacitance between the mask 8 and the protective substrate 16.

  After the power of the electrostatic chuck 1 is turned on and the mask 8 is held by the electrostatic chuck 1, the distance between the surface of the multilayer film 7 and the protective substrate 16 changes when the mask lifting mechanism 10 is lowered. . It is possible to determine whether or not the ground pin 12a is in contact with the surface of the multilayer film 7 also by the change in capacitance at this time.

  In the present embodiment, if there is only one ground pin for grounding the surface of the mask, the configuration is simple, and the possibility of foreign matter being generated by contact is low. Further, in this embodiment, even after the support pin 19 and the multilayer film 7 are separated from each other, the contact state can be determined for a while, so that the change in the contact state of the ground pin 12a due to the lowering of the mask lifting mechanism 10 is determined. Is also possible. In addition, if the support pin 19 of this embodiment is comprised with the conductor, the grounding of a mask can be detected by the method similar to Embodiment 1. FIG. Further, in the present embodiment, it is only necessary to have two opposing conductors, and it is not necessary to be the inner base of the double pod opposing the entire mask surface, and only a part of the mask surface may be the opposing conductor. In the present embodiment, the mask ground may be determined by measuring the reactance (capacitive reactance).

[Embodiment 4]
Next, an exposure apparatus according to Embodiment 4 of the present invention will be described. FIG. 4 is an enlarged view of a main part of the exposure apparatus 100d of the present embodiment.

  The electrostatic chuck 1 in the present embodiment is a Johnson-Labeck type (JR type) electrostatic chuck. As shown in FIG. 4, in the JR type electrostatic chuck, the semiconductor member 4 made of ceramic is provided with two positive and negative electrodes 2 and 3, and a closed loop is formed between the electrode layer 5 provided on the back surface of the mask 8. Composed. As described above, the electrostatic chuck 1 according to the present embodiment includes the electrode 2 (first electrode) to which a positive voltage is applied and the electrode 3 (second electrode) to which a negative voltage is applied. 3 is a bipolar electrostatic chuck that holds or releases the mask 8 in accordance with positive and negative voltages applied to each of the three.

Since ceramic exhibits a large resistance value, a minute current flows between the mask 8 and the electrostatic chuck 1. Positive and negative voltages having the same absolute value of 50 to several KV are applied to the electrodes 2 and 3, respectively. Although the voltage of the electrode layer 5 on the back surface of the mask is substantially zero, it is not always exactly zero. This is because the absolute values of the voltages applied to the electrodes 2 and 3 are not necessarily equal, or the electrical resistance Ra between the electrode 2 and the electrode layer 5 and the electrical resistance Rb between the electrode 3 and the electrode layer 5 Is not equal. In addition, the electrical resistances Ra and Rb can vary depending on the contact state between the electrode layer 5 and the surface of the electrostatic chuck 1. For this reason, the electrode layer 5 does not always show the same potential. If the electrode layer 5 is not grounded in this way, polarization is caused in the mask substrate 6 that is an insulator, and the surface potential of the mask 8 is not zero, and a force that attracts foreign matters such as dust to the mask surface is generated.
For this reason, the exposure apparatus 100d detects the potential of the electrode layer 5 deposited on the back surface of the mask 8 using a not-shown electrometer, and controls the potential of the electrode layer 5 to be the ground potential. That is, the exposure apparatus 100d includes an electrometer that is a potential detection unit that detects the potential of the mask 8. The control means (not shown) controls at least one of the positive voltage and the negative voltage so that the potential of the mask 8 detected by the electrometer becomes zero (ground potential).

  The exposure apparatus 100d of the present embodiment is configured so that the surface potential of the mask 8 is also at the ground potential by controlling the electrode layer 5 to be at the ground potential. As shown in FIG. 4, first, the ground pin 12 e (fifth ground pin) provided on the electrostatic chuck 1 contacts the electrode layer 5 of the mask 8. At this time, whether or not the electrode layer 5 is grounded may be determined using a plurality of ground pins as in the first embodiment, but can also be determined by the configuration of the present embodiment shown in FIG. The ground pin 12 e is connected to the ground line 13 c and grounded via the ammeter 21. In this state, a voltage of + V volts is applied to the electrode 2 using the power source 22a, and a voltage of −V volts is applied to the electrode 3 using the power source 22b. At this time, when the relationship between the electric resistances Ra and Rb is Ra> Rb, the voltage of the electrode layer 5 becomes a negative value, and a current flows through the ammeter 21 toward the electrode layer 5. Therefore, the current flowing through the ammeter 21 can be reduced to zero by increasing the voltage applied to the electrode 3.

  In the present embodiment, the electrode layer 5 on the back surface of the mask can be adjusted to the ground potential, whereby the degree of polarization of the mask substrate 6 can be sufficiently reduced. Therefore, since the surface potential of the mask 8 is also sufficiently close to the ground potential, foreign matter such as dust adhering to the mask surface is reduced. Also, by controlling the applied voltage of the electrostatic chuck so that the current flowing between the mask back surface and the ground is substantially zero (within an allowable range), the positive electrode attracts the mask substrate with a negative force. The force with which the electrode attracts the mask substrate can be made substantially equal.

  A voltmeter may be used instead of the ammeter 21. Moreover, even if the contact resistance between the electrostatic chuck 1 and the electrode layer 5 changes during chucking (holding) of the original plate by the electrostatic chuck 1, the ground potential of the mask surface can be maintained. Control may always be performed.

[Embodiment 5]
Next, an exposure apparatus according to Embodiment 5 of the present invention will be described. FIG. 5 is an enlarged view of a main part of the exposure apparatus 100e of the present embodiment.

  The exposure apparatus 100e controls the back surface of the mask to the ground potential even when the electrode layer on the back surface of the mask is not at the ground potential. As shown in FIG. 5, the mask 81 of this embodiment is provided with a ground layer 31 in addition to the mask 8 of the above embodiment. The mask 81 is provided with an insulating layer 32 between the ground layer 31 and the electrode layer 5, and the ground layer 31 and the electrode layer 5 are insulated. The electrode layer 5 and the insulating layer 32 are partly peeled off, and the surface of the earth layer 31 is exposed. At this exposed position, the ground pin 12 f (sixth ground pin) and the ground pin 12 g (seventh ground pin) are provided on the electrostatic chuck 1 so as to contact the ground layer 31. Thus, the ground pins 12f and 12g are provided on the electrostatic chuck 1 so as to be in contact with the ground layer 31 provided between the front surface and the back surface of the mask 81 and exposed on the back surface side. In FIG. 5, for easy understanding, the mask 81 is separated from the electrostatic chuck 1, but actually, the mask 81 is in contact with the electrostatic chuck 1.

  As described in the fourth embodiment, even when the absolute values of the positive and negative voltages applied to the electrodes 2 and 3 of the electrostatic chuck 1 are equal, the electrode layer 5 is not always at the ground potential. Therefore, in the present embodiment, the ground layer 31 is provided separately from the electrode layer 5, the ground pins 12f and 12g are brought into contact with the ground layer 31, and the ground layer 31 is grounded and the ground is detected as in the second embodiment ( Confirmation). Here, even if the electrode layer 5 is not necessarily at the ground potential, since the insulating layer 32 is provided between the earth layer 31 and the electrode layer 5, no current flows even if the earth layer 31 is grounded. Can be at ground potential. Therefore, the potential on the mask surface side from the ground layer 31 can be adjusted to the ground potential regardless of the potential of the electrode layer 5.

  In the present embodiment, even when the electrode layer on the back surface of the mask is not at the ground potential, the mask substrate 6 is not polarized, and the surface potential of the mask 81 can be set to the ground potential. Therefore, it is not necessary to control the voltage applied to the electrostatic chuck as shown in the fourth embodiment.

[Embodiment 6]
Next, an exposure apparatus according to Embodiment 6 of the present invention will be described. FIG. 6 is an enlarged view of a main part of the exposure apparatus of the present embodiment.

  The exposure apparatus 100f of this embodiment directly measures the charged state of the mask surface. Specifically, a surface potential meter 35 is mounted on the mask lifting mechanism 10 in the vacuum chamber 11, and the potential of the mask surface when a voltage is applied to the electrostatic chuck 1 is measured. If the potential on the mask surface changes when a voltage is applied to the electrostatic chuck 1, the grounding of the mask 8 is insufficient. At this time, the operation for grounding the mask 8 and the grounding confirmation are performed again without starting the exposure. Further, if the voltage applied to the electrostatic chuck 1 is gradually changed and the change in the potential of the mask surface is measured to see the relationship between the two, the grounding state of the mask 8 can be more reliably determined.

  This embodiment is particularly effective in reducing foreign matter that adheres due to charging during mask recovery. Even after the voltage supply to the electrostatic chuck 1 is cut off and the mask 8 is detached from the electrostatic chuck 1, electric charge remains in the electrostatic chuck 1, and the surface of the electrostatic chuck 1 does not reach the ground potential. Therefore, if the mask 8 is not grounded at the time of mask recovery, the surface of the mask 8 is charged. Therefore, as shown in FIG. 6, the mask lifting mechanism 10 is provided with a mechanism for grounding the surface of the mask 8, and at the same time, the surface potential of the mask 8 is measured by the surface potential meter 35 to prevent the mask surface from being charged. Check. Thereafter, the mask lifting mechanism 10 that has received the mask 8 is lowered to recover the mask 8. If the surface potential of the mask 8 rises after the mask 8 is detached from the electrostatic chuck 1, it means that the mask 8 is not sufficiently grounded. For this reason, the grounding pin 12b is raised to reliably ground the mask 8.

  According to the present embodiment, since the charge on the mask surface is directly measured, foreign matters such as dust adhering to the mask surface can be more reliably reduced.

  In this embodiment, a mechanism for grounding the mask surface is attached to the mask lifting mechanism so that the mask surface can be always grounded even during mask recovery. However, a mechanism for grounding the back surface or side surface of the mask may be attached. In addition, a mechanism for grounding and a surface electrometer may be similarly provided in the mask conveyance system.

  In the present embodiment, as in the fourth embodiment, the voltage applied to at least one of the electrode 2 and the electrode 3 is measured so that the surface potential of the mask becomes the ground potential while measuring the surface potential of the mask with a surface potential meter. To be adjusted. Thereby, it is not necessary to contact the ground pin with the back surface or the surface of the mask, and the flatness of the mask is not affected, and no foreign matter is attached to the mask surface. Furthermore, if the configuration is such that the surface potential of the mask is always measured using a surface potentiometer, including during exposure, and the voltage applied to at least one of the electrodes 2 and 3 is adjusted, the surface of the mask is always charged. Can be protected.

  As described above, according to each of the above embodiments, it is possible to provide an exposure apparatus that can effectively reduce foreign substances adhering to the original.

  As a modification of the present embodiment, the following configuration may be used to measure the mask potential without using a surface electrometer. That is, a plurality of ground pins may be brought into contact with the back surface of the mask, and a voltmeter may be connected to one of them to measure the potential on the back surface of the mask. In this state, when the potential on the back surface of the mask changes when a voltage is applied to the electrostatic chuck 1, the mask 8 is insufficiently grounded, and therefore the same processing as in this embodiment may be performed.

[Embodiment 7]
Next, an exposure apparatus according to Embodiment 7 of the present invention will be described. FIG. 7 is an enlarged view of a main part of the exposure apparatus 100g of the present embodiment.

  Even when the back surface of the mask is at ground potential, charging may occur when the mask is detached from the electrostatic chuck. When this occurs, a phenomenon called so-called peeling charging, the electrostatic chuck and the mask are charged with charges having opposite polarities. If the mask is moved away from the electrostatic chuck in this state, the mask may have a potential of several kV. For this reason, the mask may have foreign matters attached or sometimes discharged. The purpose of this embodiment is to avoid this, reduce the amount of adhering foreign matter, and safely collect the mask.

  In this embodiment, even after the mask is detached from the electrostatic chuck, the electrode layer on the back surface of the mask or the multilayer film layer on the surface is grounded. Preferably, it is continuously grounded before and after separation.

  Specifically, as shown in FIG. 7, a ground pin 12a made of an elastic body protrudes from the surface of a semiconductor member 4 such as ceramic as a main body of the electrostatic chuck. Even when the mask is detached from the electrostatic chuck as indicated by an arrow A, the ground pin 12a is deformed as indicated by an arrow B so that the contact with the electrode layer 5 on the back surface of the mask is maintained. Therefore, even if peeling electrification occurs when the mask is detached, the charge generated in the mask immediately flows to the ground through the ground pin 12a, and the potential of the mask can be maintained at the ground potential. It is preferable that the ground pin 12a is in contact with the back surface of the mask and the state where the detached mask is supported by the elevating mechanism is continued for a time sufficient to release the charge.

Furthermore, a ground pin for grounding the mask in this state may be provided in the lifting mechanism. In this case, in addition to the structure in which the ground pin is in contact with the surface of the mask, a structure in which the ground pin is in contact with the back surface of the mask may be employed. Further, the support pin 9 which is a part of the lifting mechanism may be replaced with a grounded conductive member as a grounded conductive member. When such a conductive support pin 9 is used, the support pin 9 is brought into light contact with the mask surface before the mask is detached from the electrostatic chuck. The back surface of the mask is grounded by the ground pin 12a and the front surface is grounded by the support pin 9, and when the release of the mask from the electrostatic chuck is confirmed, the mask is lowered by the mask lifting mechanism. Accordingly, the mask is continuously grounded before and after the mask is detached from the electrostatic chuck, and the degree of charging of the mask can be more reliably reduced.
[Embodiment of Device Manufacturing Method]
Next, a method for manufacturing a device (semiconductor device, liquid crystal display device, etc.) according to an embodiment of the present invention will be described. In this method, an exposure apparatus to which the present invention is applied can be used.

  A semiconductor device is manufactured through a pre-process for producing an integrated circuit on a wafer (semiconductor substrate) and a post-process for completing an integrated circuit chip on the wafer produced in the pre-process as a product. The pre-process can include a step of exposing the wafer coated with the photosensitive agent using the exposure apparatus described above, and a step of developing the wafer exposed in the step. The post-process can include an assembly process (dicing, bonding) and a packaging process (encapsulation). Moreover, a liquid crystal display device is manufactured by passing through the process of forming a transparent electrode. The step of forming the transparent electrode includes a step of applying a photosensitive agent to a glass substrate on which a transparent conductive film is deposited, a step of exposing the glass substrate on which the photosensitive agent is applied, using the above-described exposure apparatus, and the step And a step of developing the glass substrate exposed in step (b).

  The device manufacturing method of this embodiment is more advantageous than the conventional one in at least one of device productivity, quality, and production cost.

  The embodiment of the present invention has been specifically described above. However, the present invention is not limited to the matters described as the above-described embodiments, and can be appropriately changed without departing from the technical idea of the present invention.

1: Electrostatic chuck 8: Mask 9: Support pin 10: Mask lifting mechanism 12a-12g: Ground pin 13a-13c: Ground wire 14: Resistance meter 17: Capacitance measuring instrument 21: Current system 100a-100g: Exposure apparatus

Claims (9)

An exposure apparatus that has a holding unit that holds an original according to an applied voltage, and that exposes a substrate through the original held by the holding unit,
Elevating means for elevating the original with respect to the holding means;
A grounding means provided on at least one of the holding means and the elevating means to ground at least a part of the original;
Detecting means for detecting that the original is grounded;
Control means for controlling the voltage applied to the holding means according to the output of the detection means;
An exposure apparatus comprising:   2. The control unit according to claim 1, wherein the control unit controls the voltage so that the holding unit holds the original plate after the detection unit detects that the original plate is grounded. 3. Exposure device. The grounding means has a first grounding pin provided on the holding means so as to contact the original plate, and a second grounding pin provided on the lifting means so as to contact the original plate,
The exposure apparatus according to claim 1, wherein the detection unit includes an ohmmeter that detects a resistance between the first ground pin and the second ground pin. The grounding means has a first grounding pin and a third grounding pin provided on the holding means so as to contact the original plate,
2. The exposure apparatus according to claim 1, wherein the detection unit includes an ohmmeter that detects a resistance between the first ground pin and the third ground pin. The elevating means has a metal substrate having a support pin made of a dielectric, and is configured to support the original plate on the support pin,
The grounding means has a first grounding pin provided on the holding means so as to contact the original plate, and a fourth grounding pin provided on the elevating means so as to contact the metal substrate,
The exposure apparatus according to claim 1, wherein the detection unit includes a capacitance meter that detects a capacitance between the original plate and the metal substrate. A holding unit that includes a first electrode to which a positive voltage is applied and a second electrode to which a negative voltage is applied, and holds an original according to a voltage applied to the first electrode and the second electrode An exposure apparatus that exposes a substrate through an original plate held by the holding means,
Detecting means for detecting the potential of the original;
Control means for controlling at least one of the positive voltage and the negative voltage so that the original has a ground potential based on the output of the detection means;
An exposure apparatus comprising: The grounding means has a sixth grounding pin and a seventh grounding pin provided on the holding means so as to be in contact with an earth layer provided between the front surface and the back surface of the original plate and exposed on the back surface side. And
The exposure apparatus according to claim 1, wherein the detection unit includes an ohmmeter that detects a resistance between the sixth ground pin and the seventh ground pin. An exposure apparatus that has a holding unit that holds an original according to an applied voltage, and that exposes a substrate through the original held by the holding unit,
Elevating means for elevating the original with respect to the holding means;
Detecting means for detecting the potential of the original;
Control means for lowering the original by the elevating means after determining that the original has a ground potential based on the output of the detecting means;
An exposure apparatus comprising: A step of exposing the substrate using the exposure apparatus according to claim 1;
Developing the substrate exposed in the step;
A device manufacturing method comprising: