JP2010182866A - Electrostatic attraction holding device, aligner, exposure method, and method of manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic attraction holding device which can enhance the flatness of a body to be attracted to an attraction surface, and to provide an aligner, an exposure method, and a method of manufacturing a device. <P>SOLUTION: A second electrostatic attraction holding device 34 includes a base 42 formed of a dielectric material with flexibility and having one surface 42b where an attraction surface 34a for attracting a wafer W is formed, a first electrode part 45 and a second electrode part 46 provided in the base 42, and a driving device 41 which applies driving force to the other surface 42a of the base 42 on the opposite side from the one surface 42b to change the shape of the attraction surface 34a of the base 42. When the shape of the attraction surface 34a is changed through the driving of the driving device 41, the flatness is improved of an irradiated surface Wa of the wafer electrostatically attracted to the attraction surface 34a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrostatic adsorption holding device that holds an object to be adsorbed such as a substrate and a mask with an electrostatic adsorption force, an exposure apparatus including the electrostatic adsorption holding device, an exposure method for forming a pattern on a substrate, and the exposure apparatus The present invention relates to a method of manufacturing a device using

  In general, an exposure apparatus for manufacturing a microdevice such as a semiconductor integrated circuit includes an illumination optical system that irradiates exposure light onto a mask such as a reticle on which a predetermined pattern is formed, and a pattern of the mask irradiated with the exposure light. A projection optical system for projecting an image onto a substrate such as a wafer or a glass plate coated with a photosensitive material. In such an exposure apparatus, a higher resolution of the projection optical system is demanded in order to achieve higher integration of the semiconductor integrated circuit and finer pattern images associated with the higher integration. For this reason, the wavelength of exposure light used in the exposure apparatus has been shortened, and in recent years, an exposure apparatus that uses EUV (Extreme Ultraviolet) light or EB (Electron Beam) as exposure light has been developed.

  An exposure apparatus using EUV light includes a chamber whose interior is set to a vacuum atmosphere, and various optical systems, a holding device for holding a mask, a holding device for holding a substrate, and the like are arranged in the chamber. Each of these holding devices is provided with an electrostatic chuck holding device having a base made of a dielectric material such as ceramic and a plurality of electrode portions. Then, an object to be adsorbed such as a mask or a substrate is electrostatically adsorbed on the adsorption surface of the substrate of the electrostatic adsorption holding device by the Coulomb force generated by the electrostatic adsorption holding device (for example, patent Reference 1).

Japanese Patent Laid-Open No. 11-219900

  By the way, it is desirable that the irradiated surface of the substrate on which the pattern image is projected has a higher flatness in order to achieve the purpose of suppressing the occurrence of defects such as defective pattern formation. The flatness of the irradiated surface of the substrate depends on the processing accuracy of the substrate and the substrate of the electrostatic chucking holding device. However, in recent years, the size of the substrate and the substrate holding the substrate has increased, and it has become very difficult to process the substrate so that the flatness of the suction surface of the substrate and the irradiated surface of the substrate is increased. If the flatness of the substrate or the substrate is low, the flatness of the irradiated surface of the substrate electrostatically attracted to the attracting surface of the substrate further decreases, and as a result, a pattern is suitably formed on the substrate. Could become difficult. Such a problem may occur not only in the holding device that holds the substrate but also in the holding device that holds the reticle.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an electrostatic adsorption holding device, an exposure apparatus, an exposure method, and an electrostatic adsorption holding device capable of increasing the flatness of an object to be adsorbed electrostatically on the adsorption surface. It is to provide a device manufacturing method.

In order to solve the above-described problems, the present invention adopts the following configuration corresponding to FIGS. 1 to 9 shown in the embodiment.
The electrostatic adsorption holding device of the present invention is an electrostatic adsorption holding device (25, 34) for adsorbing an object to be adsorbed (R, W), formed of a flexible dielectric material, and A substrate (42) having one surface (42b) on which adsorption surfaces (25a, 34a) for adsorbing adsorbed material (R, W) are formed, and electrode portions (45, 46) provided on the substrate (42) Then, a driving force is applied to the other surface (42a) opposite to the one surface (42b) of the base body (42), and the shape of the suction surface (25a, 34a) of the base body (42) is changed. And a driving device (41, 41A, 41B) to be deformed.

  According to the said structure, the base | substrate (42) which has the adsorption | suction surface (25a, 34a) to which an adsorbate (R, W) is electrostatically adsorbed has flexibility. The suction surface (25a, 34a) of the base body (42) is deformed into a shape corresponding to the applied driving force by applying a driving force to the base body (42) from the driving device (41, 41A, 41B). To do. Therefore, the shape of the object to be attracted (R, W) that is electrostatically attracted to the attracting surfaces (25a, 34a) can be changed to a desired shape.

  In addition, the exposure method of the present invention is a substrate (42) formed of a flexible dielectric material in the exposure method of exposing the substrate (W) through a predetermined pattern formed on the mask (R). An adsorption step (S10) for electrostatically adsorbing the object to be adsorbed (R, W) to the adsorption surface (25a, 34a), and the object to be adsorbed (R) electrostatically adsorbed to the adsorption surface (25a, 34a) , W), the measurement step (S11) for measuring the flatness of the irradiated surface (Ra, Wa) irradiated with the radiation beam (EL), and the irradiation target based on the measurement result in the measuring step (S11). The present invention includes a deformation step (S13) for deforming the shape of the adsorption surface (25a, 34a) of the base (42) so as to increase the flatness of the surfaces (Ra, Wa).

  According to the above configuration, after the object to be adsorbed (R, W) is electrostatically adsorbed on the adsorption surface (25a, 34a) of the flexible base body (42), the object to be adsorbed (R, W) The flatness of the irradiated surface (Ra, Wa) is measured. And based on this measurement result, the shape of the base body (42) is deformed so that the flatness of the irradiated surface (Ra, Wa) of the object to be adsorbed (R, W) is increased. The irradiated surface (Ra, Wa) is irradiated with a radiation beam (EL). As a result, an appropriately shaped pattern is formed on the substrate (W).

  In order to explain the present invention in an easy-to-understand manner, it has been described in association with the reference numerals of the drawings showing the embodiments, but it goes without saying that the present invention is not limited to the embodiments.

  According to the present invention, it is possible to increase the flatness of an object to be attracted electrostatically to the attracting surface.

1 is a schematic block diagram that shows an exposure apparatus according to a first embodiment. Sectional drawing which shows a 2nd electrostatic suction holding | maintenance apparatus typically. Sectional drawing which shows a mode that the shape of a base | substrate is deformed in a 2nd electrostatic attraction holding | maintenance apparatus. The flowchart explaining the flatness improvement process routine in 1st Embodiment. (A) is sectional drawing which shows typically a mode before changing the shape of the to-be-irradiated surface of a wafer, (b) is sectional drawing which shows typically a mode that the flatness of the to-be-irradiated surface of a wafer became high. Sectional drawing which shows typically the 2nd electrostatic suction holding | maintenance apparatus in 2nd Embodiment. Sectional drawing which shows typically the 2nd electrostatic adsorption holding | maintenance apparatus in 3rd Embodiment. The flowchart of the manufacture example of a device. The detailed flowchart regarding the board | substrate process in the case of a semiconductor device.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
As shown in FIG. 1, the exposure apparatus 11 of the present embodiment emits extreme ultraviolet light, ie, EUV (Extreme Ultraviolet) light, which is a soft X-ray region having a wavelength of about 100 nm or less, emitted from a light source device 12 as exposure light. It is an EUV exposure apparatus used as an EL. Such an exposure apparatus 11 includes a chamber 13 (a portion surrounded by a two-dot chain line in FIG. 1) in which the inside is set to a vacuum atmosphere lower in pressure than the atmosphere, and a predetermined pattern is formed in the chamber 13. The formed reflective reticle R and a wafer W having a surface coated with a photosensitive material such as a resist are placed. Note that a laser-excited plasma light source is used as the light source device 12 of the present embodiment, and the light source device 12 emits EUV light having a wavelength of 5 to 20 nm (for example, 13.5 nm) as the exposure light EL. It is like that.

  The exposure light EL emitted from the light source device 12 disposed outside the chamber 13 enters the chamber 13. The exposure light EL that has entered the chamber 13 illuminates the reticle R held by the reticle stage 15 via the illumination optical system 14, and the exposure light EL reflected by the reticle R passes through the projection optical system 16. The wafer W held on the wafer stage 17 is irradiated through the via. Further, in the exposure apparatus 11 of the present embodiment, a plane for measuring the flatness of the irradiated surface Wa (the surface on the + Z direction side, which is the upper surface in FIG. 1) of the wafer W held by the wafer stage 17. A degree measuring device 35 is provided. Therefore, actually, after the flatness measuring device 35 confirms that the flatness of the irradiated surface Wa of the wafer W held by the wafer stage 17 is maintained high, the exposure processing for the wafer W is performed. Be started.

  The illumination optical system 14 includes a housing 18 (a portion surrounded by a one-dot chain line in FIG. 1) in which the inside is set to a vacuum atmosphere, similarly to the inside of the chamber 13. A collimating mirror 19 for condensing the exposure light EL emitted from the light source device 12 is provided in the casing 18, and the collimation mirror 19 converts the incident exposure light EL into a substantially parallel shape. It comes to inject. The exposure light EL emitted from the collimating mirror 19 is incident on a fly-eye optical system 20 (a part surrounded by a broken line in FIG. 1) which is a kind of optical integrator. The fly-eye optical system 20 includes a pair of fly-eye mirrors 21 and 22, and an incident-side fly-eye mirror 21 arranged on the incident side of the fly-eye mirrors 21 and 22 is irradiated with the reticle R. It is disposed at a position optically conjugate with the surface Ra (that is, the lower surface in FIG. 1 and the pattern formation surface). The exposure light EL reflected by the incident-side fly-eye mirror 21 is incident on the emission-side fly-eye mirror 22 arranged on the emission side.

  Further, the illumination optical system 14 is provided with a condenser mirror 23 that emits the exposure light EL emitted from the exit-side fly-eye mirror 22 to the outside of the housing 18. Then, the exposure light EL emitted from the condenser mirror 23 is guided to the reticle R held on the reticle stage 15 by a reflection mirror 24 for folding, which is installed in a lens barrel 27 described later. A reflective layer that reflects the exposure light EL is formed on the reflective surfaces of the mirrors 19 and 21 to 24 constituting the illumination optical system 14, respectively. The reflective layer is composed of a multilayer film in which molybdenum (Mo) and silicon (Si) are alternately stacked.

  The reticle stage 15 is disposed on the object plane side of the projection optical system 16 and includes a first electrostatic chuck holding device 25 for electrostatic chucking of the reticle R. The first electrostatic chucking and holding device 25 includes a base (not shown) made of a dielectric material such as stainless steel and having a suction surface 25a, and a plurality of electrodes (not shown) arranged in the base. When a current is supplied to each electrode from a current supply unit (not shown), the reticle R is electrostatically attracted to the attracting surface 25a by the Coulomb force generated from the base.

  The reticle stage 15 includes a reticle stage driving unit (not shown) that moves the reticle R in the Y-axis direction (left-right direction in FIG. 1) with a predetermined stroke, and a support stage 26 that supports the first electrostatic chucking holding device 25. Is provided. The reticle stage drive unit is configured to be able to move the reticle R in the X-axis direction (direction orthogonal to the paper surface in FIG. 1) and the θz direction (rotation direction around the Z-axis). Note that, when the exposure light EL is illuminated on the irradiated surface Ra of the reticle R, a substantially arc-shaped illumination region extending in the X-axis direction is formed on a part of the irradiated surface Ra. When the Y-axis direction is the scanning direction, the X-axis direction is the non-scanning direction.

  The projection optical system 16 is an optical system that reduces an image of a pattern formed by illuminating the irradiated surface Ra of the reticle R with exposure light EL to a predetermined reduction magnification (for example, 1/4 times). Similarly to the inside of the lens 13, a lens barrel 27 whose inside is set to a vacuum atmosphere is provided. A plurality of (six in this embodiment) reflective mirrors 28, 29, 30, 31, 32 and 33 are accommodated in the lens barrel 27. Each of these mirrors 28 to 33 is held by the lens barrel 27 via a mirror holding device (not shown). The exposure light EL guided from the reticle R side, which is the object plane side, is in the order of the first mirror 28, the second mirror 29, the third mirror 30, the fourth mirror 31, the fifth mirror 32, and the sixth mirror 33. The light is reflected and guided to the irradiated surface Wa of the wafer W held on the wafer stage 17. A reflection layer that reflects the exposure light EL is formed on the reflection surface of each of the mirrors 28 to 33. The reflective layer is composed of a multilayer film in which molybdenum (Mo) and silicon (Si) are alternately stacked.

  The wafer stage 17 includes a second electrostatic chucking holding device 34 for electrostatically chucking the wafer W, and a wafer stage driving unit (not shown) that moves the wafer W in a Y-axis direction with a predetermined stroke. The wafer stage driving unit is configured to be able to move the wafer W also in the X-axis direction. Further, the wafer stage 17 includes a wafer holder (not shown) that holds the second electrostatic chucking holding device 34, the position of the wafer holder in the Z-axis direction (vertical direction in FIG. 1), and inclination angles around the X axis and the Y axis. A Z leveling mechanism (not shown) for adjusting the angle is incorporated.

  Further, an oblique incidence type multi-point autofocus sensor (not shown) is provided on the image plane side of the projection optical system 16. The autofocus sensor irradiates a measurement area including the irradiated surface Wa of the wafer W with a plurality of measurement lights, and receives the plurality of measurement lights reflected from the measurement area, whereby the wafer with respect to the image plane of the projection optical system 16 is received. Average height information (that is, position information in the Z-axis direction) of the W measurement region is obtained. The wafer stage drive unit determines the defocus amount in the Z direction with respect to the image plane of the projection optical system 16 and the θx direction (rotation direction about the X axis) and θy direction (around the Y axis) based on the obtained height information. The wafer stage 17 is driven so as to adjust the inclination angle of the rotation direction of the wafer.

  When the pattern of the reticle R is exposed to one shot area on the wafer W, the reticle R is driven in the Y-axis direction by driving the reticle stage driving unit while irradiating the reticle R with the illumination area by the illumination optical system 14. The wafer W is moved by a predetermined stroke, and the wafer stage is driven by the speed ratio corresponding to the reduction magnification of the projection optical system 16 with respect to the movement of the reticle R along the Y-axis direction by driving the wafer stage driving unit. To the + Y direction side (left side to right side in FIG. 1). When the pattern formation on one shot area is completed, the pattern formation on the other shot areas of the wafer W is continuously performed.

Next, the flatness measuring device 35 will be described with reference to FIG.
As shown in FIG. 1, the flatness measuring device 35 is arranged on the + Y direction side of the projection optical system 16 and can emit a plurality of measurement lights ML toward the −Z direction side (lower side in FIG. 1). 1 includes only one light emitter 36 (for example, a halogen lamp or a laser), and each light emitter 36 is disposed along the X-axis direction. Further, on the −Z direction side of each light emitter 36, a first reflecting member 37 having a reflective surface 37 a that reflects each measurement light ML output from each light emitter 36 toward the irradiated surface Wa side of the wafer W is provided. Is provided. Each measurement light ML reflected by the reflecting surface 37 a of the first reflecting member 37 is incident on the irradiated surface Wa of the wafer W. At this time, each measurement light ML output from each light emitter 36 is incident on a different position on the irradiated surface Wa of the wafer W.

  The flatness measuring device 35 includes a plurality of (three in this embodiment) light receivers 38 (for example, CCDs) that are arranged on the −Y direction side of the projection optical system 16 and individually correspond to the light emitters 36. Is provided. On the −Z direction side of each light receiver 38, a second reflecting member 39 having a reflecting surface 39 a that reflects each measurement light ML reflected at each position of the irradiated surface Wa of the wafer W toward each light receiver 38. Is provided. Each light receiver 38 receives a flatness signal corresponding to the light receiving position when receiving each measurement light ML reflected by the irradiated surface Wa of the wafer W, that is, the flatness of the irradiated surface Wa, from the control device 50 ( (See FIG. 2). Thereafter, the control device 50 calculates the flatness at the measurement position of the irradiated surface Wa of the wafer W based on the detection signal from each light receiver 38.

  The flatness measuring device 35 adjusts the flatness of the irradiated surface Wa by adjusting the position of the irradiated surface Wa of the wafer W with respect to the image plane of the projection optical system 16 in the Z-axis direction by the autofocus sensor. Measuring.

Next, the second electrostatic adsorption holding device 34 will be described with reference to FIGS.
As shown in FIG. 2, the second electrostatic adsorption holding device 34 includes a base member 40 having a substantially rectangular parallelepiped shape, a driving device 41 disposed on the base member 40, and a base body supported by the driving device 41. 42. The surface 40a on the + Z direction side (the upper side in FIGS. 1 and 2) of the base member 40 is subjected to a planarization process such as polishing.

  The drive device 41 includes a plurality (only 11 are shown in FIG. 2) of piezoelectric elements 43 (also referred to as piezoelectric elements) arranged on the surface 40a on the + Z direction side of the base member 40, and each of the piezoelectric elements 43. Are arranged at predetermined intervals. Each piezoelectric element 43 expands and contracts along the Z-axis direction with reference to the surface 40a on the + Z direction side of the base member 40 when current is individually supplied from a first current supply unit 51 described later. It is like that. On each + Z direction side of each piezoelectric element 43, a support member 44 is provided that is supported by an end of each piezoelectric element 43 on the + Z direction side. 2 Ends on the + Z-axis direction side of each piezoelectric element 43 are fixed to the support surface 44a (the surface on the −Z direction side, which is the lower surface in FIG. 2).

  The support member 44 is made of a metal plate (for example, a stainless plate having a thickness of 10 mm) having a thickness (that is, a width in the Z-axis direction) of 20 mm or less. Further, on the opposite side of the support member 44 to the second support surface 44a, a first support surface 44b (a surface on the + Z direction side, which is an upper surface in FIG. 2) for supporting the base body 42 is formed. The 1 support surface 44b is in close contact with the base 42. As shown in FIG. 3, when each piezoelectric element 43 individually expands and contracts, the position corresponding to the piezoelectric element 43 expanded in the support member 44 is displaced in the + Z direction side while contracting in the support member 44. The position corresponding to the operated piezoelectric element 43 is displaced to the −Z direction side. In other words, the shape of the support member 44 is deformed in the Z-axis direction, that is, the thickness direction of the support member 44 according to the expansion / contraction operation of each piezoelectric element 43. When all the piezoelectric elements 43 expand or contract by the same amount, the support member 44 moves along the Z-axis direction without deformation of the shape of the first support surface 44b. ing.

  As shown in FIGS. 2 and 3, the base 42 is made of a flexible dielectric material (polyimide resin in this embodiment). Such a base 42 is opposite to the first support surface 44b of the support member 44 and is in close contact with the first support surface 44b (the surface on the -Z direction side, the lower surface in FIG. 2), and the Z One surface 42b (the surface on the + Z direction side, which is the upper surface in FIG. 2) located on the opposite side of the other surface 42a in the axial direction. At least a part of the one surface 42b functions as an attracting surface 34a on which the wafer W is electrostatically attracted (see FIG. 1). Further, when the support member 44 is deformed by the individual expansion / contraction operation of each piezoelectric element 43, the base body 42 is deformed according to the deformation state of the first support surface 44 b of the support member 44.

  In addition, as shown in FIG. 2, a plurality of (three in the present embodiment) first electrode portions 45 to which positive charges are supplied from a second current supply portion 52 to be described later, A plurality of (three in this embodiment) second electrode portions 46 to which negative charges are supplied from the current supply portion 52 are provided. Each of the first electrode portions 45 and the second electrode portions 46 is formed of a flexible conductive material (for example, a thin plate made of copper). Each first electrode portion 45 and each second electrode portion 46 are formed so as to extend in the X-axis direction. The first electrode portions 45 are arranged along the Y-axis direction, and the positions between the first electrode portions 45 adjacent to each other in the Y-axis direction and the positions of the first electrode portions 45. Among these, the second electrode portion 46 is disposed at a position on the + Y direction side of the first electrode portion 45 located closest to the + Y direction side. That is, in this embodiment, the 1st electrode part 45 and the 2nd electrode part 46 are arrange | positioned alternately along the Y-axis direction. When positive charges and negative charges are respectively supplied from the second current supply unit 52 to the first electrode portions 45 and the second electrode portions 46, the Coulomb force is exerted from the base 42, and An attracted surface Wb (lower surface in FIG. 1) of the wafer W is electrostatically attracted to the attracting surface 34a.

Next, the control device 50 that controls the exposure apparatus 11 of the present embodiment will be described with reference to FIG.
As shown in FIG. 2, the flatness measuring device 35 is electrically connected to the interface of the control device 50, and the control device 50 measures the flatness of the irradiated surface Wa of the wafer W. A control command is output to the flatness measuring device 35. Further, flatness information corresponding to the flatness of the irradiated surface Wa of the wafer W is input to the control device 50 from each light receiver 38 of the flatness measuring device 35. Further, the interface of the control device 50 includes a first current supply unit 51 for individually supplying current to each piezoelectric element 43, and a current to each first electrode unit 45 and each second electrode unit 46. A second current supply unit 52 for supply is electrically connected. The first current supply unit 51 individually adjusts the amount of current supplied to each piezoelectric element 43 in accordance with a control command from the control device 50. The second current supply unit 52 supplies positive charges to the first electrode units 45 and negative charges to the second electrode units 46 in response to control commands from the control device 50. It is supposed to be.

  The control device 50 is provided with a digital computer including a CPU, a ROM, a RAM, and the like (not shown). In the ROM, various control processes for controlling the exposure apparatus 11 (for example, flatness improving process shown in FIG. 4), various threshold values, and the like are stored in advance. Further, the RAM appropriately stores various parameters (for example, the flatness of the irradiated surface Wa) that are appropriately rewritten while the exposure apparatus 11 is being driven.

  The first current supply unit 51 includes an A / D converter (not shown) that converts an alternating current from a power source (not shown) into a direct current, and an illustration (not shown) that individually adjusts the amount of current supplied to each piezoelectric element 43. And an adjustment circuit. The second current supply unit 52 adjusts the amount of positive charge supplied to each A / D converter (not shown) that converts an alternating current from a power supply (not shown) into a direct current and each first electrode unit 45. A first adjustment circuit (not shown) and a second adjustment circuit (not shown) for adjusting the amount of negative charge supplied to each second electrode portion 46 are provided.

  Next, in the control process executed by the control device 50 of the present embodiment, the flatness is improved to improve the flatness of the irradiated surface Wa of the wafer W electrostatically attracted to the second electrostatic attraction / holding device 34. The processing routine will be described with reference to the flowchart shown in FIG. 4 and the operation diagrams shown in FIGS. This flatness improving process routine is executed when the wafer W to be subjected to the exposure process is loaded into the chamber 13. 5 (a) and 5 (b), the deformation mode of the irradiated surface Wa of the wafer W is exaggerated.

  Now, in the flatness improvement processing routine, the control device 50 issues a control command for supplying positive charges and negative charges to the first electrode portions 45 and the second electrode portions 46, respectively. (Step S10). That is, the control device 50 causes the wafer W to be electrostatically attracted to the attracting surface 34 a of the base 42 in the second electrostatic attraction and holding device 34. Subsequently, the control device 50 causes the flatness measuring device 35 to measure the flatness of the irradiated surface Wa of the wafer W (Step S11). Specifically, the control device 50 drives the wafer stage driving unit to move the wafer W stepwise from the −Y direction side to the + Y direction side. Then, each light emitter 36 outputs measurement light ML at any time during the step movement of the wafer W. As a result, the flatness measuring device 35 measures the flatness for each position of the irradiated surface Wa of the wafer W. Then, from each of the light receivers 38, flatness information relating to the flatness of the irradiated surface Wa of the wafer W is output. Then, the control device 50 calculates the flatness for each position of the irradiated surface Wa of the wafer W based on the flatness information from the flatness measuring device 35 side, and temporarily stores the calculation result in the RAM.

  Subsequently, the control device 50 determines whether or not the flatness for each position of the irradiated surface Wa of the wafer W temporarily stored in the RAM is within an allowable range (step S12). Specifically, in step S12, the amount of deviation in the Z-axis direction from the image plane 53 of the projection optical system 16 (indicated by the alternate long and short dash line in FIG. 5) out of the permissible range among the positions of the irradiated surface Wa. It is determined whether there is no position. If the determination result in step S12 is affirmative, the control device 50 determines that the flatness of each position of the irradiated surface Wa of the wafer W at the current time is sufficiently high, and the process proceeds to step S14 described later. Transition.

  On the other hand, if the determination result of step S12 is negative, the control device 50 determines that there is a position with low flatness on the irradiated surface Wa of the wafer W at the current time, and executes flatness correction processing (step S13). ). Specifically, as shown in FIGS. 5A and 5B, the control device 50 determines a position located on the + Z direction side of the image plane 53 among the positions of the irradiated surface Wa of the wafer W −. Each piezoelectric element 43 corresponding to the position is contracted along the Z-axis direction so as to be displaced in the Z direction side. In addition, the control device 50 causes each piezoelectric element corresponding to the position to be displaced to the + Z direction side from the position on the irradiated surface Wa of the wafer W so as to be displaced to the + Z direction side from the image plane 53. The element 43 is extended along the Z-axis direction. Thereafter, the control device 50 shifts the process to the above-described step S11. That is, in this embodiment, the flatness correction process is repeatedly executed until all the positions of the irradiated surface Wa of the wafer W are within the allowable range.

  In step S <b> 14, the control device 50 causes the wafer W to perform an exposure process, and patterns are sequentially formed in each shot area on the irradiated surface Wa of the wafer W. When the formation of the pattern on the wafer W is completed, the control device 50 ends the flatness improvement processing routine. In the present embodiment, as shown in FIGS. 5A and 5B, even when the flatness of the irradiated surface Wa of the wafer W is low before the flatness correction processing is executed, the flatness correction processing is performed. Is executed at least once, the flatness of the irradiated surface Wa of the wafer W becomes very high. When exposure processing is performed on such a wafer W, the occurrence of pattern distortion due to the low flatness of the wafer W is suppressed.

Therefore, in this embodiment, the following effects can be obtained.
(1) The base 42 having the attracting surface 34a on which the wafer W is electrostatically attracted has flexibility. The suction surface 34 a of the base 42 is deformed into a shape corresponding to the applied driving force when a driving force is applied from the piezoelectric elements 43 to the base 42. Therefore, the shape of the wafer W electrostatically attracted to the attracting surface 25a can be changed to a desired shape.

  (2) In the present embodiment, by individually expanding and contracting the plurality of piezoelectric elements 43, the shape of the irradiated surface Wa of the wafer W that is electrostatically attracted to the attracting surface 34a is transformed into a shape having desired flatness. Can be made. Therefore, a pattern having a desired shape can be reliably formed on the wafer W.

  (3) The flatness correction process is executed based on the flatness information from the flatness measuring device 35. Then, after the flatness correction process is finished, the flatness of the irradiated surface Wa is re-measured using the flatness measuring device 35, and the flatness is corrected when the flatness of the irradiated surface Wa is outside the allowable range. The process is executed again. Therefore, when the exposure process for the wafer W is executed, the flatness of the irradiated surface Wa of the wafer W is surely within the allowable range. Therefore, the pattern can be accurately formed on the wafer W.

  (4) The base body 42 is supported by the support member 44. Therefore, even if each piezoelectric element 43 individually expands and contracts, it is possible to suppress positional deviation in the Z-axis direction between positions adjacent to each other in the base 42.

  (5) Moreover, each 1st electrode part 45 and each 2nd electrode part 46 arrange | positioned in the base | substrate 42 are comprised with the electroconductive material which has flexibility. Therefore, according to the deformation of the support member 44, the first electrode portions 45 and the second electrode portions 46 are also deformed. Therefore, the suction surface 34a of the base body 42 can be reliably deformed into a desired shape.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, the shape of the support member is different from that of the first embodiment. Therefore, in the following description, parts different from those of the first embodiment will be mainly described, and the same or corresponding member configurations as those of the first embodiment are denoted by the same reference numerals, and redundant description will be omitted. Shall.

  As shown in FIG. 6, the second electrostatic adsorption holding device 34 of the present embodiment includes a base member 40, a drive device 41 </ b> A disposed on the surface 40 a on the + Z direction side of the base member 40, and the drive device. The base 42 is supported by 41A, and a plurality of first electrode portions 45 and second electrode portions 46 are disposed in the base 42.

  The drive device 41A includes a plurality of (only nine are shown in FIG. 2) piezoelectric elements 43 arranged on the surface 40a on the + Z direction side of the base member 40, and + Z direction side ends of the piezoelectric elements 43. And a supporting member 60 to be supported. The support member 60 has a plurality of metal thick portions 61 having a predetermined thickness (thickness of about 20 mm), and the thick portions 61 are arranged apart from each other. Further, on the −Z direction side of each thick portion 61, a second support surface 61a fixed to the end portion on the + Z direction side of the piezoelectric element 43 is formed, and the + Z direction side of each thick portion 61 is formed. Are formed with first support surfaces 61b that are in close contact with the other surface 42a of the base body 42, respectively.

  Further, the support member 60 further includes the thin portions 62 that connect the thick portions 61 adjacent to each other and have a width in the Z-axis direction, that is, a thickness that is thinner than the thick portions 61. As an example, the thin portion 62 is formed of a metal plate having a thickness of about 5 mm. On the −Z direction side of the thin portion 62, a non-support surface 62 a that does not face the + Z direction end of the piezoelectric element 43 is formed, and on the + Z direction side of the thin portion 62, the other side of the base body 42 is formed. A first support surface 62b that is in close contact with the surface 42a is formed. That is, the support member 60 of the present embodiment has the thick portions 61 and the thin portions 62 by cutting away the portions not facing the piezoelectric elements 43 on the −Z direction side of the support member 60. Yes.

  For this reason, by individually adjusting the length of each piezoelectric element 43 in the Z-axis direction, the position corresponding to the piezoelectric element 43 performing the expansion operation among the positions on the support member 60 is displaced to the + Z direction side. Of the positions on the support member 60, the position corresponding to the contracting piezoelectric element 43 is displaced to the −Z direction side.

Therefore, in this embodiment, in addition to the effects (1) to (5) of the first embodiment, the following effects can be obtained.
(6) In the present embodiment, only the portion to which the driving force is applied from the piezoelectric element 43 in the support member 60 is formed in the thick portion 61, and the portion to which the driving force is not applied from the piezoelectric element 43 is formed in the thin portion 62. . Therefore, compared with the case where the entire support member 60 is formed on the thick portion 61, the flexibility of the entire support member 60 is increased, and as a result, the coverage of the wafer W electrostatically attracted to the attracting surface 34a is increased. This can contribute to the improvement of the flatness of the irradiation surface Wa.

  (7) The surface of the thin portion 62 facing the base 42 is a first support surface 62b that is in close contact with the other surface 42a of the base 42. Therefore, unlike the case where the first support surface 62b of the thin portion 62 is not in contact with the base 42, the entire other surface 42a of the base 42 is in close contact with the support member 60. It is possible to suppress the occurrence of a large positional shift in the Z-axis direction between adjacent positions. Therefore, the flatness of the irradiated surface Wa of the wafer W electrostatically attracted to the attracting surface 34a can be reliably improved.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. In the third embodiment, the shape of the support member is different from the first and second embodiments. Therefore, in the following description, parts different from the first and second embodiments will be mainly described, and the same reference numerals are given to the same or corresponding member configurations as those of the first and second embodiments. A duplicate description will be omitted.

  As shown in FIG. 7, the second electrostatic adsorption holding device 34 of the present embodiment includes a base member 40, a driving device 41 </ b> B disposed on the surface 40 a on the + Z direction side of the base member 40, and the driving device. And a base 42 supported by 41B. In the base 42, a plurality of first electrode portions 45 and second electrode portions 46 are arranged.

  The drive device 41B includes a plurality of (only nine are shown in FIG. 2) piezoelectric elements 43 arranged on the surface 40a on the + Z direction side of the base member 40, and + Z direction side ends of the piezoelectric elements 43. And a supporting member 63 to be supported. The support member 63 includes a plurality of support portions 64 having a thickness of 20 mm or less, and each support portion 64 includes a second support surface 64a to which an end portion on the + Z direction side of the piezoelectric element 43 is fixed. And a first support surface 64b closely contacting the other surface 42a of the base body 42. That is, each piezoelectric element 43 supports the base 42 via the support portion 64. The support portions 64 are discretely arranged on the other surface 42 a of the base body 42. In other words, the support portions 64 are arranged in a state of being separated from each other.

  And if the length in the Z-axis direction of each piezoelectric element 43 is adjusted individually, the support part 64 corresponding to the piezoelectric element 43 which expand | extends among each support part 64 will displace to the + Z direction side. Moreover, the support part 64 corresponding to the piezoelectric element 43 that contracts among the support parts 64 moves to the −Z direction side. Then, one surface 42b of the base body 42 supported by each support portion 64 is deformed into a shape corresponding to the individual expansion / contraction operation of each piezoelectric element 43. As a result, the shape of the irradiated surface Wa of the wafer W electrostatically attracted to the attracting surface 34a is deformed to a desired shape. Therefore, in this embodiment, the same effects as the effects (1) to (5) of the first and second embodiments can be obtained.

In addition, you may change each said embodiment into another embodiment as follows.
In each embodiment, the measurement result obtained by the flatness measuring device 35 is displayed on a display (not shown) or the like so that an operator who views the display individually adjusts the current supply mode to each piezoelectric element 43. Good.

  -In each embodiment, each electrode part 45 and 46 may be comprised from other arbitrary metal materials (for example, copper), if it is a conductive material which has flexibility. Moreover, each electrode part 45 and 46 may be ITO (indium tin oxide), ZnO (zinc oxide), or the like.

  In each embodiment, as a driving source for applying a driving force to the support members 44, 60, 63, a driving source other than a piezoelectric element (for example, MEMS (Micro Electro Mechanical System)).

  In each embodiment, the drive devices 41, 41 </ b> A, 41 </ b> B may be configured without the support members 44, 60, 63. In this case, the base 42 is directly supported by each piezoelectric element 43.

  In each embodiment, the support members 44, 60, and 63 are any plate materials other than the stainless plate (for example, a plate material made of invar, aluminum, etc.) as long as the support members 44, 60, and 63 are plate materials that can be deformed by the expansion and contraction operations of the piezoelectric elements 43. Plate material).

  -In 2nd Embodiment, the supporting member 60 is not comprised from one board | plate material, but the thick part 61 comprised from several board | plate materials (for example, stainless steel board), and the thick part adjacent to each other The structure which has 61 and the thin part 62 comprised from the arbitrary materials (for example, synthetic resin) which have flexibility, may be sufficient.

  The present invention may be embodied in the first electrostatic adsorption / holding device 25. In this case, since the flatness of the irradiated surface Ra of the reticle R is increased, the occurrence of distortion of the pattern formed on the wafer W can be more effectively suppressed.

  In each embodiment, the flatness improving process routine may be performed not for each wafer W but for each measurement region by dividing the wafer W into a plurality of measurement regions. That is, when the flatness of one of the measurement areas is within the allowable range, a pattern is formed for each shot area included in the one measurement area. When pattern formation on all shot areas included in one measurement area is completed, the flatness improvement processing routine is executed for the other measurement areas. The measurement area here is an area partitioned so as to include at least one shot area.

  In each embodiment, the exposure apparatus 11 manufactures a reticle or mask used in not only a microdevice such as a semiconductor element but also a light exposure apparatus, an EUV exposure apparatus, an X-ray exposure apparatus, and an electron beam exposure apparatus. Therefore, an exposure apparatus that transfers a circuit pattern from a mother reticle to a glass substrate or a silicon wafer may be used. The exposure apparatus 11 is used for manufacturing a display including a liquid crystal display element (LCD) and the like, and is used for manufacturing an exposure apparatus that transfers a device pattern onto a glass plate, a thin film magnetic head, and the like. It may be an exposure apparatus that transfers to a wafer or the like, and an exposure apparatus that is used to manufacture an image sensor such as a CCD.

  In each embodiment, the exposure apparatus 11 may be mounted on a scanning stepper that transfers the pattern of the reticle R to the wafer W while the reticle R and the wafer W are relatively moved, and sequentially moves the wafer W stepwise. .

In each embodiment, the exposure apparatus 11 may be an exposure apparatus that uses EB (Electron Beam) as the exposure light EL.
In each embodiment, the light source device 12 that can output EUV light may be a light source device having a discharge plasma light source.

In each embodiment, the light source device 12 includes, for example, g-line (436 nm), i-line (365 nm), KrF excimer laser (248 nm), F ₂ laser (157 nm), Kr ₂ laser (146 nm), Ar ₂ laser (126 nm) Or the like. The light source device 12 amplifies the infrared or visible single wavelength laser light oscillated from the DFB semiconductor laser or fiber laser, for example, with a fiber amplifier doped with erbium (or both erbium and ytterbium). Alternatively, a light source capable of supplying harmonics converted into ultraviolet light using a nonlinear optical crystal may be used.

  Next, an embodiment of a microdevice manufacturing method using the device manufacturing method by the exposure apparatus 11 of the embodiment of the present invention in the lithography process will be described. FIG. 8 is a flowchart showing a manufacturing example of a microdevice (a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin film magnetic head, a micromachine, or the like).

  First, in step S101 (design step), function / performance design (for example, circuit design of a semiconductor device) of a micro device is performed, and pattern design for realizing the function is performed. Subsequently, in step S102 (mask manufacturing step), a mask (reticle R or the like) on which the designed circuit pattern is formed is manufactured. On the other hand, in step S103 (substrate manufacturing step), a substrate (a wafer W when a silicon material is used) is manufactured using a material such as silicon, glass, or ceramics.

  Next, in step S104 (substrate processing step), using the mask and substrate prepared in steps S101 to S104, an actual circuit or the like is formed on the substrate by lithography or the like, as will be described later. Next, in step S105 (device assembly step), device assembly is performed using the substrate processed in step S104. Step S105 includes processes such as a dicing process, a bonding process, and a packaging process (chip encapsulation) as necessary. Finally, in step S106 (inspection step), inspections such as an operation confirmation test and a durability test of the microdevice manufactured in step S105 are performed. After these steps, the microdevice is completed and shipped.

FIG. 9 is a diagram illustrating an example of a detailed process of step S104 in the case of a semiconductor device.
In step S111 (oxidation step), the surface of the substrate is oxidized. In step S112 (CVD step), an insulating film is formed on the substrate surface. In step S113 (electrode formation step), an electrode is formed on the substrate by vapor deposition. In step S114 (ion implantation step), ions are implanted into the substrate. Each of the above steps S111 to S114 constitutes a pretreatment process at each stage of the substrate processing, and is selected and executed according to a necessary process at each stage.

  When the above-mentioned pretreatment process is completed in each stage of the substrate process, the posttreatment process is executed as follows. In this post-processing process, first, in step S115 (resist formation step), a photosensitive material is applied to the substrate. Subsequently, in step S116 (exposure step), the circuit pattern of the mask is transferred to the substrate by the lithography system (exposure apparatus 11) described above. Next, in step S117 (development step), the substrate exposed in step S116 is developed to form a mask layer made of a circuit pattern on the surface of the substrate. Subsequently, in step S118 (etching step), the exposed member other than the portion where the resist remains is removed by etching. In step S119 (resist removal step), the photosensitive material that has become unnecessary after the etching is removed. That is, in step S118 and step S119, the surface of the substrate is processed through the mask layer. By repeatedly performing these pre-processing steps and post-processing steps, multiple circuit patterns are formed on the substrate.

  DESCRIPTION OF SYMBOLS 11 ... Exposure apparatus, 14 ... Illumination optical system, 16 ... Projection optical system, 25, 34 ... Electrostatic adsorption holding apparatus, 25a, 34a ... Adsorption surface, 35 ... Flatness measuring apparatus, 41, 41A, 41B ... Drive apparatus 42 ... Base, 42a ... The other surface, 42b ... One surface, 44, 60, 63 ... Support member, 44a, 61a, 64a ... Second support surface, 44b, 61b, 62b, 64b ... First support surface, 43 ... Pulse element as drive source, expansion / contraction part, 45 ... first electrode part, 46 ... second electrode part, 50 ... control device, 61 ... thick part, 62 ... thin part, 64 ... support part, EL ... radiation beam Exposure light as R, object to be adsorbed, reticle as mask, Ra as surface to be irradiated, W as object to be adsorbed, wafer as substrate, Wa as surface to be irradiated as second surface, Wb as surface as first surface Adsorbed surface.

Claims (16)

An electrostatic adsorption holding device that adsorbs an object to be adsorbed,
A base having one surface formed of a dielectric material having flexibility and formed with an adsorption surface for adsorbing the object to be adsorbed;
An electrode portion provided on the substrate;
An electrostatic chucking holding device comprising: a driving device that applies a driving force to the other surface of the substrate opposite to the one surface and deforms the shape of the chucking surface of the substrate. The driving device includes:
A support member having a first support surface for supporting the other surface of the base and a second support surface located on the opposite side of the first support surface;
2. The electrostatic device according to claim 1, further comprising: a plurality of driving sources that are provided on the second supporting surface side of the supporting member and apply the driving force to the base via the supporting member. Adsorption holding device. The support member is a plate material whose shape in the thickness direction of the support member that intersects the first support surface and the second support surface changes when a driving force is applied from the plurality of drive sources. The electrostatic attraction / holding device according to claim 2, wherein 3. Each of the plurality of drive sources has an expansion / contraction portion that can expand and contract along the thickness direction of the support member that intersects the first support surface and the second support surface, respectively. Item 4. The electrostatic chucking holding device according to Item 3. The support member includes a plurality of thick portions having a predetermined thickness, and a thin portion that connects the thick portions adjacent to each other and is thinner than the thick portion,
The first support surface is formed in the thick portion and the thin portion, and the second support surface is formed in the thick portion. The electrostatic attraction holding device according to any one of the above. 5. The support member according to claim 2, further comprising a plurality of support portions that are discretely arranged on the other surface of the base body and are provided corresponding to each of the plurality of drive sources. The electrostatic attraction holding device according to any one of the above. The electrostatic support device according to any one of claims 2 to 6, wherein the support member is made of a metal plate having a thickness of 20 mm or less. The electrostatic attraction / holding device according to claim 1, wherein the base is made of a polyimide resin. The electrostatic section according to any one of claims 1 to 8, wherein the electrode section is provided inside the base body and is made of a conductive material having flexibility. Adsorption holding device. The said electrode part has a 1st electrode part to which a positive charge is provided, and a 2nd electrode part to which a negative charge is provided, The any one of Claims 1-9 characterized by the above-mentioned. The electrostatic adsorption holding device according to 1. An illumination optical system for directing a radiation beam to a mask on which a predetermined pattern is formed;
A projection optical system for irradiating a substrate coated with a photosensitive material with a radiation beam through the mask;
An electrostatic chuck holding device according to any one of claims 1 to 10, wherein at least one of the mask and the substrate is held as the chucked object. . When an electric current is supplied to the electrode portion, a plate-shaped object to be adsorbed is adsorbed on the adsorption surface of the base body,
Flatness measurement for measuring the flatness of the second surface on the opposite side of the first surface that comes into contact with the suction surface in the object to be attracted electrostatically to the suction surface and on which the radiation beam is incident Equipment,
The control apparatus which controls the said drive device so that the flatness of the said 2nd surface of the said to-be-adsorbed object may become high based on the measurement result by this flatness measuring apparatus further, It is characterized by the above-mentioned. The exposure apparatus described. In an exposure method for exposing a substrate through a predetermined pattern formed on a mask,
An adsorption step for electrostatically adsorbing an object to be adsorbed on an adsorption surface of a substrate formed of a dielectric material having flexibility;
A measuring step for measuring the flatness of the irradiated surface irradiated with a radiation beam in the object to be attracted electrostatically to the attracting surface;
An exposure method comprising: a deforming step of deforming the shape of the suction surface of the substrate to increase the flatness of the irradiated surface based on a measurement result in the measuring step. The exposure method according to claim 13, further comprising a forming step of irradiating the irradiated surface with the radiation beam and forming a pattern on the substrate after performing the deformation step. 15. The radiation beam according to claim 14, wherein at least one of the substrate and the mask is irradiated with the radiation beam in a state in which the substrate is electrostatically adsorbed on the adsorption surface of the substrate as the object to be adsorbed. Exposure method. In a device manufacturing method including a lithography process,
13. A device manufacturing method using the exposure apparatus according to claim 11 or 12 in the lithography process.

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