JP2010182942A - Mask, stage device, aligner, exposure method, and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mask capable of suppressing an exposure defect, a stage device, an aligner, an exposure method, and a device manufacturing method. <P>SOLUTION: A mask holding part 3 of a mask stage 1 has a first holding member 8 and a second holding member 9. The first holding member 8 and second holding member 9 differ in coefficient of thermal expansion. The mask M is deformed with the difference in the coefficient of thermal expansion between the first holding member 8 and second holding member 9. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

An exposure apparatus used in a photolithography process illuminates a mask with exposure light, and exposes the substrate with exposure light passing through the mask. A predetermined pattern to be projected onto the substrate is formed on the mask. The exposure apparatus includes a stage device that holds a mask as disclosed in Patent Document 1, and exposes the substrate with exposure light through the mask held by the stage device.
US Patent Application Publication No. 2005/0248744

  When the mask is deformed, an exposure failure such as a defect in a pattern formed on the substrate may occur. As a result, a defective device may occur.

  An object of an aspect of the present invention is to provide a mask, a stage apparatus, and an exposure apparatus that can suppress the occurrence of exposure failure due to mask deformation or the like. Another object of the present invention is to provide an exposure method and a device manufacturing method that can suppress the occurrence of defective devices.

  According to the first aspect of the present invention, the holding unit that holds the plate-like object is provided, and the contact surface of the holding unit with the plate-like object is at least part of the surface of the first member having the first coefficient of thermal expansion. There is provided a stage apparatus including a first region including a second region including at least a part of a surface of a second member having a second coefficient of thermal expansion different from the first coefficient of thermal expansion.

  According to a second aspect of the present invention, there is provided an exposure apparatus including a projection optical system that projects an image of a mask pattern onto a substrate, the exposure apparatus including the stage device of the first aspect.

  According to a third aspect of the present invention, there is provided a device manufacturing method including exposing a substrate using the exposure apparatus according to the second aspect and developing the exposed substrate.

  According to the fourth aspect of the present invention, there is provided a lithography mask having a pattern region, the first mask including at least a part of the surface of the first member having the first thermal expansion coefficient on the first side of the pattern region. A mask is provided that includes a region and a second region that includes at least a portion of the surface of the second member having a second coefficient of thermal expansion different from the first coefficient of thermal expansion.

  According to a fifth aspect of the present invention, there is provided a device manufacturing method including exposing a substrate using the mask of the fourth aspect and developing the exposed substrate.

  According to the aspect of the present invention, the occurrence of exposure failure can be suppressed. Moreover, according to the present invention, it is possible to suppress the occurrence of defective devices.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto. In the following description, an XYZ orthogonal coordinate system is set, and the positional relationship of each member will be described with reference to this XYZ orthogonal coordinate system. A predetermined direction in the horizontal plane is defined as an X-axis direction, a direction orthogonal to the X-axis direction in the horizontal plane is defined as a Y-axis direction, and a direction orthogonal to each of the X-axis direction and the Y-axis direction (that is, a vertical direction) is defined as a Z-axis direction. Further, the rotation (inclination) directions around the X axis, Y axis, and Z axis are the θX, θY, and θZ directions, respectively.
(First embodiment)
FIG. 1 is a schematic block diagram that shows an example of an exposure apparatus EX according to the first embodiment. In FIG. 1, an exposure apparatus EX exposes a mask stage 1 that can move while holding a mask M, a substrate stage 2 that can move while holding a substrate P, and a mask M held by the mask stage 1 as exposure light. An illumination system IL that illuminates with EL, and a projection optical system PL that projects an image of the pattern of the mask M illuminated with the exposure light EL onto the substrate P held on the substrate stage 2 are provided.

  In the present embodiment, the exposure apparatus EX is a step-and-repeat method in which the pattern of the mask M is collectively exposed while the mask M and the substrate P are stationary, and the substrate P is sequentially moved stepwise.

  The mask M includes a reticle on which a device pattern projected onto the substrate P is formed. In the present embodiment, the mask M is a transmissive mask in which a predetermined pattern is formed on a transparent plate such as a glass plate using a light shielding film such as chrome. This transmission type mask is not limited to a binary mask in which a pattern is formed by a light shielding film, and includes, for example, a phase shift mask such as a halftone type or a spatial frequency modulation type.

  The mask M includes a mask body MH and a pattern area AP. In the present embodiment, the mask body MH is a plate-like member that is rectangular in the XY plane and has a thickness in the Z-axis direction, as shown in FIG. As shown in FIG. 4, the pattern area AP is formed in a rectangular shape substantially at the center of the mask body MH on the XY plane. The pattern area AP is formed on the back surface Mb of the mask M in this embodiment. In the present embodiment, the mask body MH is made of quartz glass and is transparent to the exposure light EL.

  In the present embodiment, the illumination system IL illuminates the pattern area AP from the surface Ma side of the mask M with the exposure light EL.

  In the present embodiment, ArF excimer laser light is used as the exposure light EL.

  The mask stage 1 can hold the mask M so that the back surface Mb (pattern forming surface) of the mask M and the XY plane are substantially parallel. The mask stage 1 is movable in three directions, ie, the X axis, the Y axis, and the θZ direction while holding the mask M.

  The projection optical system PL projects an image of the pattern of the mask M at a predetermined projection magnification onto at least a part of the substrate P arranged in the projection region PR. The projection optical system PL of the present embodiment is a reduction system whose projection magnification is, for example, 1/4, 1/5, or 1/8. Note that the projection optical system PL may be either an equal magnification system or an enlargement system. In the present embodiment, the optical axis AX of the projection optical system PL is substantially parallel to the Z axis.

  The substrate stage 2 can hold the substrate P so that the surface Pa (exposure surface) of the substrate P and the XY plane are substantially parallel to each other. The substrate stage 2 can move in six directions including the X axis, the Y axis, the Z axis, the θX, the θY, and the θZ directions while holding the substrate P.

  The positional information of the mask stage 1 and the substrate stage 2 in the X-axis direction and the Y-axis direction is measured by an interferometer system (not shown) including a laser interferometer. Further, the position information of the surface of the substrate P held on the substrate stage 2 is detected by a focus leveling detection system (not shown).

  In the present embodiment, the substrate P is a circular substrate for manufacturing a device, and includes a film of a photosensitive material (photoresist) Rg.

  Next, the mask stage 1 will be described with reference to FIGS. FIG. 2 is a side sectional view showing an example of the mask stage 1 according to the present embodiment. In FIG. 2, the mask M is held on the mask stage 1. FIG. 3 is an example of a plan view of the mask stage 1 according to the present embodiment as viewed from above (+ Z side). In FIG. 3, the mask M is not held on the mask stage 1.

  Mask stage 1 includes a mask stage main body ST, a mask holding unit 3, and a transmission area TA.

  In the present embodiment, the mask stage main body ST is a plate-like member that is rectangular in the XY plane and has a thickness in the Z-axis direction, as shown in FIG. As shown in FIG. 3, the transmissive area TA is a rectangular opening that is formed substantially at the center of the mask stage main body ST in the XY plane and has the Y-axis direction as a longitudinal direction. In the present embodiment, the mask stage main body ST has an upper surface 1a formed around the mask holding unit 3 and the transmission region TA. A part of the upper surface 1 a faces the back surface Mb of the mask M held by the mask holding unit 3.

  In the present embodiment, as shown in FIG. 2, the mask holding unit 3 detachably holds the mask M so that the back surface Mb (pattern forming surface) of the mask M and the XY plane are substantially parallel to each other. In the present embodiment, the mask holding unit 3 can hold the mask M on the back surface Mb side of the mask M.

  In the present embodiment, the mask holding unit 3 includes a first mask holding unit 3a and a second mask holding unit 3b. As shown in FIG. 3, in the XY plane, a first mask holding unit 3a is provided on the + X side near the transmission area TA of the mask stage 1, and a second mask holding unit 3b is provided on the −X side.

Next, the first mask holding unit 3a will be described in detail with reference to FIGS. As shown in FIG. 2, the first mask holding unit 3 a includes a recess Ou provided on the upper surface 1 a of the mask stage body ST. As shown in FIG. 3, the recess Ou of the first mask holding portion 3a extends substantially parallel to the Y-axis direction. The recess Ou of the first mask holding portion 3a includes a rectangular bottom surface 5a provided below the top surface 1a (in the −Z axis direction) and a peripheral wall H provided around the bottom surface 5a. The peripheral wall H is formed in a rectangular ring shape along the outer edge of the bottom surface 5a, and extends from the bottom surface 5a to the top surface 1a substantially parallel to the Z-axis direction. The bottom surface 5a is substantially parallel to the XY plane and is flat. Moreover, the 1st mask holding | maintenance part 3a contains the several suction opening 4 provided in the bottom face 5a. In the X-axis direction, a plurality of suction ports 4 are arranged along the Y-axis direction substantially at the center of the bottom surface 5a. In the present embodiment, five suction ports 4 are provided on the bottom surface 5a.
The number of suction ports 4 is not limited to five. The position of the suction port 4 is not limited to the center of the bottom surface 5a. Each of the plurality of suction ports 4 communicates with a suction channel 10a provided in the mask stage main body ST so as to extend substantially parallel to the Z-axis direction below the first mask holding portion 3a. Each of the plurality of suction flow paths 10a can be connected to a vacuum system 10 including a suction pump as shown in FIG. That is, the suction port 4 can be connected to the vacuum system 10 via the suction flow path 10a.

  In the present embodiment, the first mask holding unit 3 a includes the first holding member 8 and the second holding member 9. In the present embodiment, as shown in FIGS. 2 and 3, the first holding member 8 is disposed on the −X side of the recess Ou of the first mask holding portion 3a, and the second holding member 9 is provided on the + X side. ing. In the recess Ou, a gap G is formed between the first holding member 8 and the second holding member 9, and the suction port 4 is a space between the first holding member 8 and the second holding member 9. Facing (gap G). Each of the first holding member 8 and the second holding member 9 extends substantially parallel to the Y-axis direction, as shown in FIG. Each of the first holding member 8 and the second holding member 9 has substantially the same length as the concave portion Ou in the Y-axis direction, as shown in FIG. Each of the first holding member 8 and the second holding member 9 is a member having a thickness in the Z-axis direction, as shown in FIGS.

The first holding member 8 includes a side surface 8b, a side surface 8c, a side surface 8d, a side surface 8e, a first holding surface 8a that contacts the back surface Mb of the mask M, and a bottom surface 8f. In the present embodiment, the first holding member 8 is provided with a side surface 8b on the + X side, a side surface 8c on the -X side, a side surface 8d on the + Y side, and a side surface 8e on the -Y side. The side surface 8b extends from the bottom surface 5a to the first holding surface 8a on the −X side of the suction port 4 substantially in parallel with the Z-axis direction. The side surface 8b is substantially parallel and flat in the YZ plane. The side surface 8c is in contact with the peripheral wall H and extends from the bottom surface 5a to the first holding surface 8a substantially parallel to the Z-axis direction. The side surface 8c is substantially parallel and flat in the YZ plane.
The side surface 8d is in contact with the peripheral wall H and extends from the bottom surface 5a to the first holding surface 8a substantially parallel to the Z-axis direction. The side surface 8d is substantially parallel and flat in the XZ plane. The side surface 8e is in contact with the peripheral wall H and extends from the bottom surface 5a to the first holding surface 8a substantially parallel to the Z-axis direction. The side surface 8e is substantially parallel and flat in the XZ plane. The bottom surface 8f is in contact with the bottom surface 5a. The bottom surface 8f is substantially parallel and flat in the XY plane.

  The first holding surface 8a is formed between the upper end of the side surface 8b, the upper end of the side surface 8c, the upper end of the side surface 8d, and the upper end of the side surface 8e, and extends substantially parallel to the XY plane. The first holding surface 8a is flat in the XY plane. The first holding surface 8a is flush with the upper surface 1a of the mask stage body ST. The second holding member 9 has the same shape as the first holding member 8. Similar to the first holding member 8, the second holding member 9 includes a side surface 9b, a side surface 9c, a side surface 9d, a side surface 9e, a second holding surface 9a that contacts the back surface Mb of the mask M, and a bottom surface 9f. , A side surface 9b on the + X side, a side surface 9c on the -X side, a side surface 9d on the + Y side, and a side surface 9e on the -Y side. The second holding member 8 has a side surface 9 b in contact with the peripheral wall H, and a side surface 9 c extending to the + X side of the suction port 4. The side surface 9d and the side surface 9e are in contact with the peripheral wall H, and the bottom surface 9f is in contact with the bottom surface 5a. Similar to the first holding surface 8a, the second holding surface 9a is also flush with the upper surface 1a of the mask stage body ST. Therefore, it is flush with the second holding surface 9a and the first holding surface 8a.

  In the present embodiment, as shown in FIG. 3, in the XY plane, the first holding member 8 has protrusions that protrude in the + X axis direction at the + Y side end and the −Y side end, respectively. Yes. Similarly, the second holding member 9 has projecting portions that project in the −X-axis direction at each of the + Y side end portion and the −Y side end portion. Furthermore, in this embodiment, the + Y side protrusion of the first holding member 8 and the + Y side protrusion of the second holding member 9 are in contact with each other. Further, in the present embodiment, the −Y side protruding portion of the first holding member 8 and the −Y side protruding portion of the second holding portion 9 are in contact with each other. Therefore, in this embodiment, the 1st holding member 8 and the 2nd holding member 9 are arrange | positioned in the recessed part Ou so that a rectangular frame may be formed along the surrounding wall H of the recessed part Ou. In the present embodiment, the first holding unit 8 protrudes to the + X side on the + Y side and the −Y side, but it does not have to be protruded. Moreover, the 1st holding member 8 and the 2nd holding member 9 do not need to contact.

  In the present embodiment, the area of the first holding surface 8a and the area of the second holding surface 9a are the same. In the present embodiment, the thermal expansion coefficient of the first holding member 8 and the thermal expansion coefficient of the second holding member 9 are different. In the present embodiment, the first holding member 8 is formed of ceramics having a first coefficient of thermal expansion, and the second holding member 9 is formed of ceramics having a second coefficient of thermal expansion different from the first coefficient of thermal expansion. ing. In the present embodiment, the coefficient of thermal expansion of the first holding member 8 is lower than the coefficient of thermal expansion of the second holding member 9. Furthermore, in this embodiment, the thermal expansion coefficient of the 2nd holding member 9 is higher than the thermal expansion coefficient of the mask main body MH (quartz).

  As described above, the second mask holding unit 3b is disposed on the −X side of the transmission region TA. The difference between the second mask holding portion 3b and the first mask holding portion 3a is that, as shown in FIGS. 2 and 3, the first holding member 8 is disposed on the −X side of the concave portion of the second mask holding portion 3b. The second holding member 9 having a higher coefficient of thermal expansion than the first holding member 8 is disposed on the + X side. The other configuration of the second mask holding unit 3b is substantially the same as or equivalent to that of the first mask holding unit 3a, and the detailed description thereof is omitted.

  Next, a state where the mask M is held by the mask holding unit 3 of the mask stage 1 will be described with reference to FIG.

  In a state where the mask M is placed on the first mask holding portion 3a, as shown in FIG. 2, a part of the back surface Mb of the mask M, the side surface 8b of the first holding member 8, and the second holding member 9 A first space S1 surrounded by the side surface 9c and the bottom surface 5a of the recess Ou is formed. As described above, the suction port 4 can be connected to the vacuum system 10 via the suction flow path 10a. Therefore, the vacuum system 10 can suck (exhaust) the gas in the first space S <b> 1 through the suction port 4. That is, by operating the vacuum system 10, the mask M is sucked and held by the first mask holding unit 3a. By stopping the suction operation by the vacuum system 10, the mask M can be removed from the first mask holding portion 3a. Although a detailed description is omitted, the second mask holding member 3b can similarly hold the mask M by suction. That is, by operating the vacuum system 10, the mask M can be sucked and held on the mask holding unit 3, and by removing the suction operation by the vacuum system 10, the mask M is removed from the mask holding unit 3. Is possible.

  Next, an example of the operation of the exposure apparatus EX according to the present embodiment will be described.

  When the mask M is loaded on the mask stage 1, the gas in the first space S <b> 1 surrounded by the mask holding unit 3 and the back surface Mb of the mask M is exhausted by the vacuum system 10 through the suction port 4. As a result, the first space S1 has a negative pressure, and the mask M is sucked and held by the mask holding unit 3.

  Next, the substrate P before exposure is loaded onto the substrate stage 2 using a predetermined transport device, and the substrate P is held on the substrate stage 2.

  Next, exposure light EL is emitted from the illumination system IL. The exposure light EL from the illumination system IL illuminates the mask M. Thereby, the pattern image of the mask M is projected onto the surface Pa of the substrate P by the projection optical system PL, and the substrate P is exposed with the exposure light EL. In the present embodiment, as shown in FIG. 4B, the illumination area IR of the exposure light EL from the illumination system IL is set so as to cover the entire pattern area PA of the mask M, so that the mask M And the exposure of the first shot area on the substrate P are completed in a state where the substrate P and the substrate P are substantially stationary. When the exposure of the first shot is completed, the mask M and the substrate P are relatively moved, and the exposure of the second shot region on the substrate P is started. In this way, the pattern of the mask M is sequentially transferred to a plurality of shot areas on the substrate P.

  Next, the deformation of the mask M will be described with reference to FIGS. 5, 6, and 7. 5-7 is a figure for demonstrating the state of the thermal expansion (deformation) of the mask M in XY plane. 5-7, the expansion (deformation) is exaggerated.

  When the exposure light EL is irradiated to the mask M, the temperature of the mask M rises. When the temperature of the mask M rises, the mask M expands due to heat. For example, in a state where the mask M is not sucked and held by the mask holding portion, when the mask M is irradiated with the exposure light EL as shown in FIG. 4B, the mask M is thermally expanded as shown in FIG. Deform. In the example shown in FIG. 5, due to thermal expansion of the mask M, the rectangular shape M0 (dotted line) changes to a shape M1 (solid line) in which each side of the mask M is curved outward from the mask M with respect to the center of the mask M. Deform.

  Further, when the mask M is sucked and held by the mask holding part, the deformation of the mask M is suppressed in the portion (sucking part) sucked and held by the mask holding part. FIG. 6 shows an example in which the mask M is thermally expanded while being attracted and held by the suction portions V on the + X side and the −X side of the pattern area AP. Since the deformation of the mask M is partially suppressed at the suction portion V between the + X side and the −X side of the pattern area AP, the pattern area AP moves to the center of the mask M on the + X side and the −X side. The heading force acts.

  Therefore, the mask M has a shape M2 (solid line) in which the + X side and the −X side of the mask M are curved toward the center of the mask M, as shown in FIG. On the other hand, since there is no suction portion held (fixed) by the mask holding portion on the + Y side and the −Y side of the pattern area AP, the mask M has a side on the + Y side of the mask M as shown in FIG. , And the side on the −Y side is a shape M2 (solid line) curved outward with respect to the center of the mask M.

  As shown in FIG. 5, when the mask M thermally expands so that each side of the mask M is deformed substantially equally, a pattern image having a substantially desired shape is formed on the substrate P by adjusting the projection optical system PL. However, as shown in FIG. 6, when the thermal expansion of the mask M occurs so that the deformation of each side of the mask M is greatly different, the pattern image projected onto the substrate P May be difficult to project in a desired shape, and exposure failure may occur.

  Therefore, in the present embodiment, the mask holding unit 3 is provided with the first holding member 8 and the second holding member 9 having different thermal expansion coefficients.

  FIG. 7 is a view for explaining an example in which the mask M is thermally expanded while being held by the mask holding unit 3 of the present embodiment. In FIG. 7, together with the mask M, the mask holding unit 3 (3a, 3b) is shown. Hereinafter, a state in which the mask M is held in the first mask holding unit 3a of the present embodiment will be described with reference to FIG.

  When the temperature of the mask M rises while the mask M is held on the mask stage 1, the temperature of the first holding member 8 and the second holding member 9 of the first mask holding portion 3a rises due to heat from the mask M. Then, the first holding member 8 and the second holding member 9 are thermally expanded. In the present embodiment, the thermal expansion coefficient of the first holding member 8 is lower than the thermal expansion coefficient of the second holding member 9 and the thermal expansion of the first holding member 8 is larger than that of the second holding member 9. As shown in FIG. 7, the mask holding part 3a is deformed into a convex shape in the + X-axis direction. Since the first holding unit 3a holds (fixes) the mask M, a force in the + X-axis direction is applied to the vicinity of the + X side suction portion of the mask M in accordance with the deformation of the first mask holding unit 3a. Can do. That is, when the first mask holding portion 3a is thermally expanded, a force (+ X-axis direction force) directed toward the outside of the mask M with respect to the center of the mask M acts on the suction portion on the + X side of the mask M. Is stretched in the + X-axis direction. Similarly, when the second mask holding portion 3b is deformed in a convex shape in the −X axis direction, a force in the −X axis direction acts on the suction portion on the −X side of the mask M, and the mask M moves in the −X axis direction. To be stretched.

Therefore, in the present embodiment, even when the mask M is thermally expanded, the sides of the mask M are not substantially the same as the shape M2 (dotted line) in which the deformation of the sides in the X-axis direction and the sides in the Y-axis direction are substantially different. It is possible to deform the mask M into the shape M3 (solid line) deformed into the shape. As shown in FIG. 7, in the shape M3, each side is deformed almost equally, so that a pattern image having a substantially desired shape can be projected on the substrate P by adjusting the projection optical system PL. It is. Therefore, exposure failure can be suppressed.

As described above, since the first holding member 8 and the second holding member 9 having different coefficients of thermal expansion are provided in the mask holding unit 3, each mask M is provided even when the mask M is thermally expanded. It can be deformed into a shape in which the sides are deformed almost equally. Therefore, exposure failure can be suppressed.
(Second Embodiment)
Next, a second embodiment will be described. In the following description, the same or equivalent components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.

  Also in the second embodiment, the mask M is held by the mask holding unit 3 of the mask stage 1 of the first embodiment. In the second embodiment, members having different coefficients of thermal expansion may not be used for the mask holding unit 3 of the mask stage 1.

  In the second embodiment, the configuration (structure) of the mask M is different from that of the first embodiment. FIG. 8 is a plan view of the back surface Mb of the mask M according to this embodiment as viewed from above (+ Z side). FIG. 9 is a side sectional view of the mask M according to the present embodiment.

  The mask M of this embodiment will be described with reference to FIGS.

  The mask M of this embodiment includes a mask main body MH, a pattern area AP, and a mask suction unit 20. The mask holding unit 3 holds the mask suction unit 20 in a detachable manner so that the back surface Mb and the XY plane are substantially parallel.

  In the present embodiment, the mask suction unit 20 includes a first mask suction unit 20a and a second mask suction unit 20b. As shown in FIG. 8, in the XY plane, the first mask suction part 20a is provided on the + X side near the pattern area AP of the mask M, and the second mask suction part 20b is provided on the −X side.

  Next, the first mask suction unit 20a will be described in detail with reference to FIGS. As shown in FIG. 9, the first mask suction portion 20a includes a recess Ub provided on the back surface Mb of the mask body MH. As shown in FIG. 8, the concave portion Ub of the first mask suction portion 20a extends substantially parallel to the Y-axis direction. The concave portion Ub of the first mask suction portion 20a includes a rectangular bottom surface 30a provided below the back surface Mb (in the −Z axis direction) and a peripheral wall K provided around the bottom surface 30a. The peripheral wall K is formed in a rectangular ring shape along the outer edge of the bottom surface 30a, and extends from the bottom surface 30a to the back surface Mb substantially parallel to the Z-axis direction. The bottom surface 30a is substantially parallel to the XY plane and is flat.

  In the present embodiment, the first mask suction portion 20 a includes a first thermal expansion member 21 and a second thermal expansion member 22. In this embodiment, as shown in FIGS. 8 and 9, the first thermal expansion member 21 is disposed on the −X side of the concave portion Ub of the first mask suction portion 20 a, and the second thermal expansion member 22 is disposed on the + X side. Is provided. In the recess Ub, no gap is formed between the first thermal expansion member 21 and the second thermal expansion member 22, and the first thermal expansion member 21 and the second thermal expansion member 22 are in close contact with each other. . Note that a gap may be provided between the first thermal expansion member 21 and the second thermal expansion member 22.

  As shown in FIGS. 8 and 9, each of the first thermal expansion member 21 and the second thermal expansion member 22 is a member having a thickness in the Z-axis direction.

  The first thermal expansion member 21 includes a side surface 21b, a side surface 21c, a side surface 21d, a side surface 21e, and a first suction portion 21a held by the first holding surface 8a of the first mask holding portion 3a of the mask stage 1. , And bottom surface 21f. In the present embodiment, as shown in FIGS. 8 and 9, the side surface 21 b is on the + X side of the first thermal expansion member 21, the side surface 21 c is on the −X side, and the side surface 21 d is on the + Y side of the first thermal expansion member 21. A side surface 21e is provided on the side, and a bottom surface 21f is provided on the -Z side. The side surface 21b is in contact with the side surface 22c of the second thermal expansion member 22, and extends from the bottom surface 30a to the first adsorption portion 21a substantially parallel to the Z-axis direction. The side surface 21b is substantially parallel in the YZ plane. The side surface 21c is in contact with the peripheral wall K and extends from the bottom surface 30a to the first suction portion 21a substantially parallel to the Z-axis direction. The side surface 21c is substantially parallel in the YZ plane. The side surface 21d is in contact with the peripheral wall K and extends from the bottom surface 30a to the first suction portion 21a substantially parallel to the Z-axis direction. The side surface 21d is substantially parallel in the XZ plane. The side surface 21e is in contact with the peripheral wall K and extends from the bottom surface 30a to the first suction portion 21a substantially parallel to the Z-axis direction. The side surface 21e is substantially parallel in the XZ plane. The bottom surface 21f is in contact with the bottom surface 30a. The bottom surface 21f is substantially parallel and flat in the XY plane.

  The first suction portion 21a is formed between the upper end of the side surface 21b, the upper end of the side surface 21c, the upper end of the side surface 21d, and the upper end of the side surface 21e, and extends substantially parallel to the XY plane. The first suction portion 21a is flush with the back surface Mb of the mask M.

  The second thermal expansion member 22 includes a side surface 22b, a side surface 22c, a side surface 22d, a side surface 22e, and a second adsorption portion 22a held by the second holding surface 9a of the first mask holding portion 3a of the mask stage 1. , And bottom surface 22f. The second thermal expansion member 22 has the same shape as the first thermal expansion member 21. Similar to the first thermal expansion member 21, the second thermal expansion member 22 includes a side surface 22b on the + X side, a side surface 22c on the -X side, a side surface 22d on the + Y side, a side surface 22e on the -Y side, and a bottom surface 22f on the -Z side. Is provided.

  The second thermal expansion member 22 has a side surface 22 b in contact with the peripheral wall K and a side surface 22 c in contact with the side surface 21 b of the first thermal expansion member 21. The side surface 22d is in contact with the peripheral wall K, the side surface 22e is in contact with the peripheral wall K, and the bottom surface 22f is in contact with the bottom surface 30a. Similar to the first suction portion 21a, the second suction portion 22a is flush with the back surface Mb of the mask M. That is, the second suction part 22a and the first suction part 21a are flush with each other.

  In this embodiment, the area of the 1st adsorption | suction part 21a and the area of the 2nd adsorption | suction part 22a are the same. In the present embodiment, the thermal expansion coefficient of the first thermal expansion member 21 and the thermal expansion coefficient of the second thermal expansion member 22 are different. In the present embodiment, the thermal expansion coefficient of the first thermal expansion member 21 is lower than the thermal expansion coefficient of the second thermal expansion member 22.

  As described above, the second mask suction portion 20b is disposed on the −X side of the pattern area AP. As shown in FIGS. 8 and 9, the difference between the first mask suction part 20a and the second mask suction part 20b is that the first thermal expansion member 21 is arranged on the −X side of the recess Ub of the second mask suction part 20b. The second thermal expansion member 22 is disposed on the + X side. The other configuration of the second mask suction unit 20b is substantially the same as or equivalent to that of the first mask suction unit 20a, and the detailed description thereof is omitted.

  In the present embodiment, a state in which the mask M is held by the mask holding unit 3 of the mask stage 1 will be described.

  In a state where the mask M is placed on the mask holding part 3 (3a, 3b), a part of the first suction part 21a is in contact with the first holding surface 8a, and a part of the second suction part 22a is 2 Contact with the holding surface 9a. Although a detailed description is omitted, the first space S <b> 1 is formed by the mask suction unit 20 and the mask holding unit 3. As described above, by operating the vacuum system 10, the mask M can be sucked and held on the mask holding unit 3, and when the suction operation by the vacuum system 10 is stopped, the mask M is removed from the mask holding unit 3. Can be removed.

  Next, an exposure process using the mask M having the above configuration will be described.

  As described above, when the mask M is thermally expanded while the mask M is held by suction on the + X side and the −X side of the pattern area AP, the mask M becomes a shape M2 (solid line) as shown in FIG. There is a possibility of deformation. In the shape M2 (solid line), the X-side and Y-side sides of the mask M are greatly different from each other, so that it is difficult to project the pattern image projected on the substrate P in a desired shape, resulting in poor exposure. May occur.

  Therefore, in the present embodiment, the mask suction portion 20 is provided with the first thermal expansion member 21 and the second thermal expansion member 22 having different thermal expansion coefficients.

  A state where the first mask suction unit 20a of the mask M is held by the first mask holding unit 3a will be described.

  As described above, when the mask M is irradiated with the exposure light EL, the temperature of the mask M rises. When the temperature of the mask M rises, the first thermal expansion member 21 and the second thermal expansion member 22 of the first mask adsorption unit 20a are thermally expanded. In the present embodiment, since the thermal expansion coefficient of the first thermal expansion member 21 is lower than the thermal expansion coefficient of the second thermal expansion member 22, the first mask adsorption unit 20a is + X, like the first mask holding unit 3a. Deforms in a convex shape in the axial direction. Along with the deformation of the first mask suction part 20a, a force in the + X-axis direction can be applied to the vicinity of the first mask suction part 20a of the mask M. Similarly, a force in the −X axis direction can be applied in the vicinity of the second mask suction portion 20b. In the present embodiment, not only the deformation (thermal expansion) of the mask holding unit 3 but also the deformation (thermal expansion) of the first mask suction unit 20a and the second mask suction unit 20b causes a force to act on the vicinity thereof. Therefore, even when the mask M is thermally expanded, each side of the mask M can be deformed into substantially the same shape.

  As described above, in the present embodiment, the mask suction portion 20 is provided with the first thermal expansion member 21 and the second thermal expansion member 22 having different thermal expansion coefficients. Even in this case, each side of the mask M can be transformed into a substantially equivalent shape. Therefore, exposure failure can be suppressed.

  As the first thermal expansion member 21 and the second thermal expansion member 22, it is desirable to select an optimal material such as a metal, an organic material, an inorganic material, or a mixture thereof as appropriate. In the above-described embodiment, two types of materials (materials) having different thermal expansion coefficients are used. However, the types of materials are not limited to two types. For example, the same material is used for the first thermal expansion member 21 and the second thermal expansion member 22 and the physical properties such as density are changed, so that the thermal expansion coefficient of the first thermal expansion member 21 and the thermal expansion of the second thermal expansion member 22 are changed. The rate may be different.

  In the above-described embodiment, the first mask suction part 20a is provided on the + X side of the pattern area AP and the second mask suction part 20b is provided on the −X side, but are provided on the + Y side and the −Y side. Also good. Further, the mask suction part 20 may be provided with at least one mask suction part 20 on at least one side in the vicinity of the pattern area AP.

In the above-described embodiment, the area of the first suction part 21a and the area of the second suction part 22a are the same, but they may be different.
That is, it is desirable that the first thermal expansion member 21 and the second thermal expansion member 22 have optimal length, width, and thickness as appropriate.

  Moreover, in the above-mentioned embodiment, although the 1st adsorption | suction part 21a and the 2nd adsorption | suction part 22a and the back surface Mb of the mask M were flushed, the position of the Z-axis direction of the 1st adsorption | suction part 21a and the 2nd adsorption | suction part 22a The position in the Z-axis direction and the position in the Z-axis direction of the back surface Mb of the mask M may be different. Further, the first thermal expansion member 21 and the second thermal expansion member 22 are partially embedded in the mask M, but the mask M may be embedded by providing a through hole. Further, the back surface Mb or the front surface Ma of the mask M may be brought into contact (adhesion), or embedding and contact may be used in combination.

  In the above-described embodiment, the thermal expansion coefficient of the second thermal expansion member 22 is higher than the thermal expansion coefficient of the mask M, but the thermal expansion coefficient of the second thermal expansion member 22 is equal to the thermal expansion coefficient of the mask M. Or it may be lowered. Further, the thermal expansion coefficient of the first thermal expansion member 21 may be higher than the thermal expansion coefficient of the mask M. That is, it is desirable that the first thermal expansion member 21 and the second thermal expansion member 22 are appropriately selected to have an optimal coefficient of thermal expansion.

  In the above-described embodiment, a force is applied to the + X side in the vicinity of the first mask suction portion 20a to change the mask M to a desired shape, but the −X side of the concave portion Ub of the first mask suction portion 20a. The second thermal expansion member 22 is disposed on the side, the first thermal expansion member 21 is provided on the + X side, a force is applied to the −X side in the vicinity of the first mask suction portion 20a, and the mask M is changed to a desired shape. May be. That is, it is desirable that the first thermal expansion member 21 and the second thermal expansion member 22 be optimally disposed as appropriate.

In the above-described embodiment, ceramics are used for the first holding member 8 and the second holding member 9, but the present invention is not limited to this. As the first holding member 8 and the second holding member 9, it is desirable to select an optimal material such as a metal, an organic material, an inorganic material, or a mixture thereof as appropriate.
In the above-described embodiment, two types of materials (materials) having different thermal expansion coefficients are used. However, the types of materials are not limited to two types. For example, the same material is used for the first holding member 8 and the second holding member 9, and the thermal expansion coefficient of the first holding member 8 and the thermal expansion coefficient of the second holding member 9 are different by changing physical properties such as density. It may be.

  In each of the above-described embodiments, the first mask holding unit 3a is provided on the + X side in the vicinity of the transmission region TA, and the second mask holding unit 3b is provided on the −X side, but the + Y side and the −Y side are provided. May be provided. The mask holding unit 3 may be provided with at least one mask holding unit 3 on at least one side in the vicinity of the transmission area TA of the mask stage 1.

  In the above-described embodiment, the area of the first holding surface 8a and the area of the second holding surface 9a are the same, but they may be different. In other words, it is desirable that the first holding member 8 and the second holding member 9 have optimal length, width and thickness as appropriate.

  In the above-described embodiment, a gap is provided between the first holding member 8 and the second holding member 9, but a gap may not be provided between the first holding member 8 and the second holding member 9. Good. For example, the first holding member 8 and the second holding member 9 may be adjacent to each other, a gap may be provided between the second holding member 9 and the peripheral wall H, and the suction port 4 may be disposed so as to face the gap. .

  In the above-described embodiment, the first holding surface 8a and the second holding surface 9a and the upper surface 1a of the mask stage 1 are flush with each other. However, the position of the first holding surface 8a in the Z-axis direction and the second holding surface 9a. The position in the Z-axis direction and the position in the Z-axis direction of the upper surface 1a of the mask stage 1 may be different.

  In the above-described embodiment, the thermal expansion coefficient of the second holding member 9 is higher than the thermal expansion coefficient of the mask M. However, the thermal expansion coefficient of the second holding member 9 is equal to or lower than the thermal expansion coefficient of the mask M. It doesn't matter. Further, the thermal expansion coefficient of the first holding member 8 may be higher than the thermal expansion coefficient of the mask M. That is, it is desirable that the first holding member 8 and the second holding member 9 are appropriately selected to have an optimal coefficient of thermal expansion.

  In the above-described embodiment, a force is applied to the + X side in the vicinity of the first mask holding portion 3a to change the mask M into a desired shape. However, the −X side of the concave portion Ou of the first mask holding portion 3a. Even if the second holding member 9 is arranged, the first holding member 8 is provided on the + X side, a force is applied to the −X side in the vicinity of the first mask holding portion 3a, and the mask M is changed to a desired shape. good. That is, it is desirable that the first holding member 8 and the second holding member 9 are optimally disposed as appropriate.

  The mask holder 3 may include a pin chuck structure. The mask holding part 3 including the pin chuck structure is described in, for example, European Patent Application No. 1713115.

  In this embodiment, a force is applied in the vicinity of the suction portion of the mask M due to the difference in thermal expansion coefficient, but the generated force is not limited to this. For example, using the first holding member 8 and the second holding member 9 having the same thermal expansion coefficient, the width of the second holding portion surface 9a in the X-axis direction is made thinner than the width of the first holding surface 8a in the X-axis direction, A force may be generated by a difference in the width in the axial direction.

  In the above-described embodiment, the first mask holding unit 3a and the second mask holding unit 3b can be connected to the same vacuum system 10, and the first mask holding unit 3a and the second mask holding unit 3b are controlled simultaneously. Although possible, the first mask holding unit 3a and the second mask holding unit 3b may be connected to an independent vacuum system, and the first mask holding unit 3a and the second mask holding unit 3b may be controlled independently. The vacuum system 10 may be included in the exposure apparatus EX, or may be equipment such as a factory where the exposure apparatus EX is installed.

  In this embodiment, quartz glass is used for the mask main body MH. However, the mask main body MH may be made of an optimal material such as quartz glass doped with fluorine, fluorite, magnesium fluoride, or quartz in addition to quartz glass. It is desirable to choose one.

  In the first and second embodiments described above, the mask M is deformed, but other plate-like objects (for example, the substrate P) may be used.

  In the first embodiment and the second embodiment described above, the mask M is sucked under reduced pressure and held on the mask stage 1. For example, the mask M is obtained by using electrostatic chucking or using vacuum suction and electrostatic chucking together. May be held on the mask stage 1.

  As the substrate P in each of the above embodiments, not only a semiconductor wafer for manufacturing a semiconductor device, but also a glass substrate for a display device, a ceramic wafer for a thin film magnetic head, or an original mask or reticle used in an exposure apparatus. (Synthetic quartz, silicon wafer) or the like is applied.

  As the exposure apparatus EX, a step-and-repeat type projection exposure apparatus is used, but is not limited thereto. For example, the present invention can also be applied to a scanning exposure apparatus (scanning stepper) of a step-and-scan method in which the mask M and the substrate P are moved synchronously to scan and expose the pattern of the mask M.

  Furthermore, in the step-and-repeat exposure, after the reduced image of the first pattern is transferred onto the substrate P using the projection optical system while the first pattern and the substrate P are substantially stationary, the second pattern With the projection optical system, the reduced image of the second pattern may be partially overlapped with the first pattern and collectively exposed on the substrate P (stitch type batch exposure apparatus). ). Further, the stitch type exposure apparatus can be applied to a step-and-stitch type exposure apparatus in which at least two patterns are partially transferred on the substrate P, and the substrate P is sequentially moved.

  Further, as disclosed in, for example, US Pat. No. 6,611,316, two mask patterns are synthesized on a substrate via a projection optical system, and one shot on the substrate is obtained by one scanning exposure. The present invention can also be applied to an exposure apparatus that performs double exposure of a region almost simultaneously. The present invention can also be applied to proximity type exposure apparatuses, mirror projection aligners, and the like.

  The present invention also relates to a twin stage type exposure apparatus having a plurality of substrate stages as disclosed in US Pat. No. 6,341,007, US Pat. No. 6,208,407, US Pat. No. 6,262,796, and the like. It can also be applied to.

  Furthermore, as disclosed in, for example, US Pat. No. 6,897,963, etc., a substrate stage for holding a substrate, a reference member on which a reference mark is formed, and / or a measurement stage on which various photoelectric sensors are mounted. The present invention can also be applied to other exposure apparatuses.

  Further, for example, as disclosed in corresponding US Patent Application Publication No. 2005/0219488, European Patent Application Publication No. 1713115, US Patent Application Publication No. 2007/0273856, etc. The present invention can also be applied to an immersion exposure apparatus that exposes a substrate with exposure light.

  The type of the exposure apparatus EX is not limited to an exposure apparatus for manufacturing a semiconductor element that exposes a semiconductor element pattern on the substrate P, but an exposure apparatus for manufacturing a liquid crystal display element or a display, a thin film magnetic head, an image sensor (CCD). ), An exposure apparatus for manufacturing a micromachine, a MEMS, a DNA chip, a reticle, a mask, or the like.

  In each of the above-described embodiments, an ArF excimer laser may be used as a light source device that generates ArF excimer laser light as exposure light EL. For example, as disclosed in US Pat. No. 7,023,610. A harmonic generator that outputs pulsed light with a wavelength of 193 nm may be used, including a solid-state laser light source such as a DFB semiconductor laser or a fiber laser, an optical amplification unit having a fiber amplifier, a wavelength conversion unit, and the like. Furthermore, in the above-described embodiment, each illumination area and the projection area described above are rectangular, but other shapes such as an arc shape may be used.

  In each of the above-described embodiments, a light-transmitting mask in which a predetermined light-shielding pattern (or phase pattern / dimming pattern) is formed on a light-transmitting substrate is used. Instead of this mask, a reflective type is used. You can use a mask. Further, as disclosed in, for example, U.S. Pat. No. 6,778,257, a variable shaped mask (an electronic mask, an active mask, an active mask, or an active mask) that forms a transmission pattern, a reflection pattern, or a light emission pattern based on electronic data of a pattern to be exposed. Alternatively, an image generator may be used. The variable shaping mask includes, for example, a DMD (Digital Micro-mirror Device) which is a kind of non-light emitting image display element (spatial light modulator). Further, a pattern forming apparatus including a self-luminous image display element may be provided instead of the variable molding mask including the non-luminous image display element. As a self-luminous type image display element, for example, CRT (Cathode Ray Tube), inorganic EL display, organic EL display (OLED: Organic Light Emitting Diode), LED display, LD display, field emission display (FED: Field Emission Display) And a plasma display panel (PDP).

  In each of the above embodiments, the exposure apparatus provided with the projection optical system PL has been described as an example. However, the present invention can be applied to an exposure apparatus and an exposure method that do not use the projection optical system PL.

  Further, as disclosed in, for example, International Publication No. 2001/035168, an exposure apparatus (lithography system) that exposes a line and space pattern on the substrate P by forming interference fringes on the substrate P. The present invention can also be applied to.

  As described above, the exposure apparatus EX according to the embodiment of the present application maintains various mechanical subsystems including the respective constituent elements recited in the claims of the present application so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. Manufactured by assembling. In order to ensure these various accuracies, before and after assembly, various optical systems are adjusted to achieve optical accuracy, various mechanical systems are adjusted to achieve mechanical accuracy, and various electrical systems are Adjustments are made to achieve electrical accuracy. The assembly process from the various subsystems to the exposure apparatus includes mechanical connection, electrical circuit wiring connection, pneumatic circuit piping connection and the like between the various subsystems. Needless to say, there is an assembly process for each subsystem before the assembly process from the various subsystems to the exposure apparatus. When the assembly process of the various subsystems to the exposure apparatus is completed, comprehensive adjustment is performed to ensure various accuracies as the entire exposure apparatus. The exposure apparatus is preferably manufactured in a clean room where the temperature, cleanliness, etc. are controlled.

  As shown in FIG. 10, a microdevice such as a semiconductor device includes a step 201 for designing a function / performance of the microdevice, a step 202 for producing a mask (reticle) based on the design step, and a substrate as a substrate of the device. Substrate processing step 204, including substrate processing (exposure processing) including exposing the substrate with exposure light using a mask pattern and developing the exposed substrate according to the above-described embodiment. The device is manufactured through a device assembly step (including processing processes such as a dicing process, a bonding process, and a package process) 205, an inspection step 206, and the like.

  Note that the requirements of the above-described embodiments can be combined as appropriate. In addition, as long as it is permitted by law, the disclosure of all published publications and U.S. patents related to the exposure apparatus and the like cited in the above-described embodiments and modifications are incorporated as part of the description of the text.

It is a schematic block diagram which shows the exposure apparatus EX which concerns on this embodiment. It is a sectional side view which shows an example of the mask stage 1 which concerns on this embodiment. It is a top view which shows an example of the mask stage 1 which concerns on this embodiment. 2 is a plan view showing an example of a mask M. FIG. It is a figure explaining the mode of the thermal expansion of the mask. It is a figure which shows the shape of the mask M. It is a figure which shows the shape of the mask M which concerns on this embodiment. It is a top view which shows an example of the mask M which concerns on this embodiment. It is a sectional side view which shows an example of the mask M which concerns on this embodiment. The flowchart which shows an example of the manufacturing process of a microdevice.

1 --- mask stage, 1a --- top surface, 2 --- substrate stage, 3 --- mask holding part, 3a --- first mask holding part, 3b --- second mask holding part, 4-- --Suction port, 5a --- Top, 8 --- First holding member, 8a --- First holding surface, 8b --- Side, 8c --- Side, 8d --- Side, 8e-- -Side, 8f --- Bottom, 9 --- Second holding member, 9a --- Second holding, 9b --- Side, 9c --- Side, 9d --- Side, 9e--Side 9f --- Bottom surface, 10 --- Vacuum system, 10a --- Suction flow path, 20 --- Mask suction part, 20a --- First mask suction part, 20b --- Second mask suction part, 21 --- first thermal expansion member, 21a --- first adsorption portion, 21b --- side surface, 21c --- side surface, 21d --- side surface, 21e --- side surface, 21f --- bottom surface, 22 --- second thermal expansion member, 22a --- second adsorbing part, 22b --- side surface, 22c --- side surface, 22d --- side surface, 22e --- side surface, 22f --- bottom surface, 0a --- upper surface, AP --- pattern area, AX --- optical axis, EL --- exposure light, EX --- exposure device, G --- gap, H --- peripheral wall, IL --- Illumination system, IR --- Illumination area, K --- Surround wall, M --- Mask, Ma --- Front, Mb --- Back, MH --- Mask body, M0 --- Shape, M1-- -Shape, M2 --- Shape, M3 --- Shape, Ou --- Recess, P --- Substrate, Pa --- Surface, PL --- Projection optical system, PR --- Projection region, Rg-- --Sensitive material, S1 --- First space, ST --- Stage body, TA --- Transmission area, Ub --- Recess, V --- Suction part

Claims (15)

A stage device for holding a plate-like object,
A holding unit for holding the plate-like object;
The contact surface of the holding part with the plate-like object has a first region including at least a part of the surface of the first member having the first thermal expansion coefficient, and a second thermal expansion coefficient different from the first thermal expansion coefficient. And a second region including at least a part of the surface of the second member. 2. The stage device according to claim 1, wherein the first region is closer to a central portion of the plate-like object than the second region in a state where the plate-like object is held by the holding unit. The stage apparatus according to claim 1, wherein the first region and the second region have different areas. The stage device according to any one of claims 1 to 3, wherein the first member and the second member are made of the same material. The stage device according to any one of claims 1 to 4, wherein the first thermal expansion coefficient is lower than the second thermal expansion coefficient. 6. The stage apparatus according to claim 1, wherein the second coefficient of thermal expansion is higher than the coefficient of thermal expansion of the plate-like object. The holding part has a first space;
The plate-like object is adsorbed on the contact surface by placing the plate-like object on the holding portion to make the first space substantially closed and reducing the pressure of the first space. The stage apparatus as described in any one of 1-6. An exposure apparatus comprising a projection optical system that projects an image of a mask pattern onto a substrate, comprising the stage apparatus according to claim 1. The exposure apparatus according to claim 8, wherein the plate-like object includes the mask or the substrate. Exposing the substrate using the exposure apparatus according to claim 8 or 9,
Developing the exposed substrate;
A device manufacturing method including: A mask for lithography in which the mask body has a pattern region,
A first region including at least a part of the surface of the first member having the first coefficient of thermal expansion on the first side of the pattern region, and a surface of the second member having a second coefficient of thermal expansion different from the first coefficient of thermal expansion. And a second region including at least a part of the mask. The mask according to claim 11, wherein the first region is closer to a central portion of the pattern region than the second region. The mask according to claim 11, wherein the first coefficient of thermal expansion is lower than the second coefficient of thermal expansion. The mask according to any one of claims 11 to 13, wherein the second coefficient of thermal expansion is higher than the coefficient of thermal expansion of the mask body. A device manufacturing method comprising exposing a substrate using the mask according to claim 11 and developing the exposed substrate.