TWI810443B - Substrate holding device, photolithography device and method of manufacturing article - Google Patents

Abstract

[Problem] It is advantageous to provide a technique for efficiently holding a bent substrate. [Solution] A substrate holding device for holding a substrate, comprising a base having exhaust holes on a surface facing the held substrate, and a support member protruding from the base to support the substrate, The above-mentioned supporting member is constituted to have a continuous helical shape around the central portion of the aforementioned facing surface at least 3 times, and in the direction from the central portion to the outside, the n-th round portion (n is a natural number) and the The interval between the n+1-th week part is relatively narrow.

Description

Substrate holding device, photolithography device and method of manufacturing article

The invention relates to a substrate holding device, a photolithography device and a manufacturing method of an article.

In the manufacturing process of semiconductor devices and liquid crystal display devices in recent years, multiple layers may be deposited on substrates such as semiconductor wafers and glass plates, or films with strong stress relative to the substrates or relatively thick films may be formed. In such a case, concave curvature may be formed on the substrate, and it may be difficult for the substrate holding device (substrate stage) to properly hold the substrate in a process of forming a pattern on the substrate with a photolithography apparatus. In Patent Document 1, a wafer chuck is disclosed, in which a suction groove for wafer adsorption and an exhaust groove for air discharge are formed on the surface of the chuck in a spiral shape at a fixed interval in parallel, and the outer peripheral end of the exhaust groove is opened. On the outer edge of the main body, so that the proper adsorption of the wafer and the improvement of the plane precision.

[Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Publication No. 60-142036

For example, it is difficult to correct a concavely warped substrate as it moves toward the outer periphery. Therefore, in order to efficiently hold the substrate by the substrate holding device, it is preferable to increase the force (attraction force) for attracting the substrate toward the outer peripheral portion of the substrate.

Therefore, an object of the present invention is to provide a technique that is advantageous in efficiently holding a bent substrate.

In order to achieve the above objects, a substrate holding device as an aspect of the present invention is a substrate holding device that holds a substrate and includes a base having an exhaust hole on a surface facing the held substrate, and A support member protruding from the base to support the substrate, the support member is configured to have a continuous spiral shape that goes around the center of the facing surface at least three times, and in the direction from the center to the outside, more than The interval between the nth week part (n is a natural number) and the n+1th week part is relatively narrow.

Further objects and other aspects of the present invention will be clarified through preferred embodiments described below with reference to the drawings.

According to the present invention, for example, it is possible to provide a technique which is advantageous in order to efficiently hold a bent substrate.

10a, 10b: substrate holding device

11: Base

11a: Vent

12: Partition wall member

13: Supporting member

14: Second supporting member

15: Runner

[ Fig. 1] Fig. 1 is a schematic diagram illustrating the configuration of a substrate holding device according to a first embodiment.

[ Fig. 2] Fig. 2 is a cross-sectional view showing the structure of the substrate holding device according to the first embodiment.

[ Fig. 3 ] A diagram showing a substrate holding process in a conventional substrate holding device.

[ Fig. 4] Fig. 4 is a diagram for explaining a configuration example of a substrate holding device.

[ Fig. 5 ] A diagram showing the number of turns of the helical shape of the supporting member.

[Fig. 6] A diagram showing the channel width of the supporting member.

[ Fig. 7 ] A diagram showing warping of a substrate.

[ Fig. 8 ] A diagram showing the channel width required to maintain the attractive force of the substrate.

[ Fig. 9] Fig. 9 is a schematic diagram illustrating the configuration of a substrate holding device according to a second embodiment.

[ Fig. 10 ] A schematic diagram showing the configuration of an exposure apparatus.

Embodiments will be described in detail below with reference to the drawings. In addition, the following embodiments do not limit the inventors of the claims. Although plural features are described in the embodiments, all of these plural features are not limited to being essential to the invention, and plural features may be combined arbitrarily. Furthermore, In the drawings, the same reference symbols are assigned to the same or similar configurations, and overlapping explanations are omitted.

<First Embodiment>

The configuration of the substrate holding device 10a according to the first embodiment of the present invention will be described. The substrate holding device 10 a is for holding a substrate W such as a semiconductor wafer or a glass plate, and may include, for example, a base 11 , a partition wall member 12 , and a support member 13 . In the present embodiment, a configuration example of a substrate holding device 10a that holds a circular substrate W such as a semiconductor wafer will be described. FIG. 1 is a view of a substrate holding device 10 a according to the present embodiment seen from above (+Z direction side), and FIG. 2 is an A-A sectional view of the substrate holding device 10 a shown in FIG. 1 . In addition, in each drawing, let the directions orthogonal to each other on the horizontal plane be the X direction and the Y direction, and let the vertical direction be the Z direction.

The base 11 has a facing surface (surface on the +Z direction side) facing the substrate W when the substrate W is normally held by the substrate holding device 10a, and has an exhaust hole 11a on the facing surface. The exhaust hole 11a communicates with an exhaust device 30 such as a vacuum pump as shown in FIG. W. In the case of the present embodiment, as shown in FIG. 1 , a plurality of (three) exhaust holes 11 a are provided in the base 11 at the position where the center portion of the substrate W is arranged as shown in FIG. 1 . In addition, the number of exhaust holes 11a is not limited to three, and may be 1 to 2 or more than 4.

The partition wall member 12 is a member protruding from the base 1 in the +Z direction so as to support the outer peripheral portion of the substrate W. As shown in FIG. The partition wall member 12 can be configured as The shape (ring shape in this embodiment) along the outer peripheral portion of the substrate W so as to form a closed space between the substrate W and the base 11 when the substrate W is normally held by the substrate holding device 10a.

The support member 13 is a member protruding from the base 11 in the +Z direction so as to support the substrate W inside the partition wall member 12 . As shown in FIG. 1 , the supporting member 13 has a continuous (continuous) spiral shape that goes around the center of the facing surface of the base 11 at least three times on the base. In the case of the present embodiment, it has a continuous spiral shape of at least three turns centering on a region 11b including the exhaust hole 11a (hereinafter sometimes referred to as "central region 11b"). In addition, one end of the supporting member 13 is located between the plurality of exhaust holes 11a (specifically, the center of gravity of the facing surface of the base 11 and the center of gravity of the partition wall member 12), and the other end of the supporting member 13 The part is connected to the partition wall member 12. The support member 13 is formed spirally in this way, so that the gas flow path 15 discharged from the exhaust hole 11a is formed spirally, so that the substrate W can be gradually held (suctioned) from the center to the outer periphery.

In addition, the substrate holding device 10a is to reduce the deflection of the substrate W after holding, and as shown in FIG. The second supporting member 14 is composed of a plurality of needle-shaped and elongated ribs. In the example shown in FIG. 1, in order to make the figure easy to understand, although the second support member 14 constituted by a plurality of needles is only provided on a part of the inner side of the partition wall member 12, the second support member 14 can be It is provided with respect to the whole inside of the partition wall member 12 .

In such a substrate holding device 10a having a support member 13 formed in a spiral shape, a plurality of layers is deposited or a relatively thick film is formed. Therefore, the concavely warped substrate W can be held while correcting the warp. For example, immediately after the concavely bent substrate W is transported to the substrate holding device 10a, the center portion of the substrate W is in contact with the support member 13, but the outer peripheral portion of the substrate W floats relative to the support member 13 ( separated) state. In this state, the exhaust device 30 is controlled to start the exhaust between the substrate W and the base 11 through the exhaust hole 11a. On the other hand, the spiral flow channel 15 is gradually held (attracted). In this way, the substrate holding device 10a gradually sucks the substrate W from the center portion toward the outer peripheral portion along the flow path 15 formed in a spiral shape, and can hold the substrate W while correcting the curvature of the substrate W.

In addition, the board|substrate W which bends concavely becomes difficult to correct as it goes to the outer peripheral part. Therefore, in order to efficiently hold the substrate W while correcting the curvature of the substrate W by the substrate holding device 10a, it is preferable to increase the force (attractive force) for attracting the substrate W toward the outer peripheral portion of the substrate W. In terms of methods to increase the attractive force, there are, for example, adding an exhaust device 30 or increasing the exhaust volume of the exhaust device 30, but these methods may lead to complex and large-scale devices.

Therefore, in the substrate holding device 10a of the present embodiment, the supporting member 13 is configured such that, as shown in _FIG . The interval (flow path width W _n+1 ) between the n+1-th round portion and the n+2-th round portion is narrow. For example, the support member 13 is configured such that the interval between the nth round part and the n+1th round part becomes narrower as it goes outward. In addition, "n" represents the number of turns of the supporting member 13 formed in a helical shape, and is a natural number of 1 or more. In the substrate holding device 10a configured in this way, when holding the substrate W having a concave warp, the suction force of the substrate W can be increased as it goes toward the outer peripheral portion of the substrate W, so that the curvature of the substrate W can be corrected efficiently. Hold the substrate W securely.

For example, the support member 13 may be configured such that the interval between the n+1th round portion and the n+2th round portion (the flow channel width W _n+1 ) is greater than the interval between the n+1th round portion and the n+1th round portion. (runner width W _n ) is in the range of 60 to 95%. More preferably, the supporting member 13 can be configured to include a part, which is the interval (flow path width W _n+1 ) between the n+1th round part and the n+2th round part relative to the nth round part and the n+2th round part. Parts within the range of 75% to 85% of the interval (runner width W _n ) between the n+1th round parts.

[Principle of plane correction of substrate W]

The principle that the substrate holding device 10 a of this embodiment can efficiently hold the substrate W while straightening it will be described in comparison with a conventional substrate holding device 50 having a ring-shaped support member.

FIG. 3 is a diagram illustrating a holding process of a substrate W in a conventional substrate holding device 50 . FIG. 3( a) is a view of a conventional substrate holding device 50 viewed from above (+Z direction), and FIGS. 3( b ) to (c) are views of the conventional substrate holding device 50 shown in FIG. 3( a). B-B section view. A conventional substrate holding device 50, as shown in FIG. A plurality of support members 53 in shape. On the base 51 , an exhaust hole 51 a is provided between a plurality of ring-shaped supporting members 53 .

In the conventional substrate holder 50 configured in this way, gas flows in from the gap between the substrate W and the substrate holder 50 while gradually holding the concavely curved substrate W from the center to the outer periphery. The area of such a gap is 2π×r1×h when the substrate W is held at the position of the radius r1 as shown in FIG. 3( b ) when the height of the gap is defined by “h”. In addition, as shown in FIG. 3( c ), when the substrate W is held at a position of a radius r2 larger than the radius r1, it is 2π×r2×h. In this case, the ratio of the circumference at the holding position of the substrate W to that of FIG. That is, the closer the holding position of the substrate W is to the outer peripheral portion of the substrate W, the more difficult it may be to straighten and hold the substrate W.

On the other hand, when the substrate holding device 10a of the present embodiment having the spiral support member 13 gradually holds the substrate W having a concave curvature from the center to the outer periphery, the gas flows from the substrate W to the outer periphery. 11. The flow channel 15 defined by the support member 13 and the substrate W flows in. That is, the area of the gap where the gas flows does not depend on the radius of the position where the substrate W is held, but depends on the distance between the nth and n+1th circumferences of the support member 13 (flow path width W _n ). For example, when the substrate W is held at the position P indicated by the dashed-dotted line in FIG. 4 , the area of the gap into which the gas flows is (rn ₊₁ - _rn )×h. " _rn " indicates the radius of the n-th round, and "r _n+1 " indicates the radius of the n+1-th round.

In the case of the present embodiment, the interval (flow path width W _n ) between the nth peripheral part and the n+1th peripheral part of the support member 13 becomes narrower toward the outside. That is, as the holding position of the substrate W goes toward the outer peripheral portion of the substrate W, the cross-sectional area of the flow channel 15 defined by the nth peripheral portion and the (n+1)th peripheral portion becomes smaller. Therefore, as the holding position of the substrate W goes toward the outer peripheral portion of the substrate W, the flow velocity of the gas increases, and the suction force of the substrate W increases accordingly. Thereby, even if the substrate W is significantly concavely bent, the substrate W can be efficiently and reliably held up to the outer peripheral portion while being corrected.

[Configuration example of support member]

Next, a specific configuration example of the support member 13 having a spiral shape will be described.

The helical shape of the support member 13 can be represented by, for example, a spiral curve. As shown in FIG. 4, as shown in FIG. 4, the length of the vector (length of the radius vector) up to the n-th circle in the polar coordinate system with the center of gravity of the partition wall member 12 as the origin is r _n , and the rotation of the radius vector is When the angle is θ, it is represented by the formula r _n =a×θ ^b . In this formula, the constant a is a value for defining the size (for example, the size of the radial length) of the first peripheral portion of the support member 13 . In addition, the constant b is a constant for defining the decrease rate of the interval (flow path width W _n ) between the nth round part and the n+1th round part with respect to the rotation angle θ. When the constant b is larger than 0 and smaller than 1 (0<b<1), the channel width W _n becomes narrower as it goes to the outside, and when it is equal to 1 (b=1), it becomes For a certain flow path width W _n , if it is larger than 1 (b>1), the outer side of the flow path width W _n becomes wider. The support member 13 of this embodiment is configured such that the channel width W _n becomes narrower as it goes outward, so the constant b can be set so as to satisfy 0<b<1. The constant a and the constant b can be set arbitrarily, and can be set as appropriate according to the curved shape and amount of the substrate W to be held, the size of the substrate W, and the exhaust volume from the exhaust hole 11a.

For example, in the case of a=25 and b=0.5, the number of helical turns of the supporting member 13 is 5 as shown in FIG. As shown in FIG. 6 , the interval between parts (flow path width W _n ) decreases toward the outside. Here, in the example shown in Fig. 6, the flow path width W _n increases monotonously in the range where the radius vector length r _n is 62.9 [mm] or less, and this shows that up to 62.9 [mm] is the first round portion, The 2nd week part starts after this value. The support member 13 of the present embodiment has a structure in which the interval (flow channel width W _n ) between the nth and n+1th circumferential parts becomes narrower as it goes outward, and "n" is a natural number of 1 or more. That is, the support member 13 in this embodiment is configured such that the rotation angle θ of the flow channel 15 is formed between the first and second circumferential portions starting from the second circumferential portion, that is, when the radius vector length After r _n =62.9[mm], the channel width W _n gradually decreases.

On the other hand, the curved shape of the substrate W is generally a parabolic shape during film formation and heat treatment in the semiconductor manufacturing process. The paraboloid is expressed by the formula z=c× ^r2 when the height z, the radius r, and the curvature of the curved shape are c in the case of a plane uniaxial cross-section passing through the center. In this case, when the substrate W having such a curved shape is placed only on the substrate holding device 10a (support member 13), as shown in FIG. The larger the gap with the substrate W is. That is, it is difficult to form a negative pressure capable of correcting the substrate W in the gap toward the outer peripheral portion of the substrate W, and it becomes difficult to correct the substrate W.

When holding the substrate W having such a curved shape while being corrected, it is preferable to increase the suction force of the substrate W toward the outer peripheral portion of the substrate W. However, there is a limitation on the exhaust volume of the exhaust device 30 , and adding the exhaust device 30 may lead to a complication of the device and an increase in the cost of the device. Therefore, in the substrate holding device 10a of this embodiment, in order to increase the suction force while limiting the exhaust volume of the exhaust device 30, the flow path width _Wn is narrowed toward the outer peripheral portion of the substrate W, The flow rate of the gas between the substrate W and the substrate holding device 10 is thereby increased.

As shown in FIG. 7, the gap between the substrate W and the substrate holding device 10a becomes wider as the square of the radius vector length r _n (r ² ) goes toward the outer periphery of the substrate W, so the flow rate of the gas in the gap decreases to 1/ r ² , the attraction decreases to 1/r ⁴ . Therefore, in order to maintain the suction force toward the outer peripheral portion of the substrate W, it is preferable to reduce the channel width by a ratio of 1/r ² or more. Thereby, the attraction force of the substrate W which decreases toward the outer peripheral portion is compensated (that is, the attraction force is maintained), and the substrate W can be held efficiently while being corrected. Specifically, in the case where the channel width W _n is defined as W _n = (rn _{+1 -rn} ), in order to maintain the attractive force of the substrate W, it is necessary to satisfy W _n /(r _n /k) ² ≦ (a×(θ+2π) ^b -a×θ ^b ). In the above formula, " _rn " represents the radius vector length of the n-th round, and "rn ₊₁ " represents the radius vector length of the n+1-th round. In addition, "k" represents the dimension (for example, radius vector length) of the 1st peripheral part of the support member 13. As shown in FIG. For example, in the case of a=25 and b=0.5, the flow path width W _n required to maintain the attractive force of the substrate W is shown in FIG. 8 ,

As described above, the substrate holding device 10a of the present embodiment is configured to include the helical support member 13, and the distance between the n-th and n+1-th turn portions of the support member 13 (flow path width W _n ) Narrows outward. Thereby, even if the substrate W is concavely bent, the suction force increases toward the outer peripheral portion of the substrate W, and the substrate W can be efficiently held while being corrected.

<Second Embodiment>

The substrate holding device 10b according to the second embodiment of the present invention will be described. The substrate holding device 10b of the present embodiment basically inherits the structure of the substrate holding device 10a of the first embodiment, but the shapes of the partition wall members 12 and the support members 13 are different. Specifically, the substrate holding device 10 a of the first embodiment is configured in a circular shape to hold a circular substrate W such as a semiconductor wafer, while the substrate holding device 10 b of the present embodiment is configured to hold a rectangular substrate W such as a glass plate. The substrate W is configured as a rectangle.

Fig. 9 is a diagram of the substrate holding device 10b according to the present embodiment seen from above (+Z direction). As shown in FIG. 9, in the board|substrate holding|maintenance apparatus 10b of this embodiment, the partition wall member 12 and the support member 13 are comprised in rectangular shape. In this case, as in the first embodiment, even if the substrate W is concavely bent, the suction force increases toward the outer peripheral portion of the substrate W, and the substrate W can be efficiently held while being corrected.

<third embodiment>

A third embodiment of the present invention will be described. In this embodiment, an example in which the above-mentioned substrate holding device is applied to a photolithography apparatus will be described. In terms of photolithography equipment, there are, for example, exposure equipment for exposing a substrate, and molding equipment (imprint equipment) for molding a composition on a substrate using a mold. devices, planarization devices), drawing devices that use charged particle beams to form patterns on substrates, etc. Hereinafter, an example in which the above-mentioned substrate holding device is applied to an exposure device will be described.

FIG. 10 is a schematic diagram illustrating the structure of the exposure device 100 . The exposure apparatus 100 may include, for example, an illumination optical system 101 , a mask stage 102 , a projection optical system 103 , a substrate stage 104 , and a control unit 105 . The control unit 105 is constituted by, for example, a computer having a CPU, a memory, etc., and controls each part of the exposure apparatus 100 (controls the exposure process of the substrate W). In addition, the control unit 105 may be configured to control the above-mentioned exhaust device 30 .

The illumination optical system 101 illuminates a part of the mask M (master plate) with illumination light emitted from a light source (not shown). As illumination light, for example, i-rays (wavelength: 365 nm), g-rays (wavelength: 436 nm), KrF light (wavelength: 248 nm), ArF light (wavelength: 193 nm), etc. can be used. The mask stage 102 is configured to hold the mask M and move in the XY direction. The projection optical system 103 projects on the substrate W an image of a part of the pattern formed on the mask M and illuminated by the illumination optical system 101 . The substrate stage 104 is configured to hold the substrate W and move in the XY direction. The substrate stage 104 includes, for example, a substrate holder 104a that holds a substrate, and a substrate drive unit 104b that drives the substrate holder 104a (substrate W) in the XY direction. The above-mentioned substrate holding device 10a of the first embodiment or the substrate holding device 10b of the second embodiment can be used as the substrate holder 104a.

The position of the mask stand 102 is measured through the first measurement unit 106 . The first measurement unit 106 includes, for example, a laser interferometer, irradiates light (laser light) to the mirror 107 provided on the mask table 102, and transmits light from the mirror 107. The position of the mask table 102 is measured by reflecting the light. In addition, the position of the substrate stage 104 is measured through the second measurement unit 108 . The second measurement unit 108 includes, for example, a laser interferometer, irradiates light (laser light) to a mirror 109 provided on the substrate stage 104 , and measures the position of the substrate stage 104 by transmitting reflected light from the mirror 109 .

The mask M held through the mask stage 102 and the substrate W held through the substrate stage are disposed at optically conjugate positions (the object plane and the image plane of the projection optical system 103 ) via the projection optical system 103 . The control unit 105 relatively synchronously scans the mask table 102 and the substrate stage 104 at a speed ratio corresponding to the projection magnification of the projection optical system 103 based on the measurement results of the first measurement unit 106 and the second measurement unit 108 . Thereby, the pattern of the mask M can be transferred onto the substrate.

<Embodiment of Manufacturing Method of Article>

The method of manufacturing an article according to the embodiment of the present invention is suitable for manufacturing articles such as microdevices such as semiconductor devices and elements having a fine structure. The manufacturing method of the article of this embodiment includes a forming process of forming a pattern on the substrate using the above-mentioned photolithography apparatus (exposure apparatus) on the photosensitive agent applied to the substrate, and a processing process of processing the substrate patterned by the forming process. . Furthermore, such manufacturing methods include other well-known procedures (oxidation, film formation, evaporation, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.). The method of manufacturing an article according to this embodiment is advantageous in at least one of article performance, quality, productivity, and production cost compared to conventional methods.

The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the scope of the patent application is drafted to disclose the scope of the invention.

10a: Substrate holding device

11: Base

11a: Vent

11b: Area

12: Partition wall member

13: Supporting member

14: Second supporting member

15: Runner

Claims (12)

A substrate holding device for holding a substrate, comprising: a base having exhaust holes on a surface facing the held substrate, and a support member protruding from the base to support the substrate, the support structure The material is constituted to have a continuous helical shape that goes around the central part of the aforementioned facing surface at least 3 times. As for the interval between the week parts, the interval between the n+1th week part and the n+2th week part is relatively narrow. The substrate holding device according to claim 1, wherein the supporting member is configured such that the distance between the nth peripheral portion and the n+1th peripheral portion becomes narrower as it goes outward. The substrate holding device according to claim 1, wherein the supporting member includes a part in the direction, and the part is the distance between the n+1th round part and the n+2th round part relative to the distance between the nth round part and the The interval between the above n+1th week parts is within the range of 75% to 85%. The substrate holding device according to claim 1, wherein the base has a plurality of vent holes, and one end of the support member is located between the plurality of vent holes. The substrate holding device according to claim 4, which has a partition wall member disposed on the outside of the support member and protruding from the base to support the outer periphery of the substrate, The other end of the support member is connected to the partition wall member. The substrate holding device according to claim 1, further comprising a needle-shaped second support member protruding from the base to support the substrate. The substrate holding device according to claim 1, wherein the supporting member has a circular spiral shape. The substrate holding device according to claim 1, wherein the support member has a rectangular spiral shape. The substrate holding device according to claim 1, wherein when the vector to the n-th circle portion in a polar coordinate system with the center of gravity of the facing surface as the origin is r _n and the rotation angle of the vector is θ, the aforementioned The helical shape of the supporting member is constructed so as to satisfy r _n =a×θ ^b , the constant a is the value used to define the size of the first circumference of the supporting member, and the constant b is used to define the aforementioned value with respect to the rotation angle θ The value for the decrease rate of the interval between the n-th round portion and the aforementioned n+1-th round portion is set to a value greater than 0 and smaller than 1. The substrate holding device according to claim 9, wherein when the interval between the nth round portion and the n+1th round portion is W _n , and the size of the first round portion of the support member is k, the support structure The material is configured so as to satisfy W _n /(r _n /k) ² ≦(a×(θ+2π) ^b −a×θ ^b ). A lithographic apparatus for forming a pattern on a substrate, comprising the substrate according to any one of claims 1 to 10 holding the aforementioned substrate Keep the device. A method of manufacturing an article, comprising: a forming procedure for forming a pattern on a substrate using the lithography apparatus according to claim 11; and a processing procedure for processing the substrate patterned in the foregoing forming procedure; An article is manufactured from the aforementioned substrate processed in the aforementioned processing procedure.

Images