JP2022134074A - Chuck, substrate-holding device, substrate-processing device, and production method of article - Google Patents

Abstract

To provide a chuck capable of reducing warp of a substrate by having arrangement positions of a partition wall and protrusions a predetermined relation.SOLUTION: A chuck for holding a substrate by suction includes: a plurality of protrusions contacting to a back surface of the substrate held by suction; an annular partition wall; and a bottom part arranged with the plurality of protrusions and the partition wall, where the plurality of protrusions are constituted by a plurality of groups of a group composed of a first protrusion arranged outside of the partition wall and a second protrusion arranged inside of the partition wall at a position abutting the first protrusion interposing the partition wall, and satisfy s/L<0.5 when L is a distance between the first protrusion and the second protrusion contained in the plurality of respective groups, and s is a distance between the second protrusion and the partition wall.SELECTED DRAWING: Figure 3

Description

The present invention relates to a chuck, a substrate holding device, a substrate processing device, and an article manufacturing method.

2. Description of the Related Art In recent years, an exposure apparatus (reduction projection exposure apparatus) used for manufacturing semiconductor devices and the like has been increasing in NA to cope with miniaturization of devices. Increasing the NA improves the resolving power, but reduces the effective depth of focus. Therefore, in order to maintain the resolving power and secure a sufficient practical depth of field, it is necessary to reduce the field curvature of the projection optical system, improve the thickness unevenness of the wafer (substrate), and improve the flatness accuracy of the chuck that holds the wafer. Attempts have been made to improve wafer flatness (the flatness of the substrate surface).

One of the causes of lowering the flatness of the substrate surface is foreign matter sandwiched between the chuck and the substrate. If a foreign object is sandwiched, the portion of the substrate where the foreign matter is sandwiched is deformed so as to swell, which may cause defective pattern formation on the substrate and reduce the yield. In order to stochastically avoid the decrease in yield due to such foreign matter, a pin contact chuck (pin chuck) using a so-called pin (convex portion), which greatly reduces the contact rate between the chuck and the substrate, is used. there is

When this pin chuck is used, the substrate may be deformed by the vacuum suction force between the protrusions and bent (distorted), which may reduce the flatness of the substrate surface. Various proposals have been made. For example, in Patent Document 1, the pin chuck is provided with an annular partition wall (bank) surrounding a plurality of convex portions, and the partition wall is arranged to form a convex portion on the outer peripheral side and a convex portion adjacent to the convex portion on the outer peripheral side. It is arranged between the convex portions on the inner peripheral side which are the portions. The partition walls are arranged so as to be as close to the protrusions on the outer peripheral side as possible.

In addition, in Patent Document 2, the partition wall is positioned outside the outermost protrusion, or between the outermost protrusion, the outermost protrusion, and the inner protrusion adjacent to the outermost protrusion. are placed. As for the arrangement position of this partition, the partition is arranged at a position within a predetermined range in the outer peripheral direction from the center of the distance between the outermost protrusion and the inner protrusion adjacent to the outermost protrusion. there is

Japanese Patent No. 4298078 Japanese Patent Application Laid-Open No. 2001-185607

When the substrate is vacuum-sucked, the inner side of the partition wall is maintained at a substantially vacuum pressure and a suction force is generated, but the outer side of the partition wall is at atmospheric pressure and almost no suction force is generated. In Patent Literatures 1 and 2, the partition wall is arranged at a position close to the outer peripheral convex portion in order to apply the adsorption force to the outside of the substrate as much as possible. However, since the adsorption force acts on the outside of the substrate, the flatness of the substrate surface is reduced, and the distortion of the substrate is increased.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a chuck capable of reducing the distortion of a substrate, for example, by setting the arrangement positions of partition walls and projections in a predetermined relationship.

In order to achieve the above object, a chuck as one aspect of the present invention includes a plurality of projections abutting against the back surface of a substrate held by suction, an annular partition, and a bottom portion on which the plurality of projections and the partition and, the plurality of protrusions include a first protrusion arranged outside the partition wall, and a second protrusion arranged inside the partition wall and adjacent to the first protrusion with the partition wall interposed therebetween. L is the distance between the first convex portion and the second convex portion included in each of the plurality of groups, and s is the distance between the second convex portion and the partition wall. is characterized by satisfying s/L<0.5.

According to the present invention, there is provided a chuck capable of reducing the distortion of the substrate, for example, by setting the arrangement positions of the partition walls and the projections in a predetermined relationship.

1 is a schematic diagram illustrating the configuration of an exposure apparatus of Example 1; FIG. FIG. 4 illustrates a material mechanics model of a one-sided fixed and one-sided free beam subjected to an evenly distributed load; 1 is a diagram illustrating a substrate holding device of Example 1; FIG. 1 is a diagram illustrating a material mechanics model of Example 1. FIG. 5 is a diagram illustrating the relationship between the partition wall position and distortion in Example 1. FIG. FIG. 10 is a diagram illustrating a substrate holding device of Example 2; FIG. 11 is a diagram illustrating a substrate holding device of Example 3; FIG. 4 illustrates a material mechanics model for a cantilever; FIG. 11 illustrates a cross-sectional view of the chuck of Example 3; FIG. 11 is a diagram illustrating a substrate holding device of Example 5; 4 is a flow chart illustrating the manufacturing process of the device; 4 is a flow chart illustrating a wafer process; It is the figure which illustrated the pin chuck used with a common board|substrate holding apparatus.

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below using examples and drawings with reference to the accompanying drawings. In each figure, the same members or elements are denoted by the same reference numerals, and overlapping descriptions are omitted or simplified.

<Example 1>
FIG. 1 is a configuration diagram schematically illustrating the configuration of an exposure apparatus 100 of this embodiment. The exposure apparatus 100 is an apparatus capable of irradiating and curing a resist with light (exposure light) emitted from a light source, and forming a pattern of a cured product in which the pattern formed on the reticle 104 is transferred.

In the following description, the direction parallel to the optical axis of the light irradiated onto the resist on the substrate 110 is defined as the Z-axis direction, and the two directions orthogonal to each other in a plane perpendicular to the Z-axis direction are defined as the X-axis direction and the Y-axis direction. direction. The exposure apparatus 100 of the present embodiment can be applied to an apparatus that performs sequential focus driving on a plurality of pattern formation areas (exposure areas), an apparatus that performs sequential exposure (projection exposure apparatus, substrate processing apparatus), and the like. An exposure apparatus 100 of this embodiment will be described below with reference to FIG. Note that the exposure apparatus 100 of this embodiment will be described as a step-and-repeat type exposure apparatus.

A substrate (wafer) 110 is a substrate to be processed whose surface is coated with a photosensitive agent (resist) that effectively causes a chemical reaction with exposure light. Glass, ceramics, metal, silicon, resin, or the like is used for the substrate 110, and if necessary, a member made of a material different from that of the substrate 110 may be formed on the surface thereof. Further, the substrate 110 may be various substrates such as a gallium arsenide wafer, a composite bonded wafer, a glass wafer containing quartz as a material, a liquid crystal panel substrate, and a reticle. The outer shape may be not only circular but also rectangular. In this case, the outer shape of the chuck 1, which will be described later, may be made to match the outer shape of the substrate.

A reticle (original) 104 is mounted on a reticle stage 103 which is movable in a plane perpendicular to the optical axis of the projection optical system 106 and in the direction of the optical axis. The reticle 104 has a rectangular outer peripheral shape, and has a pattern portion provided with a three-dimensional pattern (an uneven pattern to be transferred to the substrate, such as a circuit pattern) on a surface (pattern surface) facing the substrate 110 . have. The reticle 104 is made of a material capable of transmitting light, such as quartz.

The exposure apparatus 100 of this embodiment also functions as a substrate processing apparatus, and includes a substrate holding apparatus 101, a substrate stage 102, a reticle stage 103, an illumination optical system 105, a projection optical system 106, an off-axis scope 107, A measurement unit 108 and a control unit 109 may be included.

The substrate holding device 101 includes a chuck 1 for sucking and holding a substrate 110, a suction unit (not shown) as a vacuum source for sucking (exhausting) the space between the back surface of the substrate 110 and the chuck 1, and a suction unit. and a control unit (not shown) for controlling. The details of the substrate holding device 101 in this embodiment will be described later.

The substrate stage 102 includes a θZ tilt stage that holds the substrate 110 via the substrate holding device 101, an XY stage (not shown) that supports the θZ tilt stage, and a base (not shown) that supports the XY stage. The substrate stage 102 is driven by a driving device (not shown) such as a linear motor. The driving device can be driven in six axial directions of X, Y, Z, θX, θY, and θZ, and is controlled by a control section 109 which will be described later. Although the driving device is drivable in six axial directions, it may be drivable in any one of one to six axial directions.

The reticle stage 103 is, for example, configured to be movable within a plane perpendicular to the optical axis of the projection optical system 106, which will be described later, that is, within the XY plane, and to be rotatable in the θZ direction. The reticle stage 103 is driven by a driving device (not shown) such as a linear motor. The driving device can be driven in three axial directions of X, Y and θZ, and is controlled by a control unit 109 which will be described later. Although the driving device is drivable in three axial directions, it may be drivable in any of one to six axial directions.

The illumination optical system 105 has a light source (not shown) and illuminates the reticle 104 on which a circuit pattern for transfer (reticle pattern) is formed. For example, a laser is used as the light source included in the light source. Usable lasers include an ArF excimer laser with a wavelength of about 193 nm, a KrF excimer laser with a wavelength of about 248 nm, and an F2 excimer laser with a wavelength of about 157 nm. The type of laser is not limited to an excimer laser, and for example, a YAG laser may be used, and the number of lasers is not limited. When a laser is used in the light source, it is preferable to use a beam shaping optical system for shaping a parallel beam from the laser light source into a desired beam shape, and an incoherent optical system for making a coherent laser incoherent. Furthermore, the light sources that can be used are not limited to lasers, but can also be one or more lamps such as mercury lamps or xenon lamps.

Also, the illumination optical system 105 includes a lens, a mirror, a light integrator, an aperture, and the like (not shown). Generally, the internal optical system is arranged in the order of condenser lens, fly's eye, aperture stop, condenser lens, slit, and imaging optical system. In this case, the light integrator includes a fly-eye lens, an integrator configured by stacking two sets of cylindrical lens array plates, and the like.

The projection optical system 106 projects the diffracted light of the pattern on the reticle 104 illuminated by the exposure light from the illumination optical system 105 onto the substrate 110 at a predetermined magnification (for example, 1/2, 1/4, or 1/5). Imaging, interfering. The interference image formed on substrate 110 forms an image substantially identical to the reticle pattern. This interference image is generally called an optical image, and the shape of the optical image determines the line width formed on the substrate 110 . The projection optical system 106 can employ an optical system consisting only of a plurality of optical elements, or an optical system (catadioptric optical system) consisting of a plurality of optical elements and at least one concave mirror. Alternatively, as the projection optical system 106, an optical system composed of a plurality of optical elements and at least one diffractive optical element such as kinoform, an all-mirror optical system, or the like can be employed.

The off-axis scope 107 is used to position the substrate 110 and detect the positions of the patterned regions of the substrate 110 . A relative position between a reference mark arranged on the substrate stage 102 and a mark formed on the substrate 110 mounted on the substrate stage 102 can be detected and measured. The measuring unit (surface position measuring means) 108 is a measuring device capable of focusing the projection optical system 106 on the exposure target area of the substrate 110, and is a focusing device for focusing the projection optical system 106 on the substrate surface. Configure.

The control unit 109 includes a CPU, a memory (storage unit), and the like, is composed of at least one computer, and is connected to each component of the exposure apparatus 100 via a line. Further, the control unit 109 comprehensively controls the operation and adjustment of each component of the entire exposure apparatus 100 according to the programs stored in the memory. Further, the control unit 109 may be configured integrally with other parts of the exposure apparatus 100 (within a common housing), or may be configured separately from the other parts of the exposure apparatus 100 (within another housing). Alternatively, it may be installed at a location different from the exposure apparatus 100 and controlled remotely.

Here, the exposure sequence of exposure apparatus 100 will be described below. Note that each operation (process) shown in the exposure sequence is controlled by the control unit 109 executing a computer program. When starting the exposure sequence, the substrate 110 is set in the exposure apparatus 100 automatically or manually by an operator, and the operation of the exposure apparatus 100 is started by an exposure start command.

First, the first substrate 110 to be exposed first is loaded into the substrate carrier in the exposure apparatus 100 by a transport mechanism (not shown) (loading step). Next, the substrate 110 is sent onto the chuck 1 mounted on the substrate stage 102 by the transport mechanism, and held by suction by the substrate holding device 101 (substrate holding step).

Next, a plurality of marks formed on the substrate 110 are detected by the off-axis scope 107 mounted on the exposure apparatus 100 to determine the magnification, rotation, and displacement amount of the substrate 110 in the X-axis and Y-axis directions. Correction is performed (alignment step).

Next, the substrate stage 102 moves the substrate 110 so that the predetermined pattern formation area of the mounted substrate 110 to be exposed first matches the exposure position of the exposure apparatus 100 . Next, after focusing by the measurement unit 108, light is emitted from the light source to expose the resist coated in the predetermined pattern formation region for a predetermined time (exposure step). Note that the exposure time is, for example, approximately 0.2 seconds.

Next, the substrate stage 102 moves (steps) the substrate 110 to the next pattern formation region on the substrate 110 and performs exposure in the same manner as described above. The same pattern forming process is sequentially repeated until exposure is completed in all pattern forming regions to be exposed. Thereby, the pattern formed on the reticle 104 can be formed on one substrate 110 . Then, the substrate 110 transferred from the chuck 1 to a collection transfer hand (not shown) is returned to the substrate carrier in the exposure apparatus 100 (unloading step). After carrying out the substrate 110, for example, the substrate 110 is subjected to processing such as etching to process the substrate 110 (processing step), and unnecessary hardened materials and the like are removed from the processed substrate 110. An article can be manufactured by

In this embodiment, a step-and-repeat type exposure apparatus is assumed as described above, but the present invention is not limited to this, and can also be applied to a scanning type exposure apparatus. When applied to a scanning exposure apparatus, the reticle and substrate 110 are scanned synchronously based on the exposure magnification, and exposure is performed during scanning.

It should be noted that the substrate holding device 101 of this embodiment is not limited to use in the exposure apparatus 100 . For example, it can be used in substrate processing equipment including imprint equipment (lithography equipment), liquid crystal substrate manufacturing equipment, magnetic head manufacturing equipment, semiconductor inspection equipment, liquid crystal substrate inspection equipment, magnetic head inspection equipment, manufacturing of micromachines, etc. can.

Here, when the chuck 1 is caused to hold the substrate 110 by suction, foreign matter may be sandwiched between the substrate 110 and the chuck 1 . For example, even if the foreign matter is several μm in size, if the foreign matter is sandwiched between the substrates 110 , the sandwiched portion of the substrate 110 may be deformed and partly swelled, resulting in defective pattern formation. For example, this may occur when the effective depth of focus is 1 μm or less.

In order to avoid such foreign matter from being pinched, a so-called pin contact chuck (hereinafter referred to as a chuck) having pin-shaped protrusions formed at portions to be brought into contact with the back surface of the substrate 110 is used to reduce the contact area with the substrate 110 . has decreased significantly. A chuck used in a conventional general substrate holding device will be described below with reference to FIG.

FIG. 13 is a diagram illustrating a chuck 200 used in a general substrate holding device. FIG. 13A is a plan view of the chuck 200 viewed from the +Z direction. FIG. 13B is a partial cross-sectional view of the chuck 200 shown in FIG. 13A. The substrate holding device illustrated in FIG. 13 can be composed of a chuck 200 , a convex portion 201 , a partition (first partition) 204 and a suction port 205 .

The convex portion 201 functions as a contact surface (a support surface that supports the substrate after it is placed) that is brought into contact with the back surface of the substrate 110 . The plurality of pin-shaped protrusions 201 includes a plurality of pin-shaped protrusions (outer periphery-side protrusions) 202, a plurality of pin-shaped protrusions (inner periphery-side protrusions) 203, and the outer periphery-side protrusions 202 and the inner periphery. A plurality of pin-shaped protrusions different from the side protrusions 203 may be included.

The partition wall 204 is provided in an annular shape at the bottom of the chuck 200 so as to be inside the outer peripheral convex portion 202 . The height of the partition wall 204 is lower than the upper surface of the outer peripheral protrusion 202 by about 1 to 2 μm. The suction port 205 is a through hole formed in the bottom of the chuck 200, and is connected to a channel formed by a pipe or the like that communicates with a vacuum source (suction portion) (not shown).

The outer protrusion 202 is arranged outside the partition wall 204 so as to abut on the back surface of the substrate 110 in the outer peripheral direction. A plurality of outer peripheral side protrusions 202 are arranged on the outer periphery having the same radius as the substrate 110 . The outer-periphery-side protrusion 202 illustrated in FIG. 13 is a protrusion arranged on the outermost side (outermost periphery) of the chuck 200 . The inner peripheral convex portion 203 is arranged inside the partition wall 204 so as to abut on the back surface of the substrate 110 in the inner peripheral direction. A plurality of inner circumference-side protrusions 203 are arranged on the inner circumference having the same radius as the substrate 110 . The inner peripheral convex portion 203 illustrated in FIG. 13 is arranged next to the outer peripheral convex portion 202 arranged on the outermost bottom portion with a partition wall 204 interposed therebetween. Also, the plurality of pin-shaped protrusions 201 on the chuck 200 can be arranged in a grid pattern at predetermined distances (intervals, cycles, widths). In addition, the outer peripheral side convex portion 202 arranged outside the partition wall 204 and the inner peripheral side convex portion 203 arranged inside the partition wall 204 and adjacent to the outer peripheral side convex portion 202 with the partition wall 204 interposed therebetween are 1 configure each as one group. Then, the plurality of protrusions composed of the outer periphery-side protrusion 202 and the inner periphery-side protrusion 203 are configured from a plurality of groups including each group.

A method of sucking the substrate 110 with the chuck 200 configured as described above will be described below. First, the substrate 110 is placed on the convex portion 201 of the chuck 200 . As a result, the rear surface of the substrate 110 abuts on the plurality of protrusions 201 . Next, the substrate 110 is vacuum-sucked through the suction port 205 by operation of a vacuum source (not shown), so that the substrate 110 is supported by the projections 201 of the chuck 200 and held by suction. At this time, the substrate 110 is deformed and bent between the protrusions 201 by the vacuum adsorption force. The bending of the substrate 110 lowers the flatness of the substrate 110 and causes so-called wafer distortion (hereinafter referred to as distortion).

Using the arrangement position of the partition wall 204 illustrated in FIG. 13B as an example, the flatness of the substrate 110 and the amount of distortion generated in the outer peripheral convex portion 202 are calculated from a material mechanics model with reference to FIG. to explain. FIG. 2 is a diagram exemplifying a material mechanics model of a one-sided fixed and one-sided free beam subjected to an evenly distributed load. A material mechanics model of the bending state of the substrate 110 in the outer peripheral region (outer peripheral portion) of the chuck 200 applies to the model illustrated in FIG. In addition, as illustrated in FIG. 13B, the partition wall 204 is arranged at a position closer to the outer peripheral protrusion 202 than to the inner peripheral protrusion 203 .

Let E be the Young's modulus of the substrate 110 and h be the thickness of the substrate 110 . Next, let L be the distance between the outer peripheral side convex portion 202 and the inner peripheral side convex portion 203 included in each of the plurality of groups (hereinafter referred to as a plurality of groups). Further, let w be the acting force per unit length, y be the deflection, and x be the radial position based on the inner circumference side protrusion 203 . At this time, the inclination (θ) dy/dx is represented by the following formula (1). Note that the distance L may be an average value of the distances between the outer circumference-side protrusions 202 and the inner circumference-side protrusions 203 included in each of a plurality of groups.

上記式（１）における傾斜ｄｙ／ｄｘは、ｘ＝Ｌで最大となり以下の式（２）で表される。

The slope dy/dx in the above formula (1) becomes maximum at x=L and is represented by the following formula (2).

ここで、上記式（２）における、マイナス表記は傾斜ｄｙ／ｄｘが反時計回り（ＣＣＷ）の回転方向であることを示している。また、真空源による吸引圧を吸引圧力Ｐｖとして、奥行寸法をｂとすると、単位長さあたりの作用力ｗは、以下の式（３）で表される。

Here, the minus notation in the above equation (2) indicates that the tilt dy/dx is in the counterclockwise (CCW) rotation direction. Further, when the suction pressure by the vacuum source is Pv and the depth dimension is b, the acting force w per unit length is expressed by the following equation (3).

ここで、片側自由の梁における断面二次モーメントＥ＝１／１２ｂｈ^３として、上記式（３）を上記式（２）に代入すると、以下の式（４）が得られる。

Here, when the geometrical moment of inertia E=1/12bh ³ in the beam with one side free and substituting the above formula (3) into the above formula (2), the following formula (4) is obtained.

そして、ディストーションｄｘは以下の式（５）で表される。

Then, the distortion dx is represented by the following equation (5).

なお、厳密には、外周側凸部２０２は、吸引等により基板１１０に荷重が掛かった際に基板１１０の変形により、当該外周側凸部２０２の中心部（外周側凸部の中心軸上における支持面）ではなく、中心部からずれた角部で基板１１０を支持することになる。そのため、この場合の上記距離Ｌ（ｍｍ）は、厳密には当該外周側凸部２０２の基板１１０の中心方向に対して外周側凸部２０２の角部から隔壁２０４を挟んで当該外周側凸部の隣に配置される内周側凸部２０３の中心軸までの距離となる。上記ディストーションを算出する上では、距離Ｌにおける距離が長い方がディストーションは大きくなるため、安全側で計算すべくディストーションの算出には上記の距離Ｌを採用している。

Strictly speaking, when a load is applied to the substrate 110 by suction or the like, the deformation of the substrate 110 causes the center portion of the outer periphery side protrusion 202 (on the central axis of the outer periphery side protrusion to The substrate 110 is supported not by the support surface), but by the corners that are displaced from the center. Therefore, strictly speaking, the distance L (mm) in this case is the distance from the corner of the outer protrusion 202 to the center of the substrate 110 of the outer protrusion 202 with the partition wall 204 interposed therebetween. is the distance to the central axis of the inner peripheral side convex portion 203 arranged next to the . In calculating the distortion, the longer the distance L, the larger the distortion. Therefore, the distance L is used for the calculation of the distortion in order to calculate the distortion on the safe side.

Here, as an example, by substituting E = 160 GPa, Pv = 0.1 MPa, L = 2 mm, and h = 0.7 mm into the above equation (5), dx = 1.29 nm is obtained. be done. For example, an overlay error tolerance of 1.5 nm relative to the ideal horizontal reference leaves only 0.29 nm of that tolerance. Further, for example, even if the tolerance for overlay error relative to an ideal horizontal reference is, for example, 3 nm or 5 nm, a distortion of 1.29 nm is significant in performing the process of patterning the substrate 110. . Therefore, in order to perform processing such as pattern formation after the substrate 110 is sucked and held, it is necessary to suck and hold the substrate 110 in a state in which distortion is reduced.

Therefore, in the present embodiment, a chuck capable of reducing distortion can be provided by setting the arrangement position of the partition wall 5 in a predetermined relationship with respect to the convex portion 2, which will be described later. The substrate holding device 101 of this embodiment will be described in detail below with reference to FIGS. 3 to 5. FIG.

FIG. 3 is a diagram illustrating the substrate holding device 101 of this embodiment. FIG. 3A is a plan view of the substrate holding device 101 viewed from the +Z direction. FIG. 3B is a partial cross-sectional view of the substrate holding device 101 of FIG. 3A. Hereinafter, the substrate holding device 101 of this embodiment will be described in detail with reference to FIG. The substrate holding device 101 of this embodiment can include the chuck 1, a suction unit (not shown), and a control unit.

The chuck 1 is configured in a circular shape with a diameter smaller than that of the substrate 110, and can include a plurality of pin-shaped protrusions 2, partition walls (first partition walls) 5, and suction ports (first suction ports) 6. . Also, the chuck 1 is arranged on the substrate stage 102 .

The protrusions 2 are a plurality of pin-shaped protrusions (pins) arranged on the bottom of the chuck 1 . is abutted. The protrusions 2 are arranged on the bottom of the chuck 1 in a grid pattern at a predetermined distance L (mm). The diameter of the projection 2 varies depending on the specifications of the chuck 1, but the general diameter is about φ0.2 mm. In addition, the projections 2 may be arranged concentrically in addition to the lattice arrangement, or may be arranged in an angular arrangement, for example, in a 60-degree staggered lattice arrangement. Moreover, it can be a random sequence, or a combination of these sequences.

The convex portion 2 includes a plurality of pin-shaped convex portions (outer circumferential side convex portion, first convex portion) 3, a plurality of pin-shaped convex portions (inner circumferential side convex portion, second convex portion) 4, and an outer circumferential side convex portion. A plurality of pin-shaped protrusions (third protrusions) different from the portion 3 and the inner circumference side protrusion 4 may be included. The outer convex portion 3 is arranged outside the partition wall 5 so as to abut on the rear surface of the substrate 110 in the outer peripheral direction. The outer peripheral side protrusions 3 are protrusions arranged in plurality on the outer periphery having the same radius as the substrate 110 . The outer peripheral side protrusion 3 illustrated in FIG. 3 is arranged on the outermost side (outermost periphery) of the chuck 1 . The inner peripheral convex portion 4 is arranged inside the partition wall 5 so as to abut against the back surface of the substrate 110 in the inner peripheral direction. A plurality of inner peripheral side protrusions 4 are arranged on the inner periphery having the same radius as the substrate 110 . The inner peripheral convex portion 4 illustrated in FIG. 3 is arranged next to the outer peripheral convex portion 3 arranged at the bottom on the outermost side with the partition wall 5 interposed therebetween. In this embodiment, the plurality of protrusions 2 except for the third protrusion are divided into an outer periphery side protrusion 3 arranged outside the partition wall 5 and an outer periphery side protrusion inside the partition wall 5 with the partition wall 5 interposed therebetween. 3 and the inner peripheral side protrusions 4 arranged at positions adjacent to each other are formed into one group.

At least one partition wall 5 is arranged in an annular shape at the bottom of the chuck 1 so as to surround a part of the plurality of protrusions 2 . The partition wall 5 of this embodiment is arranged at a position close to the inner peripheral convex portion 4 adjacent to the outer peripheral convex portion 3 with the partition wall 5 interposed therebetween. The partition wall 5 is formed lower than the plurality of inner peripheral convex portions 4 . The height of the plurality of inner peripheral side protrusions 4 is, for example, an average height. Moreover, the height of the partition wall 5 may be lower than the height of a specific inner peripheral side protrusion 4 , for example, the inner peripheral side protrusion 4 having the lowest height among the plurality of inner peripheral side protrusions 4 . Moreover, the height of the partition wall 5 may be formed lower than the upper surfaces of the plurality of protrusions 2 by about 1 to 2 μm. Even if the gap is about 1 to 2 μm low, the space (region) between the back surface of the substrate 110 and the chuck 1 is sucked by a suction unit described later, and the vacuum pressure when the substrate 110 is sucked and held by a gap of about 1 to 2 μm. is slight and does not pose a problem. In addition, even if foreign matter such as dust or particles having a diameter smaller than the difference of about 1 to 2 μm adheres to the partition wall 5, the probability that the adhered foreign matter contacts the back surface of the substrate 110 is very low. Even if the height is formed to be about 1 to 2 μm lower than the upper surfaces of the plurality of projections 2, no problem arises.

The suction port 6 is a through hole formed in the chuck 1, and in this embodiment, it serves as a suction port when a suction portion (to be described later) sucks (exhausts) the space between the back surface of the substrate 110 and the chuck 1. Function. Although only one suction port 6 is provided in FIG. 3 , the chuck 1 may be provided with one or more suction ports 6 .

The suction unit is a vacuum source (not shown) capable of sucking the space between the back surface of the substrate 110 and the chuck 1 by vacuum suction or the like. The suction unit starts operating in response to a signal from the control unit 109, and sucks the space between the back surface of the substrate 110 and the chuck 1 through the suction port 6 and the flow path such as a pipe connected to the suction unit. , the substrate 110 can be attracted to the chuck 1 . Note that the suction unit is not limited to being arranged in the substrate holding device 101 , and may be arranged outside the substrate holding device 101 or outside the exposure apparatus 100 .

FIG. 4 is a diagram exemplifying a material mechanics model at the arrangement position of the partition wall 5 of the present embodiment. FIG. 4A is a partial cross-sectional view of the substrate holding device 101 of this embodiment. FIG. 4(B) is a diagram illustrating the material mechanics model in the partial cross-sectional view of FIG. 4(A).

In FIG. 4(B), since the slope dy/dx is 0 (zero) at the inner circumferential convex portion 4, this is approximated by a fixed end. Further, in FIG. 4B, the force due to the vacuum pressure P acts as a uniformly distributed load from the inner peripheral side protrusion 4 to the position of the partition wall 5, and the partition wall 5 is sandwiched between the inner peripheral side protrusion 4 and the adjacent inner peripheral side protrusion 4. In FIG. The force does not act up to the outer peripheral side convex portion 3 which is fitted. Therefore, since the inclination dy/dx is free at the outer peripheral convex portion 3, this is approximated by a free end. This is a so-called statically indeterminate beam as in FIG. The force Rp and the moment Mf at the fixed end can be calculated. Calculation of the distortion in the substrate holding device 101 of this embodiment using the material mechanics model in FIG. 4B will be described below.

Deflection is defined as y, and among the outer peripheral side protrusions 3 and the inner peripheral side protrusions 4 adjacent to the outer peripheral side protrusions 3 included in each of the plurality of groups with the partition wall 5 interposed therebetween, the outer peripheral side protrusions 3 are arranged at the closest position in a straight line distance. Let distance s be the distance from the inner peripheral convex portion 4 to the partition wall 5 . Next, a distance L is defined as the distance between the outer peripheral side convex portion 3 and the inner peripheral side convex portion 4 included in each of the plurality of groups. Note that the distance L may be an average value of the distances between the outer circumference-side protrusions 3 and the inner circumference-side protrusions 4 included in each of a plurality of groups. At this time, the equation of deflection can be represented by the following equation (6) using Rf, Rp, and Mf described above, where 0<x≦s.

そして、ｓ＜ｘ≦Ｌとした場合では、以下の式（７）で表すことができる。

Then, when s<x≦L, it can be represented by the following equation (7).

Next, the following equation (8) is obtained by integrating the above equation (7) and inserting the condition of dy/dx=0 at the fixed end.

次に、上記式（７）を積分して、隔壁５の配置位置での傾斜ｄｙ／ｄｘが連続という条件を入れることで、以下の式（９）が得られる。

Next, the following equation (9) is obtained by integrating the above equation (7) and adding the condition that the inclination dy/dx at the position where the partition wall 5 is arranged is continuous.

Further, when Rf and Mf are calculated from the aforementioned displacement balance, force balance and moment balance, the following equations (10) and (11) are obtained using u=s/L as a parameter.

When x=L and substituting the above equation (3) and the geometrical moment of inertia E=1/ ^12bh3 into the above equation (9), the following equation (12) is obtained.

ここで、上記式（１２）における傾斜ｄｙ／ｄｘは時計回り（ＣＷ）を＋（プラス）表記としている。なお、予め反時計回り（ＣＣＷ）を＋と定義しているなら－１を掛ければ同様となる。また、傾斜ｄｙ／ｄｘに厚さｈ／２を掛けるとディストーションｄｘが以下の式（１３）によって得られる。

Here, the slope dy/dx in the above equation (12) is indicated by + (plus) for clockwise (CW). Note that if counterclockwise (CCW) is defined as + in advance, multiplying by -1 will result in the same result. Further, by multiplying the slope dy/dx by the thickness h/2, the distortion dx is obtained by the following equation (13).

Next, based on the distortion dx obtained by the above equation (13), u is determined so as to satisfy the following equation (14).

上記式（１４）における補正係数とは実質的な距離Ｌを考慮した係数であって、凸部２の配置位置により異なるが、１に近い数字である。

The correction coefficient in the above formula (14) is a coefficient considering the substantial distance L, and is a number close to 1, although it varies depending on the arrangement position of the convex portion 2 .

Further, dz is the flatness specification, and oh is the length of the portion protruding in the outer peripheral direction (outward direction) from the outermost peripheral side protrusion 3 of the substrate 110, that is, the so-called overhang length. Then u may be determined so as to satisfy the following equation (15).

FIG. 5 is a diagram illustrating the relationship of distortion with respect to the arrangement position of the partition wall 5 of this embodiment. The graph in FIG. 5 shows the correction coefficient×(h/2)×PvL ³ /4Eh ³ (3u ⁴ −4u ³ ), which is the design value of a general chuck 1, for example, E=160 GPa, Pv=0.1 MPa. , L=2 mm, and h=0.7 mm. The horizontal axis is u with u as a variable.

According to FIG. 5, if u<0.5, the maximum distortion dx can be 0.4 nm. impact can be greatly reduced.

In addition, in reality, the plurality of protrusions 2 are arranged two-dimensionally, and the actual distance L between the protrusions 2 is substantially larger than the distance L defined above, including the decrease due to the corner contact of the protrusions described above. becomes smaller (shorter distance). Therefore, the distance L used in the calculation of the distortion is larger (longer) than the actual arrangement, so the distortion becomes large. In this embodiment, the above distance L is used for calculating the distortion in order to calculate on the safe side.

As described above, in the present embodiment, distortion is reduced by adjusting the arrangement position of the partition wall 5 so as to satisfy u<0.5 (the arrangement position of the partition wall 5 is set in a predetermined relationship with respect to the convex portion 2). can be made As a result, it is possible to provide a chuck capable of holding the substrate 110 by suction in an optimum state when carrying out processing such as pattern formation.

<Example 2>
The substrate holding apparatus 101 of this embodiment has an auxiliary partition (second partition) 7 as a partition different from the partition (first partition) 5 in the chuck 1 of Example 1, and a suction port different from the suction port 6. It is a substrate holding device further provided with a certain suction port (second suction port) 8 . That is, in the substrate holding device 101 of Example 2, the first partition is configured to be composed of adjacent double partitions. In this embodiment, the outer partition wall of the double partition walls is called an auxiliary partition wall (second partition wall). The substrate holding device 101 of this embodiment will be described below with reference to FIG. FIG. 6 is a diagram illustrating the substrate holding device 101 of this embodiment. FIG. 6A is a plan view of the substrate holding device 101 viewed from the +Z direction. FIG. 6B is a partial cross-sectional view of the substrate holding device 101 of FIG. 6A. Note that the structure of the substrate holding device 101 of the present embodiment is similar to that of the substrate holding device 101 of the first embodiment, and thus overlapping descriptions will be omitted.

The chuck 1 of this embodiment includes a plurality of pin-shaped projections 2, partition walls 5, and suction ports 6, and may further include auxiliary partition walls 7 and suction ports 8, as in the first embodiment.

The auxiliary partition wall 7 is arranged between the partition wall 5 and the outer peripheral protrusion 3 arranged next to the partition wall 5 on the outer peripheral side. That is, it is arranged at a position closer to the outer peripheral protrusion 3 than to the inner peripheral protrusion 4 . At this time, the arrangement position of the auxiliary partition wall 7 is arranged after comparing the average values of the positions of the convex portions 2 included in the plurality of groups (hereinafter referred to as the plurality of groups) shown in the first embodiment. Further, it is preferable that the auxiliary partition wall 7 is arranged at a position as close as possible to the outer peripheral side convex portion 3 arranged next to the outer peripheral side of the partition wall 5 from the center position of the distance L. In this embodiment, the auxiliary partition walls 7 are arranged so that u≈1. As for the arrangement position of the partition wall 5, it is the same as the first embodiment in that it is arranged so as to satisfy u<0.5. Further, the height of the auxiliary partition wall 7 is formed to be lower than the height of the outer peripheral side protrusions 3 included in each of the plurality of groups. The height of the outer peripheral side protrusions 3 included in each of the plurality of groups is, for example, the average height. In addition, the height of the auxiliary partition wall 7 is set lower than the height of a specific outer peripheral protrusion 3, for example, the lowest outer peripheral protrusion 3 among the outer protrusions 3 included in each of the plurality of groups. may

The suction port 8 has the same function as the suction port 6 of the first embodiment and is formed between the partition wall 5 and the auxiliary partition wall 7 . The suction port 8 is connected to the suction part by a channel such as a pipe, like the suction port 6 of the first embodiment. Further, the suction part in the substrate holding apparatus 101 of this embodiment includes a valve (switching valve) (not shown) for opening and closing the flow path for suction, and a flow path connecting the suction port 6 and the suction port 8 to the suction part. can be prepared for each. In this embodiment, the valve arranged between the suction port 6 and the suction portion is called a first valve, and the valve arranged between the suction port 8 and the suction portion is called a second valve.

In this embodiment, the substrate 110 is sucked through the suction port 6 and the suction port 8 when the chuck 1 sucks and holds the substrate 110 . The suction process for the substrate 110 in this embodiment will be described below. Note that the suction process is controlled by a control unit (not shown) of the substrate holding device 101 executing a computer program.

First, a control unit (not shown) transmits an operation command to the suction unit to start suction (exhaust). When the suction unit starts suction, the space between the back surface of the substrate 110 and the chuck 1 is sucked through the suction port 6 and the suction port 8 . As a result, the area inside the substrate 110 from the auxiliary partition wall 7 becomes a suction area, generating a greater suction force, and it becomes possible to correct the warpage of even a substrate with a large warpage. Distortion occurs when the warpage of the substrate 110 is corrected and the suction is completed.

Next, a control unit (not shown) controls the second valve to stop the suction of the area through the suction port 8 . As a result, the space between the partition wall 5 and the auxiliary partition wall 7 is opened to the atmosphere from the suction port 8 , and the suctioned region shifts to the region inside the substrate 110 from the partition wall 5 through the suction port 6 . , distortion is reduced. Various controls in these suction processes may be performed by the control unit 109 .

The substrate 110 once corrected has a low probability of returning to its original state even if the suction force on the outer peripheral side (outer peripheral portion) of the substrate 110 is stopped or the suction force is reduced. The distortion is thus kept small.

As described above, in this embodiment, in addition to the reduction in distortion, the warpage of the substrate 110 can be reduced as in the first embodiment. As a result, it is possible to provide a chuck capable of holding the substrate 110 by suction in an optimum state when carrying out processing such as pattern formation.

In addition, there are many cases where the warp returns when the suction port 8 is exposed to the atmosphere in the substrate 110 having a large warp. In this case, a negative pressure of about α×−1 atmospheric pressure (α is an integer smaller than 1) may be applied by the suction portion through the suction port 8 depending on the warpage of the substrate 110 . Alternatively, before the space between the back surface of the substrate 110 and the chuck 1 is sucked by the suction unit, the pressure from the suction port 8 is set to a negative pressure of about minus 1 atmosphere, and the pressure from the suction port 8 is set to α×minus 1 atmosphere (α is an integer smaller than 1). As a result, there is no need to switch between before and after correcting the substrate 110, and the warp is not restored.

<Example 3>
In this embodiment, a chuck capable of reducing distortion can be provided by establishing a predetermined relationship between the heights of the inner peripheral side protrusion 4 and the outer peripheral side protrusion 3, which will be described later. The substrate holding device 101 of this embodiment will be described in detail below with reference to FIGS. 7 to 9. FIG.

FIG. 7 is a diagram illustrating the substrate holding device 101 of this embodiment. FIG. 7A is a plan view of the substrate holding device 101 viewed from the +Z direction. FIG. 7B is a partial cross-sectional view of the substrate holding device 101 of FIG. 7A. Hereinafter, the substrate holding device 101 of this embodiment will be described in detail with reference to FIG. The substrate holding device 101 of this embodiment can include the chuck 1, a suction unit (not shown), and a control unit.

The chuck 1 is configured in a circular shape with a diameter smaller than that of the substrate 110, and can include a plurality of pin-shaped protrusions 2, partition walls (first partition walls) 5, and suction ports (first suction ports) 6. . Also, the chuck 1 is arranged on the substrate stage 102 .

The protrusions 2 are a plurality of pin-shaped protrusions arranged on the bottom of the chuck 1 , and when the substrate 110 is placed on the chuck 1 , the rear surface of the substrate 110 abuts on the upper surface of the protrusions 2 . be done. The protrusions 2 are arranged on the bottom of the chuck 1 in a grid pattern at a predetermined distance L (mm). The diameter of the projection 2 varies depending on the specifications of the chuck 1, but the general diameter is about φ0.2 mm. In addition, the projections 2 may be arranged concentrically in addition to the lattice arrangement, or may be arranged in an angular arrangement, for example, in a 60-degree staggered lattice arrangement. Moreover, it can be a random sequence, or a combination of these sequences.

The convex portion 2 includes a plurality of pin-shaped convex portions (outer circumferential side convex portion, first convex portion) 3, a plurality of pin-shaped convex portions (inner circumferential side convex portion, second convex portion) 4, and an outer circumferential side convex portion. A plurality of pin-shaped protrusions (third protrusions) different from the portion 3 and the inner circumference side protrusion 4 may be included. The outer convex portion 3 is arranged outside the partition wall 5 so as to abut on the rear surface of the substrate 110 in the outer peripheral direction. The outer peripheral side protrusions 3 are protrusions arranged in plurality on the outer periphery having the same radius as the substrate 110 . The outer peripheral side protrusion 3 illustrated in FIG. 7 is arranged on the outermost side (outermost periphery) of the chuck 1 . The inner peripheral convex portion 4 is arranged inside the partition wall 5 so as to abut against the back surface of the substrate 110 in the inner peripheral direction. A plurality of inner peripheral side protrusions 4 are arranged on the inner periphery having the same radius as the substrate 110 . The inner peripheral convex portion 4 illustrated in FIG. 7 is arranged next to the outer peripheral convex portion 3 arranged at the bottom on the outermost peripheral side with the partition wall 5 interposed therebetween. In this embodiment, the plurality of protrusions 2 except for the third protrusion are divided into an outer periphery side protrusion 3 arranged outside the partition wall 5 and an outer periphery side protrusion inside the partition wall 5 with the partition wall 5 interposed therebetween. 3 and the inner peripheral side protrusions 4 arranged at positions adjacent to each other are formed into one group. As will be described later, the outer peripheral protrusions 3 included in each of the plurality of groups are lower in height than the inner peripheral protrusions 4 .

At least one partition wall 5 is arranged in an annular shape at the bottom of the chuck 1 so as to surround a part of the plurality of protrusions 2 . The suction port 6 is a through hole formed in the chuck 1, and in this embodiment, it serves as a suction port when a suction portion (to be described later) sucks (exhausts) the space between the back surface of the substrate 110 and the chuck 1. Function. Although only one suction port 6 is provided in FIG. 7, the chuck 1 may be provided with one or more suction ports 6 without being limited thereto.

The suction unit is a vacuum source (not shown) capable of sucking the space between the back surface of the substrate 110 and the chuck 1 by vacuum suction or the like. The suction unit starts operating in response to a signal from the control unit 109, and sucks the space between the back surface of the substrate 110 and the chuck 1 through the suction port 6 and the flow path such as a pipe connected to the suction unit. , the substrate 110 can be attracted to the chuck 1 . Note that the suction unit is not limited to being arranged in the substrate holding device 101 , and may be arranged outside the substrate holding device 101 or outside the exposure apparatus 100 .

Next, let ho be the height of the outer peripheral side protrusions 3 included in each of the plurality of groups described above (hereinafter referred to as a plurality of groups). Assuming that the height of the inner peripheral side protrusions 4 included in each of the plurality of groups is hi, a desirable value of ho will be described below with reference to FIGS. 8 and 9. FIG. In this embodiment, ho is the average height of the outer peripheral side protrusions 3 included in each of the plurality of groups, and hi is the average height of the inner peripheral side protrusions 4 included in each of the plurality of groups. . FIG. 8 is a diagram exemplifying a material mechanics model of the cantilever when the outer peripheral side convex portion 3 of the present embodiment is eliminated. The model shown in FIG. 8 is a cantilever beam. FIG. 9 is a diagram illustrating a cross-sectional view of the chuck 1 of this embodiment.

FIG. 9 shows a model 2 min of the deflection of the substrate 110 without the outer protrusion 3 as shown in FIG. 8 and a model 2 j of the deflection of the substrate 110 when ho=hi.

Here, dy/dx is the inclination of the deflection model illustrated in FIG. and the distance between the convex portion 4 on the inner circumference side is L. Accordingly, the inclination dy/dx with respect to u=x/L can be expressed by the following equation (16), and the deflection y can be expressed by the following equation (17).

上記式（１８）は、ｈｏをｈｉ－（ＰｖＬ^４）／（Ｅｈ^３）よりも小さくすると、基板１１０の裏面が外周側凸部３の支持面に触れなくなることを示している。そのため、以下の式（１９）を満たすことで、ｈｉ＝ｈｏとしたときよりも傾斜ｄｙ／ｄｘを低減することができ、ディストーションを低減することができる。

Then, when u=1, y _max can be expressed by the following equation (18).

The above formula (18) shows that the back surface of the substrate 110 does not come into contact with the supporting surface of the outer convex portion 3 when ho is made smaller than hi−(PvL ⁴ )/(Eh ³ ). Therefore, by satisfying the following equation (19), the slope dy/dx can be reduced more than when hi=ho, and the distortion can be reduced.

Moreover, the height of the partition wall 5 is set to be lower than the inner peripheral side protrusions 4 included in each of the plurality of groups and equal to or lower than the outer peripheral side protrusions 3 included in each of the plurality of groups. This is because if the partition walls 5 are made higher than the outer peripheral protrusions 3 included in each of the plurality of groups, the partition walls 5 perform the same function as the outer peripheral protrusions 3 included in each of the plurality of groups. In addition, the partition wall 5 is arranged at a position closer to the outer peripheral side protrusions 3 included in each of the plurality of groups than to the inner peripheral side protrusions 4 included in each of the plurality of groups. At this time, the arrangement position of the partition wall 5 is arranged after comparing the average values of the positions of the convex portions included in each of the plurality of groups. Moreover, the partition walls 5 are preferably arranged as close as possible to the outer peripheral side projections 3 included in the plurality of groups. In this embodiment, the partition walls 5 are arranged so that u≈1.

As described above, in this embodiment, the distortion can be reduced by setting the height of hi with respect to ho so as to satisfy hi−ho<(PvL ⁴ )/(Eh ³ ). As a result, it is possible to provide a chuck capable of holding the substrate 110 by suction in an optimum state when carrying out processing such as pattern formation.

For example, if Pv=0.1013 MPa, L=2 mm, and E=160 GPa are substituted into the above equation (18), ymax=44.3 nm when h=0.7 mm. In this case, distortion can be reduced by designing hi-ho to be smaller than about 45 nm, for example.

<Example 4>
In the substrate holding device 101 of this embodiment, the cross-sectional areas of the outer peripheral side projections 3 included in each of the plurality of groups shown in Embodiment 3 (hereinafter referred to as a plurality of groups) are This substrate holding device has a cross-sectional area smaller than that of the circumferential convex portion 4 . Note that the structure of the substrate holding device 101 is the same as that of the substrate holding device 101 of the third embodiment, and thus redundant description will be omitted.

In this embodiment, when the cross-sectional area of the outer peripheral side protrusions 3 included in each of the plurality of groups is So, and the cross-sectional area of the inner peripheral side protrusions 4 included in each of the plurality of groups is Si, Si>So The outer peripheral side convex portion 3 and the inner peripheral side convex portion 4 are designed and processed so that As a result, the machining resistance of the outer peripheral side convex portion 3 is reduced during machining, and the machining of the convex portion is facilitated. In this embodiment, So is the average value of the cross-sectional areas of the outer peripheral side protrusions 3 included in each of the plurality of groups, and Si is the average value of the cross-sectional areas of the inner peripheral side protrusions 4 included in each of the plurality of groups. Average value.

Furthermore, the reduction in the machining resistance increases the amount of removal of the outer peripheral side protrusions 3 included in each of the plurality of groups, and as a result contributes to hi>ho. Furthermore, the rigidity in the vertical direction of the outer peripheral side protrusions 3 included in each of the plurality of groups is smaller than that of the inner peripheral side protrusions 4 included in each of the plurality of groups. As a result, the amount of compression in the vertical direction of the substrate 110 increases when the substrate 110 is sucked by the suction unit, which contributes to hi>ho. As processing of the convex portion 2, for example, processing by lapping can be considered.

As described above, in the present embodiment, the outer peripheral side protrusions 3 included in each of the plurality of groups and the inner peripheral side protrusions 4 included in each of the plurality of groups are processed so that Si>So. As a result, the machining accuracy can be improved and the machining time can be shortened. Furthermore, distortion can be reduced in the same manner as in the third embodiment, and a chuck capable of holding the substrate 110 in an optimal state by suction can be provided in carrying out processing such as pattern formation. .

<Example 5>
The substrate holding apparatus 101 of this embodiment has an auxiliary partition (second partition) 7 as a partition different from the partition (first partition) 5 in the chuck 1 of Example 3, and a suction port different from the suction port 6. It is a substrate holding device further provided with a certain suction port (second suction port) 8 . In other words, in the substrate holding device 101 of the fifth embodiment, the first partition is composed of adjacent double partitions. In this embodiment, the outer partition wall of the double partition walls is called an auxiliary partition wall (second partition wall). The substrate holding device 101 of this embodiment will be described below with reference to FIG. FIG. 10 is a diagram illustrating the substrate holding device 101 of this embodiment. FIG. 10A is a plan view of the substrate holding device 101 viewed from the +Z direction. FIG. 10B is a partial cross-sectional view of the substrate holding device 101 of FIG. 10A. The configuration of the substrate holding device 101 of this embodiment is the same as that of the substrate holding device 101 of the third embodiment, and thus redundant description will be omitted.

The chuck 1 of this embodiment includes a plurality of pin-shaped projections 2, partition walls 5, and suction ports 6, and may further include auxiliary partition walls 7 and suction ports 8, as in the third embodiment.

The auxiliary partition wall 7 is arranged between the partition wall 5 and the inner peripheral convex portion 4 arranged next to the inner peripheral side of the partition wall 5 . It is preferable that the auxiliary partition wall 7 be arranged at a position closer to the inner peripheral side convex portion 4 arranged adjacent to the inner peripheral side of the partition wall 5 than the center position of the distance L. For example, they are arranged so as to satisfy u<0.5. As for the arrangement position of the partition wall 5, it is the same as the third embodiment in that it is arranged so that u≈1.

The height of the auxiliary partition wall 7 is formed to be lower than the height of the inner peripheral side protrusions 4 included in each of the plurality of groups. The height of the inner circumference side protrusions 4 included in each of the plurality of groups is, for example, the average height. Further, the height of the auxiliary partition wall 7 is set to the height of a specific inner peripheral side convex portion 4, for example, the inner peripheral side convex portion 4 having the lowest height among the inner peripheral side convex portions 4 included in each of the plurality of groups. It can be lower. Further, the height of the auxiliary partition wall 7 may be formed lower than the upper surfaces of the plurality of protrusions 2 by about 1 to 2 μm. Even if the gap is about 1 to 2 μm low, the space (area) between the back surface of the substrate 110 and the chuck 1 is sucked by the suction unit, and the vacuum pressure drops when the substrate 110 is sucked and held. is small and does not pose a problem. Further, even if foreign matter such as dust or particles having a diameter smaller than the difference of about 1 to 2 μm adheres to the auxiliary barrier ribs 7, the probability that the adhered foreign matter contacts the rear surface of the substrate 110 is extremely low. Therefore, even if the height of the auxiliary barrier ribs 7 is formed lower than the upper surfaces of the plurality of projections 2 by about 1 to 2 μm, no problem arises.

The suction port 8 has the same function as the suction port 6 of the third embodiment, and is formed between the partition wall 5 and the auxiliary partition wall 7 . The suction port 8 is connected to the suction part by a channel such as a pipe, like the suction port 6 of the third embodiment. Further, the suction part in the substrate holding apparatus 101 of this embodiment includes a valve (switching valve) (not shown) for opening and closing the flow path for suction, and a flow path connecting the suction port 6 and the suction port 8 to the suction part. can be prepared for each. In this embodiment, the valve arranged between the suction port 6 and the suction portion is called a first valve, and the valve arranged between the suction port 8 and the suction portion is called a second valve.

In this embodiment, the substrate 110 is sucked through the suction port 6 and the suction port 8 when the chuck 1 sucks and holds the substrate 110 . The suction process for the substrate 110 in this embodiment will be described below. Note that the suction process is controlled by a control unit (not shown) of the substrate holding device 101 executing a computer program.

First, a control unit (not shown) transmits an operation command to the suction unit to start suction (exhaust). When the suction unit starts suction, the space between the back surface of the substrate 110 and the chuck 1 is sucked through the suction port 6 and the suction port 8 . As a result, the area inside the substrate 110 from the partition wall 5 becomes a suction area, generating a larger suction force, and it is possible to correct the warp even if the substrate has a large warp. Distortion occurs when the warpage of the substrate 110 is corrected and the suction is completed.

Next, a control unit (not shown) controls the second valve to stop the suction of the area through the suction port 8 . As a result, the space between the partition wall 5 and the auxiliary partition wall 7 from the suction port 8 is opened to the atmosphere, and the suctioned region shifts to the region inside the substrate 110 from the auxiliary partition wall 7 through the suction port 6. and distortion is reduced. Various controls in these suction processes may be performed by the control unit 109 .

The substrate 110 once corrected has a low probability of returning to its original state even if the suction force on the outer peripheral side (outer peripheral portion) of the substrate 110 is stopped or the suction force is reduced. The distortion is thus kept small.

As described above, in this embodiment, in addition to the reduction in distortion, the warpage of the substrate 110 can be reduced as in the third embodiment. As a result, it is possible to provide a chuck capable of holding the substrate 110 by suction in an optimum state when carrying out processing such as pattern formation.

In addition, there are many cases where the warp returns when the suction port 8 is exposed to the atmosphere in the substrate 110 having a large warp. In this case, a negative pressure of about α×−1 atmospheric pressure (α is an integer smaller than 1) may be applied by the suction portion through the suction port 8 depending on the warpage of the substrate 110 . Alternatively, before the space between the back surface of the substrate 110 and the chuck 1 is sucked by the suction unit, the pressure from the suction port 8 is set to a negative pressure of about minus 1 atmosphere, and the pressure from the suction port 8 is set to α×minus 1 atmosphere (α is an integer smaller than 1). As a result, there is no need to switch between before and after correcting the substrate 110, and the warp is not restored.

Further, for example, at least two of the substrate holding devices 101 of the above embodiments may be combined. That is, the substrate holding device 101 may use a chuck that is a combination of at least two of the chucks 1 shown in FIGS.

In each of the embodiments described above, the protrusions 2 are arranged on the bottom of the chuck 1 at a predetermined distance in a grid pattern, but the present invention is not limited to this. For example, the distance between the protrusions 2 may be arbitrarily set on each of the inner peripheral side and the outer peripheral side of the substrate 110 . Furthermore, the distance may be non-uniform instead of uniform.

Further, although the chuck 1 in each of the above embodiments is of the vacuum chucking type, it is not limited to this, and may be of the electrostatic chucking type, or may be of the vacuum chucking type and the electrostatic chucking type. It may be used in combination. In those cases, the vacuum pressure P in this embodiment may be replaced with another type of adsorption force or with a vacuum pressure added thereto.

Moreover, although the chuck 1 in each of the above embodiments uses a pin chuck, it is not limited to this, and other shapes may be used. For example, it may be a so-called ring-shaped chuck in which concentric annular concave portions that are suction grooves and concentric annular convex portions that are substrate support surfaces are alternately formed. Moreover, the partition walls are not limited to the partition walls 5 and the auxiliary partition walls 7 , and partition walls other than the partition walls 5 and the auxiliary partition walls 7 may be arranged in the chuck 1 .

<Example related to article manufacturing method>
Next, an embodiment of a device manufacturing method using the exposure apparatus 100 of each embodiment described above will be described. FIG. 11 shows a manufacturing flow of microdevices (semiconductor chips such as ICs and LSIs, liquid crystal panels, CCDs, thin film magnetic heads, micromachines, etc.). In step 1 (circuit design), device pattern design is performed.

In step 2 (mask production), a mask (mold) having the designed pattern is produced. On the other hand, in step 3 (wafer production), a wafer (substrate) is produced using a material such as silicon or glass. Step 4 (wafer process) is called a pre-process, and the mask and wafer prepared above are used to form actual circuits on the wafer by lithography.

The next step 5 (assembly) is called a post-process, and is a process of converting the wafer produced in step 4 into semiconductor chips. including. In step 6 (inspection), the semiconductor device manufactured in step 5 is inspected such as an operation confirmation test and a durability test. A semiconductor device is completed through these steps and shipped (step 7).

FIG. 12 shows a detailed flow of the above wafer process. In step 11 (oxidation), the surface of the wafer is oxidized. In step 12 (CVD), an insulating film is formed on the wafer surface. In step 13 (electrode formation), electrodes are formed on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted into the wafer. In step 15 (resist processing), a resist is applied to the wafer. In step 16 (exposure), the circuit pattern of the mask is laid out on a plurality of pattern forming regions of the wafer and printed and exposed by the above-described projection exposure apparatus. In step 17 (development), the exposed wafer is developed. In step 18 (etching), portions other than the developed resist image are scraped off. In step 19 (resist stripping), the unnecessary resist after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer.

As described above, according to the device manufacturing method using the chuck 1 of the present embodiment, the distortion and warp of the substrate are suppressed, so that the precision and yield of the device are improved. As a result, a highly integrated device, which has been difficult to manufacture in the past, can be stably manufactured at low cost.

<Other Examples>
The present invention has been described in detail above based on its preferred embodiments, but the present invention is not limited to the above embodiments, and various modifications are possible based on the gist of the present invention. They are not excluded from the scope of the invention.

Further, a computer program that implements the functions of the above embodiments may be supplied to the substrate holding apparatus 101, the substrate processing apparatus, etc. via a network or various storage media for part or all of the control in the above embodiments. . Then, the computer (or CPU, MPU, etc.) in the substrate holding device 101, the substrate processing device, or the like may read and execute the program. In that case, the program and the storage medium storing the program constitute the present invention.

101 Substrate holding device 1 Chuck 2 Projection 3 Projection (peripheral projection)
4 Convex part (inner peripheral side convex part)
5 partition wall 6 suction port

Claims (20)

A chuck for holding a substrate by suction,
a plurality of protrusions abutting on the rear surface of the substrate held by suction;
an annular partition;
including a bottom portion on which the plurality of convex portions and the partition walls are arranged;
The plurality of protrusions include a first protrusion arranged outside the partition wall, and a second protrusion arranged inside the partition wall and adjacent to the first protrusion portion with the partition wall interposed therebetween. is composed of multiple groups with
When the distance between the first convex portion and the second convex portion included in each of the plurality of groups is L, and the distance between the second convex portion and the partition wall is s,
s/L<0.5
A chuck characterized by satisfying 2. The chuck according to claim 1, wherein the partition wall has a height lower than that of the second projections included in each of the plurality of groups. 3. The chuck according to claim 1, wherein said partition is composed of two adjacent partitions. 4. The chuck according to claim 3, wherein outer partition walls of said double partition walls are lower in height than said first projections included in each of said plurality of groups. 5. The chuck according to any one of claims 1 to 4, wherein the bottom portion is provided with a first suction port for sucking the inner peripheral side of the partition wall. 5. The chuck according to claim 3, wherein the bottom portion is provided with a second suction port for sucking between the double partition walls. 7. The chuck according to claim 1, wherein said partition has a diameter smaller than that of said substrate. 8. The chuck according to any one of claims 1 to 7, further comprising a third protrusion that is different from the plurality of protrusions. When the height of the first convex portion included in each of the plurality of groups is ho, and the height of the second convex portion included in each of the plurality of groups is hi,
hi>ho
9. The chuck according to any one of claims 1 to 8, wherein: 10. The method according to claim 9, wherein the first convex portion included in each of the plurality of groups is a convex portion arranged on the outermost side of the plurality of convex portions arranged on the bottom portion. Chuck as described. 11. The chuck according to claim 9, wherein the height of the partition wall is equal to or less than the height of the second protrusions included in each of the plurality of groups. When the cross-sectional area of the first convex portion included in each of the plurality of groups is So, and the cross-sectional area of the second convex portion included in each of the plurality of groups is Si,
Si>So
12. The chuck according to any one of claims 9 to 11, wherein: 9. The partition wall is arranged at a position closer to the first protrusions included in each of the plurality of groups than to the second protrusions included in each of the plurality of groups. 13. The chuck of claim 12. 14. The chuck according to any one of claims 9 to 13, wherein said partition consists of two adjacent partitions. 15. The chuck according to claim 14, wherein outer partition walls of said double partition walls are lower in height than said second protrusions included in each of said plurality of groups. A substrate holding device for sucking and holding the substrate having the chuck according to claim 1,
When the distortion indicating the distortion of the substrate is dx, the Young's modulus of the substrate is E, the thickness of the substrate is h, and the suction pressure to the substrate is Pv,
The arrangement position of the partition is
dx<correction coefficient×(h/2)×PvL ³ /4Eh ³ (3u ⁴ −4u ³ )
A substrate holding device characterized by satisfying: When the flatness of the substrate is dz, and the dimension of the substrate projecting outward from the first convex portion arranged on the outermost periphery is oh,
The arrangement position of the partition is
dz<correction coefficient×oh×PvL ³ /4Eh ³ (3u ⁴ −4u ³ )
17. The substrate holding device according to claim 16, wherein: 18. The substrate holding apparatus according to claim 16, further comprising a valve for opening and closing a channel for sucking the inner peripheral side of said partition wall, and a controller for controlling said valve. 19. A substrate processing apparatus, wherein a pattern forming process is performed on the substrate held by suction by the substrate holding device according to claim 16. a pattern forming step of forming a pattern on a substrate using the substrate processing apparatus according to claim 19;
a processing step of processing the substrate on which the pattern is formed in the pattern forming step;
a step of manufacturing an article from the substrate processed in the processing step;
A method for manufacturing an article, comprising:

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