Method for manufacturing chuck, substrate holding device, substrate processing device and article

Abstract

This invention provides a chuck, a substrate holding device, a substrate processing device, and a method for manufacturing an article, which can reduce substrate distortion by setting the heights of the protrusions on the inner and outer peripheral sides to a predetermined relationship. The chuck is for adsorbing and holding substrates, characterized in that it includes: a plurality of protrusions abutting against the back side of the substrate being adsorbed and held; an annular partition; and a bottom having a plurality of protrusions and a partition. The plurality of protrusions are composed of multiple groups forming a group of first protrusions disposed on the outer side of the partition and second protrusions disposed on the inner side of the partition and adjacent to the first protrusions across the partition. When the height of the first protrusions in each group is set to ho, and the height of the second protrusions in each group is set to hi, hi > ho.

Description

Technical Field

[0001] This invention relates to a chuck, a substrate holding device, a substrate processing device, and a method for manufacturing articles. Background Technology

[0002] In recent years, projection exposure equipment used in semiconductor device manufacturing and other applications has undergone high-NA (nanoscale) enhancement to accommodate device miniaturization. While high NA increases resolution, it reduces the effective depth of focus. Therefore, to maintain resolution and ensure sufficient practical depth, efforts are being made to improve wafer flatness (the flatness of the substrate surface), such as reducing image plane curvature in the projection optics system, improving wafer (substrate) thickness uniformity, and increasing the planarity accuracy of the chucks used to hold and hold the wafer.

[0003] One reason for reduced flatness of the substrate surface is the inclusion of foreign objects between the chuck and the substrate. If foreign objects are included, the substrate portion deforms by bulging, resulting in poor pattern formation and reduced yield. To minimize the yield reduction caused by these foreign objects, pin-contact chucks (pin-type chucks) using pins (protrusions) are employed, significantly reducing the contact rate between the chuck and the substrate.

[0004] When this pin-type chuck is used, the substrate deforms and flexes (twirls) between the protrusions due to vacuum attraction, which causes substrate deformation and reduces the flatness of the substrate surface. Various solutions have been proposed to improve this situation.

[0005] For example, in Japanese Patent No. 4298078, an annular partition (barrier) surrounding multiple protrusions is provided on a pin chuck, and the partition is positioned between the protrusions on the outer peripheral side and the protrusions on the inner peripheral side adjacent to the protrusions on the same outer peripheral side. Moreover, the partition is positioned as close as possible to the protrusions on the outer peripheral side.

[0006] Furthermore, in Japanese Patent Application Publication No. 2001-185607, the partition wall is positioned outside the protrusion located on the outermost periphery, or between the protrusion on the outermost periphery and the protrusion on the inner periphery adjacent to the protrusion on the outermost periphery. As for the placement of this partition wall, it is positioned within a predetermined range in the peripheral direction from the center of the distance between the protrusion on the outermost periphery and the protrusion on the inner periphery adjacent to the protrusion on the outermost periphery.

[0007] When vacuum adsorption is applied to a substrate, the inner side of the partition wall is maintained at approximately a vacuum pressure and an adsorption force is generated, but the outer side of the partition wall is under atmospheric pressure and essentially no adsorption force is generated. In Japanese Patent No. 4298078 and Japanese Unexamined Patent Application Publication No. 2001-185607, the partition wall is positioned near the outer peripheral protrusion to maximize the adsorption force on the outer side of the substrate. However, because the adsorption force acts on the outer side of the substrate, there are problems such as reduced flatness of the substrate surface and increased substrate distortion. Summary of the Invention

[0008] In this invention, the objective is to provide, for example, a chuck capable of reducing substrate distortion by setting the heights of the inner peripheral protrusion and the outer peripheral protrusion to a predetermined relationship.

[0009] The chuck, as a technical solution of the present invention, is characterized by comprising: a plurality of protrusions abutting against the back side of a substrate held by adsorption; an annular partition; and a bottom having a plurality of protrusions and a partition, wherein the plurality of protrusions are composed of a plurality of groups forming a first protrusion disposed on the outer side of the partition and a second protrusion disposed on the inner side of the partition and adjacent to the first protrusion across the partition, wherein when the height of the first protrusion included in each of the plurality of groups is set as ho and the height of the second protrusion included in each of the plurality of groups is set as hi, hi > ho.

[0010] Further features of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0011] Figure 1 This is a schematic diagram illustrating the structure of the exposure apparatus of Example 1.

[0012] Figure 2 This is a diagram illustrating a material mechanics model of a beam that is fixed on one side and free on the other side under a uniformly distributed load.

[0013] Figure 3A and Figure 3B This is a diagram illustrating the substrate holding device of Embodiment 1.

[0014] Figure 4 This is a diagram illustrating the material mechanics model of a cantilever beam.

[0015] Figure 5 This is a cross-sectional view of the chuck of Example 1.

[0016] Figure 6A and Figure 6B This is a diagram illustrating the substrate holding device of Embodiment 3.

[0017] Figure 7 This is a flowchart illustrating the manufacturing process of an example device.

[0018] Figure 8 This is a flowchart illustrating the wafer fabrication process.

[0019] Figure 9A and Figure 9B This is a diagram illustrating a pin-type chuck used in a typical substrate holding device. Detailed Implementation

[0020] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, in the drawings, the same reference numerals are used to label the same components or elements, and repeated descriptions are omitted or simplified.

[0021] (Example 1)

[0022] Figure 1 This is a structural diagram that schematically illustrates the structure of the exposure apparatus 100 of Embodiment 1. The exposure apparatus 100 is an apparatus capable of curing a resist by irradiating it with light (exposure light) irradiated from a light source, and forming a pattern of a cured material with a pattern formed on an intermediate mask 104.

[0023] Furthermore, hereinafter, the direction parallel to the optical axis of the light irradiating the resist on the substrate 110 will be defined as the Z-axis direction, and the two mutually orthogonal directions in a plane perpendicular to the Z-axis direction will be defined as the X-axis direction and the Y-axis direction. The exposure apparatus 100 of Embodiment 1 can be applied to apparatuses that sequentially drive and focus multiple pattern forming areas (exposure areas) and apparatuses that sequentially expose (projection exposure apparatus, substrate processing apparatus, etc.). Hereinafter, refer to... Figure 1 The exposure apparatus 100 of Embodiment 1 will be described. Furthermore, the exposure apparatus 100 of Embodiment 1 will be described as an exposure apparatus using a step-by-step repetition method.

[0024] The substrate (wafer) 110 is a processed substrate on which a photosensitive agent (resist) is coated on its surface, which can be effectively chemically reacted by exposure to light. The substrate 110 can be made of glass, ceramic, metal, silicon, resin, etc., and, as needed, components made of a different material from the substrate 110 can be formed on its surface. In addition, the substrate 110 can also be a gallium arsenide wafer, a composite bonded wafer, a glass wafer containing quartz, a liquid crystal panel substrate, an intermediate mask, and other various substrates. Furthermore, its shape is not limited to circular; it can also be square, etc. In this case, the shape of the chuck can also be a shape that matches the shape of the substrate.

[0025] An intermediate mask (original) 104 is placed on an intermediate mask stage 103, which is configured to move within a plane orthogonal to the optical axis of the projection optical system 106 and along that optical axis. The intermediate mask 104 has a rectangular outer perimeter and a patterned portion on a surface (patterned surface) facing the substrate 110, having a three-dimensional pattern (circuit pattern, etc., an embossed pattern to be transferred onto the substrate). The intermediate mask 104 is made of a light-transmitting material, such as quartz.

[0026] The exposure apparatus 100 of Embodiment 1 also functions as a substrate processing apparatus, including a substrate holding apparatus 101, a substrate stage 102, an intermediate mask stage 103, an illumination optical system 105, a projection optical system 106, an off-axis mirror 107, a measuring unit 108, and a control unit 109.

[0027] The substrate holding device 101 includes: a chuck 1 for adsorbing and holding the substrate 110; a suction unit (not shown) serving as a vacuum source for suction (venting) the space between the back side of the substrate 110 and the chuck 1; and a control unit (not shown) for controlling the suction unit. Details of the substrate holding device 101 in Embodiment 1 will be described later.

[0028] The substrate mounting stage 102 includes: an θZ tilting mounting stage that holds the substrate 110 via a substrate holding device 101; an XY mounting stage (not shown) that supports the θZ tilting mounting stage; and a base (not shown) that supports the XY mounting stage. The substrate mounting stage 102 is driven by a drive device (not shown) such as a linear motor. The drive device can drive in six axial directions: X, Y, Z, θX, θY, and θZ, and is controlled by a control unit 109 described later. Furthermore, although the drive device can drive in six axial directions, it can also drive in any of the six axial directions.

[0029] The intermediate mask stage 103 is capable of moving, for example, in a plane perpendicular to the optical axis of the projection optical system 106 described later, i.e., in the XY plane, and can rotate in the θZ direction. The intermediate mask stage 103 is driven by a drive device (not shown) such as a linear motor, which can drive in the X, Y, and θZ axes and is controlled by the control unit 109 described later. Furthermore, although the drive device can drive in three axes, it can also drive in any number of axes from one to six.

[0030] The illumination optical system 105 includes a light source (not shown) to illuminate the intermediate mask 104 on which the circuit pattern (intermediate mask pattern) for transfer is formed. The light source included in the light source can be, for example, a laser. Usable lasers include ArF excimer lasers with a wavelength of approximately 193 nm, KrF excimer lasers with a wavelength of approximately 248 nm, and F2 excimer lasers with a wavelength of approximately 157 nm. Furthermore, the type of laser is not limited to excimer lasers; for example, YAG lasers can also be used, and the number of lasers is not limited. In addition, when a laser is used in the light source section, it is preferable to use a beam-shaping optical system that shapes the parallel beam from the laser light source into a desired beam shape, or an incoherent optical system that decoheres a coherent laser. Moreover, the light source that can be used is not limited to a laser; one or more mercury lamps, xenon lamps, etc., can also be used.

[0031] Furthermore, although not shown, the illumination optical system 105 includes lenses, mirrors, optical integrators, and apertures. Generally, the internal optical system is arranged in the order of condenser lens, compound eye, aperture stop, condenser lens, slit, and imaging optical system. In this case, the optical integrator includes an integrator formed by overlapping a compound eye lens and two sets of cylindrical lens array plates.

[0032] The projection optical system 106 images the diffracted light from the pattern on the intermediate mask 104, illuminated by exposure light from the illumination optical system 105, onto the substrate 110 at a predetermined magnification (e.g., 1 / 2, 1 / 4, or 1 / 5), causing interference. The interference image formed on the substrate 110 forms an image that is substantially identical to the intermediate mask pattern. This interference image is generally referred to as an optical image, and its shape determines the linewidth formed on the substrate 110. The projection optical system 106 can be an optical system consisting of only a number of optical elements, or an optical system consisting of a number of optical elements and at least one concave mirror (a reflection and refraction optical system). Alternatively, the projection optical system 106 can also be an optical system consisting of a number of optical elements and at least one diffractive optical element such as a Cairn hologram, or a total reflection mirror type optical system.

[0033] The off-axis lens 107 is used to position the substrate 110 and detect the positions of multiple pattern-forming areas on the substrate 110. It can detect and measure the relative positions of a reference mark disposed on the substrate stage 102 and a mark formed on the substrate 110 mounted on the substrate stage 102. The measuring unit (surface position measuring component) 108 is a measuring device capable of aligning the focal point of the projection optical system 106 with the exposure target area of ​​the substrate 110, constituting a focusing device for aligning the focal point of the projection optical system 106 with the substrate surface.

[0034] The control unit 109 includes a CPU, a memory (storage unit), etc., and is composed of at least one computer. It is connected to each component of the exposure apparatus 100 via circuitry. Furthermore, the control unit 109 uniformly controls the operation and adjustments of each component of the exposure apparatus 100 according to a program stored in the memory. Moreover, the control unit 109 can be integrally constructed with other parts of the exposure apparatus 100 (within a common housing), or it can be separately constructed from other parts of the exposure apparatus 100 (within a different housing). It can also be located in a different location from the exposure apparatus 100 and remotely controlled.

[0035] The exposure sequence of the exposure apparatus 100 will be described below. Furthermore, each action (process) shown in this exposure sequence is controlled by a computer program executed by the control unit 109. When the exposure sequence begins, the exposure apparatus 100 starts operating according to the exposure start command, starting from the state where the substrate 110 is automatically or manually set in the exposure apparatus 100.

[0036] First, the first substrate 110 to be initially exposed is moved into the substrate carrier inside the exposure apparatus 100 by a transfer mechanism (not shown) (transfer process). Next, the substrate 110 is fed into the chuck 1 mounted on the substrate stage 102 by the transfer mechanism and held by the substrate holding device 101 (substrate holding process).

[0037] Next, the off-axis mirror 107 mounted on the exposure apparatus 100 detects multiple marks formed on the substrate 110, determines the magnification, rotation, and offset of the substrate 110 in the X and Y directions, and performs position correction (position alignment process).

[0038] Next, the substrate stage 102 moves the substrate 110 so that the initially exposed pattern-forming area of ​​the substrate 110 aligns with the exposure position of the exposure apparatus 100. Then, after focusing using the measuring unit 108, light is irradiated from the light source, passing through the illumination optical system 105 and the intermediate mask (pattern-forming unit) 104, and reduced at a predetermined magnification by the projection optical system 106, irradiating the resist applied to the substrate 110. The resist applied in the predetermined pattern-forming area is exposed for a predetermined time (exposure process). The exposure time is, for example, approximately 0.2 seconds.

[0039] Next, the substrate stage 102 moves (stepwise moves) the substrate 110 to the next patterning area, and exposes it in the same manner as described above. This patterning process is repeated sequentially until exposure is complete in all patterning areas. Thus, a pattern formed on the intermediate mask 104 can be formed on a single substrate 110. Then, the substrate 110, transferred from the chuck 1 to a return transport hand (not shown), is returned to the substrate carrier within the exposure apparatus 100 (removal process). Furthermore, after the removal process of the substrate 110, it undergoes processing such as etching to remove unwanted cured material, thereby enabling the manufacture of an article.

[0040] In Embodiment 1, as described above, an exposure apparatus employing a step-by-step repetitive method is envisioned, but it is not limited to this and can also be applied to a scanning exposure apparatus. In the case of an application to a scanning exposure apparatus, the original 104 and the substrate 110 are scanned synchronously based on the exposure magnification, and are exposed during the scan.

[0041] Furthermore, the substrate holding device 101 of Embodiment 1 is not limited to use in the exposure apparatus 100. For example, the present invention can also be used to manufacture substrate processing apparatuses including imprinting apparatuses (photolithography apparatuses), liquid crystal substrate manufacturing apparatuses, magnetic head manufacturing apparatuses, semiconductor inspection apparatuses, liquid crystal substrate inspection apparatuses, magnetic head inspection apparatuses, and micromachines.

[0042] Here, when the chuck 1 holds the substrate 110, foreign objects may sometimes get trapped between the substrate 110 and the chuck 1. For example, even a foreign object of about a few μm in size can cause deformation and bulging of the trapped portion of the substrate 110, sometimes resulting in poor pattern formation. As an example, this may occur when the effective focal depth is less than 1 μm.

[0043] To avoid such foreign object-based clamping, a so-called pin-contact chuck (hereinafter referred to as chuck) is used, in which a pin-shaped protrusion is formed on the back side of the substrate 110, thereby significantly reducing the contact area with the substrate 110. The chuck used in a conventional substrate holding device will now be described with reference to FIG9.

[0044] Figure 9 is a diagram illustrating a chuck 200 used in a typical substrate holding device. Figure 9A This is a top view of the chuck at 200 degrees when viewed from the +Z direction. Figure 9B yes Figure 9A A partial cross-sectional view of the chuck 200 shown in Figure 9. The substrate holding device illustrated in Figure 9 consists of a chuck 200, a protrusion 201, a partition 204, and a suction port 205.

[0045] The protrusion 201 functions as an abutment surface that abuts against the back side of the substrate 110 (a support surface that supports the substrate after it is placed). The plurality of pin-shaped protrusions 201 include a pin-shaped protrusion (outer peripheral side protrusion) 202, a pin-shaped protrusion (inner peripheral side protrusion) 203, and a plurality of pin-shaped protrusions that are different from the outer peripheral side protrusion 202 and the inner peripheral side protrusion 203.

[0046] The partition wall 204 is arranged in a ring shape at the bottom of the chuck 200, positioned closer to the inner side of the outer peripheral protrusion 202. The height of the partition wall 204 is set to be approximately 1 to 2 μm lower than the upper surface of the outer peripheral protrusion 202. The suction port 205 is a through hole formed at the bottom of the chuck 200, connected to a flow path formed by a pipe or the like connected to a vacuum source (suction section) (not shown).

[0047] The outer peripheral protrusion 202 is positioned further outward than the partition wall 204 to abut against the back surface of the substrate 110 in the outer peripheral direction. Multiple outer peripheral protrusions 202 are arranged on the outer periphery with the same radius as the substrate 110. The outer peripheral protrusion 202 illustrated in FIG9 is a protrusion located on the outermost peripheral side (outermost periphery) of the chuck 200. The inner peripheral protrusion 203 is positioned further inward than the partition wall 204 to abut against the back surface of the substrate 110 in the inner peripheral direction. Multiple inner peripheral protrusions 203 are arranged on the inner periphery with the same radius as the substrate 110. The inner peripheral protrusion 203 illustrated in FIG9 is arranged adjacent to the outer peripheral protrusion 202 located at the bottom of the outermost peripheral side, separated by the partition wall 204. Furthermore, the multiple pin-shaped protrusions 201 of the chuck 200 are arranged in a grid pattern at predetermined distances (intervals, periods, widths). Furthermore, the outer peripheral protrusion 202 disposed on the outer side of the partition wall 204 and the inner peripheral protrusion 203 disposed on the inner side of the partition wall 204 and adjacent to the outer peripheral protrusion 202 across the partition wall 204 are each configured as a group. Moreover, the plurality of protrusions composed of the outer peripheral protrusion 202 and the inner peripheral protrusion 203 are composed of a plurality of groups including each group.

[0048] The method for adsorbing the substrate 110 using the chuck 200 configured as described above will now be described. First, the substrate 110 is placed on the protrusions 201 of the chuck 200. Thus, the back side of the substrate 110 abuts against the protrusions 201. Next, the substrate 110 is vacuum-attracted via the suction port 205 by the operation of a vacuum source (not shown), thereby supporting and holding the substrate 110 by the protrusions 201 of the chuck 200. During this time, the substrate 110 deforms and flexes between the protrusions 201 due to the vacuum suction force. Because the substrate 110 flexes, its flatness decreases, resulting in so-called wafer distortion (hereinafter referred to as distortion). Therefore, the flatness of the substrate 110 decreases.

[0049] Below, based on the model in mechanics of materials, referring to... Figure 2 ,Will Figure 9B The arrangement of the partition 204 is illustrated as an example to illustrate the flatness and amount of distortion of the substrate 110 at the outer peripheral protrusion 202. Figure 2 This is a diagram illustrating a material mechanics model of a beam that is fixed on one side and free on the other side under a uniformly distributed load. Furthermore, the material mechanics model of the flexural state of the base plate 110 in the outer peripheral region (outer periphery) of the chuck 200 is applicable to... Figure 2 The illustrated model. Additionally, as... Figure 9B As illustrated, the partition wall 204 is positioned closer to the outer peripheral protrusion 202 than the inner peripheral protrusion 203.

[0050] Let E be the Young's modulus of substrate 110, and h be the thickness of substrate 110. Next, let L be the distance between the outer peripheral protrusions 202 and the inner peripheral protrusions 203 included in the aforementioned plurality of groups. Furthermore, let w be the force per unit length, y be the deflection, and x be the radial position of the inner peripheral protrusion 203. Alternatively, the distance L can be the average value of the distances between the outer peripheral protrusions 202 and the inner peripheral protrusions 203 of each of the plurality of groups.

[0051] Mathematical Formula 1

[0052]

[0053] The inclination dy / dx in the above equation (1) is the largest when x = L, and is expressed by the following equation (2).

[0054] Mathematical formula 2

[0055]

[0056] Here, the "-" symbol in the above equation (2) indicates that the tilt angle dy / dx is the direction of rotation around the counterclockwise (CCW). If the suction pressure of the vacuum source is set as the suction pressure Pv and the depth dimension is set as b, then the force w per unit length is represented by the following equation (3).

[0057] Mathematical Formula 3

[0058] w = Pvb (3)

[0059] Here, the second moment of the section of the beam that is free on one side is E = 1 / 12bh. 3 If we substitute equation (3) into equation (2), we get equation (4).

[0060] Mathematical expression 4

[0061]

[0062] Moreover, the distortion dx is represented by the following equation (5).

[0063] Mathematical formula 5

[0064]

[0065] Furthermore, strictly speaking, the deformation of the substrate 110 when a load is applied to the substrate 110 due to attraction or the like causes the outer peripheral protrusion 202 to support the substrate 110 not at the center of the outer peripheral protrusion 202 (the support surface on the central axis of the outer peripheral protrusion), but at a corner offset from the center. Therefore, strictly speaking, in this case, the aforementioned distance L (mm) becomes the distance from the corner of the outer peripheral protrusion 202 in the direction relative to the center of the substrate 110 to the central axis of the inner peripheral protrusion 203 disposed at an adjacent position of the outer peripheral protrusion, separated by the partition wall 204. In calculating the aforementioned distortion, since the longer the distance L, the greater the distortion, the aforementioned distance L is used in the distortion calculation.

[0066] Here, as an example, in the design values ​​of a typical chuck, substituting E = 160 GPa, Pv = 0.1 MPa, L = 2 mm, and h = 0.7 mm into the above equation (5), we obtain dx = 1.29 nm. For example, if the tolerance for the overlap error relative to the ideal level is 1.5 nm, then this tolerance is only 0.29 nm. Moreover, even if the tolerance for the overlap error relative to the ideal level is, for example, 3 nm or 5 nm, a distortion of 1.29 nm has a significant impact on the process of forming patterns on the substrate. Therefore, after adsorbing and holding the substrate 110, in order to perform processes such as pattern formation, it is necessary to adsorb and hold the substrate 110 in a state of reduced distortion.

[0067] Therefore, in Embodiment 1, a chuck is provided that reduces distortion by setting the heights of the inner peripheral side protrusion 4 and the outer peripheral side protrusion 3 (described later) to a predetermined relationship. Referring now to Figure 3... Figure 4 and Figure 5 The substrate holding device 101 of Embodiment 1 is described in detail.

[0068] Figure 3 is a diagram illustrating the substrate holding device 101 of Embodiment 1. Figure 3A This is a top view of the substrate holding device 101 viewed from the +Z direction. Figure 3B yes Figure 3A A partial cross-sectional view of the substrate holding device 101. The substrate holding device 101 of Embodiment 1 will now be described in detail with reference to FIG3. The substrate holding device 101 of Embodiment 1 includes a chuck 1, a suction section (not shown), and a control section.

[0069] The chuck 1 is circular with a diameter smaller than that of the substrate 110, and includes a plurality of pin-shaped protrusions 2, a partition (first partition) 5, and a suction port (first suction port) 6. In addition, the chuck 1 is disposed on the substrate mounting stage 102.

[0070] The protrusions 2 are multiple pin-shaped protrusions disposed on the bottom of the chuck 1. When the substrate 110 is placed on the chuck 1, the back surface of the substrate 110 abuts against the upper surface of the protrusions 2. The protrusions 2 are arranged in a grid pattern at a predetermined distance L (mm) on the bottom of the chuck 1. The diameter of the protrusions 2 varies depending on the specifications of the chuck 1, but is generally about φ0.2mm. In addition to a grid pattern, the protrusions 2 can be arranged in concentric circles or at an angle, such as a grid pattern with 60-degree staggers. They can also be arranged randomly or in combination.

[0071] The protrusion 2 includes multiple pin-shaped protrusions (outer peripheral protrusions, first protrusions) 3, multiple pin-shaped protrusions (inner peripheral protrusions, second protrusions) 4, and multiple pin-shaped protrusions (third protrusions) different from the outer peripheral protrusions 3 and the inner peripheral protrusions 4. The outer peripheral protrusions 3 are positioned further outward than the partition wall 5 to abut against the back surface of the substrate 110 in the outer peripheral direction. Multiple outer peripheral protrusions 3 are arranged on the outer periphery of the substrate 110 with the same radius. The outer peripheral protrusions 3 illustrated in FIG3 are positioned on the outermost peripheral side (outermost periphery) of the chuck 1. The inner peripheral protrusions 4 are positioned further inward than the partition wall 5 to abut against the back surface of the substrate 110 in the inner peripheral direction. Multiple inner peripheral protrusions 4 are arranged on the inner periphery of the substrate 110 with the same radius. Furthermore, the inner peripheral protrusions 4 are arranged adjacent to the outer peripheral protrusions 3 positioned at the bottom of the outermost peripheral side, separated by the partition wall 5. In Embodiment 1, the plurality of protrusions 2 other than the third protrusion are composed of a plurality of groups, each consisting of an outer peripheral side protrusion 3 disposed on the outer side of the partition wall 5 and an inner peripheral side protrusion 4 disposed on the inner side of the partition wall 5 and adjacent to the outer peripheral side protrusion 3 across the partition wall 5. As will be described later, the outer peripheral side protrusion 3 included in each of these plurality of groups is formed to be lower in height than the inner peripheral side protrusion 4.

[0072] At least one partition 5 is arranged in a ring around a portion of the plurality of protrusions 2 on the bottom of the chuck 1. The suction port 6 is a through hole formed on the chuck 1. In Embodiment 1, the suction portion, described later, functions as a suction port for suction (venting) of the space between the back side of the substrate 110 and the chuck 1. Furthermore, only one suction port 6 is shown in FIG. 3, but this is not a limitation; more than one suction port 6 may be formed on the chuck 1.

[0073] The suction unit is a vacuum source (not shown) configured to attract the space between the back side of the substrate 110 and the chuck 1 using vacuum suction or the like. The suction unit starts operating based on a signal from the control unit 109, and through a flow path such as piping connected to the suction unit and the suction port 6, it attracts the space between the back side of the substrate 110 and the chuck 1, enabling the substrate 110 to be adsorbed onto the chuck 1. Furthermore, the suction unit is not limited to being disposed on the substrate holding device 101; it can also be disposed outside the substrate holding device 101 or outside the exposure apparatus 100.

[0074] Next, the height of the outer peripheral convex portion 3 included in each of the aforementioned groups (hereinafter referred to as the multiple groups) is set to ho. Furthermore, the height of the inner peripheral convex portion 4 included in each of the multiple groups is set to hi, as referred to below. Figure 4 and Figure 5 The desired value of ho is explained. Furthermore, in Embodiment 1, ho is the average height of the outer peripheral convex portion 3 included in each of the plurality of groups, and hi is the average height of the inner peripheral convex portion 4 included in each of the plurality of groups. Figure 4 This is a diagram illustrating the material mechanics model of a cantilever beam without the outer peripheral convex portion 3 of Embodiment 1. Figure 5 This is a cross-sectional view illustrating the chuck 1 of Embodiment 1.

[0075] exist Figure 5 The middle indicates that there is no such thing as Figure 4 The bending model 2min of the substrate 110 with the outer peripheral side protrusion 3 as shown, and the bending model 2j of the substrate 110 when ho = hi.

[0076] Here, Figure 5 The tilt of the illustrated flexure model is set as dy / dx, the deflection as y, the radial position of the inner peripheral convex part 4 as x, and the distance between the outer peripheral convex part 3 and the inner peripheral convex part 4 contained in each of the multiple groups as L. Thus, the tilt dy / dx with respect to u=x / L can be expressed by the following equation (6), and the deflection y can be expressed by the following equation (7).

[0077] Mathematical formula 6

[0078]

[0079]

[0080] Moreover, when u = 1, ymax can be expressed by the following equation (8).

[0081] Mathematical Formula 7

[0082]

[0083] Equation (8) above indicates that if ho is made less than hi-(PvL) 4 ) / (Eh 3 If the back surface of the substrate 110 does not contact the support surface of the outer peripheral protrusion 3, then by satisfying the following equation (9), the tilt angle dy / dx can be reduced compared to when hi = ho, and the distortion can be reduced.

[0084] Mathematical formula 8

[0085]

[0086] Furthermore, the height of the partition wall 5 is lower than the inner peripheral side protrusions 4 included in each of the plurality of groups, and is also lower than the outer peripheral side protrusions 3 included in each of the plurality of groups. This is because if the partition wall 5 is higher than the outer peripheral side protrusions 3 included in each of the plurality of groups, the partition wall 5 will perform the same function as the outer peripheral side protrusions 3 included in each of the plurality of groups. In addition, the partition wall 5 is positioned 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. The position of the partition wall 5 is configured based on a comparison of the average positions of the protrusions included in each of the plurality of groups. Furthermore, the partition wall 5 is preferably positioned as close as possible to the outer peripheral side protrusions 3 included in the plurality of groups. In Embodiment 1, the partition wall 5 is configured with u≈1.

[0087] In Example 1, by satisfying hi-ho<(PvL) 4 ) / (Eh 3 By setting the height of hi relative to ho, distortion can be reduced. Therefore, a chuck can be provided that can optimally hold the substrate 110 while performing processes such as pattern formation.

[0088] Furthermore, for example, if Pv = 0.1013 MPa, L = 2 mm, and E = 160 GPa are substituted into equation (8) above, then ymax = 44.3 nm when h = 0.7 mm. In this case, distortion can be reduced by designing hi-ho to be, for example, smaller than 45 nm.

[0089] (Example 2)

[0090] The substrate holding device 101 of Embodiment 2 is a substrate holding device in which the cross-sectional area of ​​the outer peripheral side protrusion 3 included in each of the plurality of groups shown in Embodiment 1 (hereinafter referred to as the plurality of groups) is smaller than the cross-sectional area of ​​the inner peripheral side protrusion 4 included in each of the plurality of groups. In addition, the structure of the substrate holding device 101 is the same as that of the substrate holding device 101 of Embodiment 1, so the description of the repeated parts is omitted.

[0091] In Embodiment 2, when the cross-sectional area of ​​the outer peripheral protrusion 3 included in each of the multiple groups is set to So, and the cross-sectional area of ​​the inner peripheral protrusion 4 included in each of the multiple groups is set to Si, the outer peripheral protrusion 3 and the inner peripheral protrusion 4 are designed and processed in a manner where Si > So. As a result, the processing resistance of the outer peripheral protrusion 3 is reduced during processing, and the processing of the protrusions becomes easier. Furthermore, in Embodiment 2, So is the average cross-sectional area of ​​the outer peripheral protrusion 3 included in each of the multiple groups, and Si is the average cross-sectional area of ​​the inner peripheral protrusion 4 included in each of the multiple groups.

[0092] Furthermore, by reducing processing resistance, the amount of removal of the outer peripheral protrusions 3 included in each of the multiple groups increases, resulting in hi > ho. Moreover, the vertical rigidity of the outer peripheral protrusions 3 included in each of the multiple groups is less than the vertical rigidity of the inner peripheral protrusions 4 included in each of the multiple groups. Therefore, when attracted by the suction part, the vertical compression of the substrate 110 increases, resulting in hi > ho. Additionally, for the processing of the protrusions 2, for example, grinding-based processing is considered, but it is not limited to this; any processing method capable of achieving Si > So can be used.

[0093] In Embodiment 2, the outer peripheral protrusions 3 and inner peripheral protrusions 4 of each of the multiple groups are processed in a manner where Si > So. This improves processing accuracy and reduces processing time. Furthermore, similar to Embodiment 1, distortion is reduced. Consequently, a chuck that can optimally hold the substrate 110 while performing patterning and other processing is provided.

[0094] (Example 3)

[0095] The substrate holding device 101 of Embodiment 3 is a substrate holding device further provided with an auxiliary partition (second partition) 7, which is a partition different from the partition 5 in the chuck 1 of Embodiment 1, and a suction port (second suction port) 8, which is a suction port different from the suction port 6. That is, in Embodiment 3, the first partition is composed of adjacent double-layer partitions, and the partition on the outer side of the double-layer partition is referred to as the auxiliary partition (second partition). Hereinafter, the substrate holding device 101 of Embodiment 3 will be described with reference to FIG6. FIG6 is a diagram illustrating the substrate holding device 101 of Embodiment 3. Figure 6A This is a top view of the substrate holding device 101 viewed from the +Z direction. Figure 6B yes Figure 6A A partial cross-sectional view of the substrate holding device 101. Since the structure of the substrate holding device 101 in Embodiment 3 is the same as that in Embodiment 1, the description of the repeated parts is omitted.

[0096] The chuck 1 of Embodiment 3, like that of Embodiment 1, includes multiple pin-shaped protrusions 2, partitions 5, suction ports 6, and also includes auxiliary partitions 7 and suction ports 8.

[0097] An auxiliary partition 7 is disposed between the partition 5 and an inner peripheral protrusion 4 disposed at an adjacent position on the inner peripheral side of the partition 5. The auxiliary partition 7 is preferably disposed at a position closer to the inner peripheral protrusion 4 disposed at an adjacent position on the inner peripheral side of the partition 5 than the center position of the distance L. For example, it is configured to satisfy u < 0.5. Furthermore, the partition 5 is configured such that u ≈ 1, which is the same as in Embodiment 1.

[0098] The height of the auxiliary partition 7 is lower than the height of the inner peripheral side protrusions 4 included in each of the multiple groups. The height of the inner peripheral side protrusions 4 included in each of the multiple groups is, for example, an average height. Alternatively, it may be lower than the height of a specific inner peripheral side protrusion 4, such as the inner peripheral side protrusion 4 with the lowest height among the inner peripheral side protrusions 4 included in each of the multiple groups. In addition, the height of the auxiliary partition 7 may be formed to be about 1 to 2 μm lower than the upper surface of the multiple protrusions 2. Even if it is formed to be about 1 to 2 μm lower, the reduction in vacuum pressure when the substrate 110 is held in the space (area) between the back side of the substrate 110 and the chuck 1 by the suction part in the gap of about 1 to 2 μm is minimal and will not be a problem. In addition, even if foreign objects such as dust and particles with a diameter of about 1 to 2 μm adhere to the auxiliary partition 7, the probability of the adhered foreign objects contacting the back side of the substrate 110 is very low. Therefore, even if the height of the auxiliary partition 7 is formed to be about 1 to 2 μm lower than the upper surface of the multiple protrusions 2, it will not be a problem.

[0099] The suction port 8 has the same function as the suction port 6 in Embodiment 1 and is formed between the partition wall 5 and the auxiliary partition wall 7. Like the suction port 6 in Embodiment 1, the suction port 8 is connected to the suction section via a flow path such as a pipe. Furthermore, the suction section in the substrate holding device 101 of Embodiment 3 is equipped with valves (not shown) on the flow paths connecting the suction port 6 and the suction port 8 to the suction section, respectively, for opening and closing the flow paths used for suction. In Embodiment 3, the valve disposed between the suction port 6 and the suction section is designated as the first valve, and the valve disposed between the suction port 8 and the suction section is designated as the second valve.

[0100] In Example 3, when the substrate 110 is held in the chuck 1, it is attracted via the suction port 6 and the suction port 8. The suction process of the substrate 110 in Example 3 will be described below. Furthermore, the suction process is controlled by a computer program executed by a control unit (not shown) of the substrate holding device 101.

[0101] First, a control unit (not shown) sends an operation command to the suction unit to begin suction (exhaust). Suction begins via the suction unit, drawing in the space between the back side of the substrate 110 and the clamping plate 1 through suction ports 6 and 8. As a result, the area of ​​the substrate 110 that is closer to the inner side than the partition wall 5 becomes the suction area, generating a greater suction force, which can correct even large warps on the substrate. However, distortion occurs at the moment when the warp of the substrate 110 is corrected and suction is complete.

[0102] Next, a control unit (not shown) controls the second valve to stop suction through the area via suction port 8. As a result, the space between partition wall 5 and auxiliary partition wall 7 opens from suction port 8 to the atmosphere, and the suctioned area shifts to a region closer to the substrate 110 than the area via suction port 6, via auxiliary partition wall 7, thus reducing distortion. Furthermore, various controls during these suction processes can also be performed by the control unit 109.

[0103] Even if the attraction of the outer periphery (outer periphery) of the substrate 110 is stopped or the attraction is reduced, the probability of the substrate 110, which has been corrected, returning to its original state is low. Therefore, the distortion is kept to a minimum.

[0104] As described above, in Embodiment 3, similarly to Embodiment 1, in addition to reducing distortion, warpage of the substrate 110 can also be reduced. Therefore, a chuck that can optimally hold the substrate 110 while performing processes such as pattern formation can be provided.

[0105] Furthermore, in some substrates 110 with large warpages, the warpage often recovers when the suction port 8 is opened to the atmosphere. In this case, depending on the warpage of the substrate 110, a negative pressure of approximately α × negative 1 atmosphere (α is an integer less than 1) can be applied from the suction port 8. Alternatively, before the suction port 8 draws the space between the back side of the substrate 110 and the chuck 1, a negative pressure of approximately negative 1 atmosphere can be applied, and the pressure from the suction port 8 can be a negative pressure of α × negative 1 atmosphere (α is an integer less than 1). Therefore, it is not necessary to switch between before and after the correction of the substrate 110, and the warpage does not recover.

[0106] Furthermore, for example, the substrate holding device 101 of Embodiment 3 and Embodiment 2 can be combined, or the substrate holding device 101 of Embodiment 2 and Embodiment 3 can be combined.

[0107] Furthermore, in the above embodiments, the protrusions 2 are arranged in a grid pattern at a predetermined distance on the bottom of the chuck 1, but this is not a limitation. For example, the distance between the protrusions 2 can be arbitrarily set on the inner and outer peripheral sides of the substrate 110, respectively. Moreover, the distance between the protrusions 2 does not need to be uniform; it can also be non-uniform.

[0108] Furthermore, the chuck 1 in the above embodiments employs a vacuum adsorption method, but is not limited to this. For example, an electrostatic chuck method can also be used, or other methods such as vacuum adsorption and electrostatic chuck methods can be combined. In these cases, the vacuum pressure P in each embodiment can simply be replaced by an adsorption force of other methods, or a combination of vacuum pressure applied thereto.

[0109] Furthermore, while the chuck 1 in the above embodiments uses a pin-type chuck, it is not limited to this and may also have other shapes. For example, it may be a so-called annular chuck, which alternates between concentric annular recesses serving as adsorption grooves and concentric annular protrusions serving as substrate support surfaces. In addition, the partitions are not limited to partition 5 and auxiliary partition 7; partitions other than partition 5 and auxiliary partition 7 may also be arranged on the chuck 1.

[0110] (An example of a method for manufacturing an article)

[0111] Next, an embodiment of a method for manufacturing a device using the exposure apparatus 100 described in the above embodiments will be explained. Figure 7 This describes the manufacturing process of microdevices (ICs, LSIs, and other semiconductor chips, LCD panels, CCDs, thin-film magnetic heads, micromachines, etc.). The device pattern design is performed in step 1 (circuit design).

[0112] In step 2 (mask fabrication), a mask (mold, die) with the designed pattern is fabricated. On the other hand, in step 3 (wafer fabrication), a wafer (substrate) is fabricated using materials such as silicon and glass. Step 4 (wafer process), also known as the front-end process, uses the prepared mask and wafer to form the actual circuitry on the wafer through photolithography.

[0113] Step 5 (assembly) is called the post-processing stage, which involves using the wafer fabricated in step 4 to create a semiconductor chip. This includes assembly processes (punching, bonding), packaging processes (chip encapsulation), and other steps. In step 6 (inspection), operational verification tests and durability tests are performed on the semiconductor device fabricated in step 5. After these processes, the semiconductor device is complete and ready for shipment (step 7).

[0114] Figure 8This describes the detailed process flow of the above wafer fabrication 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 treatment), a resist is applied to the wafer. In step 16 (exposure), the circuit pattern of the mask is arranged on multiple patterning areas of the wafer using the projection exposure apparatus described above, and then exposed. In step 17 (development), the exposed wafer is developed. In step 18 (etching), the portion outside the developed resist image is removed. In step 19 (resist stripping), the unwanted resist after etching is removed. By repeating these steps, a multilayer circuit pattern is formed on the wafer.

[0115] Thus, according to the manufacturing method of the device using chuck 1 in this embodiment, since the twisting and warping of the substrate are suppressed, the accuracy and yield of the device are improved, and therefore it is possible to stably manufacture highly integrated devices that were previously difficult to manufacture at low cost.

[0116] The present invention has been described in detail above based on preferred embodiments, but the present invention is not limited to the above embodiments. Various modifications can be made based on the spirit of the present invention, and these modifications are not excluded from the scope of the present invention.

[0117] Alternatively, a computer program that implements some or all of the functions of the above embodiments can be supplied to the substrate holding device 101, substrate processing device, etc., via a network or various storage media. Furthermore, the program can be read and executed by a computer (or CPU, MPU, etc.) in the substrate holding device 101 or substrate processing device. In this case, the program and the storage medium storing the program constitute the present invention.

[0118] Although the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be given the broadest interpretation to cover all such modifications and equivalent structures and functions.

[0119] This application claims priority to Japanese Patent Application No. 2021-032667, filed on March 2, 2021, the entire contents of which are incorporated herein by reference.

Claims

1. A chuck for adsorbing and holding a substrate, characterized in that, The chuck includes: Multiple protrusions abut against the back side of the substrate that is adsorbed and held; Annular septa; and The bottom is provided with the plurality of protrusions and the partition wall. The plurality of protrusions are composed of a group of first protrusions disposed on the outer side of the partition wall and second protrusions disposed on the inner side of the partition wall and adjacent to the first protrusions across the partition wall. When the height of the first protrusion in each of the plurality of groups is set to ho, and the height of the second protrusion in each of the plurality of groups is set to hi, hi > ho is satisfied. The height of the partition is below the height of the first protrusion included in each of the plurality of groups.

2. The chuck according to claim 1, characterized in that, The first protrusion included in each of the plurality of groups is the protrusion disposed on the outermost peripheral side among the plurality of protrusions disposed on the bottom.

3. The chuck according to claim 1, characterized in that, The height of the partition is lower than the height of the first protrusion contained in each of the plurality of groups.

4. The chuck according to claim 1, characterized in that, The height of the partition is below the height of the second protrusion included in each of the plurality of groups.

5. The chuck according to claim 1, characterized in that, When the cross-sectional area of ​​the first protrusion included in each of the plurality of groups is set to So, and the cross-sectional area of ​​the second protrusion included in each of the plurality of groups is set to Si, The condition Si > So is satisfied.

6. The chuck according to claim 1, characterized in that, The partition is positioned closer to the first protrusion of each of the plurality of groups than to the second protrusion of each of the plurality of groups.

7. The chuck according to claim 1, characterized in that, The partition is composed of adjacent double-layer partitions.

8. The chuck according to claim 7, characterized in that, The height of the outer partition wall within the double-layer partition wall is lower than the height of the second protrusion included in each of the plurality of groups.

9. The chuck according to claim 4, characterized in that, The bottom has a first suction port for attracting the inner circumferential side of the partition.

10. The chuck according to claim 7, characterized in that, The bottom has a second suction port for attracting the area between the double-layered partitions.

11. The chuck according to claim 1, characterized in that, The diameter of the partition is smaller than the diameter of the substrate.

12. The chuck according to claim 1, characterized in that, The chuck has a third protrusion that is different from the plurality of protrusions.

13. A substrate holding device, characterized in that, The substrate holding device has a chuck as described in claim 1, which is used to attract the inner periphery of the partition wall to hold the substrate.

14. The substrate holding device according to claim 13, characterized in that, The substrate holding device includes: a valve for opening and closing a flow path for attracting the inner periphery of the partition wall; and a control unit for controlling the valve.

15. The substrate holding device according to claim 13, characterized in that, When the height of the first protrusion in each of the plurality of groups is set to ho, the height of the second protrusion in each of the plurality of groups is set to hi, the Young's modulus of the substrate is set to E, the thickness of the substrate is set to h, the attractive force on the substrate is set to Pv, and the distance between the first protrusion and the second protrusion in each of the plurality of groups is set to L, Satisfying hi-ho < (PvL) 4 ) / (Eh 3 ).

16. A substrate processing apparatus, characterized in that, The substrate processing apparatus has a pattern forming section that forms a pattern on the substrate held by the substrate holding device according to claim 13.

17. A method for manufacturing an article, characterized in that, The method of manufacturing this item includes: The pattern forming process involves processing the substrate using the substrate processing apparatus according to claim 16 to form a pattern on the substrate. The processing steps include processing the substrate after the pattern has been formed through the pattern forming process; and... The process of manufacturing articles from the substrate processed through the aforementioned processing steps.

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