Rotary holding device

Abstract

To provide a rotary holding device capable of performing uniform processing over the entire substrate suctioned and held by a suction holding part.SOLUTION: A rotary holding device 10 includes: A suction holding part 11 having an upper surface 11u that suctions and holds a central part of a lower surface of a substrate W; and a rotary driving part 13 that rotates the suction holding part 11 in a circumference of a vertical axis. The rotary holding device 10 includes a plurality of gas nozzles 17 as a temperature adjustment part. The plurality of gas nozzles 17 are arranged in a circumferential direction of the substrate W suctioned and held by the suction holding part 11. Each of the plurality of gas nozzles 17 is disposed such that a gas ejection part extends in a diameter direction of the substrate W suctioned and held by the suction holding part 11. A gas supply system 18 is connected to a gas introduction part of each gas nozzle 17.SELECTED DRAWING: Figure 22

Description

Technical Field

[0001] The present invention relates to a rotary holding device that rotates while adsorbing and holding the central portion of the lower surface of a substrate.

Background Art

[0002] A substrate processing apparatus is used to perform various processes on substrates such as semiconductor substrates, FPD (Flat Panel Display) substrates for liquid crystal display devices or organic EL (Electro Luminescence) display devices, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, photomask substrates, ceramic substrates, or solar cell substrates.

[0003] As an example of a substrate processing apparatus, there is a coating apparatus that forms a resist film on the surface of a substrate. In the coating processing apparatus, various processing liquids such as a cleaning liquid or a resist liquid are supplied to the rotating substrate. This coating processing apparatus includes a spin chuck that rotates while holding a single substrate in a horizontal posture.

[0004] As an example of such a spin chuck, Patent Document 1 describes a spin chuck that adsorbs and holds the central portion of the back surface of a substrate. The spin chuck has a circular upper surface. On the upper surface of the spin chuck, a convex portion is formed at the peripheral edge, and a plurality of minute protrusions are formed inside the convex portion. Further, a plurality of suction holes are formed on the upper surface of the spin chuck.

[0005] With the substrate placed on the spin chuck, the atmosphere in the space formed between the upper surface of the spin chuck and the substrate and inside the annular convex portion is sucked, whereby the substrate is adsorbed and held on the spin chuck.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In recent years, the thinning of substrates according to the applications of semiconductor products has been promoted. Such thinning of the substrate reduces the rigidity of the substrate. Therefore, depending on the configuration of the spin chuck, when the substrate rotates, the portion of the substrate that is not adsorbed by the spin chuck may deform, resulting in an unstable holding state of the substrate. Alternatively, a temperature difference may occur between the portion of the substrate that is not adsorbed by the spin chuck and the portion that is adsorbed by the spin chuck during rotation of the substrate.

[0008] The instability of the holding state of the rotating substrate and the temperature difference generated between multiple portions of the rotating substrate as described above reduce the uniformity of the processing across the entire substrate.

[0009] An object of the present invention is to provide a rotation holding device that enables uniform processing across the entire substrate adsorbed and held by an adsorption holding portion.

Means for Solving the Problems

[0010] (1) The rotation holding device according to the present invention is a rotation holding device that rotates while adsorbing and holding the central portion of the lower surface of the substrate, and includes an adsorption holding portion that adsorbs and holds the central portion of the lower surface of the substrate, a rotation driving portion that rotates the adsorption holding portion around a rotation axis extending in the vertical direction, and a temperature adjusting portion that adjusts the temperature of at least a part of the peripheral edge portion of the lower surface of the substrate that is not adsorbed and held by the adsorption holding portion in a state where the adsorption holding portion adsorbs and holds the substrate.

[0011] In the rotation holding device, the central portion of the lower surface of the substrate is adsorbed and held by the adsorption holding portion. The adsorption holding portion that adsorbs and holds the substrate is rotated by the rotation driving portion. According to the temperature adjusting portion, when processing is performed on the substrate rotated by the rotation holding device, it is possible to suppress the occurrence of a temperature difference between multiple portions of the substrate. Therefore, uniform processing across the entire substrate becomes possible.

[0012] (2) The temperature adjustment unit may include a gas supply unit that supplies a temperature adjustment gas to at least a part of the lower surface peripheral portion. In this case, the temperature of the portion of the substrate including the lower surface peripheral portion is adjusted by the temperature adjustment gas. Thereby, since it is not necessary to provide a heat generating device such as a heater or an ultraviolet lamp in the rotation holding device, the processing environment of the substrate is not affected by excessive heat.

[0013] (3) The temperature adjustment gas may be a gas adjusted so that the temperature of the portion of the substrate including the lower surface peripheral portion is made to coincide with or approach the temperature of the portion of the substrate including the lower surface central portion by being supplied to at least a part of the lower surface peripheral portion.

[0014] In this case, by supplying the temperature adjustment gas to at least a part of the lower surface peripheral portion of the substrate, the generation of a temperature difference between a plurality of portions of the substrate is suppressed. Therefore, more uniform processing over the entire substrate becomes possible.

[0015] (4) The gas supply unit may supply the temperature adjustment gas to a region including the inner edge of the lower surface peripheral portion of the substrate among the lower surface peripheral portion of the substrate. In this case, it is possible to prevent the temperature of the inner edge of the lower surface peripheral portion and the portion of the substrate located in the vicinity thereof from decreasing. Thereby, uniform processing can be performed on the entire lower surface of the substrate.

[0016] (5) The gas supply unit may be configured to be able to simultaneously inject the temperature adjustment gas to a plurality of different portions in the lower surface peripheral portion of the substrate in a state where the adsorption holding unit adsorbs and holds the substrate.

[0017] In this case, the temperature adjustment gas can be simultaneously injected into a plurality of portions of the lower surface peripheral portion of the substrate. Therefore, without excessively increasing the flow rate of the temperature adjustment gas supplied to each of the plurality of portions, the temperature of the portion of the substrate including the lower surface peripheral portion can be made to coincide with or approach the temperature of the portion of the substrate including the lower surface central portion. As a result, deformation and breakage of the substrate due to the supply of the temperature adjustment gas at an excessive flow rate to the lower surface peripheral portion of the substrate are prevented.

[0018] (6) The gas supply unit includes a first annular facing surface that surrounds the adsorption holding unit and faces at least a part of the peripheral edge portion of the lower surface of the substrate in a state where the adsorption holding unit adsorbs and holds the substrate. In the first annular facing surface, a plurality of gas injection ports for simultaneously injecting a temperature adjustment gas to at least a part of the peripheral edge portion of the lower surface of the substrate may be formed in a state where the adsorption holding unit adsorbs and holds the substrate. In this case, the temperature adjustment gas is supplied from the plurality of gas injection ports formed in the first annular facing surface to at least a part of the peripheral edge portion of the lower surface of the substrate.

[0019] (7) At least a part of the plurality of gas injection ports may be dispersedly arranged in a rotational direction around the rotation axis. In this case, the temperature adjustment gas is simultaneously supplied to a plurality of portions in the circumferential direction of the substrate among the peripheral edge portion of the lower surface of the substrate.

[0020] (8) The first annular facing surface faces a first annular portion of the peripheral edge portion of the lower surface of the substrate in a state where the adsorption holding unit adsorbs and holds the substrate. The gas supply unit is provided so as to surround the first annular facing surface and face a second annular portion that surrounds the first annular portion of the peripheral edge portion of the lower surface of the substrate in a state where the adsorption holding unit adsorbs and holds the substrate. The gas supply unit may further include a second annular facing surface that guides the temperature adjustment gas injected from the plurality of gas injection ports of the first annular facing surface to the outer peripheral end portion of the substrate.

[0021] In this case, in the space between the peripheral edge portion of the lower surface of the substrate and the first and second annular facing surfaces, a flow of the temperature adjustment gas from the adsorption holding unit toward the outer peripheral end portion of the substrate is generated. Thereby, when a processing liquid is supplied to the upper surface of the substrate adsorbed and held by the adsorption holding unit, it is possible to prevent the processing liquid supplied to the upper surface of the substrate from flowing around to the lower surface through the outer peripheral end portion.

[0022] (9) The adsorption holding unit has an upper surface that adsorbs and holds the central portion of the lower surface of the substrate. The upper surface has a peripheral edge portion region along the outer edge and a central portion region surrounded by the peripheral edge portion region. A plurality of first suction holes are provided in the peripheral edge portion region, and a plurality of second suction holes are provided in the central portion region. The surface density of the plurality of first suction holes in the peripheral edge portion region may be larger than the surface density of the plurality of second suction holes in the central portion region.

[0023] According to the configuration of the adsorption and holding part described above, when the substrate adsorbed and held by the adsorption and holding part rotates, the portion of the substrate located in the peripheral region is suppressed from lifting off the upper surface of the adsorption and holding part, and the holding state of the substrate is stabilized. Therefore, it is possible to prevent variations in the processing of the substrate at a plurality of portions on the substrate due to a part of the substrate lifting off the upper surface of the adsorption and holding part. As a result, uniform processing over the entire substrate becomes possible.

[0024] The substrate processing apparatus may include the above-described rotation holding apparatus. According to the above-described rotation holding apparatus, it is possible to suppress the occurrence of a temperature difference between a plurality of portions of the rotating substrate. Therefore, it is possible to perform uniform processing using a processing liquid on the entire substrate rotated by the rotation holding apparatus.

Advantages of the Invention

[0025] According to the present invention, it becomes possible to perform uniform processing on the entire substrate adsorbed and held by the adsorption and holding part.

Brief Description of the Drawings

[0026]

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Embodiments for Carrying Out the Invention

[0027] Hereinafter, a rotation holding device and a substrate processing device according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the substrate refers to a substrate for a flat panel display (FPD) such as a liquid crystal display device or an organic EL (Electro Luminescence) display device, a semiconductor substrate, a substrate for an optical disk, a substrate for a magnetic disk, a substrate for a magneto-optical disk, a substrate for a photomask, a ceramic substrate, or a substrate for a solar cell. In the following description, as an example of the substrate processing device, a coating device that applies a resist solution to a substrate will be described. Further, in the following description, the substrate to be processed has an outer peripheral end portion that is at least partially circular. A notch or an orientation flat for identifying the position and orientation of the substrate is locally formed at the outer peripheral end portion of the substrate. Further, an outer support ring is formed over the entire circumference at the outer peripheral end portion of the substrate. In the substrate, the thickness of the region inside the rim portion (substrate thickness) is 200 μm or less and is smaller than the thickness of the rim portion.

[0028] 1. First Embodiment [1] Overall Configuration of Coating Device FIG. 1 is a schematic cross-sectional view of a coating device according to the first embodiment, and FIG. 2 is a schematic plan view of the coating device 1 of FIG. 1. In FIG. 2, illustration of some of the components of the coating device 1 shown in FIG. 1 is omitted. Further, the substrate W shown in FIG. 1 is indicated by a dashed line.

[0029] As shown in FIG. 1, the coating device 1 according to the present embodiment mainly includes a rotation holding device 10 and a processing liquid supply device 20. The rotation holding device 10 is configured to be able to rotate while sucking and holding the central portion of the lower surface of the substrate W.

[0030] The processing liquid supply device 20 includes a liquid nozzle 21 and a processing liquid supply system 22. The processing liquid supply system 22 supplies a resist liquid to the liquid nozzle 21. The liquid nozzle 21 discharges the supplied resist liquid onto the upper surface of a substrate W that is rotationally held by the processing liquid supply device 20. Thereby, a resist film is formed on the upper surface of the unprocessed substrate W (coating process). The substrate W on which the resist film is formed is carried out from the coating device 1 and is subjected to an exposure process in an exposure device (not shown).

[0031] A specific configuration of the rotation holding device 10 will be described. The rotation holding device 10 includes a suction holding part 11, a rotation shaft 12, a rotation drive part 13, a suction device 14, a cup 15, a drain guide pipe 16, a gas nozzle 17, and a gas supply system 18.

[0032] The suction holding part 11 has a flat upper surface 11u that suction holds the central part of the lower surface of the substrate W, and is attached to the upper end part of a rotation shaft 12 that extends in the vertical direction. A large number of suction holes vh1, vh2 (see FIG. 4 described later) are formed in the upper surface 11u of the suction holding part 11. The rotation drive part 13 rotates the rotation shaft 12 around its axis.

[0033] As shown by the thick dotted line in FIG. 1, an intake path vp is formed inside the suction holding part 11 and the rotation shaft 12. The intake path vp is connected to the suction device 14. The suction device 14 includes a suction mechanism such as an aspirator, etc., sucks the atmosphere of the space on the upper surface 11u of the suction holding part 11 through the intake path vp, and discharges it to the outside of the coating device 1.

[0034] As shown in FIG. 2, the cup 15 is provided so as to surround the periphery of the suction holding part 11 in a plan view, and is configured to be movable to a plurality of positions in the vertical direction by an elevating mechanism (not shown). As shown in FIG. 1, the cup 15 includes a bottom part 15x and an outer peripheral wall part 15y. The bottom part 15x has a substantially annular shape. The inner peripheral end part of the bottom part 15x is bent upward by a predetermined height. The outer peripheral wall part 15y extends upward by a predetermined height from the outer peripheral end part of the bottom part 15x, is bent, and is further formed to extend obliquely upward toward the suction holding part 11.

[0035] A drain 15d is formed in the bottom 15x of the cup 15. A drain guide pipe 16 is attached to the portion of the bottom 15x where the drain 15d is formed. The lower end of the drain guide pipe 16 is connected to a drainage system (not shown).

[0036] As shown in FIG. 2, a gas nozzle 17 is provided at a position between the inner peripheral end of the outer peripheral wall portion 15y of the cup 15 and the outer peripheral end of the suction holding portion 11 in a plan view. FIG. 3 is an external perspective view of the gas nozzle 17. As shown in FIG. 3, the gas nozzle 17 has a substantially L shape and includes a gas introduction portion 17a and a gas ejection portion 17b. The gas introduction portion 17a has a cylindrical shape and is provided at the lower portion of the gas nozzle 17. The gas ejection portion 17b is a slit-shaped opening and is formed at the upper end of the gas nozzle 17. Inside the gas nozzle 17, a gas supply path 17v connecting the gas introduction portion 17a to the gas ejection portion 17b is formed.

[0037] As shown in FIGS. 1 and 2, the gas nozzle 17 is arranged such that the gas ejection portion 17b faces the lower surface of the substrate W adsorbed and held by the adsorption holding portion 11 at a position near the outer peripheral end of the adsorption holding portion 11. The coating apparatus 1 has a configuration in which a rotation holding apparatus 10 and a processing liquid supply apparatus 20 are housed in a housing (not shown). The gas nozzle 17 is fixed to, for example, the housing of the coating apparatus 1. In a state where the substrate W is adsorbed and held by the adsorption holding portion 11, the distance between the lower surface of the substrate W and the upper end (gas ejection portion 17b) of the gas nozzle 17 is set to about 0.5 mm to 10 mm, for example. Further, the gas nozzle 17 is arranged such that the slit-shaped opening of the gas ejection portion 17b extends in the diameter direction of the substrate W adsorbed and held by the adsorption holding portion 11. Furthermore, a gas supply system 18 is connected to the gas introduction portion 17a (FIG. 3) of the gas nozzle 17.

[0038] In the coating apparatus 1 having the above-described configuration, during the coating process of the substrate W, the substrate W is held in a horizontal posture by the suction holding unit 11. Further, the cup 15 is positioned in the vertical direction such that the inner peripheral surface of the outer peripheral wall portion 15y faces the outer peripheral end portion of the substrate W in the horizontal direction. In this state, when the rotation driving unit 13 operates, the substrate W is rotated.

[0039] Subsequently, the liquid nozzle 21 is moved above the substrate W by a nozzle moving device (not shown). In this state, a resist liquid is discharged from the moved liquid nozzle 21 onto the substrate W. Thereby, the resist liquid is applied onto the rotating substrate W. The resist liquid scattered outward from the rotating substrate W is received by the inner peripheral surface of the outer peripheral wall portion 15y of the cup 15. The received resist liquid is collected at the bottom portion 15x of the cup 15 and led to a drainage system (not shown) through the drain 15d and the drain guide pipe 16.

[0040] In the coating apparatus 1, the temperature of the substrate W (hereinafter referred to as the processing temperature) to be maintained during the coating process is predetermined. The processing temperature is, for example, 23°C. However, as will be described later, when the substrate W adsorbed and held by the suction holding unit 11 rotates, the temperature of the portion of the substrate W that is not in contact with the suction holding unit 11 may be lower than the temperature of the other portion that is in contact with the suction holding unit 11. Therefore, even when the temperature of the portion of the substrate W in contact with the suction holding unit 11 is maintained at the processing temperature, the temperature of the portion of the substrate W not in contact with the suction holding unit 11 may be maintained at a temperature lower than the processing temperature.

[0041] Therefore, the gas supply system 18 supplies a gas (hereinafter referred to as the temperature-adjusting gas) having a temperature higher than, for example, the processing temperature to the gas nozzle 17 during the coating process. In this case, the temperature-adjusting gas supplied to the gas nozzle 17 is jetted from the gas jetting portion 17b of the gas nozzle 17 onto a part of the lower surface of the substrate W being processed. Thereby, the temperature of the portion of the substrate W that is not in contact with the suction holding unit 11 becomes equal to or approaches the temperature (for example, the processing temperature) of the other portion of the substrate W that is in contact with the suction holding unit 11.

[0042] In addition, during the coating process of the substrate W, the flow rate of the temperature-adjusted gas jetted from the gas jetting portion 17b to the substrate W is adjusted to such an extent that the substrate W adsorbed and held by the adsorption holding portion 11 is not peeled off from the upper surface 11u of the adsorption holding portion 11. As the temperature-adjusted gas supplied to the gas nozzle 17, heated nitrogen gas is used. Alternatively, heated dry air can also be used as the temperature-adjusted gas supplied to the gas nozzle 17.

[0043] Incidentally, in the coating apparatus 1 according to the present embodiment, the adsorption holding portion 11 has a configuration for stabilizing the holding state of the substrate W during the coating process. Hereinafter, a specific configuration example of the adsorption holding portion 11 will be described.

[0044] [2] Specific configuration example of the adsorption holding portion 11 (1) First configuration example FIG. 4 is an exploded perspective view of the adsorption holding portion 11 according to the first configuration example. FIG. 5 is a plan view of the adsorption holding portion 11 of FIG. 4 according to the first configuration example. FIG. 6 is a longitudinal sectional view taken along line A-A of the adsorption holding portion 11 of FIG. 5. In FIG. 5, in addition to the overall plan view of the adsorption holding portion 11, an enlarged plan view of a part of the outer peripheral end portion of the adsorption holding portion 11 and its peripheral portion is shown in the blowout.

[0045] As shown in FIG. 4, the adsorption holding portion 11 according to the first configuration example is mainly composed of a disk-shaped member 40 and an annular member 50. The disk-shaped member 40 and the annular member 50 are made of, for example, a resin excellent in corrosion resistance. The disk-shaped member 40 has an adsorption portion 41, an intake path forming portion 42, and a support portion 43 arranged from top to bottom. The adsorption portion 41 includes the upper surface 11u of the adsorption holding portion 11 and is configured to be able to adsorb and hold the central portion of the lower surface of the substrate W.

[0046] The diameter of the upper surface 11u is within a range of 15% of the diameter of the substrate W with the radius of the substrate W as the central value. When the diameter of the substrate W is 300 mm, the diameter of the upper surface 11u is preferably within a range of 130 mm or more and 170 mm or less. When the diameter of the upper surface 11u is within a range of 15% of the diameter of the substrate W with the radius of the substrate W as the central value, compared with the case where the diameter of the upper surface 11u is smaller than that range, the central portion of the lower surface of the substrate W is adsorbed over a wide range, and the holding state becomes stable. Further, compared with the case where the diameter of the upper surface 11u is larger than the above range, it becomes easier to fabricate the adsorption holding portion 11 having a flat upper surface 11u over the whole.

[0047] As shown in FIG. 6, in the disk-shaped member 40, the diameters of the intake path forming portion 42 and the support portion 43 are smaller than the diameter of the adsorption portion 41. Thereby, the outer peripheral end portion of the adsorption portion 41 and its peripheral portion project in a flange shape outward (sideward) of the disk-shaped member 40 at a position above the intake path forming portion 42 and the support portion 43.

[0048] In the following description, a virtual axis extending in the vertical direction through the center of the adsorption holding portion 11 is called a central axis 11c. In the intake path forming portion 42, a plurality of horizontal holes linearly extending in the horizontal direction from the central axis 11c toward the outer peripheral end portion of the adsorption holding portion 11 are formed. The internal space of each of these plurality of horizontal holes constitutes a linear path LP which is a part of the intake path vp described above. As shown in FIG. 5, the plurality of linear paths LP are formed at a constant angular pitch β around the central axis 11c. The internal spaces of the plurality of linear paths LP communicate with each other at the central portion of the adsorption holding portion 11. In this example, the angular pitch β is 30°. Note that the angular pitch β may be 15° or 60°.

[0049] As shown in FIG. 6, the support portion 43 located at the lowermost part of the disk-shaped member 40 has a mounting portion 43a that is attached to the upper end portion of the rotating shaft 12 in FIG. 1. The mounting portion 43a has a cylindrical shape surrounding the central axis 11c and is formed to protrude downward from other portions around the central axis 11c. Further, a communication hole 43b is formed in the support portion 43 along the central axis 11c. The communication hole 43b communicates the internal space of the plurality of linear paths LP with the space below the disk-shaped member 40.

[0050] When the support portion 43 is attached to the upper end portion of the rotating shaft 12, the central axis 11c coincides with the axis of the rotating shaft 12, and the internal space of the plurality of linear paths LP communicates with the internal space of the intake path vp formed in the rotating shaft 12 through the communication hole 43b.

[0051] As shown in FIG. 4, the annular member 50 has a bottom portion 51 and an outer peripheral wall portion 52. The bottom portion 51 has an annular shape. The inner peripheral end portion of the bottom portion 51 is configured to be connectable to the outer peripheral lower end portion of the support portion 43 of the disk-shaped member 40. The outer peripheral wall portion 52 is formed to extend upward from the outer peripheral end portion of the bottom portion 51 by a certain height. The upper end portion of the outer peripheral wall portion 52 is configured to be connectable to the outer peripheral lower end portion of the suction portion 41 of the disk-shaped member 40.

[0052] The annular member 50 is attached to the disk-shaped member 40 so as to connect the outer peripheral lower end portion of the suction portion 41 and the outer peripheral lower end portion of the support portion 43, as indicated by the thick solid arrow in FIG. 4. At the time of this attachment, the connection portion between the disk-shaped member 40 and the annular member 50 is welded. Thereby, an annular space is formed below the peripheral edge portion of the suction portion 41. This annular space constitutes an annular path RP (FIGS. 5 and 6), which is a part of the intake path vp in the suction holding portion 11. The annular path RP surrounds the plurality of linear paths LP in plan view. The end portions of the plurality of linear paths LP on the side opposite to the central axis 11c are open to the space within the annular path RP. Therefore, the internal space of the annular path RP and the internal spaces of the plurality of linear paths LP communicate with each other.

[0053] As shown by the thick dashed - circle in FIG. 5, the upper surface 11u of the adsorption holding part 11 according to the present embodiment is partitioned into a peripheral region R1 along the outer peripheral end of the adsorption holding part 11 and a central region R2 surrounded by the peripheral region R1.

[0054] The peripheral region R1 in this example is an annular region with a certain width from the outer peripheral end of the adsorption holding part 11, and overlaps with the annular member 50 in plan view. When the diameter of the upper surface 11u is 150 mm, the radial width of the peripheral region R1 is in the range of 5 mm or more and 30 mm or less.

[0055] On the upper surface 11u of the adsorption holding part 11, a plurality of suction holes for sucking the lower surface of the substrate W are formed over the entire peripheral region R1 and the central region R2. In the following description, among the plurality of suction holes formed on the upper surface 11u of the adsorption holding part 11, the suction holes formed in the peripheral region R1 are called suction holes vh1, and the suction holes formed in the central region R2 are called suction holes vh2.

[0056] The plurality of suction holes vh1 are formed on a plurality of linear paths LP in the peripheral region R1, and communicate the space on the upper surface 11u with the internal space of the linear path LP. Also, the plurality of suction holes vh2 are formed on the annular path RP in the central region R2, and communicate the space on the upper surface 11u with the internal space of the annular path RP. Thereby, when the suction device 14 in FIG. 1 operates, the atmosphere on the peripheral region R1 of the adsorption holding part 11 is guided to the suction device 14 through the plurality of suction holes vh1, the annular path RP, the plurality of linear paths LP, and the intake path vp of the rotating shaft 12. Also, the atmosphere on the central region R2 of the adsorption holding part 11 is guided to the suction device 14 through the plurality of suction holes vh2, the plurality of linear paths LP, and the intake path vp of the rotating shaft 12.

[0057] The plurality of suction holes vh1, vh2 have circular openings with a diameter of, for example, 0.1 mm or more and 0.4 mm or less, and are arranged on virtual concentric circles centered on the central axis 11c. More specifically, the plurality of suction holes vh1 are arranged on four virtual circles centered on the central axis 11c in the peripheral region R1, and the plurality of suction holes vh2 are arranged on five virtual circles centered on the central axis 11c in the central region R2. In FIG. 5, a part of the virtual concentric circle is shown by a two-dot chain line.

[0058] As shown in the blowout in FIG. 5, the radii of the virtual circles on which the plurality of suction holes vh1 are arranged in the peripheral region R1 are determined so as to increase sequentially from the smallest virtual circle at the first pitch pt1. On the other hand, the radii of the virtual circles on which the plurality of suction holes vh2 are arranged in the central region R2 are determined so as to increase sequentially from the smallest virtual circle at a second pitch pt2 larger than the first pitch pt1. The first pitch pt1 and the second pitch pt2 are so-called PCD (Pitch Circle diameter) pitches. The first pitch pt1 is, for example, 1 mm or more and 3 mm or less, and the second pitch pt2 is, for example, 5 mm or more and 40 mm or less.

[0059] During the manufacture of the suction holding portion 11, in order to form the plurality of suction holes vh1, vh2, drilling is performed on the suction portion 41 using a drill. In the peripheral region R1, the plurality of suction holes vh1 formed on one of the two adjacent virtual circles and the plurality of suction holes vh1 formed on the other virtual circle are arranged in a staggered pattern (zigzag pattern) in the rotational direction centered on the central axis 11c. In this case, compared with the case where the plurality of suction holes vh1 formed on each two adjacent virtual circles are arranged so as to be aligned in the radial direction of the upper surface 11u, the distance between the plurality of adjacent suction holes vh1 can be increased. Thereby, the formation of the plurality of suction holes vh1 in the peripheral region R1 becomes easy, and the first pitch pt1 can be made sufficiently smaller than the second pitch pt2 with a simple configuration.

[0060] Incidentally, if all of the plurality of suction holes vh1 and vh2 are configured to have the same size, the suction force generated by each of the plurality of suction holes vh1 arranged on the largest virtual circle may be significantly greater than the suction force generated by each of the other suction holes vh1 and vh2. In this case, when the substrate W is adsorbed and held by the adsorption holding portion 11, there is a possibility that the substrate W may be deformed because a part of the substrate W is locally strongly sucked. Therefore, in the present embodiment, the size of a part of the suction holes vh1 arranged on the largest virtual circle centered on the central axis 11c is set to be smaller than the size of the other remaining suction holes vh1 and vh2. Specifically, each opening of a part of the suction holes vh1 has a diameter of, for example, 0.1 mm or more and 0.2 mm or less, and each opening of the other remaining suction holes vh1 and vh2 has a diameter of, for example, 0.2 mm or more and 0.4 mm or less. Thereby, deformation of the substrate W due to a part of the substrate W being locally strongly sucked is prevented.

[0061] In the adsorption holding portion 11 according to the above first configuration example, the surface density of the suction holes vh1 in the peripheral region R1 is larger than the surface density of the suction holes vh2 in the central region R2. In this case, when the substrate W is adsorbed and held by the adsorption holding portion 11, the portion of the substrate W facing the peripheral region R1 is adsorbed with a larger suction force than the portion of the substrate W facing the central region R2. Thereby, when the adsorbed and held substrate W rotates, it is suppressed that the portion of the substrate W located on the peripheral region R1 floats from the upper surface 11u of the adsorption holding portion 11 against the suction force acting on the portion, and the holding state of the substrate W is stabilized.

[0062] Note that the surface density of the suction holes vh1 in the peripheral region R1 can be calculated by dividing the total opening area of the plurality of suction holes vh1 formed in the peripheral region R1 by the area of the peripheral region R1. Further, the surface density of the suction holes vh2 in the central region R2 can be calculated by dividing the total opening area of the plurality of suction holes vh2 formed in the central region R2 by the area of the central region R2.

[0063] In the adsorption and holding part 11 according to this embodiment, the plurality of suction holes vh1 and vh2 further have the following relationship. The linear density of the plurality of suction holes vh1 distributed and arranged on each virtual circle in the peripheral region R1 is greater than the linear density of the plurality of suction holes vh2 distributed and arranged on any virtual circle in the central region R2. In this case, the plurality of suction holes vh1 are distributed and arranged on each virtual circle in the peripheral region R1, and the plurality of suction holes vh2 are distributed and arranged on each virtual circle in the central region R2, so that the central part of the lower surface of the substrate W is more stably adsorbed and held on the adsorption and holding part 11.

[0064] The number of the plurality of suction holes vh1 arranged on each virtual circle in the peripheral region R1 is greater than the number of the plurality of suction holes vh2 arranged on any virtual circle in the central region R2. In this case, with a simple configuration, the surface density of the suction holes vh1 in the peripheral region R1 can be made greater than the surface density of the suction holes vh2 in the central region R2.

[0065] In the central region R2, the plurality of suction holes vh2 are arranged so as to line up on the plurality of linear paths LP. Therefore, the angular pitch between every two adjacent suction holes vh2 on each virtual circle in the central region R2 becomes the above-mentioned angular pitch β. On the other hand, the angular pitch α between every two adjacent suction holes vh1 on each virtual circle in the peripheral region R1 is smaller than the angular pitch β between every two adjacent suction holes vh2 on any virtual circle in the central region R2. In this embodiment, the angular pitch α is preferably greater than 0° and 4° or less, and more preferably 1° or more and 3° or less. In this case, with a simple configuration, the surface density of the suction holes vh1 in the peripheral region R1 can be made greater than the surface density of the suction holes vh2 in the central region R2.

[0066] In the suction holding portion 11, it is desirable that the distance (shortest distance) md (Fig. 5) from each of a part of the suction holes vh1 arranged on the largest virtual circle among the plurality of suction holes vh1 to the outer peripheral end portion of the suction holding portion 11 is as small as possible. In the suction holding portion 11 according to the first configuration example, the distance md is 2 mm or more and 4 mm or less. In this case, when the substrate W is suction-held by the suction holding portion 11, the portion of the substrate W facing the vicinity of the outer peripheral end portion of the suction holding portion 11 is suction-held on the upper surface 11u of the suction holding portion 11. Thereby, the central portion of the lower surface of the substrate W is suppressed from rising from the upper surface 11u of the suction holding portion 11, and the holding state of the substrate W becomes more stable.

[0067] (2) Second configuration example Regarding the suction holding portion 11 according to the second configuration example, the differences from the suction holding portion 11 according to the first configuration example will be described. Fig. 7 is an exploded perspective view of the suction holding portion 11 according to the second configuration example. As shown in Fig. 7, the suction holding portion 11 according to the second configuration example mainly includes an upper circular member 60, a lower circular member 70, and a seal member 79.

[0068] The upper circular member 60 is made of, for example, a resin excellent in corrosion resistance, and has a disk-shaped suction portion 61 and a cylindrical outer peripheral wall portion 62. The outer peripheral wall portion 62 is formed so as to extend downward from the outer peripheral end portion of the suction portion 61. The suction portion 61 includes the upper surface 11u of the suction holding portion 11 and is configured to be able to suction-hold the central portion of the lower surface of the substrate W. The configuration of the upper surface 11u of the suction holding portion 11 in this example is exactly the same as the configuration of the upper surface 11u (Fig. 5) of the suction holding portion 11 according to the first configuration example.

[0069] Fig. 8 is a bottom view of the upper circular member 60 in Fig. 7, and Fig. 9 is a longitudinal sectional view of the suction holding portion 11 according to the second configuration example. The sectional view in Fig. 9 corresponds to the longitudinal sectional view in Fig. 6 according to the first configuration example. As shown in Fig. 8, also on the lower surface 60b of the upper circular member 60, a peripheral region R1 and a central region R2 are partitioned in the same manner as the upper surface 11u.

[0070] On the lower surface 60b of the upper circular member 60, an annular groove portion RG overlapping the peripheral region R1 is formed. Further, on the lower surface 60b of the upper circular member 60, a plurality of linear groove portions LG overlapping the central region R2 are formed. The plurality of linear groove portions LG linearly extend in the horizontal direction from the central axis 11c toward the outer peripheral wall portion 62 and are formed to be arranged at a constant angular pitch β (FIG. 5) around the central axis 11c.

[0071] Each linear groove portion LG is formed such that the depth gradually decreases from the central axis 11c toward the peripheral region R1. The depth of the annular groove portion RG is substantially constant over the entire circumference of the peripheral region R1 and is substantially equal to the maximum depth of the plurality of linear groove portions LG. In each of the plurality of portions surrounded by the plurality of linear groove portions LG and the annular groove portion RG on the lower surface 60b of the upper circular member 60, a screw hole 65 is formed.

[0072] As shown in FIG. 7, the lower circular member 70 has a disk-shaped support portion 71 and a cylindrical outer peripheral wall portion 72 and is made of, for example, a metal material having high rigidity. A communication hole 73 penetrating in the vertical direction is formed in the central portion of the support portion 71. Further, in the support portion 71, a plurality of through holes 74 corresponding to the plurality of screw holes 65 (FIG. 8) of the upper circular member 60 are formed so as to surround the communication hole 73.

[0073] The outer peripheral wall portion 72 is formed so as to extend upward from the outer peripheral end portion of the support portion 71. The outer diameter of the outer peripheral wall portion 72 is slightly smaller than the inner diameter of the outer peripheral wall portion 62 of the upper circular member 60. A groove 72g extending in the circumferential direction with a constant width is formed on the outer peripheral surface of the outer peripheral wall portion 72. The seal member 79 is an O-ring that can be fitted into the groove 72g of the outer peripheral wall portion 72. As shown by the white arrow in FIG. 7, the seal member 79 is fitted into the groove 72g of the outer peripheral wall portion 72. Further, as shown by the thick solid arrow in FIG. 7, the lower circular member 70 is further fitted into the upper circular member 60. In this state, a plurality of screw members BL (FIG. 9) are attached from below the lower circular member 70 through a plurality of through holes 74 (FIG. 7) formed in the lower circular member 70 to a plurality of screw holes 65 (FIG. 8) of the upper circular member 60. Thereby, as shown in FIG. 9, the upper circular member 60 and the lower circular member 70 are connected.

[0074] In a state where the upper circular member 60 and the lower circular member 70 are connected, an annularly extending space is formed between the annular groove portion RG of the upper circular member 60 and the outer peripheral portion of the lower circular member 70. This space functions as the above-described annular path RP. Further, a linearly extending space is formed between the bottom portions of the plurality of linear groove portions LG of the upper circular member 60 and the support portion 71 of the lower circular member 70. These spaces function as a plurality of linear paths LP.

[0075] Similar to the support portion 43 in FIG. 6, the support portion 71 has a mounting portion 71a that is attached to the upper end portion of the rotating shaft 12 in FIG. 1. The communication hole 73 is formed inside the mounting portion 71a along the central axis 11c.

[0076] As described above, in the adsorption and holding portion 11 according to the second configuration example, each of the plurality of linear groove portions LG formed on the lower surface 60b of the upper circular member 60 is formed such that the depth gradually decreases from the central axis 11c toward the peripheral region R1. Thereby, the cross-sectional area orthogonal to the gas flow direction of each linear path LP gradually decreases from the center to the outer peripheral end of the adsorption and holding portion 11. According to this configuration, even when the sizes of the plurality of suction holes vh2 formed so as to overlap each linear path LP are the same, the suction forces generated in the plurality of suction holes vh2 are made uniform. Therefore, the entire central portion of the lower surface of the substrate W is sucked with a substantially uniform force.

[0077] Further, the adsorption and holding portion 11 according to the second configuration example has a configuration in which the upper circular member 60 and the lower circular member 70 are connected by a plurality of screw members BL. Thereby, the maintenance inside the adsorption and holding portion 11 can be easily performed.

[0078] [3] Consideration and Effects (1) First Consideration by the Present Inventors FIG. 10 is a plan view of the adsorption and holding portion according to the reference form, and FIG. 11 is a longitudinal sectional view taken along line B-B of the adsorption and holding portion of FIG. 10. As shown in FIGS. 10 and 11, the adsorption and holding portion 99 according to the present reference form basically has the same configuration as the adsorption and holding portion 11 according to the first configuration example, except that the annular path RP and the plurality of suction holes vh2 are not formed.

[0079] Specifically, the adsorption and holding portion 99 according to this reference embodiment has a flat upper surface 99u that adsorbs and holds the central portion of the lower surface of the substrate W, and is configured to be attachable to the rotation axis 12 in FIG. 1. Here, a virtual axis extending in the vertical direction from the outer peripheral end portion through the center of the adsorption and holding portion 99 is called the central axis 99c. Inside the adsorption and holding portion 99, a plurality of linear paths LP extending linearly in the horizontal direction from the central axis 99c toward the outer peripheral end portion of the adsorption and holding portion 99 are formed at a constant angular pitch (in this example, 30°) around the central axis 99c. The end portions on the side opposite to the central axis 99c among the plurality of linear paths LP are blocked. On the upper surface 99u of the adsorption and holding portion 99, a plurality of suction holes vh are formed at regular intervals so as to overlap with each linear path LP in a plan view.

[0080] The inventors of the present invention used a coating apparatus including the adsorption and holding portion 99 according to this reference embodiment to perform a coating process on a substrate W having a thickness of 100 μm or less. As a result, coating unevenness that could be visually confirmed occurred on the substrate W after the coating process. The coating unevenness confirmed here is called the first coating unevenness.

[0081] FIG. 12 is a plan view showing an example of the first coating unevenness generated on the substrate W after the coating process using the adsorption and holding portion 99 according to the reference embodiment. In FIG. 12, a portion of the substrate W that overlaps with the outer peripheral end portion of the adsorption and holding portion 99 during the coating process (hereinafter referred to as the outer edge of the held area) is indicated by a dotted line. As shown by the dot pattern in FIG. 12, the first coating unevenness is formed such that a plurality of curves extend a certain distance while curving in a common rotation direction with the center of the substrate W as the rotation center from a plurality of portions of the outer edge of the held area toward the outer peripheral end portion of the substrate W.

[0082] The inventors have presumed the following first and second mechanisms as the mechanism of the occurrence of the first coating unevenness. FIG. 13 is a cross-sectional view for explaining the first mechanism presumed for the occurrence of the first coating unevenness in FIG. 12. When the substrate W adsorbed and held by the adsorption holding portion 99 rotates at high speed, a phenomenon occurs in which the outer peripheral portion of the substrate W rises above the upper surface 99u of the adsorption holding portion 99 as indicated by the thick dashed arrow in the upper part of FIG. 12. This phenomenon is likely to occur when rotating the substrate W having a small thickness (a thickness of 100 μm or less in this example). This is because the rigidity of the substrate W is low.

[0083] When the upward force of the outer peripheral portion of the substrate W exceeds the suction force generated by the suction holes vh formed near the outer peripheral end portion of the adsorption holding portion 99, a gap is formed between the outer edge of the held area of the substrate W and the upper surface 99u of the adsorption holding portion 99. In this case, as shown by the thick solid arrow in the upper part of FIG. 13, the atmosphere around the substrate W enters the suction holes vh near the outer peripheral end portion of the adsorption holding portion 99 through the gap between the substrate W and the upper surface 99u of the adsorption holding portion 99. Thereby, due to the local flow of gas near the outer peripheral end portion of the adsorption holding portion 99, the outer edge of the held area of the substrate W is locally cooled.

[0084] On the other hand, the resist liquid RL supplied from the liquid nozzle 21 to the central portion of the substrate W when the coating process is started spreads toward the outer peripheral end portion of the substrate W as indicated by the white arrow in the upper part of FIG. 13. At this time, when the temperature of the outer edge of the held area of the substrate W locally decreases, the resist liquid RL spread on the substrate W is locally cooled. The fluidity of the resist liquid RL on the substrate W is higher as the temperature of the resist liquid RL is higher and lower as the temperature of the resist liquid RL is lower. Therefore, on the substrate W, the fluidity of the resist liquid RL locally decreases on the outer peripheral end portion of the adsorption holding portion 99. Thereby, in a plurality of portions of the outer edge of the held area of the substrate W, as shown in the lower part of FIG. 13, the resist liquid RL stays.

[0085] When a certain amount of resist liquid RL stays at the outer edge of the held area of the substrate W, the subsequent resist liquid RL flowing further over the stayed resist liquid RL is less likely to be affected by the local temperature drop of the substrate W. As a result, the subsequent resist liquid RL gets over the resist liquid RL staying in a certain amount at the outer edge of the held area of the substrate W and further flows toward the outer peripheral end of the substrate W. At this time, the above-described first coating unevenness occurs.

[0086] FIG. 14 is a cross-sectional view for explaining a second mechanism estimated for the occurrence of the first coating unevenness in FIG. 12. In FIG. 14, the state of the substrate W rotating at two different speeds by the adsorption holding portion 99 in FIG. 10 is shown in an external perspective view. Further, in FIG. 14, the substrate W held on the adsorption holding portion 99 is shown by a one-dot chain line and a dot pattern, and the upper surface 99u of the adsorption holding portion 99 is shown in a state of passing through the substrate W.

[0087] As shown in the upper stage of FIG. 14, when the rotation speed of the substrate W is relatively low, the substrate W adsorbed and held by the adsorption holding portion 99 is maintained in a relatively flat state along the upper surface 99u of the adsorption holding portion 99. However, when the rotation speed of the substrate W is relatively high, an upward force is generated on the entire substrate W. As a result, as shown in the lower stage of FIG. 14, the portion of the substrate W not sucked by the plurality of suction holes vh is deformed so as to float from the upper surface 99u.

[0088] Here, the plurality of suction holes vh of the adsorption holding portion 99 overlap with the plurality of linear paths LP in FIG. 10. Therefore, the substrate W is deformed so as to undulate in the circumferential direction. In FIG. 14, the virtual line on the upper surface 99u overlapping with the plurality of linear paths LP in FIG. 10 is shown by a two-dot chain line.

[0089] During the coating process of the substrate W by the suction holding portion 99, the rotation speed of the substrate W changes in multiple stages. When the rotation speed of the substrate W changes significantly in a short period of time, a large inertial force is generated between the portion of the substrate W adsorbed and held by the plurality of suction holes vh of the suction holding portion 99 and the portion of the substrate W that deforms in a wavy manner outside the suction holding portion 99. At this time, an annular twist occurs in a part of the substrate W at a position outside the suction holding portion 99. As a result, the first coating unevenness is generated due to the twist.

[0090] The first coating unevenness is presumed to be generated according to any one of the above-described first and second mechanisms. Considering the above-described first and second mechanisms, the inventors considered that if the outer edge of the held area of the substrate W does not lift from the upper surface 99u of the suction holding portion 99 during the coating process, the holding state of the substrate W by the suction holding portion 99 is stable and the first coating unevenness does not occur. In addition, the inventors considered that in the configuration of the suction holding portion 99 according to the reference embodiment, a suction force capable of suppressing the outer edge of the held area of the substrate W from lifting from the upper surface 99u of the suction holding portion 99 cannot be obtained. Considering these points, the inventors devised the suction holding portion 11 according to the above-described first and second configuration examples.

[0091] (2) Second study by the inventors The inventors performed a coating process on a substrate W having a thickness of 100 μm or less using a coating apparatus having the same configuration as the coating apparatus 1 in FIG. 1 except that the gas nozzle 17 and the gas supply system 18 are not provided. As a result, coating unevenness that can be visually confirmed occurred on the substrate W after the coating process. The coating unevenness confirmed here is called the second coating unevenness.

[0092] FIG. 15 is a plan view showing an example of the second coating unevenness generated on the substrate W after the coating process. Also in FIG. 15, the outer edge of the held area is indicated by a dotted line as in the example of FIG. 12. As shown by the dot pattern in FIG. 15, the second coating unevenness is formed so as to show an annular shape with a certain width surrounding the center of the substrate W. The inner edge of the second coating unevenness is located at the outer edge of the held area.

[0093] The inventors of the present invention have estimated the mechanism of the occurrence of the second coating unevenness. FIG. 16 is a cross-sectional view for explaining the estimated mechanism of the occurrence of the second coating unevenness in FIG. 15.

[0094] The coating apparatus is basically housed in a clean room. In the space surrounding the coating apparatus, a downward flow (downflow) of clean air maintained at a predetermined temperature (for example, 23° C.) is formed. As a result, as indicated by the white arrow in the upper part of FIG. 16, gas is continuously blown onto the substrate W during the coating process from above the coating apparatus.

[0095] On the other hand, the resist liquid RL supplied from the liquid nozzle 21 to the substrate W when the coating process is started spreads from the center of the substrate W toward the outer peripheral end. The resist liquid RL in this example contains a volatile solvent. In this case, as indicated by the thick wavy arrow in the upper part of FIG. 16, the solvent of the resist liquid RL spread on the substrate W vaporizes. At this time, the downflow from the position above the coating apparatus toward the substrate W promotes the vaporization of the solvent of the resist liquid RL coated on the substrate W.

[0096] Here, the heat capacity of the portion of the substrate W that does not contact the adsorption holding portion 11 (hereinafter referred to as the non-contact portion nc) is smaller than the heat capacity of the other portions (hereinafter referred to as the contact portions). Therefore, when the vaporization of the solvent of the resist liquid RL on the substrate W is promoted, due to the influence of the heat of vaporization, the temperature of the non-contact portion nc decreases compared to the contact portions.

[0097] The resist liquid RL takes a longer time to cure as the temperature is lower. Therefore, the resist liquid RL spread on the non-contact portion nc is in a state where it is relatively easy to flow due to the rotation of the substrate W. However, in reality, even in the non-contact portion nc, in the outer peripheral end of the substrate W and the region in the vicinity thereof, the vaporization of the solvent of the resist liquid RL is further promoted due to the high rotation speed, and the resist liquid RL is likely to cure. Therefore, finally, as shown in the lower part of FIG. 16, a resist film RC is formed with a substantially constant thickness except for a range of a certain width from the outer edge of the held area of the substrate W. As a result, the above-described second coating unevenness occurs.

[0098] Considering the mechanism estimated as described above, the inventors considered adjusting the temperature of each part of the substrate W so that the temperature of the portion not adsorbed and held by the adsorption holding portion 11 coincides with or approaches the temperature of the portion adsorbed and held by the adsorption holding portion 11 during the coating process. Considering these points, the inventors devised the coating apparatus 1 of FIG. 1 including a gas nozzle 17 and a gas supply system 18 for heating the non-contact portion of the substrate W.

[0099] (3) Effect In the above-described coating apparatus 1, the adsorption holding portions 11 according to the first and second configuration examples are used in the rotary holding device 10. According to the above-described adsorption holding portion 11, the central portion of the lower surface of the substrate W is suppressed from rising from the upper surface 11u, and the holding state of the substrate W is stabilized. Therefore, when a process is performed on the substrate W rotated by the above-described rotary holding device 10, it is possible to prevent the process of the substrate W from varying at a plurality of portions on the substrate W due to a part of the substrate W rising from the upper surface 11u of the adsorption holding portion 11. As a result, the occurrence of the first coating unevenness is suppressed, and uniform processing over the entire substrate W becomes possible.

[0100] In the above-described coating apparatus 1, a gas nozzle 17 and a gas supply system 18 for adjusting the temperature of the non-contact portion of the substrate W are provided in the rotary holding device 10. Thereby, during the coating process of the substrate W, the temperature of the non-contact portion of the substrate W coincides with or approaches the temperature of the contact portion. In this case, it is possible to suppress the occurrence of a temperature difference between a plurality of portions of the substrate W during the coating process. As a result, the occurrence of the second coating unevenness is suppressed, and uniform processing over the entire substrate W becomes possible.

[0101] Further, in the present embodiment, the temperature of the non-contact portion nc of the substrate W is adjusted by the temperature-adjusting gas jetted from the gas nozzle 17 to the substrate W. In this case, in order to adjust the temperature of the non-contact portion nc of the substrate W, it is not necessary to provide a heating device such as a heater or an ultraviolet lamp in the vicinity of the adsorption holding portion 11. Thereby, the processing environment of the substrate W is not affected by excessive heat.

[0102] [4] Confirmation Test for the First Coating Unevenness In order to confirm the effect of the adsorption and holding part 11 described above, the present inventors conducted the following confirmation test. First, the present inventors fabricated an adsorption and holding part having basically the same configuration as the adsorption and holding part 11 in FIGS. 4 to 6 as the adsorption and holding part of the example. In addition, the present inventors fabricated an adsorption and holding part having basically the same configuration as the adsorption and holding part 99 in FIG. 10 according to the reference form as the adsorption and holding part of the comparative example.

[0103] Furthermore, the present inventors attached the fabricated adsorption and holding part of the example to the coating apparatus 1 in FIG. 1 and performed the coating process on the substrate W. In addition, the present inventors attached the fabricated adsorption and holding part of the comparative example to the coating apparatus 1 in FIG. 1 and performed the coating process on the substrate W.

[0104] Thereafter, the upper surface of each substrate was visually inspected with the substrate W after the coating process using the adsorption and holding part of the example as the example substrate and the substrate W after the coating process using the adsorption and holding part of the comparative example as the comparative example substrate. As a result, the above-described first coating unevenness could not be confirmed on the example substrate. On the other hand, the above-described first coating unevenness occurred on the comparative example substrate. From this visual inspection result, in order to more detailedly confirm the state of the film on the substrate W, the film thickness of the resist film was measured at a plurality of portions of each substrate W.

[0105] FIG. 17 is a plan view for explaining a portion of the substrate W that is the object of film thickness measurement in the confirmation test for the first coating unevenness. In FIG. 17, the outer edge of the held area is indicated by a dotted line. As shown in FIG. 17, the present inventors determined a plurality of portions arranged at a 1.6° pitch on the first circle C1 that substantially overlaps the outer edge of the held area as the first measurement target portion group. In addition, the present inventors determined a plurality of portions arranged at a 1.6° pitch on the second circle C2 that is concentric with the first circle C1 and has a radius smaller than that of the first circle C1 as the second measurement target portion group. Furthermore, the present inventors determined a plurality of portions arranged at a 1.6° pitch on the third circle C3 that is concentric with the first circle C1 and has a radius larger than that of the first circle C1 as the third measurement target portion group.

[0106] In FIG. 17, in each of the first to third circles C1 to C3, a part of a plurality of measurement target portions arranged at a pitch of 1.6° is indicated by small black dots. In FIG. 17, the angular pitch between a plurality of measurement points on the same circle is exaggeratedly shown so that the relationship between the plurality of measurement portions can be easily understood.

[0107] FIG. 18 is a diagram showing the results of a confirmation test for the first coating unevenness. In FIG. 18, the film thickness measurement results of the example substrate and the comparative example substrate are shown for each of the first to third measurement target portion groups. In each graph shown in FIG. 18, the vertical axis represents the film thickness, and the horizontal axis represents the measurement portions (measurement positions) in each of the first to third circles C1 to C3 in FIG. 17. Further, in each graph, the symbol "tt" shown on the vertical axis represents the thickness of the resist film to be formed by the coating process, that is, the target film thickness. Furthermore, in each graph, the line connecting the plurality of film thickness measurement results of the example substrate is represented by a thick solid line, and the line connecting the plurality of film thickness measurement results of the comparative example substrate is represented by a dotted line.

[0108] As shown in FIG. 18, the film thickness measurement results of the example substrate have less variation in film thickness than the film thickness measurement results of the comparative example substrate in any of the first to third measurement target portion groups. Also, the film thickness measurement results of the example substrate are closer to the target film thickness tt as a whole than the film thickness measurement results of the comparative example substrate in any of the first to third measurement target portion groups. According to the film thickness measurement results of the first and third measurement target portion groups, in the comparative example substrate, particularly significant variation in film thickness is observed in the range from the outer edge of the held region to the outer peripheral end of the substrate. This significant variation in film thickness corresponds to the first coating unevenness.

[0109] As a result of these, it has been clarified that by using the adsorption holding portions 11 according to the above first and second configuration examples instead of the adsorption holding portion 99 in FIG. 10, the occurrence of the first coating unevenness is sufficiently suppressed.

[0110] [5] Confirmation test for the second coating unevenness (1) Regarding the temperature of the substrate W during the coating process In order to confirm how the temperature state of the substrate W differs between the case where the temperature-adjusting gas is supplied from the gas nozzle 17 in FIG. 1 to the substrate W during the coating process of the substrate W and the case where the temperature-adjusting gas is not supplied, the inventors conducted the temperature-adjusting confirmation test described below.

[0111] FIG. 19 is a schematic cross-sectional view of the coating apparatus 1 for explaining the temperature-adjusting confirmation test. As shown in FIG. 19, the inventors set a non-contact type first temperature sensor s1 on the coating apparatus 1 so that the temperature measurement point is located at the portion of the substrate W positioned on the adsorption holding portion 11. Further, the inventors set a non-contact type second temperature sensor s2 on the coating apparatus 1 so that the temperature measurement point is located at the portion of the substrate W positioned on the gas nozzle 17.

[0112] In this state, the outputs (temperature measurement results) of the first and second temperature sensors s1 and s2 were recorded when the coating process of the substrate W was performed while the heated temperature-adjusting gas was being supplied from the gas nozzle 17 to the substrate W. Also, the outputs (temperature measurement results) of the first and second temperature sensors s1 and s2 were recorded when the coating process was performed with no temperature-adjusting gas being supplied from the gas nozzle 17 to the substrate W.

[0113] FIG. 20 is a diagram showing the results of the temperature-adjusting confirmation test. In the graph of FIG. 20, the vertical axis represents temperature and the horizontal axis represents time. In the horizontal axis of FIG. 20, the time point t1 represents the time point when the supply of the resist liquid RL to the substrate W was stopped after the coating process was started. The time point t2 represents the end point of the coating process, that is, the time point when the entire resist liquid RL spread on the substrate W was cured. Also, the symbol "pt" shown on the vertical axis of FIG. 20 represents the processing temperature.

[0114] Furthermore, in the graph of FIG. 20, the outputs (temperature measurement results) of the first and second temperature sensors s1 and s2 when the coating process of the substrate W is performed while the temperature-adjusted gas heated from the gas nozzle 17 is supplied to the substrate W are indicated by the thick solid line and the thick one-dot chain line. Furthermore, in the graph of FIG. 20, the outputs (temperature measurement results) of the first and second temperature sensors s1 and s2 when the coating process of the substrate W is performed in a state where the temperature-adjusted gas is not supplied from the gas nozzle 17 to the substrate W are indicated by the dotted line and the two-dot chain line.

[0115] According to the temperature adjustment confirmation test results in FIG. 20, when the temperature-adjusted gas heated from the gas nozzle 17 is supplied to the substrate W, the variation in the outputs of the temperature sensors s1 and s2 is slightly smaller than when the temperature-adjusted gas is not supplied from the gas nozzle 17 to the substrate W. Also, when the temperature-adjusted gas heated from the gas nozzle 17 is supplied to the substrate W, the outputs of the temperature sensors s1 and s2 are slightly closer to the processing temperature pt than when the temperature-adjusted gas is not supplied from the gas nozzle 17 to the substrate W. From these results, it was confirmed that supplying the temperature-adjusted gas heated from the gas nozzle 17 in FIG. 1 to the substrate W suppresses the occurrence of a large temperature difference between a plurality of portions of the substrate W during the coating process. Also, it was confirmed that supplying the temperature-adjusted gas heated from the gas nozzle 17 in FIG. 1 to the substrate W causes the temperature of the substrate W during the coating process to approach the processing temperature pt as a whole.

[0116] (2) Occurrence state of the second coating unevenness The inventors performed the coating process on a plurality of substrates W while changing the supply mode of the temperature-adjusted gas from the gas nozzle 17 to the substrate W in the coating apparatus 1 of FIG. 1, and confirmed the occurrence state of the second coating unevenness according to the supply mode of the temperature-adjusted gas from the gas nozzle 17 to the substrate W.

[0117] Specifically, for the first substrate W out of the four substrates W, the coating process was performed without supplying the temperature-adjusting gas from the gas nozzle 17 to the substrate W. Further, for the second substrate W out of the four substrates W, the coating process was performed while supplying the temperature-adjusting gas at the first temperature from the gas nozzle 17 to the substrate W. Further, for the third substrate W out of the four substrates W, the coating process was performed while supplying the temperature-adjusting gas at the second temperature from the gas nozzle 17 to the substrate W. Further, for the fourth substrate W out of the four substrates W, the coating process was performed while supplying the temperature-adjusting gas at the third temperature from the gas nozzle 17 to the substrate W. The above first to third temperatures are higher than the processing temperature pt. Also, the second temperature is higher than the first temperature, and the third temperature is higher than the second temperature.

[0118] Thereafter, the inventors measured the film thickness distribution of the resist film on the straight line passing through the center of each substrate W for the four substrates W after the coating process obtained as described above. FIG. 21 is a diagram showing the film thickness distribution of the resist film on the four substrates W subjected to the coating process in a state where the supply modes of the temperature-adjusting gas from the gas nozzle 17 to the substrate W are different from each other.

[0119] In FIG. 21, the vertical axis represents the film thickness of the resist film, and the horizontal axis represents the position on the straight line passing through the center of the substrate W. Note that on the horizontal axis, "0" represents the center of the substrate W. Also, "150" represents one end of the straight line passing through the center of the substrate W on the surface of the substrate W, and "-150" represents the other end of the straight line passing through the center of the substrate W on the surface of the substrate W. Also, in this example, the positions of "75" and "-75" on the horizontal axis represent the positions of the outer edges of the held region.

[0120] Furthermore, in FIG. 21, the dotted line indicates the film thickness distribution corresponding to the first substrate W described above, and the solid line indicates the film thickness distribution corresponding to the second substrate W described above. Also, the dashed-dotted line indicates the film thickness distribution corresponding to the third substrate W described above, and the two-dot chain line indicates the film thickness distribution corresponding to the fourth substrate W described above.

[0121] 21, the first substrate W to which the heated temperature adjusting gas was not supplied during the coating process has a locally small film thickness at and near the outer edge of the held area. This indicates that the second coating unevenness is prominent in the first substrate W.

[0122] On the other hand, no significant decrease in film thickness was observed at or near the outer edge of the held area for the second, third and fourth substrates W. This shows that the occurrence of the second coating unevenness was suppressed.

[0123] 21, the thickness of the resist film at the outer edge of the held area and its neighboring positions increases as the temperature of the temperature adjusting gas supplied to the substrate W from the gas nozzle 17 increases. Therefore, it is desirable to adjust the temperature of the temperature adjusting gas supplied to the substrate W during the coating process so that the thickness of the resist film at the outer edge of the held area and its neighboring positions becomes closer to the thickness of the resist film at other positions.

[0124] 2. Second embodiment [1] Basic configuration of the coating apparatus according to the second embodiment The coating apparatus according to the second embodiment will be described with respect to differences from the coating apparatus according to the first embodiment. Fig. 22 is a schematic cross-sectional view showing a basic configuration example of a coating apparatus according to the second embodiment, and Fig. 23 is a schematic plan view of the coating apparatus 1 of Fig. 22. In Fig. 23, some of the components of the coating apparatus 1 shown in Fig. 22 are omitted. Also, the substrate W shown in Fig. 22 is indicated by a dashed line.

[0125] In the following description, as in the first embodiment, the portion of the underside of the substrate W that contacts the suction holding portion 11 (the portion that is suction-held by the suction holding portion 11) is referred to as the underside central portion. Furthermore, in this embodiment, the portion of the underside of the substrate W that surrounds the underside central portion and is not suction-held by the suction holding portion 11 is referred to as the underside peripheral portion.

[0126] As shown in FIGS. 22 and 23, in the coating apparatus 1 according to the present embodiment, the rotation holding device 10 includes a plurality (four in this example) of gas nozzles 17. As shown in FIG. 23, the plurality of gas nozzles 17 are provided at equal angular intervals (in this example, 90° intervals with respect to the rotation axis 12) so as to be arranged in the circumferential direction of the substrate W adsorbed and held by the adsorption holding portion 11. Further, each of the plurality of gas nozzles 17 is arranged such that the slit-shaped opening of the gas ejection portion 17b (FIG. 23) extends in the diameter direction of the substrate W adsorbed and held by the adsorption holding portion 11. A gas supply system 18 is connected to the gas introduction portion 17a (FIG. 3) of each gas nozzle 17.

[0127] In this coating apparatus 1, the gas supply system 18 supplies a temperature-adjusted gas having a temperature higher than, for example, the processing temperature to the plurality of gas nozzles 17 during the coating process. In this case, the temperature-adjusted gas having a high temperature is simultaneously ejected from the gas ejection portions 17b of the plurality of gas nozzles 17 to a plurality of portions on the peripheral edge portion of the lower surface of the substrate W being processed. Thereby, without excessively increasing the flow rate of the temperature-adjusted gas supplied to each of the plurality of portions on the peripheral edge portion of the lower surface of the substrate W, the temperature of the central portion of the lower surface of the substrate W and the temperature of the peripheral edge portion of the lower surface of the substrate W can be made to coincide with each other or brought closer to each other. As a result, deformation and breakage of the substrate W due to the supply of the temperature-adjusted gas to a part of the substrate W at an excessive flow rate are prevented.

[0128] [2] Modification example of the gas nozzle 17 In the rotation holding device 10 according to the present embodiment, the configuration of the gas nozzle 17 that supplies the temperature-adjusted gas to the peripheral edge portion of the lower surface of the substrate W is not limited to the example of FIG. 22. Hereinafter, a modification example of the gas nozzle 17 will be described.

[0129] (1) First modification example FIG. 24 is an external perspective view of a gas nozzle according to the first modification example, FIG. 25 is a plan view of the gas nozzle 170A of FIG. 24, and FIG. 26 is a bottom view of the gas nozzle 170A of FIG. 24. As shown in FIGS. 24 to 26, the gas nozzle 170A of this example has an annular shape and is configured such that the adsorption holding portion 11 can be arranged inside thereof.

[0130] As shown in FIGS. 24 and 25, the upper surface 170u of the gas nozzle 170A has an annular band shape with a flat and constant width. A plurality of through-hole groups g1 to g8 are formed on the upper surface 170u at predetermined intervals in the circumferential direction. In other words, on the upper surface 170u, a plurality (eight in this example) of through-hole groups g1 to g8 are formed at equal angular intervals (45° in this example) with respect to the center of the gas nozzle 170A in a plan view. Each of the through-hole groups g1 to g8 includes a plurality of through-holes h1 to hn (n is a natural number of 2 or more). The plurality of through-holes h1 to hn have a common inner diameter of, for example, 0.5 mm or more and 5.00 mm or less.

[0131] In each of the through-hole groups g1 to g8, the plurality of through-holes h1 to hn are arranged in a line from the inner edge to the outer edge of the gas nozzle 170A in this order. The gas nozzle 170A has an annular internal space 173 (FIG. 28) described later. The plurality of through-holes h1 to hn communicate the internal space 173 with the space above the upper surface 170u.

[0132] As shown in FIG. 26, the lower surface 170b of the gas nozzle 170A has an annular band shape with a flat and constant width, similar to the upper surface 170u. A plurality of gas introduction members 177 are provided on the lower surface 170b at predetermined intervals in the circumferential direction. In other words, on the lower surface 170b, a plurality (eight in this example) of gas introduction members 177 are provided at equal angular intervals (45° in this example) with respect to the center of the gas nozzle 170A in a plan view. Each gas introduction member 177 is provided at a position that does not overlap any of the through-hole groups g1 to g8 in a plan view. More specifically, each gas introduction member 177 is provided on the lower surface 170b so as to be located in the middle of each two adjacent through-hole groups among the through-hole groups g1 to g8 in a plan view.

[0133] The gas introduction member 177 has a gas inlet 177a, a gas flow path 177b, and a gas outlet 177c. A through-hole is formed at the attachment portion of each gas introduction member 177 on the lower surface 170b. The gas outlet 177c of the gas introduction member 177 is positioned on the through-hole of the lower surface 170b.

[0134] With such a configuration, when the temperature-adjusted gas is supplied to the gas inlet 177a, the temperature-adjusted gas is guided into the internal space 173 (FIG. 28) of the gas nozzle 170A through the gas flow path 177b, the gas outlet 177c, and the through holes in the lower surface 170b. The temperature-adjusted gas guided into the internal space 173 (FIG. 28) is further jetted from the plurality of groups of through holes g1 to g8 in the upper surface 170u into the space above the upper surface 170u. Therefore, when the gas nozzle 170A is provided in the coating apparatus 1, the gas supply system 18 (FIG. 22) is connected to the gas inlets 177a of the plurality of gas introduction members 177.

[0135] Further, two fixing members 178 are attached to the lower surface 170b of the gas nozzle 170A. The fixing member 178 has, for example, a through hole into which a screw can be inserted, and is provided so as to project from above the lower surface 170b into the inside of the gas nozzle 170A. The two fixing members 178 are fixed to the housing of the coating apparatus 1 using screws, for example. Thereby, the gas nozzle 170A is fixed in the coating apparatus 1 in a state of having a predetermined positional relationship with respect to the adsorption holding portion 11.

[0136] Note that the number of the fixing members 178 provided on the gas nozzle 170A is not limited to two. The gas nozzle 170A may be provided with three, four, or five or more fixing members 178. In this case, the plurality of fixing members 178 are preferably arranged at equal intervals on the lower surface 170b.

[0137] FIG. 27 is a diagram showing the positional relationship between the gas nozzle 170A and the adsorption holding portion 11 according to the first modification of the coating apparatus 1. As shown in FIG. 27, in the coating apparatus 1, the gas nozzle 170A is provided so as to surround the adsorption holding portion 11. Note that the upper surface 170u of the gas nozzle 170A is held at a height lower than the upper surface 11u of the adsorption holding portion 11.

[0138] FIG. 28 is a longitudinal sectional view of a plurality of portions of the suction holding portion 11 and the gas nozzle 170A in FIG. 27. In the first row of FIG. 28, a longitudinal sectional view is shown when the suction holding portion 11 and the gas nozzle 170A are cut along a vertical plane including the line Q1-Q1 in FIG. 27. In the vertical plane including the line Q1-Q1, there is the through-hole group g1 in FIG. 24. In the second row of FIG. 28, a longitudinal sectional view is shown when the suction holding portion 11 and the gas nozzle 170A are cut along a vertical plane including the line Q2-Q2 in FIG. 27. In the vertical plane including the line Q2-Q2, there is the through-hole group g2 in FIG. 24.

[0139] In the third row of FIG. 28, a longitudinal sectional view is shown when the suction holding portion 11 and the gas nozzle 170A are cut along a vertical plane including the line Q3-Q3 in FIG. 27. In the vertical plane including the line Q3-Q3, there is the through-hole group g3 in FIG. 24. In the fourth row of FIG. 28, a longitudinal sectional view is shown when the suction holding portion 11 and the gas nozzle 170A are cut along a vertical plane including the line Q4-Q4 in FIG. 27. In the vertical plane including the line Q4-Q4, there is the through-hole group g4 in FIG. 24.

[0140] In the fifth row of FIG. 28, a longitudinal sectional view is shown when the suction holding portion 11 and the gas nozzle 170A are cut along a vertical plane including the line Q5-Q5 in FIG. 27. In the vertical plane including the line Q5-Q5, there is the gas introduction member 177 in FIG. 24. In each figure of FIG. 28, together with the sectional views of the suction holding portion 11 and the gas nozzle 170A, a sectional view of the substrate W suction-held by the suction holding portion 11 is also shown.

[0141] As shown in the longitudinal sectional views of each row in FIG. 28, the gas nozzle 170A is composed of an upper surface member 171 and a lower surface member 172. The upper surface member 171 has an annular flat plate portion forming the upper surface 170u, an inner peripheral wall extending downward by a predetermined height from the inner edge of the flat plate portion, and an outer peripheral wall extending downward by a predetermined height from the outer edge of the flat plate portion. On the other hand, the lower surface member 172 is a flat plate member having an annular shape corresponding to the flat plate portion of the upper surface member 171.

[0142] The inner edge and the outer edge of the lower member 172 are respectively connected to the lower end portion of the inner peripheral wall and the lower end portion of the outer peripheral wall of the upper member 171. Thereby, an annular internal space 173 is formed between the flat plate portion of the upper member 171 and the lower member 172. The internal space 173 functions as a flow path for the temperature-adjusting gas. The connection between the upper member 171 and the lower member 172 may be performed by welding. Alternatively, the upper member 171 and the lower member 172 may be connected to each other using, for example, screws. In this case, it is preferable to provide a seal member such as an O-ring at the connection portion between the upper member 171 and the lower member 172 so that the gas in the internal space 173 does not leak through the connection portion between the upper member 171 and the lower member 172.

[0143] In the first-stage longitudinal section of FIG. 28, a plurality of through-holes h1 to hn belonging to the through-hole group g1 in FIG. 24 are formed in the upper surface 170u of the gas nozzle 170A. In the second-stage longitudinal section, a plurality of through-holes h1 to hn belonging to the through-hole group g2 in FIG. 24 are formed in the upper surface 170u of the gas nozzle 170A. In the third-stage longitudinal section, a plurality of through-holes h1 to hn belonging to the through-hole group g3 in FIG. 24 are formed in the upper surface 170u of the gas nozzle 170A. In the fourth-stage longitudinal section, a plurality of through-holes h1 to hn belonging to the through-hole group g3 in FIG. 24 are formed in the upper surface 170u of the gas nozzle 170A.

[0144] An inclined portion ut that faces inward and upward of the gas nozzle 170A is formed in the portion of the upper surface 170u that is closest to the adsorption and holding portion 11. The inclination angle of the inclined portion ut with respect to the axis extending in the vertical direction is set to be, for example, within the range of 30° to 60°. In each of the through-hole groups g1 to g8 in FIG. 24, the through-hole h1 closest to the inner edge of the gas nozzle 170A is located at the inclined portion ut. Each through-hole h1 is formed to extend in a direction orthogonal to the inclined portion ut.

[0145] In the longitudinal sectional view of the gas nozzle 170A, the inclined portion ut extends linearly for a certain length outward and obliquely upward from the inner edge of the gas nozzle 170A. Further, the inclined portion ut faces a portion including the inner edge among the peripheral portions of the lower surface of the substrate W in a state where the substrate W is adsorbed and held by the adsorption holding portion 11.

[0146] In the gas nozzle 170A, the through holes h1 of the through hole groups g1, g4, g7 among the plurality of through hole groups g1 to g8 are formed in a first region near the upper end portion of the inclined portion ut. On the other hand, the through holes h1 of the through hole groups g2, g5, g8 are formed in a second region adjacent to the first region and located below the first region of the inclined portion ut. On the other hand, the through holes h1 of the through hole groups g3, g6 are formed in a third region adjacent to the second region and located below the second region of the inclined portion ut.

[0147] As described above, the plurality of through holes h1 are formed dispersedly in a plurality of regions in the inclined portion ut. Thereby, when the substrate W adsorbed and held by the adsorption holding portion 11 rotates, the temperature adjustment gas jetted from the plurality of through holes h1 is supplied as a whole to the inner edge of the peripheral portion of the lower surface of the substrate W and the peripheral portion thereof.

[0148] Here, in the gas nozzle 170A, the direction facing outward from the center of the gas nozzle 170A in a direction orthogonal to the circumferential direction is called the radial direction. In each of the through hole groups g1 to g8 in FIG. 24, the through holes h2 to hn are arranged at a certain interval (the inner diameter of the through holes h2 to hn in this example) on a straight line extending along the radial direction on a region of the upper surface 170u excluding the inclined portion ut. Specifically, each of the through holes h1 to hn in this example has an inner diameter of 1.0 mm, and the through holes h2 to hn are arranged in a straight line at a pitch of 2.0 mm.

[0149] In each two through-hole groups that are adjacent to each other in the circumferential direction of the gas nozzle 170A, the formation positions of the through-holes h2 to hn in one through-hole group are different from the formation positions of the through-holes h2 to hn in the other through-hole group. As a result, in the gas nozzle 170A, the through-holes corresponding to each other in the plurality of through-hole groups g1 to g8 are arranged in a staggered pattern (zigzag pattern) in the circumferential direction. Thereby, when the substrate W adsorbed and held by the adsorption holding portion 11 rotates, the temperature adjustment gas ejected from the plurality of through-holes h2 to hn in the plurality of through-hole groups g1 to g8 is supplied as a whole to the portion of the lower surface peripheral portion of the substrate W that faces the upper surface 170u.

[0150] As shown in the fifth stage of FIG. 28, a through-hole 172h is formed at a substantially central portion in the radial direction at the attachment portion of the gas introduction member 177 on the lower surface 170b of the gas nozzle 170A. The gas introduction member 177 is positioned so that the gas outlet 177c overlaps the through-hole 172h and is attached to the lower surface 170b. In this state, the gas inlet 177a of the gas introduction member 177 faces the inside of the gas nozzle 170A.

[0151] As described above, when the temperature adjustment gas is supplied to the gas inlet 177a, the temperature adjustment gas is supplied to the internal space 173 through the gas flow path 177b, the gas outlet 177c, and the through-hole 172h. Here, no through-hole or opening is formed in the portion of the upper surface member 171 located above the through-hole 172h. Therefore, the temperature adjustment gas supplied from the gas introduction member 177 to the internal space 173 first collides with the upper surface member 171 and is smoothly diffused in the internal space 173. Thereby, the temperature adjustment gas is smoothly and uniformly guided from the internal space 173 to the plurality of through-hole groups g1 to g8.

[0152] Incidentally, in a state where the substrate W is adsorbed and held by the adsorption holding portion 11, the distance D1 (see the fifth stage of FIG. 28) between the lower surface of the substrate W and the upper surface 170u of the gas nozzle 170A is set to about 0.5 mm to 10 mm, for example. Further, the distance D2 (see the fifth stage of FIG. 28) between the outer edge of the adsorption holding portion 11 and the inner edge of the gas nozzle 170A is set to about 1 mm to 10 mm, for example.

[0153] (2) Second Modification Example FIG. 29 is a bottom view of the gas nozzle according to the second modification example. The gas nozzle 170B according to the second modification example has the same configuration as the gas nozzle 170A according to the first modification example, except for the points described below.

[0154] As shown in FIG. 29, on the bottom surface 170b of the gas nozzle 170B, instead of the plurality of gas introduction members 177 in FIG. 26, a single gas introduction member 179 is provided. The gas introduction member 179 basically has the same configuration as the gas introduction member 177.

[0155] Also, in this example, instead of forming a plurality of through holes 172h (FIG. 28) in the bottom surface member 172, a gas flow path 172p is formed inside the bottom surface member 172. In FIG. 29, the gas flow path 172p is shown by a dashed-dotted line and a dot pattern.

[0156] The gas flow path 172p has a single upstream end and a plurality (eight in this example) of downstream ends de. The single upstream end is located at the attachment portion of the gas introduction member 179 on the bottom surface 170b so as to be able to receive the temperature-adjusted gas supplied from the gas supply system 18 in FIG. 22 through the gas introduction member 179. The plurality of downstream ends de are located between every two adjacent through-hole groups of the plurality of through-hole groups g1 to g8 in plan view and are open to the internal space 173 of the gas nozzle 170B.

[0157] The gas supply system 18 is connected to the above-described gas introduction member 179. Thereby, the temperature-adjusted gas supplied from the gas supply system 18 to the single gas introduction member 179 is supplied to a plurality of portions in the internal space 173 through the gas flow path 172p.

[0158] (3) Third Modification Example FIG. 30 is a plan view of the gas nozzle according to the third modification example. The gas nozzle 170C according to the third modification example has the same configuration as the gas nozzle 170A according to the first modification example, except for the points described below.

[0159] As shown in FIG. 30, in the gas nozzle 170C, twelve through-hole groups g11 to g22 are formed in the upper surface 170u. These multiple through-hole groups g11 to g22 are arranged in a windmill shape at equal intervals in the circumferential direction of the gas nozzle 170C. Each of the multiple through-hole groups g11 to g22 has a configuration in which a plurality of through-holes are arranged on a curve that extends while curving from the inner edge to the outer edge of the gas nozzle 170C. Further, in the gas nozzle 170C, a large number of through-holes that do not belong to the multiple through-hole groups g11 to g22 are formed in the inclined portion ut of the upper surface 170u.

[0160] In the gas nozzle 170C according to the third modification example, compared with the gas nozzles 170A and 170B according to the first and second modification examples, the number of through-holes capable of injecting the temperature-adjusting gas is large. Thereby, the temperature-adjusting gas can be supplied more uniformly to a plurality of portions on the peripheral edge portion of the lower surface of the substrate W.

[0161] In the radial direction of each of the multiple through-hole groups g11 to g22, it is preferable that the distance between the centers of each two adjacent through-holes is determined to be equal to or less than the diameter of each through-hole. In this case, when the substrate W adsorbed and held by the adsorption holding portion 11 rotates, the temperature-adjusting gas can be supplied as a whole to the portion of the peripheral edge portion of the lower surface of the substrate W that faces the upper surface 170u.

[0162] (4) Fourth Modification Example FIG. 31 is a plan view of a gas nozzle according to the fourth modification example. The gas nozzle 170D according to the fourth modification example has the same configuration as the gas nozzle 170A according to the first modification example except for the points described below.

[0163] As shown in FIG. 31, in the gas nozzle 170D, a plurality (eight in this example) of slit-shaped openings SL are formed in the upper surface 170u instead of the plurality of through-hole groups g1 to g8 (FIG. 24). The plurality of slit-shaped openings SL are arranged at equal intervals in the circumferential direction of the gas nozzle 170D. Each slit-shaped opening SL is formed to extend linearly from the vicinity of the inner edge to the vicinity of the outer edge of the gas nozzle 170D.

[0164] With such a configuration, when the gas nozzle 170D is in use, the temperature-adjusting gas is jetted from the internal space 173 of the gas nozzle 170D through each slit-shaped opening SL into the space on the upper surface 170u.

[0165] (5) The fifth modification FIG. 32 is an external perspective view of the gas nozzle according to the fifth modification. The gas nozzle 170E according to the fifth modification has the same configuration as the gas nozzle 170A according to the first modification, except for the points described below.

[0166] As shown in FIG. 32, the gas nozzle 170E includes a plate-shaped annular member 180 that surrounds the upper end portion of the upper surface member 171 of the gas nozzle 170A. The annular member 180 has an upper surface 180u that surrounds the upper surface 170u of the upper surface member 171 and is integrally formed with the upper surface member 171. The upper surface 170u and the upper surface 180u are flush. In FIG. 32, the outer edge of the upper surface 170u of the upper surface member 171 is indicated by a dashed line.

[0167] FIG. 33 is a longitudinal sectional view for explaining the positional relationship between the gas nozzle 170E according to the fifth modification and the substrate W held by the adsorption holding portion 11. As shown in FIG. 33, the upper surface 170u of the upper surface member 171 faces a part of the lower surface peripheral portion of the substrate W that includes the inner edge. On the other hand, the upper surface 180u of the annular member 180 faces another part of the lower surface peripheral portion of the substrate W.

[0168] When the substrate W is rotated by the suction holding portion 11, the temperature adjustment gas is jetted from a plurality of through holes h1 to hn on the upper surface 170u to a part including the inner edge of the lower surface peripheral portion of the substrate W. At this time, the upper surface 180u of the gas nozzle 170E guides the temperature adjustment gas jetted above the upper surface 170u to the outer peripheral end portion of the substrate W. Thereby, in the space between the lower surface peripheral portion of the substrate W and the upper surfaces 170u and 180u of the gas nozzle 170E, as shown by the thick solid arrows in FIG. 33, a flow of the temperature adjustment gas from the suction holding portion 11 toward the outer peripheral end portion of the substrate W is generated. As a result, when the resist liquid is supplied to the upper surface of the substrate W adsorbed and held by the suction holding portion 11, it is possible to prevent the resist liquid supplied to the upper surface of the substrate W from flowing around to the lower surface of the substrate W through the outer peripheral end portion.

[0169] [3] Confirmation test for the second coating unevenness The inventors carried out a coating process on the substrate W while supplying a temperature adjustment gas at a predetermined temperature and a predetermined flow rate from the gas nozzle 170A to the substrate W in the coating apparatus 1 according to the first modification. The substrate W obtained by this coating process is referred to as an example substrate. Further, the inventors carried out a coating process on the substrate W without supplying the temperature adjustment gas to the substrate W. The substrate W obtained by this coating process is referred to as a comparative example substrate.

[0170] Thereafter, the inventors measured the film thickness distribution of the resist film on a straight line passing through the center of each substrate W for the example substrate and the comparative example substrate. FIG. 34 is a diagram showing the film thickness distribution of the resist film in the example substrate and the comparative example substrate of the second embodiment.

[0171] In FIG. 34, similarly to the example of FIG. 21, the vertical axis represents the film thickness of the resist film, and the horizontal axis represents the position on the line passing through the center of the substrate W. On the horizontal axis, "0" represents the center of the substrate W. Furthermore, "150" represents one end of the line passing through the center of the substrate W on the surface of the substrate W, and "-150" represents the other end of the line passing through the center of the substrate W on the surface of the substrate W. Furthermore, in this example, the positions "75" and "-75" on the horizontal axis represent the positions of the inner edge of the peripheral portion of the lower surface of the substrate W (the outer edge of the held area described above). Furthermore, in FIG. 34, the thick solid line represents the film thickness distribution corresponding to the example substrate, and the dotted line represents the film thickness distribution corresponding to the comparative example substrate.

[0172] 34, in the comparative example substrate, the film thickness is locally small at the outer edge of the held area and in its vicinity. This indicates that the second coating unevenness is prominent in the comparative example substrate.

[0173] On the other hand, in the case of the example substrate, no significant decrease in film thickness was observed at or near the outer edge of the held region, which shows that the occurrence of the second coating unevenness was suppressed.

[0174] 3. Other embodiments (1) In the spin holding device 10 according to the above embodiment, the suction holding unit 11 according to the first and second configuration examples is used to prevent the first coating unevenness shown in Fig. 12 from occurring on the substrate W after the coating process. Also, a gas nozzle 17 and a gas supply system 18 are provided to prevent the second coating unevenness shown in Fig. 15 from occurring on the substrate W after the coating process. However, the present invention is not limited to the above examples.

[0175] The rotation holding device 10 according to the present invention only needs to be able to prevent the occurrence of at least one of the first and second coating unevenness. Therefore, if an adsorption holding part 11 is provided in each of the coating devices 1 in FIGS. 1 and 22, the gas nozzle 17 and the gas supply system 18 may not be provided. Further, if the gas nozzle 17 and the gas supply system 18 are provided in each of the coating devices 1 in FIGS. 1 and 22, instead of the adsorption holding part 11 according to the first and second configuration examples, an adsorption holding part 99 according to the reference form in FIG. 10 may be provided.

[0176] (2) The rotation holding device 10 according to the above embodiment is used in the coating device 1, but the present invention is not limited thereto. The rotation holding device 10 may be used in a substrate processing device that performs a process other than the coating process on the substrate W instead of the coating device 1. For example, the rotation holding device 10 may be used in a substrate cleaning device that etches the upper surface of the substrate W on which a predetermined film is formed. In this case, in the substrate cleaning device, an etching solution is supplied onto the upper surface of the substrate W adsorbed and held by the adsorption holding part 11.

[0177] (3) In the rotation holding device 10 according to the above embodiment, the gas nozzle 17 and the gas supply system 18 are provided to prevent the occurrence of the second coating unevenness in FIG. 15 on the substrate W after the coating process, but the present invention is not limited thereto.

[0178] In order to prevent the occurrence of the second coating unevenness in FIG. 15 on the substrate W after the coating process, instead of the gas nozzle 17 and the gas supply system 18, a lamp heater capable of locally heating the back surface of the substrate W with radiant heat may be used.

[0179] (4) In the rotation holding device 10 of FIG. 22 according to the second embodiment, four gas nozzles 17 for heating four portions of the substrate W are provided to prevent the occurrence of the second coating unevenness of FIG. 15 on the substrate W after the coating process, but the present invention is not limited thereto. In the rotation holding device 10 according to the second embodiment, two, three, or five or more gas nozzles 17 may be provided to supply the temperature adjusting gas to a plurality of portions of the substrate W at the same time. In this case, the plurality of gas nozzles 17 may be provided so as to be arranged in the radial direction of the substrate W adsorbed and held by the adsorption holding portion 11, or may be provided so as to be arranged in the circumferential direction of the substrate W.

[0180] (5) In the rotation holding device 10 according to the above embodiment, depending on the temperature distribution of the substrate W during the coating process, the gas nozzle 17 may supply a temperature adjusting gas having a temperature lower than the processing temperature to the substrate W in order to equalize the temperature of the entire substrate W. That is, the gas nozzle 17 and the gas supply system 18 may be configured to be able to locally cool a part of the substrate W in order to equalize the temperatures of a plurality of portions of the substrate W.

[0181] (6) In the coating device 1 according to the above embodiment, the substrate W to be processed has an outer peripheral end portion that is at least partially circular, but the present invention is not limited thereto. The substrate W to be processed may have an outer peripheral end portion that is at least partially elliptical, or may have an outer peripheral end portion that is at least partially polygonal.

[0182] (7) In the coating device 1 according to the above embodiment, a rim portion is formed at the outer peripheral end portion of the substrate W to be processed, but the present invention is not limited thereto. A rim portion may not be formed at the outer peripheral end portion of the substrate W to be processed.

[0183] (8) In the gas nozzle 17 used in the rotation holding device 10 of FIGS. 1 and 22 according to the first and second embodiments, the gas ejection portion 17b has a slit-shaped opening, but the present invention is not limited thereto.

[0184] FIG. 35 is an external perspective view showing another configuration example of the gas ejection portion 17b in the gas nozzle 17 of FIGS. 1 and 22. In FIG. 35, only the configuration of the gas ejection portion 17b and its peripheral portion in the gas nozzle 17 is shown enlarged. As shown in FIG. 35, the gas ejection portion 17b of the gas nozzle 17 may be constituted by a plurality of vertical holes arranged in a straight line. Each of the plurality of vertical holes in this example has a circular opening facing upward. According to this configuration, the temperature adjustment gas is ejected upward from the plurality of vertical holes at the upper end portion of the gas nozzle 17. Thereby, a curtain-like air flow is generated from the gas nozzle 17 toward the substrate W. In the example of FIG. 35, the gas ejection portion 17b is constituted by 10 vertical holes, but the number of vertical holes constituting the gas ejection portion 17b is not limited to 10. It may be less than 10 or more than 10.

[0185] When the gas ejection portion 17b of the gas nozzle 17 is constituted by a plurality of vertical holes arranged in a straight line, the inner diameter of the circular opening of each vertical hole may be determined according to the position where the vertical hole is formed. FIG. 36 is an external perspective view showing still another configuration example of the gas ejection portion 17b in the gas nozzle 17 of FIGS. 1 and 22. In the example of FIG. 36, among the 13 vertical holes constituting the gas ejection portion 17b, the sizes of the 5 vertical holes in the range from the center of the gas nozzle 17 to one side portion sp1 are larger than the sizes of the 8 vertical holes in the range from the center of the gas nozzle 17 to the other side portion sp2. More specifically, in the example of FIG. 36, the inner diameter of each vertical hole in the range from the center of the gas nozzle 17 to one side portion sp1 is 2 mm, and the inner diameter of each vertical hole in the range from the center of the gas nozzle 17 to the other side portion sp2 is 1 mm.

[0186] Thus, by determining the sizes of the plurality of vertical holes constituting the gas ejection portion 17b according to the position, the temperature adjustment gas can be ejected from the plurality of portions of the gas ejection portion 17b at different flow rates. For example, the gas nozzle 17 of FIG. 36 is arranged such that the one side portion sp1 and the other side portion sp2 are separated from the outer peripheral end portion of the adsorption holding portion 11 in this order.

[0187] In this case, a plurality of vertical holes having a large size and a plurality of vertical holes having a small size are arranged in this order in a direction away from the adsorption holding portion 11. As a result, a plurality of vertical holes having a large size face a portion of the substrate W near the outer peripheral end portion of the adsorption holding portion 11, and a plurality of vertical holes having a small size face a portion of the substrate W at a position separated from the outer peripheral end portion of the adsorption holding portion 11 by a predetermined distance outward. Therefore, more temperature adjustment gas can be supplied to the portion of the substrate W near the outer peripheral end portion of the adsorption holding portion 11 than to the portion of the substrate W at a position separated from the outer peripheral end portion of the adsorption holding portion 11 by a predetermined distance outward. As a result, the temperature of each part of the substrate W can be adjusted with higher accuracy.

[0188] In the example of FIG. 36, the gas ejection portion 17b is composed of 13 vertical holes, but the number of vertical holes constituting the gas ejection portion 17b is not limited to 13. It may be less than 13 or more than 13. Further, the sizes of the plurality of vertical holes constituting the gas ejection portion 17b are not limited to two types, and may be three or more types. Alternatively, the sizes of all the vertical holes of the plurality of vertical holes constituting the gas ejection portion 17b may be different from each other.

[0189] (9) Each of the gas nozzles 17 in FIGS. 22 and 23 according to the second embodiment may be attached to the housing of the coating apparatus 1 so as to be position-adjustable with respect to the adsorption holding portion 11. FIGS. 37 and 38 are schematic plan views of the coating apparatus 1 showing an example in which position adjustment is performed on some of the plurality of gas nozzles 17 in FIGS. 22 and 23.

[0190] As shown by the white arrows in FIGS. 37 and 38, in the coating apparatus 1 of this example, each of the plurality of gas nozzles 17 is position - adjustable in the direction approaching and separating from the adsorption holding part 11. In the example of FIG. 37, three of the four gas nozzles 17 are fixed so as to be close to the adsorption holding part 11, and one gas nozzle 17 is fixed so as to be separated from the adsorption holding part 11 by a predetermined distance. Also, in the example of FIG. 38, two of the four gas nozzles 17 are fixed so as to be close to the adsorption holding part 11, and two gas nozzles 17 are fixed so as to be separated from the adsorption holding part 11 by a predetermined distance.

[0191] Thus, by appropriately adjusting the positions of the plurality of gas nozzles 17 with respect to the adsorption holding part 11, a desired amount of temperature - adjusting gas can be supplied to a plurality of portions (a plurality of annular portions) in the radial direction of the lower surface of the substrate W adsorbed and held on the adsorption holding part 11.

[0192] 4. Corresponding relationship between each component of the claims and each element of the embodiment Hereinafter, an example of the correspondence between each component of the claims and each element of the embodiment will be described. In the above - mentioned embodiment, the rotation holding device 10 is an example of a rotation holding device, the adsorption holding part 11 is an example of an adsorption holding part, the upper surface 11u is an example of an upper surface, the rotation shaft 12 and the rotation driving part 13 are examples of a rotation driving part, and the rotation shaft 12 and the central axis 11c are examples of a rotation axis.

[0193] Also, the peripheral region R1 is an example of a peripheral region, the central region R2 is an example of a central region, the suction hole vh1 is an example of a first suction hole, the suction hole vh2 is an example of a second suction hole, the angular pitch α is an example of the angular pitch of the first suction hole, the angular pitch β is an example of the angular pitch of the second suction hole, the linear path LP is an example of a linear path, and the annular path RP is an example of an annular path.

[0194] Furthermore, the gas nozzle 17, the gas supply system 18, and the gas nozzles 170A to 170E are examples of a temperature adjustment unit and a gas supply unit, the upper surfaces 170u of the gas nozzles 170A to 170E are examples of a first annular opposing surface, the plurality of through-holes h1 to hn of the plurality of through-hole groups g1 to g8 are examples of a plurality of gas injection ports, the upper surface 180u of the gas nozzle 170E is an example of a second annular opposing surface, the processing liquid supply device 20 is an example of a processing liquid supply device, and the coating device 1 is an example of a substrate processing device. As each component of the claims, various other elements having the configurations or functions described in the claims can also be used.

Description of Reference Numerals

[0195] 1... Coating device, 10... Rotational holding device, 11c... Central axis, 11u, 170u, 180u... Upper surface, 12... Rotation axis, 13... Rotational drive unit, 14... Suction device, 15... Cup, 15d... Drain, 15x... Bottom, 15y... Outer peripheral wall portion, 16... Drainage guide pipe, 17, 170A, 170B, 170C, 170D, 170E... Gas nozzles, 17a... Gas introduction portion, 17b... Gas ejection portion, 17v... Gas supply path, 18... Gas supply system, 20... Processing liquid supply device, 21... Liquid nozzle, 22... Processing liquid supply system, 23... Nozzle moving portion, 40... Disk-shaped member, 41, 61... Adsorbing portion, 42... Intake path forming portion, 43... Support portion, 43b, 73... Communication hole, 50, 180... Annular member, 60... Upper circular member, 60b... Lower surface, 62... Outer peripheral wall portion, 65... Threaded hole, 70... Lower circular member, 71... Support portion, 71a... Mounting portion, 72... Outer peripheral wall portion, 72g... Groove, 74, 172h, h1~hn... Through hole, 79... Sealing member, 99... Adsorbing and holding portion, 99c... Central axis, 170b... Lower surface, 171... Upper surface member, 172... Lower surface member, 172p... Gas flow path, 173... Internal space, 177, 179... Gas introduction member, 177a... Gas inlet, 177b... Gas flow path, 177c... Gas outlet, 178... Fixed member, BL... Threaded member, de... Downstream end, g1~g8, g11~g22... Group of through holes, LG... Linear groove portion, LP... Linear path, nc... Non-contact portion, pt1... First pitch, pt2... Second pitch, R1... Peripheral region, R2... Central region, RP... Annular path, RG... Annular groove portion, RL... Resist liquid, SL... Slit-shaped opening, sp1... One side portion, sp2... The other side portion, ut... Inclined portion, vh, vh1, vh2... Suction holes, vp... Intake path, W... Substrate

Claims

1. A rotary holding device that rotates while sucking and holding the central portion of the lower surface of a substrate, comprising: a suction holding portion that sucks and holds the central portion of the lower surface of the substrate; a rotary drive portion that rotates the suction holding portion around a rotary shaft extending in the vertical direction; a temperature adjustment portion that adjusts the temperature of at least a part of the peripheral edge portion of the lower surface of the substrate that is not sucked and held by the suction holding portion in a state where the suction holding portion sucks and holds the substrate.

2. The rotary holding device according to claim 1, wherein the temperature adjustment portion includes a gas supply portion that supplies a temperature adjustment gas to at least a part of the peripheral edge portion of the lower surface.

3. The rotary holding device according to claim 2, wherein the temperature adjustment gas is a gas adjusted so that the temperature of the portion of the substrate including the peripheral edge portion of the lower surface is made to coincide with or approach the temperature of the portion of the substrate including the central portion of the lower surface by being supplied to at least a part of the peripheral edge portion of the lower surface.

4. The rotary holding device according to claim 2 or 3, wherein the gas supply portion supplies the temperature adjustment gas to a region including the inner edge of the peripheral edge portion of the lower surface of the substrate.

5. The rotary holding device according to any one of claims 2 to 4, wherein the gas supply portion is configured to be able to simultaneously inject the temperature adjustment gas into a plurality of different portions of the peripheral edge portion of the lower surface of the substrate in a state where the suction holding portion sucks and holds the substrate.

6. The gas supply portion includes: a first annular opposing surface that surrounds the suction holding portion and faces at least a part of the peripheral edge portion of the lower surface of the substrate in a state where the suction holding portion sucks and holds the substrate; The rotary holding device according to any one of claims 2 to 5, wherein a plurality of gas injection ports for simultaneously injecting the temperature adjustment gas into at least a part of the peripheral edge portion of the lower surface of the substrate are formed on the first annular opposing surface in a state where the suction holding portion sucks and holds the substrate.

7. The rotary holding device according to claim 6, wherein at least a part of the plurality of gas injection ports are dispersedly arranged in the rotational direction centered on the rotary shaft.

8. The first annular opposing surface faces a first annular portion of the peripheral edge portion of the lower surface of the substrate in a state where the suction holding portion sucks and holds the substrate. The gas supply unit is provided so as to face a second annular portion that surrounds the first annular facing surface and surrounds the first annular portion of the lower surface peripheral portion of the substrate in a state where the adsorption holding unit adsorbs and holds the substrate, and further includes a second annular facing surface that guides the temperature adjustment gas jetted from the plurality of gas injection ports of the first annular facing surface to the outer peripheral end of the substrate. The rotary holding device according to claim 6 or 7.

9. The adsorption holding unit has an upper surface that adsorbs and holds the central portion of the lower surface of the substrate. The upper surface is a peripheral region along the outer edge, and a central region surrounded by the peripheral region. A plurality of first suction holes are provided in the peripheral region. A plurality of second suction holes are provided in the central region. The surface density of the plurality of first suction holes in the peripheral region is greater than the surface density of the plurality of second suction holes in the central region. The rotary holding device according to any one of claims 1 to 8.

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