Substrate processing equipment

Abstract

The objective is to provide a substrate processing apparatus that can suppress temperature variations within the surface of the substrate. [Solution] The substrate processing apparatus according to the embodiment includes a mounting table on which a substrate can be placed, a mounting section on which the placed substrate can be rotated, a cooling section capable of supplying cooling gas to the space between the mounting table and the substrate via a cooling gas nozzle, and a liquid supply section capable of supplying liquid to the surface of the substrate opposite to the surface of the mounting table. The cooling gas nozzle has at least one first nozzle hole that is inclined away from the rotational axis of the substrate as it approaches the substrate.

Description

Technical Field

[0001] Embodiments of the present invention relate to a substrate processing apparatus.

Background Art

[0002] As a method for removing contaminants such as particles adhering to the surface of a substrate such as an imprint template, a photolithography mask, or a semiconductor wafer, a freeze cleaning method has been proposed.

[0003] In the freeze cleaning method, first, a liquid is supplied to the surface of a rotating substrate. Next, the supply of the liquid is stopped, and a part of the supplied liquid is discharged to form a liquid film on the surface of the substrate. The liquid film formed on the surface of the substrate is frozen by a cooling gas supplied to the back surface of the substrate. When the liquid film freezes to form a frozen film, contaminants such as particles are incorporated into the frozen film, and the contaminants are separated from the surface of the substrate. Next, a liquid is supplied to the frozen film to melt the frozen film, and the contaminants are removed from the surface of the substrate together with the liquid.

[0004] Here, since the vicinity of the periphery of the substrate is close to the external atmosphere not only in the direction perpendicular to the surface of the substrate but also in the direction parallel to the surface of the substrate, the amount of heat input from the outside to the vicinity of the periphery of the substrate increases. Therefore, if a cooling gas is simply supplied to the back surface of the substrate, temperature variations may occur within the plane of the substrate. When temperature variations occur within the plane of the substrate, it becomes difficult to improve the removal rate of contaminants.

[0005] Therefore, the development of a substrate processing apparatus capable of suppressing the occurrence of temperature variations within the plane of the substrate has been desired.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

[0007] The problem that this invention aims to solve is to provide a substrate processing apparatus that can suppress temperature variations within the surface of the substrate. [Means for solving the problem]

[0008] The substrate processing apparatus according to the embodiment includes a mounting table on which a substrate can be placed, a mounting section on which the mounted substrate can be rotated, a cooling section capable of supplying cooling gas to the space between the mounting table and the substrate via a cooling gas nozzle, and a liquid supply section capable of supplying liquid to the surface of the substrate opposite to the surface of the mounting table. The cooling gas nozzle has at least one first nozzle hole that is inclined away from the rotational axis of the substrate as it approaches the substrate. [Effects of the Invention]

[0009] According to embodiments of the present invention, a substrate processing apparatus is provided that can suppress temperature variations within the surface of the substrate. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram illustrating the substrate processing apparatus according to this embodiment. [Figure 2] (a) is a schematic plan view of the cooling gas nozzle as seen from a direction along the rotation axis of the substrate. (b) is a schematic cross-sectional view of the cooling gas nozzle as seen from a direction intersecting the rotation axis of the substrate. [Figure 3] This is a schematic cross-sectional view illustrating a cooling gas nozzle according to another embodiment. [Figure 4] This is a schematic cross-sectional view illustrating a cooling gas nozzle according to another embodiment. [Figure 5] This is a schematic cross-sectional view illustrating a cooling gas nozzle according to another embodiment. [Figure 6]This is a timing chart illustrating the operation of a substrate processing device. [Figure 7] This is a schematic cross-sectional view illustrating a cooling gas nozzle related to a comparative example. [Figure 8] This graph illustrates the effect of the cooling gas nozzle in the comparative example. [Figure 9] This graph illustrates the effect of the cooling gas nozzle according to this embodiment. [Modes for carrying out the invention]

[0011] The embodiments will be illustrated below with reference to the drawings. In each drawing, similar components are denoted by the same reference numerals, and detailed descriptions will be omitted as appropriate.

[0012] The substrate 100 exemplified below can be, for example, a semiconductor wafer, an imprint template, a photolithography mask, or a plate-like body used in MEMS (Micro Electro Mechanical Systems). In this case, the substrate 100 may be a substrate with a pattern of raised and recessed areas formed on its surface, or it may be a substrate before the raised and recessed areas are formed (for example, a so-called bulk substrate).

[0013] Furthermore, in the following section, we will explain, as an example, the case where the substrate 100 is a photolithography mask. When the substrate 100 is a photolithography mask, the planar shape of the substrate 100 can be approximately rectangular.

[0014] Figure 1 is a schematic diagram illustrating a substrate processing apparatus 1 according to this embodiment. As shown in Figure 1, the substrate processing apparatus 1 includes, for example, a mounting unit 2, a cooling unit 3, a first liquid supply unit 4, a second liquid supply unit 5, a housing 6, a blower unit 7, a detection unit 8, an exhaust unit 9, a cooling gas nozzle 10, and a controller 11.

[0015] The placement unit 2 has, for example, a placement table 2a, a rotating shaft 2b, and a drive unit 2c. The placement table 2a is rotatably provided inside the housing 6. The placement table 2a has a plate shape. A plurality of support portions 2a1 for supporting the substrate 100 are provided on one main surface of the placement table 2a. The edges of the back surface 100a of the substrate 100 contact the plurality of support portions 2a1. When the substrate 100 is supported by the plurality of support portions 2a1, the surface 100b (the surface to be cleaned) of the substrate 100 faces away from the placement table 2a side. In addition, a hole 二aa penetrating in the thickness direction of the placement table 2a is provided at the central portion of the placement table 2a.

[0016] The rotating shaft 2b has a cylindrical shape. One end side of the rotating shaft 2b is joined to the placement table 2a. The other end side of the rotating shaft 2b is provided outside the housing 6. The rotating shaft 2b is connected to the drive unit 2c outside the housing 6.

[0017] A cooling gas supply pipe 3d described later is attached to the end of the rotating shaft 2b on the side opposite to the placement table 2a side. A rotating shaft seal (not shown) is provided between the end of the rotating shaft 2b on the side opposite to the placement table 2a side and the cooling gas supply pipe 3d. Therefore, the end of the rotating shaft 2b on the side opposite to the placement table 2a side is sealed to be airtight.

[0018] The drive unit 2c is provided outside the housing 6. The drive unit 2c is connected to the rotating shaft 2b. The drive unit 2c can have a rotating device such as a motor. The rotational force of the drive unit 2c is transmitted to the placement table 2a via the rotating shaft 2b. Therefore, the drive unit 2c can rotate the placement table 2a, and thus the substrate 100 placed on the placement table 2a.

[0019] In addition, the drive unit 2c can change not only the start and stop of rotation but also the rotation speed (rotational speed). The drive unit 2c can be provided with a control motor such as a servo motor, for example.

[0020] In other words, the mounting unit 2 has a mounting base 2a on which the substrate 100 can be placed, and the mounted substrate 100 is rotatable. In this case, the rotational axis 100c of the substrate 100 placed on the mounting base 2a can be approximately coaxial with the rotational axis of the mounting base 2a (for example, the central axis of the rotation axis 2b).

[0021] The cooling unit 3 supplies cooling gas 3a1 to the back surface 100a of the substrate 100, and to the space between the mounting base 2a and the back surface 100a of the substrate 100, via a cooling gas nozzle 10, which will be described later.

[0022] The cooling unit 3 includes, for example, a coolant section 3a, a filter 3b, a flow rate control unit 3c, and a cooling gas supply pipe 3d. The coolant section 3a, filter 3b, and flow rate control unit 3c are located outside the housing 6.

[0023] The coolant section 3a stores the coolant and generates the cooling gas 3a1. The coolant is a liquefied form of the cooling gas 3a1. The cooling gas 3a1 is not particularly limited as long as it is a gas that does not react easily with the material of the substrate 100. The cooling gas 3a1 can be an inert gas such as nitrogen gas, helium gas, or argon gas.

[0024] The coolant section 3a includes a tank for storing coolant and a vaporization section for vaporizing the coolant stored in the tank. The tank is equipped with a cooling device for maintaining the temperature of the coolant. The vaporization section raises the temperature of the coolant to generate cooling gas 3a1 from the coolant. The temperature of the cooling gas 3a1 should be below the freezing point of the liquid 101. For example, the temperature of the cooling gas 3a1 is about -170°C.

[0025] Filter 3b is connected to the coolant section 3a via piping. Filter 3b prevents contaminants such as particles contained in the coolant from flowing out to the substrate 100 side.

[0026] The flow control unit 3c is connected to the filter 3b via piping. The flow control unit 3c controls the flow rate of the cooling gas 3a1. The flow control unit 3c can be, for example, an MFC (Mass Flow Controller). Alternatively, the flow control unit 3c may indirectly control the flow rate of the cooling gas 3a1 by controlling the supply pressure of the cooling gas 3a1. In this case, the flow control unit 3c can be, for example, an APC (Auto Pressure Controller).

[0027] In the coolant section 3a, the temperature of the cooling gas 3a1 generated from the coolant is approximately at a predetermined temperature. Therefore, the flow rate control unit 3c can control the flow rate of the cooling gas 3a1, thereby controlling the temperature of the substrate 100 and, consequently, the temperature of the liquid 101 on the surface 100b of the substrate 100. For example, by controlling the flow rate of the cooling gas 3a1 with the flow rate control unit 3c, the liquid 101 can be made to a supercooled state in the supercooling process described later.

[0028] The cooling gas supply pipe 3d is cylindrical in shape. One end of the cooling gas supply pipe 3d is connected to the flow control unit 3c. The other end of the cooling gas supply pipe 3d (the end on the discharge side of the cooling gas 3a1) is provided with a cooling gas nozzle 10, which will be described later. The cooling gas 3a1, whose flow rate is controlled by the flow control unit 3c, is supplied to the cooling gas nozzle 10 via the cooling gas supply pipe 3d.

[0029] The first liquid supply unit 4 supplies liquid 101 to the surface 100b of the substrate 100 (the side opposite to the mounting base 2a). In the freezing process (solid-liquid phase) described later, when the liquid 101 changes into a solid, its volume changes, generating a pressure wave. It is believed that this pressure wave separates contaminants adhering to the surface 100b of the substrate 100. Therefore, there are no particular limitations on the liquid 101 as long as it does not react easily with the material of the substrate 100.

[0030] Furthermore, if the liquid 101 expands in volume when frozen, it is conceivable that contaminants adhering to the surface of the substrate 100 can be separated by utilizing the physical force associated with the volume increase. For this reason, it is preferable that the liquid 101 is a liquid that does not react easily with the material of the substrate 100 and expands in volume when frozen. For example, the liquid 101 can be water (e.g., pure water or ultrapure water) or a liquid mainly composed of water. A liquid mainly composed of water can be, for example, a mixture of water and alcohol, a mixture of water and an acidic solution, or a mixture of water and an alkaline solution.

[0031] The first liquid supply unit 4 includes, for example, a liquid storage unit 4a, a supply unit 4b, a flow rate control unit 4c, and a liquid nozzle 4d. The liquid storage unit 4a, the supply unit 4b, and the flow rate control unit 4c are located outside the housing 6.

[0032] The liquid storage section 4a stores the liquid 101. The liquid 101 is stored in the liquid storage section 4a at a temperature higher than its freezing point. The temperature of the liquid 101 is, for example, room temperature (20°C).

[0033] The supply unit 4b is connected to the liquid storage unit 4a via piping. The supply unit 4b supplies the liquid 101 stored in the liquid storage unit 4a to the liquid nozzle 4d. The supply unit 4b is, for example, a pump resistant to the liquid 101.

[0034] The flow control unit 4c is connected to the supply unit 4b via piping. The flow control unit 4c controls the flow rate of the liquid 101 supplied by the supply unit 4b. The flow control unit 4c can be, for example, a flow control valve. The flow control unit 4c can also start and stop the supply of the liquid 101.

[0035] The liquid nozzle 4d is located inside the housing 6. The liquid nozzle 4d is cylindrical in shape. One end of the liquid nozzle 4d is connected to the flow control unit 4c via piping. The other end of the liquid nozzle 4d faces the surface 100b of the substrate 100 which is placed on the mounting base 2a. Therefore, the liquid 101 discharged from the liquid nozzle 4d is supplied to the surface 100b of the substrate 100.

[0036] The other end of the liquid nozzle 4d (the outlet for the liquid 101) is located, for example, approximately in the center of the surface 100b of the substrate 100. The liquid 101 discharged from the liquid nozzle 4d spreads from approximately in the center of the surface 100b of the substrate 100, forming a liquid film with approximately constant thickness on the surface 100b of the substrate 100. Hereafter, the film of liquid 101 formed on the surface 100b of the substrate 100 will simply be referred to as the liquid film.

[0037] The second liquid supply unit 5 supplies liquid 102 to the surface 100b of the substrate 100. The second liquid supply unit 5 includes a liquid storage unit 5a, a supply unit 5b, a flow rate control unit 5c, and a liquid nozzle 4d.

[0038] Liquid 102 can be used in the thawing process described later. Therefore, there are no particular limitations on liquid 102 as long as it does not react easily with the material of the substrate 100 and does not easily remain on the surface 100b of the substrate 100 in the drying process described later. Liquid 102 can be, for example, water (e.g., pure water or ultrapure water) or a mixture of water and alcohol.

[0039] The liquid storage unit 5a can be the same as the liquid storage unit 4a described above. The supply unit 5b can be the same as the supply unit 4b described above. The flow rate control unit 5c can be the same as the flow rate control unit 4c described above.

[0040] The temperature of liquid 102 can be higher than the freezing point of liquid 101. Alternatively, the temperature of liquid 102 can be such that it can thaw the frozen liquid 101. For example, the temperature of liquid 102 can be around room temperature (20°C).

[0041] Furthermore, liquid 101 can also be used in the thawing process described later. If liquid 101 is used in the thawing process, the second liquid supply unit 5 can be omitted. Furthermore, the liquid nozzle 4d can be used interchangeably in the first liquid supply unit 4 and the second liquid supply unit 5. Alternatively, separate liquid nozzles can be provided for discharging liquid 101 and liquid 102.

[0042] The housing 6 is box-shaped. A cover 6a is provided inside the housing 6. The cover 6a receives the liquids 101 and 102 that are supplied to the circuit board 100 and discharged to the outside of the circuit board 100 as the circuit board 100 rotates. A partition plate 6b is also provided inside the housing 6. The partition plate 6b is provided between the outer surface of the cover 6a and the inner surface of the housing 6.

[0043] An outlet 6c is provided on the bottom side of the housing 6. Used cooling gas 3a1, air 7a, liquid 101, and liquid 102 are discharged to the outside of the housing 6 through the outlet 6c. Exhaust pipes 6c1 and 6c2 are connected to the outlet 6c. Used cooling gas 3a1 and air 7a are discharged to the outside of the housing 6 via exhaust pipe 6c1. Used liquids 101 and liquid 102 are discharged to the outside of the housing 6 via exhaust pipe 6c2.

[0044] The air blower 7 is installed, for example, on the ceiling of the housing 6. The air blower 7 supplies air 7a (outside air) to the space between the partition plate 6b and the ceiling of the housing 6. As a result, the pressure in the space between the partition plate 6b and the ceiling of the housing 6 becomes higher than the external pressure. Consequently, it becomes easier to guide the air 7a supplied by the air blower 7 to the exhaust port 6c. In addition, it is possible to suppress the entry of contaminants such as particles into the interior of the housing 6 from the exhaust port 6c.

[0045] The detection unit 8 is located in the space between the partition plate 6b and the ceiling of the housing 6. The detection unit 8 detects the temperature of the liquid film and the frozen film formed when the liquid film freezes. The detection unit 8 can be, for example, a radiation thermometer, a thermoviewer, a thermocouple, or a resistance thermometer. The detected temperature of the liquid film can be used, for example, to control the supercooled state of the liquid 101 in the supercooling process described later.

[0046] The exhaust section 9 is connected to the exhaust pipe 6c1. The exhaust section 9 can be, for example, an exhaust pump such as a blower.

[0047] The controller 11 controls the operation of each element provided in the substrate processing apparatus 1. The controller 11 has, for example, an arithmetic unit such as a CPU (Central Processing Unit) and a storage unit such as semiconductor memory. The controller 11 is, for example, a computer. The storage unit can store control programs that control the operation of each element provided in the substrate processing apparatus 1. The arithmetic unit controls the operation of each element provided in the substrate processing apparatus 1 using the control programs stored in the storage unit, data input by the operator, data from the detection unit 8, etc.

[0048] If cooling gas 3a1 is simply supplied to the back surface 100a of the substrate 100, temperature differences may occur within the surface of the substrate 100. For example, the area near the periphery of the substrate 100 is in close proximity to the external atmosphere not only in the direction perpendicular to the surface of the substrate 100 but also in the direction parallel to the surface of the substrate 100, resulting in a large amount of heat input from the outside to the area near the periphery of the substrate 100. Therefore, if cooling gas 3a1 is simply supplied to the back surface 100a of the substrate, the cooling of the area near the periphery of the substrate 100 may be insufficient compared to the area near the center, and temperature variations may occur within the surface of the substrate 100. If temperature variations occur within the surface of the substrate 100, the separation state of contaminants may vary from region to region of the substrate 100 during the cooling process (supercooling process + freezing process) described later, making it difficult to improve the contaminant removal rate across the entire surface of the substrate 100.

[0049] Therefore, the substrate processing apparatus 1 according to this embodiment is provided with a cooling gas nozzle 10. The cooling gas nozzle 10 is a nozzle having at least one nozzle hole that supplies cooling gas 3a1 to the surface of the substrate 100 on the mounting table 2a side. As shown in Figure 1, the cooling gas nozzle 10 is provided at the end of the cooling gas supply pipe 3d on the outlet side of the cooling gas 3a1. The cooling gas nozzle 10 is provided, for example, inside the hole 2aa of the mounting base 2a. The end of the cooling gas nozzle 10 on the substrate 100 side may protrude further toward the substrate 100 than the substrate 100 side surface of the mounting base 2a, or it may be flush with the substrate 100 side surface of the mounting base 2a, or it may be located inside the hole 2aa of the mounting base 2a. Note that in the example shown in Figure 1, the end of the cooling gas nozzle 10 on the substrate 100 side protrudes further toward the substrate 100 than the substrate 100 side surface of the mounting base 2a.

[0050] Figure 2(a) is a schematic plan view of the cooling gas nozzle 10 as seen from a direction along the rotational axis 100c of the substrate 100. Figure 2(b) is a schematic cross-sectional view of the cooling gas nozzle 10 as seen from a direction intersecting the rotational axis 100c of the substrate 100.

[0051] As shown in Figures 1, 2(a), and 2(b), the cooling gas nozzle 10 has a cylindrical shape with both ends covered by plate-like members, and has a supply port 10a, a flow path 10b, a flow path 10c, and a nozzle hole 10d (corresponding to an example of a first nozzle hole). The supply port 10a, the flow path 10b, the flow path 10c, and the nozzle hole 10d are in communication with each other. The nozzle hole 10d is provided to open on the surface (nozzle surface) of the end of the cooling gas nozzle 10 on the substrate 100 side, serving as a flow path for supplying cooling gas 3a1 from the cooling gas nozzle 10 to the substrate 100. The cooling gas 3a1 is supplied into the cooling gas nozzle 10 from the supply port 10a and supplied to the substrate 100 through the flow paths 10b and 10c and then through the nozzle hole 10d.

[0052] The supply port 10a is located approximately in the center of the cooling gas nozzle 10 and extends along the rotational axis 100c of the substrate 100. One end of the supply port 10a opens into a plate-shaped member at the end of the cooling gas nozzle 10 opposite to the substrate 100. A cooling gas supply pipe 3d is connected to one end of the supply port 10a. The other end of the supply port 10a opens into the flow path 10b.

[0053] The flow path 10b is located inside the cooling gas nozzle 10. The flow path 10b extends in a direction intersecting, for example, the rotational axis 100c of the substrate 100. The flow path 10b can be, for example, a cylindrical space surrounded by plate-like members provided at both ends of the cooling gas nozzle 10 and its inner circumferential surface.

[0054] The flow path 10b is, for example, a space with an inner diameter larger than the inner diameter of the cooling gas supply pipe 3d. This allows the cooling gas nozzle 10 to retain the cooling gas 3a1 supplied by the cooling gas supply pipe 3d in the flow path 10b before supplying the cooling gas 3a1 to the back surface of the substrate 100 through the nozzle hole 10d. As a result, a stable cooling effect can be obtained because the cooling gas 3a1 at a constant pressure within the space of the flow path 10b can be supplied from the nozzle hole 10d. Furthermore, if the cooling gas nozzle 10 is provided with multiple nozzle holes 10d, multiple nozzle holes 10d can be connected to a single flow path 10b. This allows the cooling gas 3a1 retained in the common flow path 10b to be discharged from multiple nozzle holes 10d, supplying the cooling gas 3a1 at approximately the same pressure to each, resulting in a uniform cooling effect across the surface of the substrate 100.

[0055] The flow path 10c is located inside the cooling gas nozzle 10. The flow path 10c extends, for example, along the rotational axis 100c of the substrate 100. One end of the flow path 10c opens to the substrate 100-side end of the flow path 10b. Near the other end of the flow path 10c, the end of the nozzle hole 10d opposite to the substrate 100-side is connected. The flow path 10c can be, for example, columnar in shape, and one can be provided for each nozzle hole 10d. If multiple nozzle holes 10d are provided, one flow path 10c can be provided for each of the multiple nozzle holes 10d. For example, multiple nozzle holes 10d can be connected to an annular flow path 10c. Note that the flow path 10c is not necessarily required and can be omitted. If the flow path 10c is omitted, the nozzle hole 10d is connected to the flow path 10b.

[0056] At least one nozzle hole 10d can be provided. If multiple nozzle holes 10d are provided, for example, the multiple nozzle holes 10d can be provided at different radial positions around the rotational axis 100c of the substrate 100 (the rotational axis of the mounting base 2a). The nozzle hole 10d is connected to the supply port 10a via the flow path 10c and the flow path 10b. As shown in Figure 2(b), the nozzle hole 10d is inclined with respect to the rotational axis 100c of the substrate 100. For example, as the nozzle hole 10d approaches the substrate 100, it is inclined away from the rotational axis 100c of the substrate 100.

[0057] In this case, as shown in Figures 2(a) and (b), the distance R (corresponding to an example of a first distance) between point A (corresponding to an example of a first point) where the extension line 10d1 of the central axis of the nozzle hole 10d intersects the back surface 100a of the substrate 100 and the rotational axis 100c of the substrate 100 can be made smaller than or equal to the maximum value of the distance (corresponding to an example of a second distance) between the periphery of the substrate 100 and the rotational axis 100c of the substrate 100.

[0058] For example, if the planar shape of the substrate 100 is a rectangle, the distance R can be made to be shorter than or equal to half the length of the diagonal. For example, if the planar shape of the substrate 100 is a circle, the distance R can be made to be shorter than or equal to the radius.

[0059] Furthermore, there is a correlation between the distance R and the angle (tilt angle θ) between the extension line 10d1 of the central axis of the nozzle hole 10d and the rotational center axis 100c of the substrate 100. For example, the longer the distance R, the larger the tilt angle θ becomes.

[0060] The nozzle hole 10d may be, for example, a hole provided in the cooling gas nozzle 10, or a hole in a pipe (cylindrical member) provided in the cooling gas nozzle 10. In other words, the pipe may be inserted into a hole formed in the surface (nozzle surface) of the end of the cooling gas nozzle 10 on the substrate 100 side, thereby constituting the nozzle hole 10d. The nozzle hole 10d illustrated in Figure 2(b) is a hole in a pipe provided in the cooling gas nozzle 10. The opening da of the nozzle hole 10d on the substrate 100 side may be flush with the surface (nozzle surface) of the end of the cooling gas nozzle 10 on the substrate 100 side. Alternatively, as shown in Figure 2(b), the pipe may protrude from the surface (nozzle surface) of the end of the cooling gas nozzle 10 on the substrate 100 side, and the opening da may be in a position that protrudes from the surface (nozzle surface) of the end of the cooling gas nozzle 10 on the substrate 100 side.

[0061] In this way, if the pipe of the cooling gas nozzle 10 protrudes from the end surface (nozzle surface) on the substrate 100 side, a certain distance can be maintained between the cooling gas nozzle 10 and the substrate 100, preventing water droplets adhering to the end surface (nozzle surface) of the cooling gas nozzle 10 on the substrate 100 side from adhering to and contaminating the back surface of the substrate 100, while the opening da of the nozzle hole 10d approaches the substrate 100, allowing for the supply of a cooling gas at a lower temperature.

[0062] Furthermore, when the nozzle surface of the cooling gas nozzle 10 is processed to form a nozzle hole 10d, there is a risk that processing residue generated in the processed area may mix with the cooling gas 3a1 passing through the nozzle hole 10d and adhere to the substrate 100, becoming particles. In contrast, by inserting a pipe into the hole formed in the nozzle surface and supplying the cooling gas 3a1 through the hole in the pipe as the nozzle hole 10d, it is possible to suppress direct contact between the processed part of the nozzle surface and the cooling gas 3a1, thereby reducing the probability that particles generated from the processed part will adhere to the substrate 100 along the flow of the cooling gas 3a1.

[0063] The cooling gas 3a1 discharged from the nozzle hole 10d is supplied to the back surface 100a of the substrate 100. At this time, as the nozzle hole 10d approaches the substrate 100, it is inclined away from the rotational axis 100c of the substrate 100, so the cooling gas 3a1 discharged from the nozzle hole 10d mainly flows along the back surface 100a of the substrate 100 toward the peripheral edge of the substrate 100. In addition, a portion of the cooling gas 3a1 that collides with the back surface 100a of the substrate 100 flows along the back surface 100a of the substrate 100 toward the rotational axis 100c of the substrate 100. In this case, the flow rate of the cooling gas 3a1 flowing toward the peripheral edge of the substrate 100 is greater than the flow rate of the cooling gas 3a1 flowing toward the rotational axis 100c of the substrate 100.

[0064] As mentioned above, the amount of heat input to the substrate 100 from the outside is greater in the peripheral region of the substrate 100 than in the central region of the substrate 100. Since the cooling gas nozzle 10 according to this embodiment is provided with the nozzle hole 10d described above, the amount of cooling gas 3a1 supplied to the peripheral region of the substrate 100, where the amount of heat input is greater, can be made greater than the amount of cooling gas 3a1 supplied to the central region of the substrate 100, where the amount of heat input is less.

[0065] Therefore, it is possible to suppress temperature variations within the surface of the substrate 100. As a result, in the cooling process (supercooling process + freezing process) described later, it is possible to suppress variations in the separation state of contaminants in each region of the substrate 100, thereby improving the removal rate of contaminants across the entire surface of the substrate 100.

[0066] The number, arrangement, inclination angle θ, diameter of the nozzle holes 10d, and the distance G between the opening of the nozzle holes 10d and the back surface 100a of the substrate 100 in the direction along the rotational axis 100c of the substrate 100 can be appropriately changed according to the planar dimensions of the substrate 100. For example, if the planar dimensions of the substrate 100 are large, the number of nozzle holes 10d can be increased or the inclination angle θ can be increased. The flow rate of the cooling gas 3a1 can also be adjusted by changing the diameter of the nozzle holes 10d. Furthermore, by shortening the distance G, the flow rate of the cooling gas 3a1 directly supplied to the back surface 100a of the substrate 100 can be increased.

[0067] For example, by conducting experiments or simulations, the number, arrangement, tilt angle θ, diameter, and distance G of the nozzle holes 10d can be appropriately determined to minimize temperature variations within the plane of the substrate 100.

[0068] Figure 3 is a schematic cross-sectional view illustrating a cooling gas nozzle 20 according to another embodiment. As shown in Figure 3, the cooling gas nozzle 20 has a cylindrical shape with both ends covered by plate-like members, and has a supply port 10a, a flow path 10b, a nozzle hole 20a (corresponding to an example of a second nozzle hole), a nozzle hole 20b (corresponding to an example of a first nozzle hole), and a nozzle hole 20c (corresponding to an example of a first nozzle hole). In the cooling gas nozzle 20, the aforementioned flow path 10c is omitted. The nozzle holes 20a, 20b, and 20c are directly provided in the flow path 10b.

[0069] For example, the nozzle hole 20a supplies cooling gas 3a1 to the vicinity of the center of the back surface 100a of the substrate 100. The nozzle hole 20a extends, for example, along the rotational axis 100c of the substrate 100.

[0070] For example, nozzle hole 20b supplies cooling gas 3a1 to the vicinity of the periphery of the back surface 100a of the substrate 100. For example, nozzle hole 20c supplies cooling gas 3a1 to the region between the vicinity of the center and the vicinity of the periphery of the back surface 100a of the substrate 100. Furthermore, nozzle holes 20c and 20b, similar to the nozzle hole 10d described above, are inclined away from the rotational axis 100c of the substrate 100 as they approach the substrate 100.

[0071] The diameter of the opening 20A of the nozzle hole 20a can be made smaller than the diameters of the openings 20B and 20C of the nozzle holes 20b and 20c. In this way, the flow rate of the cooling gas 3a1 supplied directly to the central region of the back surface 100a of the substrate 100 can be reduced compared to the peripheral region, which receives a large amount of heat from the outside and is difficult to cool. This suppresses localized cooling in the central region and reduces the variation in in-plane temperature of the liquid film formed on the surface 100b of the substrate 100. Furthermore, the diameter of the opening 20B can be made larger than the diameter of the opening 20C. This allows for a larger flow rate of the cooling gas 3a1 supplied to the peripheral region, which is difficult to cool, further reducing the variation in in-plane temperature of the liquid film formed on the surface 100b of the substrate 100.

[0072] Furthermore, the distance R1 (corresponding to an example of the first distance) between point A1 (corresponding to an example of the first point) where the extension of the central axis 20b1 of the nozzle hole 20b intersects the back surface 100a of the substrate 100 and the rotational axis 100c of the substrate 100 is longer than the distance R2 (corresponding to an example of the first distance) between point A2 (corresponding to an example of the first point) where the extension of the central axis 20c1 of the nozzle hole 20c intersects the back surface 100a of the substrate 100 and the rotational axis 100c of the substrate 100. Also, the inclination angle θ1 of the nozzle hole 20b is greater than the inclination angle θ2 of the nozzle hole 20c.

[0073] Furthermore, at least one nozzle hole 20a, nozzle hole 20b, and nozzle hole 20c may be provided. In this case, the number of nozzle holes 20b can be the same as or greater than the number of nozzle holes 20c. The number of nozzle holes 20c can be the same as or greater than the number of nozzle holes 20a.

[0074] In this manner, when multiple nozzle holes are provided, each having a different distance (distance R) between the point where the extension of the central axis of the nozzle hole intersects the back surface 100a of the substrate 100 and the rotational center axis 100c of the substrate 100, the temperature variation within the plane of the substrate 100 can be reduced by arranging the multiple nozzle holes such that the relationship between the conductance of the nozzle holes and the processing area is as follows.

[0075] Conductance is the reciprocal of the resistance that occurs when a gas flows through a specific region, and in this specification, it means the ease with which a gas flows through a nozzle opening. Furthermore, when there are multiple nozzle holes with the same distance R, these nozzle holes are referred to as a "group of nozzle holes with the same distance," and multiple nozzles with different distances R relative to this group of nozzle holes with the same distance are referred to as a "group of nozzle holes with different distances." The processing area is the area of ​​the back surface 100a of the substrate 100, which is cooled by the outward flow of the cooling gas supplied from the cooling gas nozzle 10 that comes into contact with the back surface of the substrate.

[0076] First, let "C" be the ratio of the conductance of a group of nozzle holes (corresponding to an example of the conductance of a first group of nozzle holes), which is the sum of the conductances of all nozzle holes that are at the same distance R, to the sum of the conductances of all nozzle holes provided in the cooling gas nozzle 20.

[0077] For example, consider the cooling gas nozzle 20 illustrated in Figure 3, where multiple nozzle holes 20b are provided at a distance R equal to nozzle hole 20b, and multiple nozzle holes 20c are provided at a distance R equal to nozzle hole 20c. In this case, let "C1" be the ratio of the conductance of the multiple nozzle holes 20b to the sum of the conductances of all nozzle holes. Similarly, let "C2" be the ratio of the conductance of the multiple nozzle holes 20c to the sum of the conductances of all nozzle holes. If we let c0 be the conductance of nozzle hole 20a, c1 be the sum of the conductances of multiple nozzle holes 20b, and c2 be the sum of the conductances of multiple nozzle holes 20c, then we can write "C1 = c1 / (c0 + c1 + c2)" and "C2 = c2 / (c0 + c1 + c2)".

[0078] Then, "S" is defined as the ratio of the processing area of ​​a group of nozzle holes that are at equal distance from each other to the sum of the processing areas of all the nozzle holes provided in the cooling gas nozzle 20. The "processing area of ​​nozzle holes at equal distances" can be determined from the difference between the area of ​​the back surface 100a and the area of ​​a virtual circle with radius R.

[0079] For example, in the cooling gas nozzle 20 illustrated in Figure 3, the ratio of the processing area of ​​multiple nozzle holes 20b to the sum of the processing areas of all nozzle holes is "S1", and the ratio of the processing area of ​​multiple nozzle holes 20c to the sum of the processing areas of all nozzle holes is "S2". If we denote the processing area of ​​nozzle hole 20a as s0, the processing area of ​​multiple nozzle holes 20b as s1, and the processing area of ​​multiple nozzle holes 20c as s2, then we can write "S1 = s1 / (s0 + s1 + s2)" and "S2 = s2 / (s0 + s1 + s2)". Note that since the distance R of nozzle hole 20a is zero, s0 can be considered the same as the area of ​​the back surface 100a.

[0080] Then, the distance between the point where the extension of the central axis of the nozzle hole intersects the back surface 100a of the substrate 100 and the rotational central axis 100c of the substrate 100 can be set such that the difference between the maximum and minimum values ​​obtained by "V=C / S" is 3 or less.

[0081] For example, in the case of the cooling gas nozzle 20 illustrated in Figure 3, distances R1 and R2 can be set such that the difference between "V1=C1 / S1" and "V2=C2 / S2" is 3 or less.

[0082] In this way, the difference between the temperature of the substrate 100 in the region between point A1 and the periphery of the substrate 100 and the temperature of the substrate 100 in the region between point A2 and point A1 can be reduced. In other words, the temperature variation within the plane of the substrate 100 can be reduced.

[0083] In freeze-washing, the cleaning power (contaminant removal rate) is improved by repeatedly freezing and thawing. The contaminant removal rate (PRE) can be expressed by the following formula, where NI is the number of contaminants before washing and NP is the number of contaminants after washing. PRE(%) = ((NI-NP) / NI) × 100 When the temperature variation within the plane of the substrate 100 increases, the variation in cleaning power per freezing cycle within the substrate surface also increases. As a result, it becomes necessary to increase the number of freezing cycles, which worsens throughput. Therefore, it is desirable to reduce the temperature variation within the plane of the substrate 100 and reduce the variation in cleaning power per freezing cycle within the plane. As described above, by keeping the variation in "V" to 3 or less, the variation in cleaning power can be suppressed to less than 20%.

[0084] Furthermore, the conductance ca of the nozzle hole used in the formula for calculating "V" above can be calculated using the following formula, where La is the length of the central axis of the nozzle hole and sa is the cross-sectional area of ​​the nozzle hole. ca = (6.28 × 10 8 )×sa 2 / La By using the conductance determined in this way, the temperature variation within the plane of the substrate 100 is reduced.

[0085] Furthermore, it is preferable to minimize the difference between the maximum value of the ratio of the sum of the conductances of all nozzle hole groups at different distances R to the distance R, and the minimum value of the ratio of the sum of the conductances of all nozzle hole groups at different distances R to the distance R. For example, the maximum value can be set to be four times or less of the minimum value. This method further reduces temperature variations within the plane of the substrate 100.

[0086] Figure 4 is a schematic cross-sectional view illustrating a cooling gas nozzle 12 according to another embodiment. The cooling gas nozzle 12 shown in Figure 4 omits the flow path 10b, and the central axis of the flow path 10c coincides with the rotational central axis 100c. This point differs from the cooling gas nozzle of the embodiment shown in Figures 1 and 3.

[0087] As shown in Figure 4, the cooling gas nozzle 12 is, for example, cylindrical and has a supply port 10a, a flow path 10c, a nozzle hole 12a, and a nozzle hole 12b. The supply port 10a, the flow path 10c, and the nozzle hole 12a are in communication with each other.

[0088] The diameter of the flow path 10c is approximately the same as the diameter of the cooling gas supply pipe 3d. The flow path 10c is connected to the supply port 10a. The nozzle holes 12a and 12b are located inside the cooling gas nozzle 12 and intersect with the flow path 10c. The nozzle holes 12a and 12b are inclined away from the rotational axis 100c of the substrate 100 as they approach the substrate 100. One end of each nozzle hole 12a and 12b communicates with the flow path 10c. The other ends of each nozzle hole 12a and 12b open as openings 12a1 and 12b1 on the substrate 100-side end (nozzle surface) of the cooling gas nozzle 12, respectively.

[0089] The cooling gas 3a1 is supplied into the cooling gas nozzle 12 from a supply port 10a connected to the cooling gas supply pipe 3d, and then supplied to the substrate 100 through the flow path 10c and nozzle holes 12a and 12b.

[0090] The opening 12b1 of the nozzle hole 12b can be located at a different position from the opening 12a1 of the nozzle hole 12a. For example, when viewed from a direction perpendicular to the surface 100b of the substrate 100, the distance between the rotational axis 100c and the opening 12b1 of the nozzle hole 12b is different from the distance between the rotational axis 100c and the opening 12a1 of the nozzle hole 12a.

[0091] The flow path 10c has space above the position where the inclined nozzle holes 12a and 12b are connected. This allows the cooling gas nozzle 12 to retain the cooling gas 3a1 supplied by the cooling gas supply pipe 3d in the space of the flow path 10c and supply the cooling gas 3a1 to the back surface of the substrate 100 from the nozzle holes 12a and 12b. As a result, a stable cooling effect can be obtained because the cooling gas 3a1 at a constant pressure in the space of the flow path 10c can be supplied from the nozzle holes 12a and 12b. Furthermore, by connecting multiple nozzle holes to a single flow path 10c, the cooling gas 3a1 retained in the common flow path 10c can be discharged from multiple nozzle holes. As a result, the cooling gas 3a1 can be supplied from each of the multiple nozzle holes at approximately the same pressure. This results in a uniform cooling effect across the surface of the substrate 100.

[0092] In addition, similar to the nozzle hole 10a described above, a pipe (cylindrical member) may be inserted into a hole provided on the surface (nozzle surface) of the end of the cooling gas nozzle 12 on the substrate 100 side, and the hole in the pipe may constitute the nozzle holes 12a and 12b.

[0093] Figure 5 is a schematic cross-sectional view illustrating a cooling gas nozzle 13 according to another embodiment. As shown in Figure 5, the cooling gas nozzle 13 has, for example, a supply port 10a, a flow path 10c, a nozzle hole 12a, and a nozzle hole 13a. The cooling gas nozzle 13 shown in Figure 5 has a nozzle hole 13a at the end of the flow path 10c on the substrate 100 side. This is different from the cooling gas nozzle 12 in Figure 4.

[0094] The supply port 10a, the flow path 10c, and the nozzle hole 13a are in communication with each other. The nozzle hole 13a is located inside the cooling gas nozzle 13 and extends along the rotational axis 100c of the substrate 100. One end of the nozzle hole 13a communicates with the flow path 10c, and the other end of the nozzle hole 13a opens to the substrate 100 side end of the cooling gas nozzle 13.

[0095] The cooling gas 3a1 is supplied into the cooling gas nozzle 13 from a supply port 10a connected to the cooling gas supply pipe 3d, and then supplied to the substrate 100 through the flow path 10c via nozzle holes 12a, 12b, and 13a.

[0096] The opening 13a1 of the nozzle hole 13a is, for example, facing the center of the back surface 100a of the substrate 100. In this way, the cooling gas 3a1 can be directly supplied to the central region of the back surface 100a of the substrate 100. Therefore, even if the planar dimensions of the substrate 100 are large, it becomes easy to cool the entire back surface 100a of the substrate 100 to the same extent.

[0097] As shown in Figure 5, the diameter of the opening 13a1 of the nozzle hole 13a can be made smaller than the diameter of the opening 12a1 of the nozzle hole 12a and the diameter of the opening 12b1 of the nozzle hole 12b. In this way, the flow rate of the cooling gas 3a1 supplied directly to the central region of the back surface 100a of the substrate 100 can be reduced compared to the peripheral region of the back surface 100a of the substrate 100, where a large amount of heat input from the outside occurs and cooling is difficult. Therefore, localized cooling of the central region of the back surface 100a of the substrate 100 can be suppressed, and the variation in the in-plane temperature of the liquid film formed on the surface 100b of the substrate 100 can be reduced.

[0098] Furthermore, the center of the opening 13a1 of the nozzle hole 13a may be located at a position offset from the rotational axis 100c of the substrate 100. When the opening 13a1 is positioned to coincide with the rotational axis 100c, the same part of the substrate 100 (the central part) will always face the opening 13a1 even when the substrate 100 rotates. As a result, the central region of the back surface 100a of the substrate 100 is more easily cooled locally.

[0099] In contrast, if the opening 13a1 is located offset from the rotational axis 100c of the substrate, the portion of the back surface 100a of the substrate 100 that faces the opening 13a1 moves sequentially as the substrate 100 rotates. Therefore, more uniform cooling can be achieved in the central part near the rotational axis 100c and its surrounding areas.

[0100] In addition, similar to the nozzle hole 10a described above, a pipe (cylindrical member) may be inserted into a hole provided on the surface (nozzle surface) of the end of the cooling gas nozzle 13 on the substrate 100 side, and the hole in the pipe may constitute the nozzle hole 13a.

[0101] Next, we will illustrate the operation of the substrate processing apparatus 1. Figure 6 is a timing chart illustrating the operation of the substrate processing apparatus 1. Figure 6 shows the case where substrate 100 is a 6025 quartz (Qz) substrate (152 mm × 152 mm × 6.35 mm) and liquid 101 is pure water.

[0102] First, the circuit board 100 is loaded into the enclosure 6 through an inlet / outlet (not shown) of the enclosure 6. The loaded circuit board 100 is then placed and supported on multiple support parts 2a1 of the mounting base 2a.

[0103] After the substrate 100 is supported on the mounting table 2a, a freeze-cleaning process is performed, which includes a preliminary process, a cooling process (supercooling process + freezing process), a thawing process, and a drying process, as shown in Figure 6.

[0104] In the preliminary process, the controller 11 controls the supply unit 4b and the flow rate control unit 4c to supply liquid 101 at a predetermined flow rate to the surface 100b of the substrate 100. The controller 11 also controls the flow rate control unit 3c to supply cooling gas 3a1 at a predetermined flow rate to the back surface 100a of the substrate 100. The controller 11 also controls the drive unit 2c to rotate the substrate 100 at a second rotational speed.

[0105] For example, the second rotational speed is approximately 50 rpm to 500 rpm. For example, the flow rate of liquid 101 is approximately 0.1 L / min to 1 L / min. For example, the flow rate of cooling gas 3a1 is approximately 40 NL / min to 200 NL / min.

[0106] In the preliminary process, the temperature of the liquid film is approximately the same as the temperature of the supplied liquid 101, because the liquid 101 is continuously flowing. For example, if the temperature of the supplied liquid 101 is around room temperature (20°C), the temperature of the liquid film will be around room temperature (20°C).

[0107] Next, as shown in Figure 6, a cooling process (supercooling process + freezing process) is performed. In this embodiment, the cooling process is defined as the "supercooling process" from when the liquid 101 becomes supercooled until freezing begins, and the process from when the supercooled liquid 101 becomes frozen until thawing begins through the thawing process.

[0108] If the cooling rate of the liquid 101 becomes too fast, the liquid 101 will not become supercooled and will freeze immediately. Therefore, the controller 11 controls at least one of the flow rate of the cooling gas 3a1 and the rotation speed of the substrate 100 to ensure that the liquid 101 on the surface 100b of the substrate 100 becomes supercooled.

[0109] Furthermore, as mentioned above, the nozzle holes 10d, 20c, and 20b are inclined away from the rotational axis 100c of the substrate 100 as they are closer to the substrate 100. As a result, the temperature variation within the plane of the substrate 100 is reduced, making it possible to supercool the entire area of ​​the liquid 101 on the surface 100b of the substrate 100.

[0110] In the cooling process (supercooling process + freezing process), as illustrated in Figure 6, after setting the rotation speed to a first speed, the supply of liquid 101 that was supplied in the preliminary process is stopped. For example, the first rotation speed is approximately 0 rpm to 50 rpm. In other words, the controller 11 rotates the substrate 100 at a rotation speed lower than the rotation speed during the preliminary process.

[0111] In the cooling process (supercooling process + freezing process), the supply of liquid 101 is stopped, and the rotation speed of the substrate 100 is set to a first rotation speed which is lower than the second rotation speed, so that the liquid 101 present on the substrate 100 stagnates. As a result, the cooling gas 3a1 that has been continuously supplied to the back surface 100a of the substrate 100 causes the temperature of the liquid film on the substrate 100 to drop even further than the temperature of the liquid film in the preliminary process, resulting in a supercooled state.

[0112] The conditions under which liquid 101 becomes supercooled are influenced by factors such as the size of the substrate 100, the viscosity of liquid 101, and the specific heat of the cooling gas 3a1. Therefore, it is preferable to determine the control conditions for liquid 101 to become supercooled appropriately through experiments or simulations.

[0113] In a supercooled state, freezing of liquid 101 begins due to factors such as the temperature of the liquid film, the presence of contaminants such as particles or bubbles, and vibration.

[0114] When the supercooled liquid 101 begins to freeze, the process transitions from the supercooling step to the freezing step. In the initial stages of the freezing step, liquid 101 and frozen liquid 101 are present on the surface 100b of the substrate 100. Subsequently, the liquid 101 freezes completely, forming a frozen film. After the frozen film is formed, the temperature of the frozen film on the substrate 100 is further reduced by the cooling gas 3a1 continuously supplied to the back surface 100a of the substrate 100.

[0115] In this case, as described above, the nozzle holes 10d, 20c, and 20b are inclined away from the rotational axis 100c of the substrate 100 as they approach the substrate 100. Therefore, the temperature variation within the plane of the substrate 100 is reduced, and the entire area of ​​the liquid film on the substrate 100 can be frozen to form a frozen film.

[0116] Next, the thawing process is performed as shown in Figure 6. In the example shown in Figure 6, liquid 101 and liquid 102 are the same liquid. Therefore, in Figure 6, liquid 101 is supplied during the thawing process. During the thawing process, the controller 11 controls the supply unit 4b and the flow rate control unit 4c to supply liquid 101 at a predetermined flow rate to the surface 100b of the substrate 100. If liquid 101 and liquid 102 are different, the controller 11 controls the supply unit 5b and the flow rate control unit 5c to supply liquid 102 at a predetermined flow rate to the surface 100b of the substrate 100.

[0117] Furthermore, the controller 11 controls the flow control unit 3c to stop the supply of cooling gas 3a1. The controller 11 also controls the drive unit 2c to increase the rotation speed of the substrate 100 to a third rotation speed. The third rotation speed is, for example, around 200 rpm to 700 rpm. If the rotation speed of the substrate 100 increases, the liquid 101 and the frozen liquid 101 can be shaken off by centrifugal force. As a result, the liquid 101 and the frozen liquid 101 can be discharged from the surface 100b of the substrate 100. At this time, contaminants separated from the surface 100b of the substrate 100 are also discharged together with the liquid 101 and the frozen liquid 101.

[0118] In this case, by tilting the nozzle holes 10d, 20c, and 20b, a frozen film is formed over the entire surface of the substrate 100, allowing for efficient separation of contaminants across the entire surface of the substrate 100. Therefore, the efficiency of contaminant removal across the entire surface of the substrate 100 can be improved.

[0119] Next, a drying process is performed as shown in Figure 6. During the drying process, the controller 11 controls the supply unit 4b and the flow rate control unit 4c to stop the supply of liquid 101. If liquid 101 and liquid 102 are different liquids, the controller 11 controls the supply unit 5b and the flow rate control unit 5c to stop the supply of liquid 102.

[0120] Furthermore, the controller 11 controls the drive unit 2c to increase the rotation speed of the substrate 100 to a fourth rotation speed that is faster than the third rotation speed. A faster rotation speed of the substrate 100 allows for faster drying of the substrate 100. Note that the fourth rotation speed of the substrate 100 is not particularly limited as long as it allows for drying.

[0121] After the freeze-cleaning process is complete, the circuit board 100 is removed from the enclosure 6 through an inlet / outlet (not shown) of the enclosure 6. By doing so, the substrate 100 can be frozen and cleaned (contamination removed).

[0122] Next, we will further explain the effects of the inclined nozzle holes. Figure 7 is a schematic cross-sectional view illustrating a cooling gas nozzle 200 according to a comparative example. As shown in Figure 7, the cooling gas nozzle 200 is, for example, plate-shaped and has a supply port 10a, a flow path 10b, a nozzle hole 20a, a nozzle hole 220b, and a nozzle hole 220c. The nozzle hole 20a supplies cooling gas 3a1 to the vicinity of the center of the back surface 100a of the substrate 100. The nozzle hole 220b supplies cooling gas 3a1 to the vicinity of the periphery of the back surface 100a of the substrate 100. The nozzle hole 220b supplies cooling gas 3a1 to a position at a distance R1 from the rotational axis 100c of the substrate 100. The nozzle hole 220c supplies cooling gas 3a1 to the region between the vicinity of the center and the vicinity of the periphery of the back surface 100a of the substrate 100. The nozzle hole 220c supplies cooling gas 3a1 to a position at a distance R2 from the rotational axis 100c of the substrate 100.

[0123] The nozzle holes 220b and 220c are not inclined and, like the nozzle hole 20a, extend along the rotational axis 100c of the substrate 100.

[0124] By providing nozzle holes 20a, 220b, and 220c, cooling gas 3a1 can be supplied to predetermined positions on the back surface 100a of the substrate 100. However, since the cooling gas 3a1 is mainly supplied from a direction perpendicular to the back surface 100a of the substrate 100, it is not possible to increase the amount of cooling gas 3a1 that flows near the periphery of the substrate 100 where the heat input is high.

[0125] Furthermore, as shown in Figure 7, near the openings of the nozzle holes 20a, 220b, and 220c extending along the rotational axis 100c of the substrate 100, the cooling gas 3a1 that collides with the inner wall is discharged in a direction intersecting the central axis of the nozzle holes 20a, 220b, and 220c. As a result, the cooling gas 3a1 is dispersed, making it difficult to control its flow so that it flows towards the periphery of the substrate 100.

[0126] As described above, by providing multiple nozzle holes 20a, 220b, and 220c extending along the rotational axis 100c of the substrate 100, even if cooling gas 3a1 can be supplied to a wide area of ​​the back surface 100a of the substrate 100, the amount of cooling gas 3a1 supplied to the peripheral region of the substrate 100, where the heat input is high, cannot be made greater than the amount of cooling gas 3a1 supplied to the central region of the substrate 100, where the heat input is low. As a result, temperature variations are more likely to occur within the surface of the substrate 100, and the removal rate of contaminants within the surface of the substrate 100 may vary. For example, it becomes difficult to improve the removal rate of contaminants in the peripheral region of the substrate 100.

[0127] Figure 8 is a graph illustrating the effect of the cooling gas nozzle 200 in the comparative example. As mentioned above, if multiple nozzle holes 20a, 220b, and 220c are provided along the rotational axis 100c of the substrate 100, it is not possible to increase the amount of cooling gas 3a1 supplied to the peripheral region of the substrate 100, where the heat input is high. Therefore, the temperature in the peripheral region of the substrate 100 tends to be higher than the temperature in the central region of the substrate 100. As a result, as shown in Figure 8, the removal rate of contaminants in the peripheral region of the substrate 100 is lower than the removal rate of contaminants in the central region of the substrate 100.

[0128] Figure 9 is a graph illustrating the effect of the cooling gas nozzle 20 according to this embodiment. As described above, the nozzle holes 20c and 20b are inclined away from the rotational axis 100c of the substrate 100 as they approach the substrate 100. Therefore, the cooling gas 3a1 can be supplied to a wide area of ​​the back surface 100a of the substrate 100, and the amount of cooling gas 3a1 supplied to the peripheral region of the substrate 100, where the heat input is high, can be increased. As a result, the temperature variation within the plane of the substrate 100 is reduced. Consequently, as shown in Figure 9, the removal rate of contaminants can be improved across the entire back surface 100a of the substrate 100.

[0129] The embodiments described above are illustrative examples. However, the present invention is not limited to these descriptions. With respect to the embodiments described above, those who are skilled in the art may add, delete, or modify components, or add, omit, or change processes as appropriate, and these are also included within the scope of the present invention as long as they retain the features of the present invention.

[0130] For example, the shape, dimensions, number, and arrangement of each element of the substrate processing apparatus 1 are not limited to those exemplified and can be changed as appropriate. [Explanation of Symbols]

[0131] 1 Substrate processing apparatus, 2 Mounting section, 2a Mounting platform, 3 Cooling section, 3a1 Cooling gas, 4 First liquid supply section, 5 Second liquid supply section, 10 Cooling gas nozzle, 10a Supply port, 10b Flow path, 10c Flow path, 10d Nozzle hole, 20 Cooling gas nozzle, 20a Nozzle hole, 20b Nozzle hole, 20c Nozzle hole, 100 Substrate, 100a Back side, 100b Front side, 101 Liquid, 102 Liquid, θ Inclination angle

Claims

1. It has a mounting base on which a substrate can be placed, and a mounting section on which the placed substrate can be rotated, A cooling unit capable of supplying cooling gas to the space between the aforementioned mounting base and the substrate via a cooling gas nozzle, The substrate has a liquid supply unit capable of supplying liquid to the side opposite to the side facing the base described above, Equipped with, The substrate processing apparatus has at least one first nozzle hole in which the cooling gas nozzle is inclined away from the rotational axis of the substrate as it approaches the substrate side.

2. The substrate processing apparatus according to claim 1, wherein the first distance between the first point where the extension of the central axis of the first nozzle hole intersects the surface of the substrate on the stand side described above, and the rotational central axis of the substrate, is less than or equal to the maximum value of the second distance between the periphery of the substrate and the rotational central axis of the substrate.

3. Multiple first nozzle holes with different distances from the first are provided, The substrate processing apparatus according to claim 2, wherein the first nozzle hole having a longer first distance has a larger angle between the extension of the central axis of the first nozzle hole and the rotational central axis of the substrate than the first nozzle hole having a shorter first distance.

4. A plurality of first nozzle holes with different first distances and a plurality of first nozzle holes with equal first distances are provided. Let C be the ratio of the conductance of the first group of nozzle holes, which is the sum of the conductances of all the first nozzle holes that are at the same distance from each other, to the sum of the conductances of all the first nozzle holes in the cooling gas nozzle. When S is the ratio of the processing area of ​​the first nozzle hole group, which is the difference between the area of ​​the surface of the substrate on the stand side described above and the area of ​​a circle with the radius of the first distance, to the sum of the processing areas of all the first nozzle holes, The substrate processing apparatus according to claim 2 or 3, wherein the difference between the maximum and minimum values ​​obtained by C / S is 3 or less.

5. The substrate processing apparatus according to claim 4, wherein the following formula is satisfied when the conductance of the first nozzle hole is ca, the length of the central axis of the first nozzle hole is La, and the cross-sectional area of ​​the first nozzle hole is sa. ca=(6.28×10) ８ )×a ２ / La

6. The cooling unit supplies cooling gas to the cooling gas nozzle via a cooling gas supply pipe. The cooling gas nozzle has a space inside it with an inner diameter larger than the inner diameter of the cooling gas supply pipe. The substrate processing apparatus according to claim 1, wherein cooling gas is supplied from the cooling gas supply pipe through the space inside the cooling gas nozzle and the first nozzle hole.

7. It further has a second nozzle hole extending along the rotational axis, The substrate processing apparatus according to claim 1, wherein the diameter of the opening of the second nozzle hole is smaller than the diameter of the opening of the first nozzle hole, which is inclined in a direction away from the rotational center axis as it approaches the substrate side.

8. The substrate processing apparatus according to claim 1, wherein the second nozzle hole is a hole in a pipe inserted into a hole provided in the cooling gas nozzle.

9. The substrate processing apparatus according to claim 8, wherein the opening of the hole in the pipe protrudes from the surface of the end of the cooling gas nozzle on the substrate side.

10. The cooling gas nozzle has a flow path inside it that extends along the rotational axis of the substrate, The substrate processing apparatus according to claim 1, wherein the flow path is connected to a first nozzle hole that is inclined away from the rotational center axis as it approaches the substrate side, and there is space above the position to which the first nozzle hole is connected.

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