Substrate processing method

Abstract

To provide a technique that can effectively reduce the rate of collapse of a substrate pattern.SOLUTION: A substrate processing method includes a holding step, a liquid supplying step, a drying liquid supplying step, and a drying step. In the holding step, a substrate having a first main surface on which a pattern is formed and a second main surface on the opposite side to the first main surface is held. In the liquid supplying step, a processing liquid is supplied to the first main surface of the substrate. In the drying liquid supplying step, after the liquid supplying step, the drying liquid is supplied to the first main surface of the substrate at a flow rate at which the temperature of the first main surface of the substrate is less than the boiling point bp of the drying liquid while at least a part of the second main surface of the substrate is heated to a temperature equal to or higher than the boiling point bp of the drying liquid. In the drying step, after the drying liquid supplying step, the substrate is dried.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] This disclosure relates to a substrate processing method.

Background Art

[0002] Conventionally, a single-sheet substrate processing apparatus for processing a substrate has been disclosed (for example, Patent Document 1). In Patent Document 1, after supplying a rinse liquid to the substrate, isopropyl alcohol having a lower surface tension than the rinse liquid is supplied to the substrate, and then the substrate is dried. Thereby, collapse of the pattern on the substrate during drying is suppressed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in Patent Document 1, the temperature of isopropyl alcohol is not considered. Therefore, the collapse rate of the pattern cannot be effectively reduced.

[0005] Therefore, an object of this disclosure is to provide a technique capable of effectively reducing the collapse rate of the pattern of the substrate.

Means for Solving the Problems

[0006] The first embodiment is a substrate processing method comprising: a holding step of holding a substrate having a first main surface on which a pattern is formed and a second main surface on the opposite side of the first main surface; a liquid supply step of supplying a processing liquid to the first main surface of the substrate; a drying liquid supply step of supplying the drying liquid to the first main surface of the substrate at a flow rate such that the temperature of the first main surface of the substrate is below the boiling point of the drying liquid, while heating at least a portion of the second main surface of the substrate to a temperature above the boiling point of the drying liquid; and a drying step of drying the substrate after the drying liquid supply step.

[0007] A second embodiment is a substrate processing method according to the first embodiment, wherein in the drying liquid supply step, a heat transfer medium with a boiling point equal to or higher than that of the drying liquid is supplied to the second main surface of the substrate.

[0008] A third embodiment is a substrate processing method according to the first or second embodiment, wherein in the drying liquid supply step, the peripheral portion of the second main surface of the substrate is heated to a temperature above the boiling point of the drying liquid.

[0009] A fourth aspect is a substrate processing method according to the third aspect, wherein in the drying liquid supply step, the central part of the second main surface of the substrate is heated to a temperature lower than the temperature of the peripheral part of the second main surface.

[0010] A fifth aspect is a substrate processing method according to the fourth aspect, wherein in the drying liquid supply step, a heat transfer medium at a first medium temperature is supplied to the peripheral portion of the second main surface of the substrate, and a heat transfer medium at a second medium temperature lower than the first medium temperature is supplied to the central portion of the second main surface of the substrate.

[0011] The sixth aspect is a substrate processing method according to any one of the first to fifth aspects, wherein in the drying liquid supply step, the second main surface of the substrate is heated only during the time after the drying liquid supply time for supplying the drying liquid.

[0012] The seventh aspect is a substrate processing method according to any one of the first to sixth aspects, wherein in the drying liquid supply step, the temperature of the first main surface of the substrate is 60 degrees Celsius or higher and below the boiling point of the drying liquid. [Effects of the Invention]

[0013] According to the first embodiment, in the drying solution supply step, at least a portion of the second main surface of the substrate is heated to above the boiling point of the drying solution, while the drying solution is supplied at a flow rate such that the temperature of the first main surface of the substrate remains below the boiling point. As a result, the temperature of the first main surface of the substrate is brought closer to the boiling point of the drying solution, while more reliably suppressing the boiling of the drying solution and thus suppressing particle adhesion. Furthermore, because the temperature of the first main surface is close to the boiling point, the drying solution can be evaporated in a shorter time with lower surface tension in the subsequent drying step. Therefore, the pattern collapse rate can be effectively reduced.

[0014] According to the second embodiment, the temperature of at least a portion of the second main surface of the substrate can be raised above the boiling point of the drying solution with a simple configuration.

[0015] According to the third embodiment, the rate of pattern collapse at the periphery can be reduced. Since the rate of pattern collapse at the periphery tends to be higher than the rate of pattern collapse at the center, the rate of pattern collapse across the entire first main surface of the substrate can be reduced.

[0016] According to the fourth embodiment, while reducing power consumption, the rate of pattern collapse in the central part of the first main surface of the substrate can be reduced, thereby further reducing the overall rate of pattern collapse.

[0017] According to the fifth embodiment, the rate of pattern collapse across the entire first main surface of the substrate can be effectively reduced with a simple configuration.

[0018] According to the sixth aspect, power consumption can be reduced.

[0019] According to the seventh aspect, the collapse rate of the pattern can be effectively reduced.

Brief Description of the Drawings

[0020] [Figure 1] It is a plan view schematically showing an example of the configuration of a substrate processing apparatus. [Figure 2] It is a block diagram schematically showing an example of the internal configuration of a control unit. [Figure 3] It is a longitudinal sectional view schematically showing an example of the configuration of a processing unit according to the first embodiment. [Figure 4] It is a flowchart showing an example of the operation of a processing unit. [Figure 5] It is a diagram schematically showing an example of the state of a processing unit in a drying liquid supply process. [Figure 6] It is a diagram schematically showing an example of a timing chart of a processing unit, the time change of the medium temperature of a heat medium, and the time change of the temperature of the first main surface of a substrate. [Figure 7] It is a diagram schematically showing a first example of a substrate heating unit according to the second embodiment. [Figure 8] It is a diagram schematically showing a first example of a partial configuration of a processing unit according to the second embodiment. [Figure 9] It is a diagram schematically showing a second example of a substrate heating unit according to the second embodiment. [Figure 10] It is a diagram schematically showing a second example of a partial configuration of a processing unit according to the second embodiment. [Figure 11] It is a diagram schematically showing an example of a timing chart of a processing unit according to the third embodiment. [Figure 12] It is a flowchart showing a first example of the operation of a processing unit according to the fourth embodiment. [Figure 13] It is a flowchart showing a second example of the operation of a processing unit according to the fourth embodiment. [Figure 14] It is a diagram schematically showing an example of the configuration of a processing unit according to the fifth embodiment. [Modes for carrying out the invention]

[0021] The embodiments will be described in detail below with reference to the drawings. Note that, for the purpose of ease of understanding, the dimensions and number of parts in the drawings are exaggerated or simplified as needed. Also, parts with similar configurations and functions are denoted by the same reference numerals, and redundant explanations are omitted in the following description.

[0022] Furthermore, in the following explanations, similar components will be denoted by the same symbols, and their names and functions will also be the same. Therefore, detailed explanations of them may be omitted to avoid redundancy.

[0023] Furthermore, even if ordinal numbers such as "first" or "second" are used in the following descriptions, these terms are used for convenience to facilitate understanding of the embodiments and are not limited to the order that may result from these ordinal numbers.

[0024] When expressions indicating relative or absolute positional relationships are used (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.), unless otherwise specified, such expressions shall not only strictly represent the positional relationship but also represent a state in which there is a relative displacement in terms of angle or distance within a tolerance or a range in which equivalent functionality is obtained. When expressions indicating equality are used (e.g., "identical," "equal," "homogeneous," etc.), unless otherwise specified, such expressions shall not only strictly represent a state in which there is a quantitatively exact equality but also represent a state in which there is a difference within a tolerance or a range in which equivalent functionality is obtained. When expressions indicating shape are used (e.g., "quadrilateral" or "cylindrical"), unless otherwise specified, such expressions shall not only strictly represent the geometrically exact shape but also represent a shape with features such as concavities or chamfers within a range in which equivalent effects are obtained. When expressions such as "possess," "equip," "include," or "have" a single component are used, such expressions are not exclusive expressions that exclude the existence of other components. When the expression "at least one of A, B, and C" is used, it includes A only, B only, C only, any two of A, B, and C, and all of A, B, and C.

[0025] <First Embodiment> <Overall configuration of the substrate processing equipment> Figure 1 is a schematic plan view showing an example of the configuration of the substrate processing apparatus 100. The substrate processing apparatus 100 is a single-wafer processing apparatus that processes substrates W one at a time.

[0026] The substrate W is, for example, a semiconductor wafer, a substrate for liquid crystal displays, an organic electroluminescence (EL) substrate, a flat panel display (FPD) substrate, an optical display substrate, a magnetic disk substrate, an optical disk substrate, a magneto-optical disk substrate, a photomask substrate, or a solar cell substrate. The substrate W has a thin, flat shape with a first main surface Wa and a second main surface Wb. The second main surface Wb is the surface opposite to the first main surface Wa. Hereinafter, it is assumed that the substrate W is a semiconductor wafer. The substrate W has, for example, a disc shape. The diameter of the substrate W is, for example, about 300 mm, and the thickness of the substrate W is, for example, about 0.5 mm or more and about 3 mm or less. A pattern is formed on the main surface of the substrate W. The pattern here includes, for example, at least one of a wiring pattern, an electrode pattern, a semiconductor pattern, and an insulating pattern. The aspect ratio of the pattern is, for example, 5 or more and 500 or less. The pattern width is, for example, 3 nm or more and 50 nm or less. These high aspect ratio patterns are prone to collapse.

[0027] In the example shown in Figure 1, the substrate processing apparatus 100 includes an indexer block 110, a processing block 120, and a control unit 90. The processing block 120 is primarily responsible for processing the substrate W, while the indexer block 110 is primarily responsible for transporting the substrate W between the outside of the substrate processing apparatus 100 and the processing block 120.

[0028] The indexer block 110 includes a load port 111 and a first transport section 112. A substrate carrier (hereinafter referred to as a carrier) C, which is brought in from the outside, is placed on the load port 111. Multiple substrates W are housed in the carrier C, for example, arranged with spacing between them in the vertical direction. In the example shown in Figure 1, multiple load ports 111 are arranged.

[0029] The first transport unit 112 is a transport robot capable of removing unprocessed substrates W from carriers C placed on each load port 111. The first transport unit 112 may also be called an indexer robot. The first transport unit 112 transports the unprocessed substrates W removed from the carriers C to the processing block 120. The processing block 120 can process the unprocessed substrates W. The first transport unit 112 can also receive processed substrates W from the processing block 120 and transport the processed substrates W to the carriers C on the load ports 111.

[0030] In the example shown in Figure 1, the processing block 120 includes a plurality of processing units 1 and a second transport unit 122. The second transport unit 122 is a transport robot capable of transporting substrates W between the first transport unit 112 and the plurality of processing units 1. In the example shown in Figure 1, the processing block 120 also includes a mounting unit 123. The mounting unit 123 is, for example, a shelf on which a plurality of substrates W can be placed in a vertically aligned manner. The first transport unit 112 places unprocessed substrates W on the mounting unit 123. The second transport unit 122 removes the unprocessed substrates W from the mounting unit 123 and transports the substrates W to the processing unit 1. The processing unit 1 processes the substrates W. The configuration of the processing unit 1 will be described later. The second transport unit 122 removes the processed substrates W from the processing unit 1 and transports the substrates W to the mounting unit 123. The first transport unit 112 removes the substrate W from the mounting unit 123 and transports the substrate W to the carrier C of the load port 111.

[0031] In the example shown in Figure 1, multiple (for example, four) processing units 1 are arranged to surround the second transport unit 122 in a plan view. This second transport unit 122 may also be called a center robot. At each position in the plan view, multiple processing units 1 may be stacked vertically. In other words, multiple (four in the figure) towers TW, each composed of multiple processing units 1 stacked vertically, may be arranged to surround the second transport unit 122.

[0032] The control unit 90 comprehensively controls the substrate processing apparatus 100. Specifically, the control unit 90 controls the first transport unit 112, the second transport unit 122, and the processing unit 1. Figure 2 is a schematic block diagram showing an example of the internal configuration of the control unit 90. The control unit 90 is an electronic circuit and includes, for example, a data processing unit 91 and a storage unit 92. In the specific example in Figure 2, the data processing unit 91 and the storage unit 92 are interconnected via a bus 93. The data processing unit 91 may be, for example, an arithmetic processing unit such as a CPU (Central Processor Unit). The storage unit 92 may include a non-temporary storage unit (e.g., ROM (Read Only Memory)) 921 and a temporary storage unit (e.g., RAM (Random Access Memory)) 922. The non-temporary storage unit 921 may store, for example, a program that defines the processing to be executed by the control unit 90. By executing this program, the data processing unit 91 enables the control unit 90 to execute the processing defined in the program. Of course, some or all of the processing performed by the control unit 90 may be performed by hardware such as dedicated logic circuits.

[0033] <Overview of the processing unit> Figure 3 is a schematic longitudinal cross-sectional view showing an example of the configuration of a processing unit 1 according to the first embodiment. Note that not all processing units 1 belonging to the substrate processing apparatus 100 need to have the configuration exemplified in Figure 3. It is sufficient that at least one processing unit 1 of the substrate processing apparatus 100 has the configuration exemplified in Figure 3.

[0034] The processing unit 1 includes a substrate holding section 2, a discharge section 3, and a substrate heating section 4.

[0035] In the example shown in Figure 3, the processing unit 1 is also provided with a chamber 10. The chamber 10 has a box-like shape, and its internal space corresponds to the processing space for processing the substrate W. The chamber 10 is provided with an openable and closable loading / unloading port (not shown). The second transport unit 122 loads unprocessed substrates W into the chamber 10 through the loading / unloading port and loads processed substrates W out of the chamber 10 through the loading / unloading port.

[0036] In the example shown in Figure 3, a fan filter unit 11 is provided on the ceiling of the chamber 10. The fan filter unit 11 takes in air from outside the chamber 10, purifies it, and blows the purified air into the chamber 10. The operation of the fan filter unit 11 creates a downflow of clean air inside the chamber 10. In the example shown in Figure 3, the upstream end of the exhaust pipe 13 is connected to the lower part of the side wall of the chamber 10. The gas inside the chamber 10 is discharged to the outside through the exhaust pipe 13.

[0037] The substrate holder 2 is located inside the chamber 10 and holds the substrate W in a horizontal position while rotating the substrate W around the rotation axis Q1. The horizontal position here refers to the position where the thickness direction of the substrate W is aligned with the vertical direction. The rotation axis Q1 is an axis that passes through the center of the substrate W and is aligned with the vertical direction. Such a substrate holder 2 may also be called a spin chuck.

[0038] Here, the first main surface Wa of the substrate W on which the pattern is formed faces vertically upward. In other words, in the example of Figure 3, the first main surface Wa of the substrate W held by the substrate holder 2 corresponds to the top surface. The pattern includes, for example, at least one of a wiring pattern, an insulating pattern, and a semiconductor pattern.

[0039] In the example shown in Figure 3, the substrate holder 2 includes a spin base 21, chuck pins 22, and a rotation drive unit 23. The spin base 21 has a plate-like shape (e.g., a disc shape) and is positioned so that its thickness direction is aligned with the vertical direction. Multiple chuck pins 22 are provided on the upper surface of the spin base 21. The multiple chuck pins 22 are provided at equal intervals along the circumferential direction with respect to the rotation axis Q1. The multiple chuck pins 22 are provided so as to be displaceable between the holding position and the release position, which will be described below. The holding position is the position in which the chuck pins 22 contact the periphery of the substrate W. The multiple chuck pins 22 hold the substrate W by stopping at their respective holding positions. Figure 3 shows the chuck pins 22 stopped at the holding position. The release position is the position in which each chuck pin 22 is separated from the substrate W. The multiple chuck pins 22 release the substrate W by stopping at their respective release positions. The substrate holding section 2 also includes a pin drive section (not shown) that displaces the chuck pin 22. The pin drive section includes, for example, a drive source such as a motor and an air cylinder, and is controlled by the control section 90.

[0040] The rotary drive unit 23 includes a shaft 231 and a motor 232. The upper end of the shaft 231 is connected to the lower surface of the spin base 21, and the shaft 231 extends from the lower surface of the spin base 21 along the rotation axis Q1. The motor 232 is controlled by the control unit 90 and rotates the shaft 231 around the rotation axis Q1. As a result, the spin base 21, chuck pin 22, and substrate W rotate together around the rotation axis Q1.

[0041] The substrate holding section 2 does not necessarily need to have chuck pins 22. For example, the substrate holding section 2 may hold the substrate W using a chuck method such as a vacuum chuck, an electrostatic chuck, or a Bernoulli chuck.

[0042] The discharge unit 3 discharges the processing liquid toward the first main surface Wa of the substrate W held by the substrate holding unit 2. As shown in Figure 3, the discharge unit 3 includes at least one nozzle 30. The nozzle 30 discharges the processing liquid toward the first main surface Wa of the substrate W held by the substrate holding unit 2. Here, since the first main surface Wa corresponds to the upper surface of the substrate W, the nozzle 30 is positioned vertically above the substrate W held by the substrate holding unit 2. The nozzle 30 is, for example, a straight nozzle that discharges the processing liquid in a continuous flow state.

[0043] In the example shown in Figure 3, nozzles 30c, 30w, and 30i are shown as nozzles 30. In the example in Figure 3, nozzles 30c, 30w, and 30i extend vertically. In the example in Figure 3, an outlet 3c is formed on the lower surface of nozzle 30c, an outlet 3w is formed on the lower surface of nozzle 30w, and an outlet 3i is formed on the lower surface of nozzle 30i. Nozzle 30c discharges a chemical solution from the outlet 3c, nozzle 30w discharges a rinsing solution from the outlet 3w, and nozzle 30i discharges a drying solution from the outlet 3i. The chemical solution, rinsing solution, and drying solution are all examples of processing liquids, and specific examples will be described later.

[0044] Nozzles 30c, 30w, and 30i discharge the processing liquid toward the center of the first main surface Wa of the substrate W held by the substrate holding part 2. In the example of Figure 3, nozzles 30c, 30w, and 30i are adjacent to each other horizontally and fixed to each other. In the example of Figure 3, nozzles 30c, 30w, and 30i are provided inside the opposing member 60. The opposing member 60 has, for example, a cylindrical shape. The opposing member 60 has a hollow shape, and the lower end opening of its hollow portion opens on the lower surface of the opposing member 60. Nozzles 30c, 30w, and 30i are provided inside the hollow portion of the opposing member 60, and the processing liquid discharged from each nozzle 30 flows out from the lower end opening of the opposing member 60. In the example of Figure 3, the opposing member 60 is provided at a position vertically opposite to the center of the substrate W held by the substrate holding part 2.

[0045] The nozzle 30 is connected to the downstream end of the supply pipe 31, and the upstream end of the supply pipe 31 is connected to the processing liquid supply source. In the example in Figure 3, the supply pipe 31 is shown as supply pipe 31c, supply pipe 31w, and supply pipe 31i.

[0046] The downstream end of the supply pipe 31c is connected to the nozzle 30c, and the upstream end of the supply pipe 31c is connected to a chemical supply source. The chemical supply source has a tank (not shown) for storing the chemical and supplies the chemical to the upstream end of the supply pipe 31c. Examples of chemicals that can be used include hydrofluoric acid obtained by mixing hydrofluoric acid, nitric acid and water to obtain hydrofluoric acid hydrogen peroxide aqueous solution (FPM) obtained by mixing hydrofluoric acid, hydrogen peroxide and water to obtain hydrofluoric acid, tetramethylammonium hydroxide (TMAH), a mixture of sulfuric acid and hydrogen peroxide solution (SPM), ammonia water, a mixture of ammonia, hydrogen peroxide and water (SC-1), and a mixture of hydrogen chloride, hydrogen peroxide and water (SC-2). Note that the chemical may be a single solution rather than a mixture. For example, single solutions such as hydrofluoric acid (HF), hydrogen peroxide solution and sulfuric acid can be used as chemicals.

[0047] The downstream end of the supply pipe 31w is connected to the nozzle 30w, and the upstream end of the supply pipe 31w is connected to a rinse liquid supply source. The rinse liquid supply source has a tank (not shown) for storing the rinse liquid and supplies the rinse liquid to the upstream end of the supply pipe 31w. As the rinse liquid, for example, pure water, carbon dioxide water, or ozonated water can be used.

[0048] The downstream end of the supply pipe 31i is connected to the nozzle 30i, and the upstream end of the supply pipe 31i is connected to a drying liquid supply source. The drying liquid supply source has a tank (not shown) for storing the drying liquid and supplies the drying liquid to the upstream end of the supply pipe 31i. As the drying liquid, an organic solvent such as isopropyl alcohol can be used. The surface tension of the drying liquid is lower than the surface tension of the other treatment liquids (e.g., both the surface tension of the chemical solution and the surface tension of the rinsing liquid). Also, the volatility of the drying liquid is higher than the volatility of the other treatment liquids (e.g., both the volatility of the chemical solution and the volatility of the rinsing liquid).

[0049] A supply valve 32 and a flow control valve 33 are interposed in the supply pipe 31. In the example shown in Figure 3, a supply valve 32c and a flow control valve 33c are interposed in the supply pipe 31c, a supply valve 32w and a flow control valve 33w are interposed in the supply pipe 31w, and a supply valve 32i and a flow control valve 33i are interposed in the supply pipe 31i. The supply valve 32 switches the supply pipe 31 open and closed. The flow control valve 33 adjusts the flow rate of the processed liquid flowing through the supply pipe 31. The flow control valve 33 may also be a mass flow controller. The supply valve 32 and the flow control valve 33 are controlled by the control unit 90.

[0050] The discharge unit 3 discharges various processing liquids toward the first main surface Wa of the substrate W in the order described later. This allows the processing unit 1 to sequentially perform various processes on the first main surface Wa of the substrate W according to the type of processing liquid. Specific processing details will be described later.

[0051] In the example shown in Figure 3, the opposing member 60 is configured to discharge gas toward the first main surface Wa of the substrate W held by the substrate holding portion 2. In the example shown in Figure 3, the space in the hollow portion of the opposing member 60 other than the nozzle 30 functions as a gas flow path 30g. The lower end opening of the lower surface of the opposing member 60 corresponds to the discharge port of the gas flow path 30g.

[0052] In the example shown in Figure 3, the upper part of the opposing member 60 is connected to the downstream end of the supply pipe 31g. That is, the downstream end of the supply pipe 31g is connected to the gas flow path 30g. The upstream end of the supply pipe 31g is connected to a gas supply source. The gas supply source has a storage section (not shown) for storing inert gas and supplies the inert gas to the upstream end of the supply pipe 31g. The inert gas includes, for example, nitrogen gas and at least one of a noble gas. The noble gas includes, for example, argon gas.

[0053] The supply pipe 31g is equipped with a supply valve 32g, a flow control valve 33g, and a heater 34g. The supply valve 32g switches the supply pipe 31g open and closed. The flow control valve 33g adjusts the flow rate of the inert gas flowing through the supply pipe 31g. The heater 34g heats the inert gas flowing through the supply pipe 31g. The heater 34g may be, for example, an electrically resistive heater having a heating element. The supply valve 32g, the flow control valve 33g, and the heater 34g are controlled by the control unit 90.

[0054] When the supply valve 32g opens and the heater 34g is activated, high-temperature inert gas is discharged from the center of the lower surface of the opposing member 60 (i.e., the lower end of the gas passage 30g) toward the center of the first main surface Wa of the substrate W. This promotes the drying of the substrate W.

[0055] In the example shown in Figure 3, the processing unit 1 is provided with a movable drive unit 35. The movable drive unit 35 moves the discharge head, which includes nozzles 30c, 30w, 30i, and the opposing member 60, as a single unit. Specifically, the movable drive unit 35 moves the discharge head between the processing position and the standby position, which will be described below. The processing position is the position where nozzles 30c, 30w, and 30i discharge the processing liquid toward the first main surface Wa of the substrate W, for example, a position perpendicular to the center of the first main surface Wa of the substrate W. The processing position is also the position where the opposing member 60 discharges inert gas toward the first main surface Wa of the substrate W. In the example shown in Figure 3, the discharge head stopped at the processing position is shown. The standby position is the position where nozzles 30c, 30w, and 30i do not discharge the processing liquid toward the first main surface Wa of the substrate W, for example, a position radially outside the substrate holding unit 2. The standby position is also the position in which the opposing member 60 does not discharge inert gas toward the first main surface Wa of the substrate W.

[0056] Figure 3 shows an example of the specific configuration of the mobile drive unit 35. In the example in Figure 3, the mobile drive unit 35 includes an arm 351, a support column 352, and a drive source 353. The support column 352 is located radially outward from the guard 7 (described later) and extends vertically. The arm 351 extends horizontally, its tip connected to the discharge head, and its base connected to the support column 352. The drive source 353 is controlled by the control unit 90 and rotates the support column 352 in forward and reverse directions within a predetermined angular range around its central axis Q2. The drive source 353 includes, for example, a motor. When the support column 352 rotates in forward and reverse directions within a predetermined angular range around the central axis Q2, the discharge head reciprocates along the circumferential direction with respect to the central axis Q2. The support column 352 is installed such that the processing position and standby position are located on the movement trajectory of the discharge head. Note that the mobile drive unit 35 is not necessarily limited to the configuration shown in Figure 3, and may include, for example, a linear motion mechanism such as a linear motor.

[0057] The substrate heating unit 4 heats the second main surface Wb of the substrate W held by the substrate holding unit 2. In the example shown in Figure 3, the substrate heating unit 4 is positioned perpendicular to the second main surface Wb of the substrate W. In the example shown in Figure 3, the second main surface Wb of the substrate W corresponds to the bottom surface, so the substrate heating unit 4 is located directly below the substrate W. The substrate heating unit 4 heats at least a portion of the second main surface Wb of the substrate W to a temperature above the boiling point of the drying solution. The technical significance of this will be explained later.

[0058] In the example shown in Figure 3, the substrate heating unit 4 includes a nozzle 40. The nozzle 40 discharges a heat transfer medium toward the second main surface Wb of the substrate W. In the example shown in Figure 3, the second main surface Wb of the substrate W corresponds to the bottom surface, so the nozzle 40 can also be called a bottom nozzle. In the example shown in Figure 3, a through hole is formed in the center of the spin base 21 of the substrate holding unit 2, and the shaft 231 is a hollow shaft. The through hole in the spin base 21 and the hollow part of the shaft 231 are connected in the vertical direction. A part of the nozzle 40 is positioned in the through hole. An outlet is formed on the upper surface of the nozzle 40, and the outlet of the nozzle 40 faces the center of the second main surface Wb of the substrate W in the vertical direction. The nozzle 40 discharges the heat transfer medium toward the center of the second main surface Wb of the substrate W.

[0059] The downstream end of the supply pipe 41 is connected to the nozzle 40. The supply pipe 41 extends inside the shaft 231 and passes through the shaft 231. The upstream end of the supply pipe 41 is connected to a heat transfer medium supply source. The heat transfer medium is a fluid (gas or liquid), and a more specific example is a liquid such as water. The heat transfer medium supply source has, for example, a tank (not shown) for storing the heat transfer medium and supplies the heat transfer medium to the upstream end of the supply pipe 41.

[0060] In the example shown in Figure 3, the supply pipe 41 is equipped with a supply valve 42, a flow control valve 43, and a heater 44. The supply valve 42 switches the supply pipe 41 open and closed. The flow control valve 43 adjusts the flow rate of the heat transfer medium flowing through the supply pipe 41. The flow control valve 43 may also be a mass flow controller. The heater 44 heats the heat transfer medium flowing through the supply pipe 41. The heater 44 may be, for example, an electrically resistive heater with a heating element. The supply valve 42, the flow control valve 43, and the heater 44 are controlled by the control unit 90.

[0061] When the supply valve 42 opens and the heater 44 is activated, a high-temperature heat transfer medium is discharged from the nozzle 40 to the center of the second main surface Wb of the substrate W. The heat transfer medium that has landed on the center of the second main surface Wb of the substrate W is subjected to centrifugal force due to the rotation of the substrate W and flows radially outward along the second main surface Wb, scattering outward from the periphery of the substrate W. As the high-temperature heat transfer medium flows along the second main surface Wb of the substrate W, heat is transferred from the heat transfer medium to the substrate W, and the substrate W is heated.

[0062] In the example shown in Figure 3, the processing unit 1 is provided with a guard 7 and a guard lifting drive unit 71. The guard 7 has a cylindrical shape with the rotation axis Q1 as its central axis and surrounds the substrate holding part 2. The guard 7 can catch processing liquid and heat transfer medium splashing from the periphery of the substrate W. The guard lifting drive unit 71 raises and lowers the guard 7 between the upper position and the lower position, which will be described below. The upper position is the position where the upper end of the guard 7 is vertically above the substrate W held by the substrate holding part 2. When the guard 7 is in the upper position, it can catch processing liquid and heat transfer medium splashing from the periphery of the substrate W. The lower position is a position lower than the upper position, for example, the position where the upper end of the guard 7 is vertically below the upper surface of the spin base 21.

[0063] In the example shown in Figure 3, multiple guards 7 are provided. The multiple guards 7 are arranged concentrically. The multiple guards 7 may be used differently depending on the type of processing liquid. In the example shown in Figure 3, a cup 72 corresponding to each guard 7 is provided. The cup 72 has an annular (e.g., circular) recess (groove) surrounding the axis of rotation Q1. Each cup 72 receives the processing liquid that flows down the inner circumferential surface of the corresponding guard 7. The upstream end of the discharge pipe 12 is connected to, for example, the bottom of each cup 72. The processing liquid received in each cup 72 is discharged to the outside of the processing unit 1 through the discharge pipe 12.

[0064] <An example of the operation of a substrate processing device> Next, an example of the operation of the processing unit 1 will be described. Figure 4 is a flowchart showing an example of the operation of the processing unit 1. The control unit 90 causes the processing unit 1 to execute steps S1 to S7 according to a pre-set processing procedure (recipe). Figure 5 is a schematic diagram showing an example of the processing unit 1 in the drying liquid supply process, which will be described later.

[0065] First, the second transport unit 122 transports the substrate W to the processing unit 1. Then, the substrate holding unit 2 holds the substrate W received from the second transport unit 122 (step S1: holding step). As a specific example, the substrate holding unit 2 displaces multiple chuck pins 22 from their respective release positions to holding positions. As a result, the multiple chuck pins 22 hold the substrate W. The substrate holding unit 2 continues to hold the substrate W until the processing of the substrate W is completed.

[0066] Next, the substrate holder 2 starts rotating the substrate W (Step S2: Rotation start step). The substrate holder 2 may continue rotating the substrate W until the processing of the substrate W is complete.

[0067] Next, the processing unit 1 supplies a chemical solution to the first main surface Wa of the substrate W (Step S3: Chemical Solution Process). First, the moving drive unit 35 moves the discharge head to the processing position. Also, the guard lifting drive unit 71 raises the guard 7 for the chemical solution to the upper position. Then, the control unit 90 opens the supply valve 32c. In other words, the control unit 90 switches the supply valve 32c from the closed state to the open state. As a result, the chemical solution is discharged from the nozzle 30c toward the first main surface Wa of the rotating substrate W. The chemical solution that has landed on the first main surface Wa of the substrate W is affected by the centrifugal force accompanying the rotation of the substrate W and flows radially outward, scattering from the periphery of the substrate W. At this time, the chemical solution acts on the first main surface Wa of the substrate W, and chemical treatment according to the type of chemical solution is performed on the first main surface Wa of the substrate W. For example, the processing unit 1 performs a cleaning process to wash away impurities on the first main surface Wa of the substrate W, or an etching process to etch a predetermined film on the first main surface Wa of the substrate W. The chemical solution scattered from the periphery of the substrate W is caught by the guard 7 and discharged to the outside of the chamber 10 through the discharge pipe 12.

[0068] When the processing on the substrate W is sufficiently completed, the control unit 90 closes the supply valve 32c. As a specific example, the control unit 90 measures the elapsed time from the start of chemical dispensing and determines whether the elapsed time is equal to or greater than a predetermined chemical treatment time. The chemical treatment time is preset to a time sufficient for the chemical treatment to be completed. The elapsed time is measured, for example, by a timer circuit (not shown) belonging to the control unit 90. When the elapsed time is equal to or greater than the chemical treatment time, the control unit 90 switches the supply valve 32c from the open state to the closed state.

[0069] Next, the processing unit 1 supplies rinsing liquid to the first main surface Wa of the substrate W (step S4: rinsing process). If the guard 7 for the rinsing liquid is different from the guard 7 for the chemical solution, the guard lifting drive unit 71 raises and lowers the guard 7 as appropriate to position the guard 7 for the rinsing liquid in the upper position. Then, the control unit 90 opens the supply valve 32w. In other words, the control unit 90 switches the supply valve 32w from the closed state to the open state. As a result, rinsing liquid is discharged from the nozzle 30w toward the first main surface Wa of the rotating substrate W. The rinsing liquid that has landed on the first main surface Wa of the substrate W is affected by the centrifugal force accompanying the rotation of the substrate W and flows radially outward, scattering from the periphery of the substrate W. At this time, the rinsing liquid pushes the chemical solution on the first main surface Wa of the substrate W radially outward. As a result, the processing liquid on the first main surface Wa of the substrate W is replaced from the chemical solution to the rinsing liquid. The processing liquid that splashes from the periphery of the substrate W is caught by the guard 7 and discharged to the outside of the chamber 10 through the discharge pipe 12.

[0070] When the replacement of the chemical solution with the rinsing solution is sufficient, the control unit 90 closes the supply valve 32w. As a specific example, the control unit 90 measures the elapsed time from the start of rinsing solution discharge, and when this elapsed time exceeds a predetermined rinsing time, it switches the supply valve 32w from the open state to the closed state. The rinsing time is pre-set to a time sufficient for the replacement of the chemical solution with the rinsing solution to occur.

[0071] Next, the processing unit 1 supplies drying liquid to the first main surface Wa of the substrate W (Step S5: Drying liquid supply step). If the guard 7 for the drying liquid is different from the guard 7 for the rinsing liquid, the guard lifting drive unit 71 raises the guard 7 appropriately to raise the guard 7 for the drying liquid to the upper position. Then, the control unit 90 opens the supply valve 32i. In other words, the control unit 90 switches the supply valve 32i from the closed state to the open state.

[0072] When the supply valve 32i opens, as shown in Figure 5, the drying liquid is discharged from the discharge port 3i of the nozzle 30i toward the first main surface Wa of the rotating substrate W. The temperature of the drying liquid may be, for example, room temperature (for example, about 25 degrees Celsius). The temperature of the drying liquid referred to here is, for example, the temperature of the drying liquid at the discharge port 3i. Furthermore, room temperature here includes, for example, the temperature of the drying liquid upstream of the discharge port 3i when there is no heater for heating the drying liquid, or when the heater is not operating. In other words, room temperature includes the temperature of the drying liquid that has not been heated.

[0073] The drying liquid from the nozzle 30i lands on the center of the first main surface Wa of the substrate W. The drying liquid that has landed on the first main surface Wa flows radially outward due to the centrifugal force accompanying the rotation of the substrate W, and is scattered from the periphery of the substrate W. At this time, the drying liquid washes away the rinsing liquid on the first main surface Wa of the substrate W, and the processing liquid on the first main surface Wa of the substrate W is replaced from the rinsing liquid to the drying liquid. The processing liquid scattered from the periphery of the substrate W is caught by the guard 7 and discharged to the outside of the chamber 10 through the discharge pipe 12.

[0074] Here, the rotation speed of the substrate W in the drying liquid supply process may be set to, for example, 150 rpm or more and 600 rpm or less, or 200 rpm or more and 400 rpm or less. As a more specific example, the rotation speed may be set to 300 rpm.

[0075] Furthermore, the processing unit 1 heats the second main surface Wb of the substrate W when supplying the drying liquid. In other words, the substrate heating unit 4 heats the second main surface Wb of the substrate W. As a more specific example, the control unit 90 opens the supply valve 42 and activates the heater 44. As a result, as shown in Figure 5, a high-temperature heat transfer medium (e.g., hot water) is discharged from the nozzle 40 toward the center of the second main surface Wb of the rotating substrate W. The heat transfer medium that has landed on the center of the second main surface Wb of the substrate W flows radially outward due to the centrifugal force accompanying the rotation of the substrate W and scatters from the periphery of the substrate W. As the high-temperature heat transfer medium flows along the second main surface Wb of the substrate W, heat is transferred from the heat transfer medium to the substrate W, and the substrate W is heated. The heat from the substrate W is transferred to the drying liquid on the first main surface Wa. Therefore, the drying liquid on the first main surface Wa of the substrate W is also heated and its temperature rises.

[0076] The substrate heating unit 4 heats the second main surface Wb of the substrate W so that the temperature of at least a portion of the second main surface Wb of the substrate W (in this case, the central portion) is equal to or greater than the boiling point of the drying liquid. For example, the heater 44 heats the heat transfer medium so that its temperature (hereinafter also referred to as the medium temperature) is equal to or greater than the boiling point of the drying liquid. The medium temperature of the heat transfer medium referred to here is, for example, the temperature of the heat transfer medium at the discharge port of the nozzle 40. If the drying liquid is isopropyl alcohol, its boiling point is 82.4 degrees Celsius, and the medium temperature of the heat transfer medium is set to, for example, about 85 degrees Celsius. However, the medium temperature of the heat transfer medium may be set to a temperature lower than the boiling point of the heat transfer medium. For example, if the heat transfer medium is water, it may be set to a temperature of less than 90 degrees Celsius, which is 10 degrees lower than its boiling point (100 degrees Celsius). This allows compliance with SEMI standards.

[0077] The flow control valve 43 may adjust the flow rate of the heat transfer medium to a value greater than, for example, the flow rate of the drying liquid. More specifically, the flow control valve 43 may adjust the flow rate of the heat transfer medium to 1000 mL / min or more, or to 1500 mL / min or more.

[0078] The nozzle 30i discharges a drying liquid at a temperature lower than the heat transfer medium. As a result, the first main surface Wa of the substrate W is continuously supplied with low-temperature drying liquid. Therefore, the low-temperature drying liquid can cool the first main surface Wa of the substrate W. The cooling capacity of this drying liquid increases with the flow rate of the drying liquid. Therefore, the flow rate control valve 33i adjusts the flow rate of the drying liquid to a value such that the temperature of the first main surface Wa of the substrate W is below the boiling point. For example, the flow rate of the drying liquid can be set to approximately 100 mL / min or higher, and more specifically, to 250 mL / min or higher.

[0079] As described above, in the drying solution supply process, the processing unit 1 heats at least a portion of the second main surface Wb of the substrate W to a temperature above the boiling point of the drying solution, while supplying the drying solution to the first main surface Wa of the substrate W at a flow rate such that the temperature of the first main surface Wa of the substrate W is below the boiling point of the drying solution.

[0080] Once the rinsing solution has been sufficiently replaced with the drying solution, the processing unit 1 dries the substrate W (step S6: drying process). Specifically, the processing unit 1 measures the elapsed time from the start of the discharge of the drying solution and determines whether the elapsed time is equal to or greater than a predetermined drying solution supply time. The drying solution supply time is set in advance to a time sufficient for the rinsing solution to be sufficiently replaced with the drying solution. The drying solution supply time is set to, for example, several tens of seconds or more, and as a specific example, it may be set to about 40 seconds. When the elapsed time is equal to or greater than the drying solution supply time, the processing unit 1 dries the substrate W. Specifically, the control unit 90 closes the supply valve 32i. Also, the substrate heating unit 4 stops heating the second main surface Wb of the substrate W.

[0081] Furthermore, the control unit 90 increases the rotation speed of the substrate W in the substrate holding unit 2. For example, the substrate holding unit 2 may rotate the substrate W at a rotation speed of 800 rpm or more and 2500 rpm or less, or at a rotation speed of 800 rpm or more and 1500 rpm or less. Alternatively, the substrate holding unit 2 may gradually (for example, in steps) increase the rotation speed of the substrate W.

[0082] The processing unit 1 may supply inert gas toward the center of the first main surface Wa of the substrate W. Specifically, the control unit 90 may open the supply valve 32g and activate the heater 34g. As a result, high-temperature inert gas is discharged from the gas outlet in the center of the lower surface of the opposing member 60 (i.e., the lower end of the gas flow path 30g) toward the center of the first main surface Wa of the substrate W. The inert gas that hits the center of the first main surface Wa of the substrate W flows radially outward along the first main surface Wa. The heater 34g may heat the inert gas to, for example, 60 degrees Celsius or higher, 70 degrees Celsius or higher, or 80 degrees Celsius or higher. The temperature of the inert gas may be, for example, the temperature of the inert gas at the gas outlet of the gas flow path 30g. The flow rate control valve 33g may adjust the flow rate of the inert gas to, for example, 10 L / min or more and 300 L / min or less.

[0083] When the drying liquid has sufficiently evaporated, the processing unit 1 stops discharging the inert gas and stops the rotation of the substrate W. As a specific example, the control unit 90 measures the elapsed time since the discharging of the drying liquid stopped and determines whether the measured time is equal to or greater than a predetermined drying time. The drying time is preset to a time sufficient for the substrate W to dry sufficiently. When the elapsed time is equal to or greater than the drying time, the control unit 90 switches the supply valve 32g from the open state to the closed state and causes the substrate holding unit 2 to stop the rotation of the substrate W. In addition, the moving drive unit 35 moves the discharge head to the standby position, and the guard lifting drive unit 71 lowers the guard 7 to the lower position.

[0084] Next, the substrate holding unit 2 releases its grip on the substrate W (step S7: release step). Then, the second transport unit 122 transports the processed substrate W out of the processing unit 1.

[0085] As described above, the processing unit 1 can perform processing on the substrate W. Moreover, in this embodiment, the substrate heating unit 4 heats the substrate W in the drying liquid supply step after the liquid supply step which includes the chemical solution step and the rinsing step. Figure 6 is a schematic diagram showing an example of the timing chart of the processing unit 1, the time change of the medium temperature of the heat transfer medium, and the time change of the temperature of the first main surface Wa of the substrate W. Hereinafter, the temperature of the first main surface Wa of the substrate W will also be referred to as the substrate temperature. In the example of Figure 6, the substrate temperatures at different positions in the radial direction of the first main surface Wa of the substrate W are shown as graphs G1 to G5. The smaller the sign number of graphs G1 to G5, the closer it is to the rotation axis Q1. That is, graph G1 shows the substrate temperature at the most central part of the first main surface Wa of the substrate W, and graph G5 shows the substrate temperature at the most peripheral part of the first main surface Wa of the substrate W.

[0086] In the example shown in Figure 6, at time t1, the control unit 90 switches the supply valve 32i from a closed state to an open state. As a result, the drying liquid begins to be discharged from the nozzle 30i toward the first main surface Wa of the substrate W. At this time t1, the actual drying liquid supply process begins. Also, at time t1, for example, the control unit 90 switches the supply valve 42 from a closed state to an open state and activates the heater 44. As a result, a high-temperature heat transfer medium is discharged from the nozzle 40 toward the second main surface Wb of the substrate W, and the substrate W is heated. In the example shown in Figure 6, the temperature of the heat transfer medium discharged from the nozzle 40 is higher than the boiling point bp of the drying liquid.

[0087] As the heat transfer fluid begins to be discharged, the substrate temperature at each position on the first main surface Wa of the substrate W increases over time. The substrate temperature rises at a relatively high rate up to a certain point, after which it may rise more slowly or converge. As shown in Figure 6, the substrate temperature at each position on the first main surface Wa of the substrate W is lower than the boiling point bp of the drying solution. This is because, as described above, the flow rate control valve 33i adjusts the flow rate of the drying solution so that the substrate temperature is below the boiling point bp of the drying solution. In the example in Figure 6, the heat transfer fluid lands in the center of the second main surface Wb of the substrate W, so the substrate temperature on the first main surface Wa of the substrate W has the following temperature distribution. That is, as shown in Figure 6, the substrate temperature is high in the center of the substrate W and decreases towards the radially outward direction.

[0088] At time t2, which is later than time t1, the control unit 90 switches the supply valves 32i and 42 from the open state to the closed state. In other words, at time t2, the drying liquid supply process is effectively completed. At time t2, the substrate temperature at the center of the first main surface Wa is, for example, 70 degrees Celsius or higher, and may be, for example, around 80 degrees Celsius. Also, at time t2, the substrate temperature at the periphery of the first main surface Wa is, for example, 60 degrees Celsius or higher, and may specifically be around 70 degrees Celsius.

[0089] As described above, the substrate temperature during the drying solution supply process is below the boiling point bp of the drying solution. Therefore, boiling of the drying solution during the drying solution supply process can be more reliably suppressed. If the drying solution on the first main surface Wa of the substrate W boils during the supply of the drying solution, it will lead to the adhesion of particles to the first main surface Wa. In this embodiment, boiling of the drying solution is more reliably suppressed, so the adhesion of particles to the first main surface Wa of the substrate W can be more reliably suppressed.

[0090] Furthermore, during the drying solution supply process, the temperature of at least a portion of the second main surface Wb of the substrate W is above the boiling point bp of the drying solution. Therefore, during the drying solution supply process, the maximum value in the temperature distribution of the first main surface Wa of the substrate W can be brought closer to the boiling point bp. The minimum value in the temperature distribution of the first main surface Wa of the substrate W during the drying solution supply process (i.e., the substrate temperature at the periphery of the first main surface Wa) is, for example, 60 degrees Celsius or higher. In other words, the flow rate of the drying solution can be set so that the substrate temperature at each position on the first main surface Wa of the substrate W is 60 degrees Celsius or higher and below the boiling point bp of the drying solution.

[0091] Therefore, in this embodiment, during the drying solution supply process, the temperature of the drying solution on the first main surface Wa of the substrate W can be brought closer to its boiling point bp. Consequently, the temperature of the drying solution can be made higher during the drying process immediately after the supply of the drying solution is stopped. As a result, the surface tension of the drying solution can be further reduced during the drying process, while the evaporation rate of the drying solution can be further increased. By reducing the surface tension, the rate of pattern collapse can be effectively reduced. In addition, since the drying solution can be evaporated in a shorter time, the impulse on the pattern due to the surface tension of the drying solution during evaporation can also be reduced. This also effectively reduces the rate of pattern collapse.

[0092] Furthermore, the substrate heating unit 4 supplies a heat transfer medium to the second main surface Wb of the substrate W to heat the substrate W. With this configuration, the substrate heating unit 4 can heat at least a portion of the second main surface Wb of the substrate W to a temperature above the boiling point of the drying liquid.

[0093] In the example described above, the discharge unit 3 discharges a drying liquid at room temperature, but it may also discharge a high-temperature drying liquid. For example, the discharge unit 3 may further include a heater (not shown). This heater is provided in the supply pipe 31i and heats the drying liquid flowing through the supply pipe 31i. This heater is controlled by the control unit 90. The heater heats the drying liquid so that its temperature is greater than room temperature and below the boiling point bp of the drying liquid. For example, the heater may raise the temperature of the drying liquid to 60 degrees Celsius or higher, and as a specific example, it may raise it to about 70 degrees Celsius.

[0094] <Second Embodiment> It was found that the pattern collapse rate tended to be higher in the peripheral part of the first main surface Wa of the substrate W than in the central part. Therefore, in the second embodiment, the aim is to reduce the pattern collapse rate, particularly in the peripheral part of the first main surface Wa of the substrate W.

[0095] An example of the configuration of the substrate processing apparatus 100 according to the second embodiment is the same as that of the first embodiment. However, the specific configuration of the substrate heating unit 4 of the processing unit 1 differs from that of the first embodiment. Figure 7 is a schematic diagram showing a first example of the substrate heating unit 4 according to the second embodiment. Figure 7 also shows the substrate W held by the substrate holding unit 2. In the example of Figure 7, the substrate heating unit 4 is provided at a position perpendicular to the peripheral edge of the second main surface Wb of the substrate W held by the substrate holding unit 2. The substrate heating unit 4 heats the peripheral edge of the second main surface Wb of the substrate W to a temperature above the boiling point bp of the drying liquid.

[0096] Figure 8 is a schematic diagram showing a first example of the configuration of a part of the processing unit 1 according to the second embodiment. In the example of Figure 8, the substrate heating unit 4 includes a discharge tube 45 instead of a nozzle 40. The discharge tube 45 is provided directly below the substrate W held by the substrate holding unit 2. Specifically, the discharge tube 45 is provided between the substrate W held by the substrate holding unit 2 and the spin base 21. The discharge tube 45 extends radially, and its upstream end is connected to the downstream end of the supply tube 41. The downstream end of the discharge tube 45 is located radially inward from the chuck pin 22 of the substrate holding unit 2. The discharge tube 45 has a discharge port 4a that is perpendicular to the peripheral edge of the second main surface Wb of the substrate W. A heat transfer medium is discharged from the discharge port 4a of the discharge tube 45, and the heat transfer medium lies on the peripheral edge of the second main surface Wb of the substrate W. The heat transfer fluid deposited on the second main surface Wb moves radially outward as the substrate W rotates, and is scattered outward from the periphery of the substrate W. Therefore, the substrate heating unit 4 heats the peripheral portion of the second main surface Wb of the substrate W. The distance between the deposition position of the heat transfer fluid on the second main surface Wb and the rotation axis Q1 may be 60% or more, 70% or more, 80% or more, or 90% or more of the radius of the substrate W.

[0097] Similar to the first embodiment, the substrate heating unit 4 supplies a heat transfer medium at or above the boiling point bp of the drying liquid to the second main surface Wb of the substrate W. The temperature of the heat transfer medium is, for example, about 85 degrees Celsius. The substrate heating unit 4 can heat the peripheral portion of the second main surface Wb of the substrate W to or above the boiling point bp of the drying liquid. The temperature of the first main surface Wa of the substrate W decreases as it moves radially away from the point where the heat transfer medium is applied.

[0098] An example of the operation of the processing unit 1 according to the first example of the second embodiment is the same as the flowchart in Figure 4. However, in the second embodiment, in the drying liquid supply step (step S5), the substrate heating unit 4 heats the peripheral portion of the second main surface Wb of the substrate W to a temperature above the boiling point bp of the drying liquid. In other words, the central portion of the second main surface Wb of the substrate W is not heated very much.

[0099] Also, similar to the first embodiment, in the drying solution supply step, the processing unit 1 supplies the drying solution to the first main surface Wa of the substrate W at a flow rate such that the temperature of the first main surface Wa of the substrate W is below the boiling point bp of the drying solution.

[0100] As described above, in the first example of the second embodiment, the substrate heating unit 4 heats the peripheral portion of the second main surface Wb of the substrate W, so that the temperature of the peripheral portion of the first main surface Wa of the substrate W can be concentrated and increased. For example, the substrate temperature at the peripheral portion (liquid application position) of the first main surface Wa of the substrate W can be increased to about 80 degrees Celsius.

[0101] Therefore, in the drying process immediately following the cessation of the drying solution supply, the temperature of the drying solution on the peripheral portion of the first main surface Wa of the substrate W can be increased. Consequently, in the drying process, the surface tension of the drying solution on the peripheral portion can be further reduced while the evaporation rate of the drying solution on the peripheral portion can be further increased. This effectively reduces the rate of pattern collapse on the peripheral portion of the first main surface Wa of the substrate W.

[0102] As mentioned above, the pattern collapse rate at the periphery tends to be higher than that at the center. Therefore, by reducing the pattern collapse rate at the periphery, the overall pattern collapse rate on the first main surface Wa of the substrate can be reduced.

[0103] Figure 9 is a schematic diagram showing a second example of the substrate heating section 4 according to the second embodiment. In Figure 9, the substrate W held by the substrate holding section 2 is also shown. In the example of Figure 9, the substrate heating section 4 includes a peripheral heating section 4A and a central heating section 4B. The peripheral heating section 4A is provided at a position perpendicular to the peripheral portion of the second main surface Wb of the substrate W held by the substrate holding section 2. The peripheral heating section 4A heats the peripheral portion of the second main surface Wb of the substrate W to a temperature above the boiling point bp of the drying liquid. The central heating section 4B is provided radially inward from the peripheral heating section 4A and is provided at a position perpendicular to the central portion of the second main surface Wb of the substrate W. The central heating section 4B heats the central portion of the second main surface Wb of the substrate W. The central heating section 4B heats the central portion of the second main surface Wb to a temperature lower than, for example, the peripheral portion of the second main surface Wb.

[0104] Figure 10 is a schematic diagram showing a second example of the configuration of a part of the processing unit 1 according to the second embodiment. In the example in Figure 10, the peripheral heating section 4A supplies a heat transfer medium to the peripheral part of the second main surface Wb of the substrate W, and the central heating section 4B supplies a heat transfer medium to the central part of the second main surface Wb of the substrate W. The peripheral heating section 4A and the central heating section 4B can supply the heat transfer medium at different temperatures. In the example in Figure 10, the peripheral heating section 4A includes a supply pipe 41A, a supply valve 42A, a flow control valve 43A, a heater 44A, and an outlet pipe 45. The supply pipe 41A, supply valve 42A, flow control valve 43A, and heater 44A are the same as the supply pipe 41, supply valve 42, and heater 44 in Figure 8, respectively. In the example shown in Figure 10, the central heating section 4B includes a supply pipe 41B, a supply valve 42B, a flow control valve 43B, a heater 44B, and a nozzle 40. The supply pipe 41B, supply valve 42B, flow control valve 43B, and heater 44B are the same as the supply pipe 41, supply valve 42, and heater 44 in Figure 3, respectively. Parts of the supply pipes 41A and 41B are arranged adjacent to each other in the hollow section of the shaft 231.

[0105] Heater 44A heats the heat transfer medium so that the temperature of the first medium discharged from the outlet 4a of the outlet pipe 45 is equal to or greater than the boiling point bp of the drying liquid. Heater 44B heats the heat transfer medium so that the temperature of the second medium discharged from the outlet of the nozzle 40 is, for example, less than the temperature of the first medium. The temperature of the first medium may be, for example, about 85 degrees Celsius, and the temperature of the second medium may be, for example, about 70 degrees Celsius.

[0106] An example of the operation of the processing unit 1 according to the second example of the second embodiment is the same as the flowchart in Figure 4. However, in the second example of the second embodiment, in the drying liquid supply step (step S5), the substrate heating unit 4 heats the peripheral portion of the second main surface Wb of the substrate W (at least the position where the heat transfer medium is applied) to above the boiling point bp of the drying liquid, while heating the central portion of the second main surface Wb of the substrate W to a lower temperature than the peripheral portion (for example, a temperature below the boiling point bp). Specifically, in the drying liquid supply step, the control unit 90 opens supply valves 42A and 42B. Heater 44A heats the heat transfer medium so that the first medium temperature of the heat transfer medium is above the boiling point bp of the drying liquid, and heater 44B heats the heat transfer medium so that the second medium temperature of the heat transfer medium is lower than the first medium temperature. The second medium temperature is, for example, below the boiling point bp.

[0107] On the other hand, the substrate temperature at the center of the first main surface Wa of the substrate W is, for example, about 70 degrees Celsius, and the substrate temperature at the periphery of the first main surface Wa of the substrate W is, for example, about 80 degrees Celsius. Here, the substrate temperature at the center of the first main surface Wa of the substrate W is, for example, the substrate temperature at a position vertically opposite to the point where the heat transfer medium from the nozzle 40 is applied, and the substrate temperature at the periphery is, for example, the substrate temperature at a position vertically opposite to the point where the heat transfer medium from the outlet pipe 45 is applied.

[0108] As described above, in the second example of the second embodiment, the substrate heating unit 4 heats the peripheral edge of the second main surface Wb of the substrate W. Therefore, for example, the substrate temperature at the peripheral edge (liquid application position) of the first main surface Wa of the substrate W can be raised to about 80 degrees Celsius. Consequently, the rate of pattern collapse at the peripheral edge of the first main surface Wa of the substrate W can be reduced.

[0109] Furthermore, in the second example of the second embodiment, the substrate heating unit 4 also heats the central part of the second main surface Wb of the substrate W. However, the substrate temperature in the central part of the first main surface Wa of the substrate W is lower than the substrate temperature in the peripheral part. Since the pattern collapse rate in the peripheral part of the substrate W tends to be low, even if the substrate temperature in the central part is lower than the substrate temperature in the peripheral part, the pattern collapse rate in the central part can be sufficiently reduced. In addition, since the central part of the substrate W is not excessively heated, the power consumption of the substrate heating unit 4 can be reduced. In other words, the processing unit 1 can reduce power consumption while reducing the pattern collapse rate in the central part of the first main surface Wa of the substrate W, thereby further reducing the overall pattern collapse rate.

[0110] Furthermore, the substrate heating unit 4 supplies a heat transfer medium at the first medium temperature to the peripheral edge of the second main surface Wb of the substrate W, and a heat transfer medium at the second medium temperature to the central part of the second main surface Wb of the substrate W. Therefore, the processing unit 1 can reduce the overall pattern collapse rate of the first main surface Wa of the substrate W with a simple configuration.

[0111] In the example described above, the substrate heating section 4 includes a peripheral heating section 4A and a central heating section 4B, but it may include three or more heating sections. The three or more heating sections may be arranged radially. The three or more heating sections heat different portions of the second main surface Wb of the substrate W in the radial direction. In this case, heating sections located closer to the peripheral edge of the substrate W may heat the corresponding portion of the second main surface Wb of the substrate W to a higher temperature.

[0112] <Third Embodiment> In the first and second embodiments, the substrate heating unit 4 heats the second main surface Wb of the substrate W for the entire duration of the drying liquid supply process (step S5). However, it is not necessarily limited to this.

[0113] Figure 11 is a schematic diagram showing an example of a timing chart for the processing unit 1 according to the third embodiment. In the example in Figure 11, at time t1, the control unit 90 switches the supply valve 32i from a closed state to an open state. As a result, the drying liquid begins to be discharged from the nozzle 30i toward the first main surface Wa of the substrate W. In other words, the drying liquid supply process effectively begins at time t1. On the other hand, in the example in Figure 11, at time t12, which is later than time t1, the control unit 90 switches the supply valve 42 from a closed state to an open state. As a result, a high-temperature heat transfer medium begins to be discharged from the nozzle 40 toward the second main surface Wb of the substrate W. In other words, the substrate heating unit 4 begins to heat the second main surface Wb of the substrate W. Then, at time t2, which is later than time t12, the control unit 90 switches the supply valve 32i and the supply valve 42 from an open state to a closed state. In other words, the drying liquid supply process effectively ends at time t2.

[0114] As described above, in the third embodiment, the substrate heating unit 4 does not heat the second main surface Wb of the substrate W during a predetermined pre-time T1 from time t1 to time t12, within the drying liquid supply time T from time t1 to time t2, and heats the second main surface Wb of the substrate W during a predetermined post-time T2 from time t12 to time t2. The post-time T2 is predetermined to be a time such that the temperature of the first main surface Wa of the substrate W at time t2 approaches the boiling point bp of the drying liquid sufficiently. For example, the post-time T2 may be set to half or less of the drying liquid supply time T, one-third or less of the drying liquid supply time T, one-quarter or less of the drying liquid supply time T, or one-tenth or less of the drying liquid supply time T.

[0115] As described above, in the third embodiment, the substrate heating unit 4 does not heat the substrate W in the time before T1, but heats the second main surface Wb of the substrate W in the time after T2. In other words, the substrate heating unit 4 heats the second main surface Wb of the substrate W only in the time after T2. Therefore, the operating time of the substrate heating unit 4 can be shortened, and the power consumption of the substrate processing apparatus 100 can be reduced. Furthermore, if the substrate heating unit 4 supplies a high-temperature heat transfer medium to the second main surface Wb of the substrate W, the amount of heat transfer medium used can be reduced. If the heat transfer medium is a liquid, liquid reduction can be achieved.

[0116] <Fourth Embodiment> In the example described above, processing unit 1 performed the chemical solution step (step S3), rinsing step (step S4), drying solution supply step (step S5), and drying step (step S6) in this order. However, it is not necessarily limited to this order.

[0117] Figure 12 is a flowchart showing a first example of the operation of the processing unit 1 according to the fourth embodiment. In the example in Figure 12, the control unit 90 causes the processing unit 1 to execute steps S11 to S19 according to a preset processing procedure (recipe). Steps S11 to S15 are the same as steps S1 to S5, respectively. However, in step S15 (drying liquid supply step), the substrate heating unit 4 does not need to heat the substrate W.

[0118] Next, the processing unit 1 hydrophobizes the first main surface Wa of the substrate W (step S16: hydrophobization process: corresponding to the liquid supply process). Specifically, the processing unit 1 includes a nozzle for discharging a hydrophobizing liquid, and discharges the hydrophobizing liquid from the nozzle onto the first main surface Wa of the rotating substrate W. The hydrophobizing liquid includes, for example, a silicon-based hydrophobizing liquid. A silicon-based hydrophobizing liquid is a hydrophobizing liquid that hydrophobizes silicon (Si) itself and silicon-containing compounds. The hydrophobizing liquid is, for example, a silylation liquid containing a liquid silylation agent (also called a silane coupling agent). When the first main surface Wa of the substrate W has been sufficiently hydrophobized, the processing unit 1 stops discharging the hydrophobizing liquid from the nozzle.

[0119] Next, processing unit 1 executes steps S17 to S19. Steps S17 to S19 are the same as steps S5 to S7, respectively.

[0120] As described above, in the first example, the drying liquid supply step (step S17) is performed in the same manner as the drying liquid supply step (step S5) in the first to third embodiments. Therefore, the collapse rate of the pattern on the substrate W can be reduced. Moreover, since the first main surface Wa of the substrate W is hydrophobic, the contact angle of the first main surface Wa can be reduced. Therefore, the surface tension acting on the pattern can be reduced, and the collapse rate of the pattern can be further reduced.

[0121] Figure 13 is a flowchart showing a second example of the operation of the processing unit 1 according to the fourth embodiment. In the example in Figure 13, the control unit 90 causes the processing unit 1 to execute steps S21 to S26 according to a preset processing procedure (recipe). Steps S21 to S26 are the same as steps S1 to S3 and steps S5 to S7, respectively. However, at the end of step S23 (chemical solution process: corresponding to the liquid supply process), metal is exposed on the first main surface Wa of the substrate W. According to the second example, step S24 (drying liquid supply process) is performed after step S23. Therefore, water is not supplied to the first main surface Wa of the substrate W. Thus, the reaction between metal and water can be avoided, and problems caused by this reaction can be avoided. Also, in the second example described above, the drying liquid supply process (step S24) is executed in the same way as the drying liquid supply process (step S5) in the first to third embodiments. Therefore, the rate of pattern collapse on the substrate W can be reduced.

[0122] <Fifth Embodiment> Figure 14 is a schematic diagram showing an example of the configuration of the processing unit 1 according to the fifth embodiment. The processing unit 1 according to the fifth embodiment differs from the processing unit 1 according to the first embodiment in terms of the configuration of the discharge section 3 and the opposing member 60. In the example of Figure 14, the opposing member 60 includes a shielding plate 6 and a hollow shaft 61. The shielding plate 6 is provided at a position that is vertically opposite to the first main surface Wa of the substrate W held by the substrate holding section 2. In the example of Figure 14, the first main surface Wa of the substrate W corresponds to the top surface, so the shielding plate 6 is provided vertically above the substrate W. The shielding plate 6 has, for example, a plate shape and is provided in a position where its thickness direction is aligned with the vertical direction. The lower surface of the shielding plate 6 is the opposing surface that faces the first main surface Wa of the substrate W. In plan view, the shielding plate 6 has, for example, a circular shape. The diameter of the shielding plate 6 (i.e., the diameter of the opposing surface) may be, for example, 80% or more of the diameter of the substrate W, 90% or more, or greater than or equal to the diameter of the substrate W.

[0123] In the example shown in Figure 14, a hollow shaft 61 is provided on the upper surface of the shut-off plate 6. The hollow shaft 61 has a hollow section, and a through-hole is formed in the central part of the shut-off plate 6, penetrating it vertically. This hollow section is vertically connected to the through-hole in the shut-off plate 6. The nozzle 30i is provided in the hollow section of the hollow shaft 61 and the through-hole in the shut-off plate 6. The diameter of the outer surface of the nozzle 30i is smaller than the diameter of the inner surfaces of the hollow shaft 61 and the shut-off plate 6. The space between the outer surface of the nozzle 30i and the inner surfaces of the hollow shaft 61 and the shut-off plate 6 functions as a gas flow path 30g.

[0124] In the example shown in Figure 14, nozzles 30c and 30w are located outside the opposing member 60. Also in the example shown in Figure 14, a moving drive unit 35c and a moving drive unit 35w are provided as a moving drive unit 35. The moving drive unit 35c moves nozzle 30c between the processing position and the standby position, and the moving drive unit 35w moves nozzle 30w between the processing position and the standby position.

[0125] In the example shown in Figure 14, a movable drive unit 35i is provided as the movable drive unit 35. The movable drive unit 35i moves the nozzle 30i and the opposing member 60 together. The movable drive unit 35i moves the nozzle 30i and the opposing member 60 together, for example, along the vertical direction. In this case, the movable drive unit 35i can also be said to be a lifting drive unit. The movable drive unit 35i includes a drive source such as a motor and a power transmission unit that transmits power from the drive source to the nozzle 30i and the shut-off plate 6. The power transmission unit includes, for example, a cam mechanism or a ball screw mechanism.

[0126] The operation of the processing unit 1 according to the fifth embodiment is the same as the flowchart in Figure 4. However, the moving drive unit 35i lowers the nozzle 30i and the opposing member 60 to a processing position closer to the substrate W during the drying liquid supply process and the drying process, and raises them to a standby position higher than the processing position at all other times.

[0127] In the fifth embodiment, the drying liquid supply step (step S5) in the first to third embodiments is also performed. This makes it possible to reduce the rate of pattern collapse at the peripheral edge of the substrate W.

[0128] As described above, the substrate processing apparatus 100 and the substrate processing method have been described in detail, but the above description is illustrative in all respects, and this disclosure is not limited thereto. Furthermore, the various modifications described above can be applied in combination as long as they do not contradict each other. And it is understood that a number of modifications not illustrated can be conceivable without falling outside the scope of this disclosure.

[0129] In the example described above, each fluid is provided with its own dedicated nozzle, but a single nozzle may be shared by different types of fluids.

[0130] Furthermore, in the above example, the substrate heating section 4 supplies a heat transfer medium to the second main surface Wb of the substrate W, but is not necessarily limited to this. The substrate heating section 4 may include, for example, a heater provided at a position facing the second main surface Wb of the substrate W in the vertical direction. The heater may be, for example, an electrically resistive heater including a heating wire, or an optical heater that outputs heating light. For example, the peripheral heating section 4A may be an electrically resistive or optical heater. The peripheral heating section 4A may be provided so as to surround the rotation axis Q1. The central heating section 4B may also be an electrically resistive or optical heater. [Explanation of symbols]

[0131] bp boiling point S1 Holding process (step) S4, S16, S23 Liquid supply process (step) S5, S17, S24 Drying solution supply process (step) S6, S18, S25 Drying process (steps) T Drying liquid supply time T1 Previous hour T2 Later W board Wa First Main Surface Wb 2nd principal surface

Claims

1. A holding step of holding a substrate having a first main surface on which a pattern is formed and a second main surface on the opposite side of the first main surface, A liquid supply step of supplying a processing liquid to the first main surface of the substrate, Following the liquid supply step, a drying liquid supply step is performed, in which at least a portion of the second main surface of the substrate is heated to a temperature above the boiling point of the drying liquid, and the drying liquid is supplied to the first main surface of the substrate at a flow rate such that the temperature of the first main surface of the substrate is below the boiling point of the drying liquid. After the drying liquid supply step, a drying step is performed to dry the substrate. A substrate processing method comprising:

2. A substrate processing method according to claim 1, A substrate processing method comprising supplying a heat transfer medium with a boiling point or higher than the boiling point of the drying liquid to the second main surface of the substrate in the drying liquid supply step.

3. A substrate processing method according to claim 1 or claim 2, A substrate processing method comprising the step of supplying the drying solution, wherein the peripheral portion of the second main surface of the substrate is heated to a temperature above the boiling point of the drying solution.

4. A substrate processing method according to claim 3, A substrate processing method comprising the drying liquid supply step, wherein the central portion of the second main surface of the substrate is heated to a temperature lower than the temperature of the peripheral portion of the second main surface.

5. A substrate processing method according to claim 4, A substrate processing method comprising the drying liquid supply step, wherein a heat transfer medium at a first medium temperature is supplied to the peripheral portion of the second main surface of the substrate, and a heat transfer medium at a second medium temperature lower than the first medium temperature is supplied to the central portion of the second main surface of the substrate.

6. A substrate processing method according to claim 1 or claim 2, A substrate processing method comprising heating the second main surface of the substrate only during the later part of the drying liquid supply time in the drying liquid supply step.

7. A substrate processing method according to claim 1 or claim 2, A substrate processing method wherein, in the drying liquid supply step, the temperature of the first main surface of the substrate is 60 degrees Celsius or higher and below the boiling point of the drying liquid.

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