Substrate processing method

Abstract

The present invention provides a technique capable of effectively reducing the pattern collapse ratio. The substrate processing method is provided with a holding step, a liquid supply step, a drying liquid supply step and a drying step. The holding step involves holding a substrate, which has a first main surface on which a pattern is formed and a second main surface on the side thereof opposite the first main surface. The liquid supply step involves supplying a processing liquid to the first main surface of the substrate. The drying liquid supply step involves supplying a drying liquid to the first main surface of the substrate after the liquid supply step. The drying step involves heating the second main surface of the substrate during a prescribed period after the drying liquid supply step, and drying the substrate with the substrate temperature on the first main surface of the substrate at or above the substrate temperature of the drying liquid supply step.

Description

Substrate processing method

[0001] The present disclosure relates to a substrate processing method.

[0002] Single-wafer substrate processing apparatuses for processing substrates have been disclosed in the past (for example, Patent Document 1). In Patent Document 1, the substrate processing apparatus supplies a rinse liquid to the substrate, then supplies isopropyl alcohol, which has a lower surface tension than the rinse liquid, to the substrate, and then dries the substrate. This prevents the pattern on the substrate from collapsing during drying.

[0003] JP 2015-23182 A

[0004] However, Patent Document 1 does not consider the temperature of isopropyl alcohol, and therefore is unable to effectively reduce the rate of pattern collapse.

[0005] Therefore, an object of the present disclosure is to provide a technique that can effectively reduce the rate of pattern collapse.

[0006] A first aspect 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 opposite to 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 a drying liquid to the first main surface of the substrate after the liquid supply step; and a drying step of heating the second main surface of the substrate for a predetermined period of time after the drying liquid supply step to make the substrate temperature of the first main surface of the substrate equal to or higher than the substrate temperature in the drying liquid supply step, thereby drying the substrate.

[0007] A second aspect is the substrate processing method according to the first aspect, wherein the temperature of at least a part of the first main surface of the substrate is set to a boiling point of the drying liquid or higher during the predetermined period.

[0008] A third aspect is a substrate processing method according to the first or second aspect, wherein in the drying liquid supply step, the second main surface of the substrate is heated with a first amount of heat per unit time, and in the predetermined period of the drying step, the second main surface of the substrate is heated with a second amount of heat per unit time that is greater than the first amount of heat.

[0009] A fourth aspect is the substrate processing method according to any one of the first to third aspects, wherein a heat medium is supplied to the second main surface of the substrate during the predetermined period.

[0010] A fifth aspect is a substrate processing method according to the third aspect, wherein in the drying liquid supply step, a heat medium obtained by mixing a high-temperature heat medium and a low-temperature heat medium having a temperature lower than that of the high-temperature heat medium is supplied to the second main surface of the substrate, and the mixing ratio of the high-temperature heat medium and the low-temperature heat medium is adjusted so that the heat medium having a higher temperature than that of the heat medium in the drying liquid supply step is supplied to the second main surface of the substrate for at least the predetermined period of the drying step.

[0011] A sixth aspect is the substrate processing method according to the fourth or fifth aspect, wherein the heat medium having a temperature equal to or higher than the boiling point of the drying liquid is supplied to the second main surface of the substrate during the predetermined period.

[0012] A seventh aspect is a substrate processing method according to any one of the fourth to sixth aspects, wherein in the drying liquid supply step, the heat medium having a temperature equal to or higher than the boiling point of the drying liquid is supplied to the second main surface of the substrate, while the drying liquid is supplied at a flow rate such that the substrate temperature of the first main surface of the substrate becomes lower than the boiling point.

[0013] An eighth aspect is a substrate processing method according to any one of the fourth to seventh aspects, wherein the heat medium includes a liquid, and in the drying liquid supply step, the drying liquid is supplied to the first main surface of the substrate while a shielding plate having an opposing surface facing the first main surface of the substrate is positioned at a shielding processing position, and during the predetermined period of the drying step, an inert gas is supplied toward the first main surface of the substrate from a gas outlet in the center of the shielding plate while the shielding plate is moved to a drying position closer to the first main surface than the shielding processing position.

[0014] A ninth aspect is the substrate processing method according to the eighth aspect, wherein the heated inert gas is supplied to the first main surface of the substrate during the predetermined period.

[0015] A tenth aspect is a substrate processing method according to the eighth or ninth aspect, wherein in the drying liquid supply process, the inert gas is supplied to the first main surface of the substrate through a gas flow path inside the blocking plate, which has a flow path with an expanding diameter that widens as it approaches the gas outlet, and the flow rate of the inert gas is increased while the blocking plate is moved from the blocking processing position to the drying position.

[0016] An eleventh aspect is a substrate processing method according to the tenth aspect, wherein, in the drying liquid supply process, the drying liquid is supplied to the first main surface of the substrate while the blocking plate is positioned at a first blocking processing position, which is one of the blocking processing positions, and then, while supplying the drying liquid, the blocking plate is moved to a second blocking processing position, which is one of the blocking processing positions and is closer to the first main surface of the substrate than the first blocking processing position.

[0017] A twelfth aspect is a substrate processing method according to any one of the first to eleventh aspects, wherein during the predetermined period of the drying step, the substrate is rotated at a rotational speed higher than the rotational speed of the substrate during the drying liquid supply step.

[0018] A thirteenth aspect is a substrate processing method according to any one of the first to twelfth aspects, wherein in the drying liquid supply step, the second main surface of the substrate is heated only during a latter part of a drying liquid supply time during which the drying liquid is supplied.

[0019] According to the first aspect, the second main surface of the substrate is heated for a predetermined period of time. This allows the drying liquid to evaporate with a lower surface tension and a higher evaporation rate. This makes it possible to prevent the pattern from collapsing when the first main surface of the substrate is dried.

[0020] According to the second aspect, the surface tension of the drying liquid can be further reduced for a predetermined period of time, and the evaporation rate of the drying liquid can be further increased, thereby further reducing the rate of pattern collapse.

[0021] According to the third aspect, in the drying liquid supplying step, the drying liquid is supplied to the first main surface of the substrate while the second main surface of the substrate is heated with a relatively small first heat quantity. Therefore, while the drying liquid is being supplied, an increase in substrate temperature can be suppressed, and boiling of the drying liquid can be suppressed. This can suppress particle adhesion. Meanwhile, during a predetermined period of the drying step, the second main surface of the substrate is heated with a relatively large second heat quantity while the drying liquid is not being supplied to the substrate. This can further reduce the surface tension of the drying liquid over a predetermined period of time, while further improving the evaporation rate. This can further reduce the pattern collapse rate.

[0022] According to the fourth aspect, the second main surface of the substrate can be easily heated.

[0023] According to the fifth aspect, the temperature of the heat medium supplied to the second main surface of the substrate can be increased quickly by adjusting the mixture ratio, which allows the temperature of the drying liquid to be increased at an earlier timing during the drying process, thereby further reducing the rate of pattern collapse.

[0024] According to the sixth aspect, in the drying step, the evaporation rate can be further increased while the surface tension of the drying liquid is further reduced, thereby further reducing the rate of pattern collapse.

[0025] According to the seventh aspect, in the drying liquid supplying step, the temperature of the first main surface of the substrate can be increased to a temperature closer to the boiling point of the drying liquid.

[0026] According to the eighth aspect, the shield plate is positioned at a dry position close to the substrate during the predetermined period. This narrows the gap between the substrate and the shield plate, increasing the flow rate of the inert gas flowing outward in the radial direction from between the substrate and the shield plate. This prevents the heat transfer medium from flowing from the second main surface to the first main surface via the periphery of the substrate.

[0027] According to the ninth aspect, the drying liquid can be evaporated in an even shorter time, which further reduces the rate of pattern collapse.

[0028] According to the tenth aspect, the rate of pattern collapse can be further reduced while suppressing adhesion of the drying liquid to the blocking plate.

[0029] According to the eleventh aspect, the blocking plate is positioned at the second blocking processing position immediately before the drying step. This allows the blocking plate to be moved to the drying position more quickly. This allows the substrate to be dried more quickly, further reducing the rate of pattern collapse.

[0030] According to the twelfth aspect, the drying liquid can be evaporated in an even shorter time, which further reduces the rate of pattern collapse.

[0031] According to the thirteenth aspect, it is possible to reduce power consumption.

[0032] 1 is a plan view schematically showing an example of the configuration of a substrate processing apparatus; FIG. 2 is a block diagram schematically showing an example of the internal configuration of a control unit; FIG. 3 is a longitudinal sectional view schematically showing an example of the configuration of a processing unit according to a first embodiment; FIG. 4 is a flowchart showing an example of the operation of a processing unit; FIG. 5 is a diagram schematically showing an example of the state of a processing unit at each step; FIG. 6 is a diagram schematically showing an example of the state of a processing unit at each step; FIG. 7 is a diagram schematically showing an example of a timing chart of a processing unit and a change in temperature of a first main surface of a substrate over time; FIG. 8 is a diagram schematically showing an example of the configuration of a substrate heating unit according to a second embodiment; FIG. 9 is a diagram schematically showing an example of a timing chart of a processing unit, a change in flow rate of a heat medium, and a change in temperature of the heat medium over time of a processing unit according to a third embodiment; FIG. 10 is a diagram schematically showing an example of a timing chart of a processing unit, a change in flow rate of a heat medium, a change in temperature of the heat medium, and a change in temperature of the first main surface of a substrate over time of a processing unit according to a fourth embodiment; FIG. 11 is a flowchart showing a first example of the operation of a processing unit according to a fifth embodiment; FIG. 12 is a flowchart showing a second example of the operation of a processing unit according to the fifth embodiment; FIG. 13 is a diagram schematically showing a first example of the configuration of a shielding plate according to a sixth embodiment. FIG. 14 is a diagram schematically showing an example of how an inert gas is discharged. FIG. 15 is a diagram showing a first example of a timing chart of the processing unit according to the sixth embodiment. FIG. 16 is a diagram showing a second example of a timing chart of the processing unit according to the sixth embodiment. FIG. 17 is a diagram showing an example of how the processing unit is in a drying liquid supplying step. FIG. 18 is a diagram showing an example of how the processing unit is in a drying liquid supplying step according to the sixth embodiment. FIG. 19 is a diagram showing a second example of the configuration of the blocking plate according to the sixth embodiment.

[0033] Hereinafter, the embodiments will be described in detail with reference to the drawings. In the drawings, the dimensions and numbers of each part are exaggerated or simplified as necessary for ease of understanding. Parts having similar configurations and functions are assigned the same reference numerals, and duplicate explanations will be omitted below.

[0034] In the following description, the same components are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed descriptions of them may be omitted to avoid duplication.

[0035] Furthermore, in the following description, even if ordinal numbers such as "first" or "second" are used, these terms are used for convenience to facilitate understanding of the contents of the embodiments, and are not limited to the order that may result from these ordinal numbers.

[0036] When expressions indicating relative or absolute positional relationships (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.) are used, unless otherwise specified, the expressions 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 range in which tolerance or equivalent functionality is obtained. When expressions indicating an equal state (e.g., "identical," "equal," "homogeneous," etc.) are used, the expressions not only represent a state in which there is strict quantitative equality but also represent a state in which there is a difference in which tolerance or equivalent functionality is obtained, unless otherwise specified. When expressions indicating a shape (e.g., "rectangular shape" or "cylindrical shape," etc.) are used, the expressions not only represent a geometrically strict shape but also represent a shape with, for example, irregularities or chamfers within a range in which equivalent effects are obtained. When the expressions "comprise," "include," "have," "includes," "includes," or "have" are used to describe one component, the expressions are not exclusive expressions that exclude the presence of other components. When the phrase "at least one of A, B, and C" is used, the phrase includes A only, B only, C only, any two of A, B, and C, and all of A, B, and C.

[0037] First Embodiment Overall Configuration of Substrate Processing Apparatus Fig. 1 is a plan view schematically showing an example of the configuration of a substrate processing apparatus 100. The substrate processing apparatus 100 is a single-wafer processing apparatus that processes substrates W one by one.

[0038] The substrate W may be, for example, a semiconductor wafer, a liquid crystal display substrate, an organic electroluminescence (EL) (electroluminescence) substrate, an FPD (flat panel display) 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 plate 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, the substrate W is assumed to be a semiconductor wafer. The substrate W has, for example, a circular plate shape. The diameter of the substrate W is, for example, approximately 300 mm, and the thickness of the substrate W is, for example, approximately 0.5 mm or more and approximately 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. Such high aspect ratio patterns are prone to collapse.

[0039] 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 a section that mainly processes substrates W, and the indexer block 110 is a section that mainly transports substrates W between the outside of the substrate processing apparatus 100 and the processing block 120.

[0040] The indexer block 110 includes a load port 111 and a first transport part 112. A substrate container (hereinafter referred to as a carrier) C that has been carried in from outside is placed on the load port 111. The carrier C accommodates a plurality of substrates W, for example, arranged at intervals in the vertical direction. In the example of Fig. 1, a plurality of load ports 111 are arranged.

[0041] The first transport unit 112 is a transport robot and can remove unprocessed substrates W from the 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 of the load port 111.

[0042] In the example of FIG. 1 , the processing block 120 includes a plurality of processing units 1 and a second transport part 122. The second transport part 122 is a transport robot and can transport substrates W between the first transport part 112 and the plurality of processing units 1. In the example of FIG. 1 , the processing block 120 also includes a receiver 123. The receiver 123 is, for example, a shelf on which a plurality of substrates W can be placed in a vertically arranged state. The first transport part 112 places an unprocessed substrate W on the receiver 123. The second transport part 122 removes the unprocessed substrate W from the receiver 123 and transports the substrate W to the processing unit 1. The processing unit 1 processes the substrate W. The configuration of the processing unit 1 will be described later. The second transport part 122 removes the processed substrate W from the processing unit 1 and transports the substrate W to the receiver 123. The first transport part 112 takes the substrate W from the platform 123 and transports the substrate W to a carrier C in the load port 111 .

[0043] 1 , a plurality of (e.g., four) processing units 1 are arranged to surround the second transport section 122 in a plan view. This second transport section 122 may also be called a center robot. At each position in a plan view, a plurality of processing units 1 may be stacked vertically. In other words, a plurality of (four in the figure) towers TW each made up of a plurality of processing units 1 stacked vertically may be arranged to surround the second transport section 122.

[0044] The control unit 90 performs overall control of 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. FIG. 2 is a block diagram schematically illustrating 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 example illustrated in FIG. 2, the data processing unit 91 and the storage unit 92 are connected to each other via a bus 93. The data processing unit 91 may be, for example, an arithmetic processing device such as a central processing unit (CPU). The storage unit 92 may include a non-transitory storage unit (e.g., a read-only memory (ROM)) 921 and a temporary storage unit (e.g., a random access memory (RAM)) 922. The non-transitory storage unit 921 may store, for example, a program that defines the processing to be performed by the control unit 90. The data processing unit 91 executes this program, allowing the control unit 90 to perform 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 a dedicated logic circuit.

[0045] <Overview of Processing Unit> Fig. 3 is a longitudinal cross-sectional view schematically showing an example of the configuration of a processing unit 1 according to the first embodiment. Note that all processing units 1 belonging to the substrate processing apparatus 100 do not need to have the configuration illustrated in Fig. 3. It is sufficient that at least one processing unit 1 of the substrate processing apparatus 100 has the configuration illustrated in Fig. 3.

[0046] The processing unit 1 includes a substrate holder 2 , at least one nozzle 3 , and a substrate heater 40 .

[0047] 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 a processing space for processing a substrate W. The chamber 10 is provided with an openable / closable loading / unloading port (not shown). The second transport part 122 loads an unprocessed substrate W into the chamber 10 through the loading / unloading port, and loads a processed substrate W out of the chamber 10 through the loading / unloading port.

[0048] In the example of Fig. 3, a fan filter unit 11 is provided on the ceiling of chamber 10. The fan filter unit 11 takes in air from outside chamber 10, cleans it, and then blows the cleaned air into chamber 10. Operation of fan filter unit 11 creates a downflow of clean air within chamber 10. In the example of Fig. 3, the upstream end of exhaust pipe 13 is connected to the lower part of the side wall of chamber 10. Gas within chamber 10 is exhausted to the outside through exhaust pipe 13.

[0049] The substrate holder 2 is provided in the chamber 10 and holds the substrate W in a horizontal position while rotating the substrate W around a rotation axis Q1. The horizontal position here means that 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.

[0050] In this example, the first main surface Wa of the substrate W on which the pattern is formed faces vertically upward. That is, in the example of Fig. 3, the first main surface Wa of the substrate W held by the substrate holder 2 corresponds to the upper surface. The pattern includes, for example, at least one of a wiring pattern, an insulating pattern, and a semiconductor pattern.

[0051] In the example of FIG. 3 , the substrate holder 2 includes a spin base 21, chuck pins 22, and a rotation driver 23. The spin base 21 has a plate-like shape (e.g., a disk shape) and is disposed with its thickness direction aligned vertically. A plurality of chuck pins 22 are provided on the upper surface of the spin base 21. The plurality of chuck pins 22 are disposed at equal intervals along the circumferential direction about the rotation axis Q1. The plurality of chuck pins 22 are disposed so as to be displaceable between a holding position and a release position, which will be described below. The holding position is a position where the chuck pins 22 abut against the periphery of the substrate W. The plurality of chuck pins 22 hold the substrate W by stopping at their respective holding positions. FIG. 3 shows the chuck pins 22 stopped at the holding position. The release position is a position where each chuck pin 22 is separated from the substrate W. The plurality of chuck pins 22 stop at their respective release positions, thereby releasing the substrate W from the holding of the substrate W by the plurality of chuck pins 22. The substrate holder 2 also includes a pin drive unit (not shown) that displaces the chuck pins 22. The pin drive unit includes a drive source such as a motor and an air cylinder, and is controlled by the control unit 90.

[0052] The rotation 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 a rotation axis Q1. The motor 232 is controlled by the control unit 90 to rotate the shaft 231 about the rotation axis Q1. This causes the spin base 21, chuck pins 22, and substrate W to rotate integrally about the rotation axis Q1.

[0053] It should be noted that the substrate holder 2 does not necessarily have to have the chuck pins 22. For example, the substrate holder 2 may hold the substrate W by a chuck method such as a vacuum chuck, an electrostatic chuck, or a Bernoulli chuck.

[0054] At least one nozzle 3 ejects liquid toward a first main surface Wa of the substrate W held by the substrate holding part 2. In the example of Figure 3, the first main surface Wa is the upper surface, and therefore the nozzle 3 is provided vertically above the substrate W held by the substrate holding part 2.

[0055] In the example of Figure 3, nozzles 3c, 3w, and 3i are provided as nozzles 3. Nozzle 3c ejects a chemical liquid, nozzle 3w ejects a rinse liquid, and nozzle 3i ejects a drying liquid. Specific examples of the chemical liquid, rinse liquid, and drying liquid will be described later. Hereinafter, the chemical liquid, rinse liquid, and drying liquid will also be collectively referred to as processing liquid. Nozzle 3 is, for example, a straight nozzle that ejects the processing liquid in the form of a continuous flow.

[0056] In the example of Fig. 3, the nozzle 3 is provided so as to be movable by a movement drive unit 35. In the example of Fig. 3, movement drive unit 35c, movement drive unit 35w, and movement drive unit 35i are shown as the movement drive unit 35. Movement drive unit 35c moves nozzle 3c, movement drive unit 35w moves nozzle 3w, and movement drive unit 35i moves nozzle 3i.

[0057] The movement drive unit 35c moves the nozzle 3c between a first processing position and a first standby position, which will be described below. The first standby position is a position where the nozzle 3c does not eject the chemical solution toward the first main surface Wa of the substrate W, and is, for example, a position radially outward from the substrate holding unit 2. The example in Figure 3 shows the nozzle 3c stopped at the first standby position. The first processing position is a position where the nozzle 3c ejects the chemical solution toward the first main surface Wa of the substrate W, and is, for example, a position vertically opposite the center of the first main surface Wa of the substrate W.

[0058] The movement driver 35w moves the nozzle 3w between a second processing position and a second standby position, which will be described below. The second processing position is a position where the nozzle 3w ejects the rinse liquid toward the first main surface Wa of the substrate W, and is, for example, a position vertically opposite to the center of the first main surface Wa of the substrate W. The example in Figure 3 shows the nozzle 3w stopped at the second processing position. The second standby position is a position where the nozzle 3w does not eject the rinse liquid toward the first main surface Wa of the substrate W, and is, for example, a position radially outward from the substrate holder 2.

[0059] FIG. 3 shows an example of the specific configuration of the movement drive unit 35w. In the example of FIG. 3, the movement drive unit 35w includes an arm 351, a support column 352, and a drive source 353. The support column 352 is disposed radially outward of the guard 7 (described later) and extends vertically. The arm 351 extends horizontally, with its tip connected to the nozzle 3w 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 nozzle 3w reciprocates in the circumferential direction about the central axis Q2. The support column 352 is installed so that the second processing position and the second standby position are located on the movement trajectory of the nozzle 3w. 3, the movement drive unit 35w may include a direct acting mechanism such as a linear motor, etc. The movement drive unit 35c may have the same configuration as the movement drive unit 35w, for example.

[0060] The movement drive unit 35i moves the nozzle 3i between a blocking processing position and a blocking standby position, which will be described below. In the example of FIG. 3 , the nozzle 3i is integrally provided with a blocking plate 6, which will be described later, and the movement drive unit 35i moves the nozzle 3i and the blocking plate 6 together. The blocking processing position is a position where the nozzle 3i ejects drying liquid toward the first main surface Wa of the substrate W, for example, a position vertically opposite the center of the first main surface Wa of the substrate W. The blocking standby position is a position where the nozzle 3i does not eject drying liquid toward the first main surface Wa of the substrate W, for example, a position vertically above the blocking processing position. In the example of FIG. 3 , the nozzle 3i and the blocking plate 6 are shown stopped at the blocking standby position. The movement drive unit 35i moves the nozzle 3i vertically, and therefore can also be considered an elevation drive unit. The movement 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 3i and the blocking plate 6. The power transmission unit includes, for example, a cam mechanism or a ball screw mechanism.

[0061] The nozzle 3 is connected to the downstream end of a supply pipe 31, and the upstream end of the supply pipe 31 is connected to a processing liquid supply source. In the example of FIG. 3, supply pipes 31c, 31w, and 31i are shown as the supply pipes 31. The downstream end of supply pipe 31c is connected to the nozzle 3c, and the upstream end of supply pipe 31c is connected to a chemical supply source. The chemical supply source has a tank (not shown) that stores the chemical, and supplies the chemical to the upstream end of supply pipe 31c. Examples of the chemical include hydrofluoric nitric acid obtained by mixing hydrofluoric acid, nitric acid, and water, a hydrofluoric acid-hydrogen peroxide solution (FPM) obtained by mixing hydrofluoric acid, hydrogen peroxide, and water, tetramethylammonium hydroxide (TMAH), a mixture of sulfuric acid and hydrogen peroxide (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). The chemical solution may not be a mixture but may be a single solution, such as hydrofluoric acid (HF), hydrogen peroxide, or sulfuric acid.

[0062] The downstream end of the supply pipe 31w is connected to the nozzle 3w, 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) that stores the rinse liquid, and supplies the rinse liquid to the upstream end of the supply pipe 31w. The rinse liquid may be, for example, pure water, carbon dioxide water, or ozone water.

[0063] The downstream end of the supply pipe 31i is connected to the nozzle 3i, 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) that stores the drying liquid and supplies the drying liquid to the upstream end of the supply pipe 31i. For example, an organic solvent such as isopropyl alcohol can be used as the drying liquid. The surface tension of the drying liquid is lower than that of the other processing liquids (e.g., both the surface tension of the chemical liquid and the surface tension of the rinse liquid). Furthermore, the volatility of the drying liquid is higher than that of the other processing liquids (e.g., both the volatility of the chemical liquid and the volatility of the rinse liquid).

[0064] A supply valve 32 and a flow rate adjustment valve 33 are inserted in the supply pipe 31. In the example of Fig. 3, a supply valve 32c and a flow rate adjustment valve 33c are inserted in the supply pipe 31c, a supply valve 32w and a flow rate adjustment valve 33w are inserted in the supply pipe 31w, and a supply valve 32i and a flow rate adjustment valve 33i are inserted in the supply pipe 31i. The supply valve 32 switches the opening and closing of the supply pipe 31. The flow rate adjustment valve 33 adjusts the flow rate of the processing liquid flowing through the supply pipe 31. The flow rate adjustment valve 33 may be a mass flow controller. The supply valve 32 and the flow rate adjustment valve 33 are controlled by a control unit 90.

[0065] When the supply valve 32 opens while the substrate holder 2 is rotating the substrate W and the nozzle 3 is positioned at the processing position, a processing liquid is ejected from the nozzle 3 toward the first main surface Wa of the rotating substrate W. The processing liquid that has landed on the first main surface Wa of the substrate W is subjected to centrifugal force accompanying the rotation of the substrate W, and flows radially outward along the first main surface Wa, and is scattered outward from the periphery of the substrate W. In this way, processing according to the type of processing liquid is performed on the first main surface Wa of the substrate W. For example, when a cleaning chemical liquid is ejected, the first main surface Wa of the substrate W is cleaned by the chemical liquid.

[0066] The substrate heating unit 40 heats the second main surface Wb of the substrate W held by the substrate holder 2. In the example of Fig. 3, the substrate heating unit 40 is provided at a position vertically opposite to the second main surface Wb of the substrate W. In the example of Fig. 3, the second main surface Wb of the substrate W corresponds to the bottom surface, and therefore the substrate heating unit 40 is provided directly below the substrate W.

[0067] In the example of FIG. 3 , the substrate heating unit 40 includes a nozzle 4. The nozzle 4 ejects a heat medium toward the second main surface Wb of the substrate W. In the example of FIG. 3 , the second main surface Wb of the substrate W corresponds to the bottom surface, so the nozzle 4 may also be called a bottom nozzle. In the example of FIG. 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 of the spin base 21 and the hollow portion of the shaft 231 are connected in the vertical direction. A portion of the nozzle 4 is disposed in the through hole. An ejection port is formed in the upper surface of the nozzle 4, and the ejection port of the nozzle 4 faces the center of the second main surface Wb of the substrate W in the vertical direction. The nozzle 4 ejects the heat medium toward the center of the second main surface Wb of the substrate W.

[0068] The downstream end of a supply pipe 41 is connected to the nozzle 4. The supply pipe 41 extends inside the shaft 231 and penetrates the shaft 231. The upstream end of the supply pipe 41 is connected to a heat medium supply source. The heat medium is a fluid (gas or liquid), and a more specific example is a liquid such as water. The heat medium supply source has, for example, a tank (not shown) that stores the heat medium, and supplies the heat medium to the upstream end of the supply pipe 41.

[0069] In the example of Fig. 3, a supply pipe 41 is provided with a supply valve 42, a flow rate adjustment valve 43, and a heater 44. The supply valve 42 switches the supply pipe 41 between on and off. The flow rate adjustment valve 43 adjusts the flow rate of the heat medium flowing through the supply pipe 41. The flow rate adjustment valve 43 may be a mass flow controller. The heater 44 heats the heat medium flowing through the supply pipe 41. The heater 44 may be, for example, an electric resistance heater having an electric heating wire. The supply valve 42, the flow rate adjustment valve 43, and the heater 44 are controlled by a control unit 90.

[0070] When the supply valve 42 opens, the high-temperature heat medium is discharged from the nozzle 4 onto the center of the second main surface Wb of the rotating substrate W. The heat medium that has landed on the center of the second main surface Wb of the substrate W is subjected to centrifugal force accompanying the rotation of the substrate W, flows radially outward along the second main surface Wb, and is scattered outward from the periphery of the substrate W. As the high-temperature heat medium flows along the second main surface Wb of the substrate W, heat is transferred from the heat medium to the substrate W, and the substrate W is heated.

[0071] In the example of FIG. 3 , the processing unit 1 is provided with a guard 7 and a guard lifting / lowering drive unit 71. The guard 7 has a cylindrical shape with the rotation axis Q1 as its central axis and surrounds the substrate holder 2. The guard 7 can catch the processing liquid and heat medium splashed from the periphery of the substrate W. The guard lifting / lowering drive unit 71 raises and lowers the guard 7 between an upper position and a lower position, which will be described below. The upper position is a position where the upper end of the guard 7 is vertically above the substrate W held by the substrate holder 2. When the guard 7 is in the upper position, it can catch the processing liquid and heat medium splashed from the periphery of the substrate W. The lower position is a position lower than the upper position, for example, a position where the upper end of the guard 7 is vertically below the upper surface of the spin base 21.

[0072] In the example of FIG. 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 of FIG. 3 , cups 72 are provided corresponding to each guard 7. The cups 72 have an annular (e.g., annular) recess (groove) surrounding the rotation axis Q1. Each cup 72 receives the processing liquid that has flowed down the inner circumferential surface of the corresponding guard 7. The upstream end of a 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.

[0073] In the example of FIG. 3 , the processing unit 1 further includes a shielding plate 6. The shielding plate 6 is provided at a position vertically opposite the first main surface Wa of the substrate W held by the substrate holder 2. In the example of FIG. 3 , the first main surface Wa of the substrate W corresponds to the upper surface, and therefore the shielding plate 6 is provided vertically above the substrate W. The shielding plate 6 has, for example, a plate-like shape and is provided with its thickness direction aligned along the vertical direction. The lower surface of the shielding plate 6 is an opposing surface that faces the first main surface Wa of the substrate W. The shielding plate 6 has, for example, a circular shape in plan view. 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, or 90% or more, or may be equal to or greater than the diameter of the substrate W. A through-hole is formed in the center of the shielding plate 6, vertically penetrating the plate, and the nozzle 3i is provided inside the through-hole.

[0074] 3, a hollow shaft 61 is provided on the upper surface of the blocking plate 6. The hollow shaft 61 has a hollow portion that is vertically connected to the through-hole of the blocking plate 6. The diameter of the outer peripheral surface of the nozzle 3i is smaller than the diameters of the hollow shaft 61 and the inner peripheral surfaces of the blocking plate 6. The space between the outer peripheral surface of the nozzle 3i and the inner peripheral surfaces of the hollow shaft 61 and the blocking plate 6 functions as a gas flow path 3g, as described below.

[0075] In the example of Figure 3, the upper part of the hollow shaft 61 is connected to the downstream end of the supply pipe 31g. In other words, the downstream end of the supply pipe 31g is connected to the gas flow path 3g between the outer peripheral surface of the nozzle 3i and the inner peripheral surfaces of the hollow shaft 61 and the shield plate 6. 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 an inert gas and supplies the inert gas to the upstream end of the supply pipe 31g. The inert gas includes, for example, at least one of nitrogen gas and a rare gas. The rare gas includes, for example, argon gas.

[0076] The supply pipe 31g is provided with a supply valve 32g, a flow rate adjustment valve 33g, and a heater 34g. The supply valve 32g switches the supply pipe 31g between on and off. The flow rate adjustment 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 electric resistance heater having an electric heating wire. The supply valve 32g, the flow rate adjustment valve 33g, and the heater 34g are controlled by a control unit 90.

[0077] When the supply valve 32g is opened and the heater 34g is activated, high-temperature inert gas is discharged from the center of the lower surface of the shielding plate 6 (i.e., the lower end opening of the gas flow path 3g) toward the center of the first main surface Wa of the substrate W. This can promote drying of the substrate W.

[0078] <Example of Operation of Substrate Processing Apparatus> Next, an example of operation of the processing unit 1 will be described. Fig. 4 is a flowchart showing an example of operation of the processing unit 1. The control unit 90 causes the processing unit 1 to perform processes from step S1 to step S7 in accordance with a preset processing procedure (recipe). Figs. 5 and 6 are diagrams schematically showing an example of the state of the processing unit 1 at each step.

[0079] First, the second transport part 122 transports the substrate W to the processing unit 1. Then, the substrate holding part 2 holds the substrate W received from the second transport part 122 (step S1: holding step). As a specific example, the substrate holding part 2 displaces the plurality of chuck pins 22 from their respective release positions to their holding positions. As a result, the plurality of chuck pins 22 hold the substrate W. The substrate holding part 2 continues to hold the substrate W until the processing on the substrate W is completed.

[0080] 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 completed.

[0081] Next, the processing unit 1 supplies the chemical solution to the first main surface Wa of the substrate W (step S3: chemical process). First, the movement drive unit 35c moves the nozzle 3c to the first processing position. The guard lift drive unit 71 raises the chemical solution guard 7 to the upper position. Then, the control unit 90 opens the supply valve 32c. That is, the control unit 90 switches the supply valve 32c from a closed state to an open state. This causes the chemical solution to be discharged from the nozzle 3c 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 flows radially outward due to centrifugal force caused by the rotation of the substrate W and is scattered from the periphery of the substrate W. At this time, the chemical solution acts on the first main surface Wa of the substrate W, thereby performing chemical processing on the first main surface Wa of the substrate W according to the type of chemical solution. For example, the processing unit 1 performs a cleaning process to clean and remove 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 received by the guard 7 and discharged to the outside of the chamber 10 through the discharge pipe 12 .

[0082] When the substrate W has been sufficiently processed, 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 discharge and determines whether the elapsed time is equal to or greater than a predetermined chemical time. The chemical time is set in advance to a time sufficient for chemical processing to be performed. 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 time, the control unit 90 switches the supply valve 32c from an open state to a closed state. Furthermore, after closing the supply valve 32c, the movement drive unit 35c moves the nozzle 3c to the first standby position.

[0083] Next, the processing unit 1 supplies a rinse liquid to the first main surface Wa of the substrate W (step S4: rinse process). Specifically, first, the movement drive unit 35w moves the nozzle 3w to the second processing position. Furthermore, if the guard 7 for the rinse liquid is different from the guard 7 for the chemical liquid, the guard lift drive unit 71 appropriately lifts and lowers the guard 7 to position the guard 7 for the rinse liquid at the upper position. Then, the control unit 90 opens the supply valve 32w. That is, the control unit 90 switches the supply valve 32w from a closed state to an open state. As a result, as shown in FIG. 5A , the rinse liquid is ejected from the nozzle 3w toward the first main surface Wa of the rotating substrate W. The rinse liquid that has landed on the first main surface Wa of the substrate W flows radially outward due to centrifugal force caused by the rotation of the substrate W and is scattered from the periphery of the substrate W. At this time, the rinse liquid pushes the chemical liquid 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 with the rinsing liquid from the chemical liquid. The processing liquid splashed from the periphery of the substrate W is received by the guard 7 and discharged to the outside of the chamber 10 through the discharge pipe 12.

[0084] When the chemical liquid has been sufficiently replaced with the rinse liquid, 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 discharge of the rinse liquid, and when the elapsed time reaches or exceeds a predetermined rinse time, the control unit 90 switches the supply valve 32w from an open state to a closed state. The rinse time is set in advance to a time sufficient to replace the chemical liquid with the rinse liquid. After the supply valve 32w is closed, the movement drive unit 35w moves the nozzle 3w to the second standby position.

[0085] Next, the processing unit 1 supplies a drying liquid to the first main surface Wa of the substrate W (step S5: drying liquid supply step). Specifically, first, the movement drive unit 35i moves the nozzle 3i and the shield plate 6 together to the shielding processing position. Furthermore, if the guard 7 for the drying liquid is different from the guard 7 for the rinsing liquid, the guard lift drive unit 71 lifts and lowers 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. That is, the control unit 90 switches the supply valve 32i from a closed state to an open state.

[0086] When the supply valve 32i opens, as shown in FIG. 5B , drying liquid is ejected from the nozzle 3i toward the first main surface Wa of the rotating substrate W. The temperature of the drying liquid may be, for example, room temperature (e.g., approximately 25°C). The drying liquid that has landed on the first main surface Wa of the substrate W flows radially outward due to centrifugal force caused by the rotation of the substrate W and splashes off from the periphery of the substrate W. At this time, the drying liquid pushes away the rinse liquid on the first main surface Wa of the substrate W, thereby replacing the rinse liquid with the drying liquid on the first main surface Wa of the substrate W. The treatment liquid splashed off from the periphery of the substrate W is received by the guard 7 and discharged to the outside of the chamber 10 through the discharge pipe 12. The rotation speed of the substrate W during the drying liquid supply step 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.

[0087] The processing unit 1 may also heat the substrate W while supplying the drying liquid. That is, the substrate heating section 40 may heat the second main surface Wb of the substrate W. As a more specific example, the control section 90 may open the supply valve 42 and operate the heater 44. As a result, as shown in FIG. 5B , a high-temperature heat medium (e.g., hot water) is discharged from the nozzle 4 toward the second main surface Wb of the rotating substrate W. The heater 44 may heat the heat medium to, for example, 60° C. or higher, 70° C. or higher, or 80° C. or higher. The heater 44 may also adjust the temperature of the heat medium to, for example, below the boiling point of the drying liquid. The temperature of the heat medium here refers, for example, to the temperature of the heat medium at the discharge port of the nozzle 4. The flow rate adjustment valve 43 may adjust the flow rate of the heat medium to, for example, a value greater than the flow rate of the drying liquid. More specifically, the flow rate adjustment valve 43 may adjust the flow rate of the heat medium to 1000 mL (milliliters) / min or more, or to 1500 mL / min or more.

[0088] The heat medium that has landed in the center of the second main surface Wb of the substrate W flows radially outward due to centrifugal force caused by the rotation of the substrate W and is scattered from the periphery of the substrate W. As the high-temperature heat medium flows along the second main surface Wb of the substrate W, heat is transferred from the heat medium to the substrate W, heating the substrate W. The heat from the substrate W is transferred to the drying liquid on the first main surface Wa. As a result, the drying liquid on the first main surface Wa of the substrate W is also heated and its temperature rises.

[0089] Once the rinsing liquid has been sufficiently replaced with the drying liquid, 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 drying liquid discharge and determines whether the elapsed time is equal to or longer than a predetermined drying liquid supply time. The drying liquid supply time is preset to a time sufficient to completely replace the rinsing liquid with the drying liquid. The drying liquid supply time is set, for example, to several tens of seconds, specifically, to about 40 seconds. When the elapsed time is equal to or longer than the drying liquid supply time, the processing unit 1 dries the substrate W. Specifically, the control unit 90 closes the supply valve 32i, opens the supply valve 32g, operates the heater 34g, causes the movement drive unit 35i to lower the shielding plate 6 to a drying position closer to the substrate W than the shielding processing position, and causes the substrate holder 2 to increase the rotation speed of the substrate W.

[0090] When the supply valve 32g opens, as shown in FIG. 6( a), high-temperature inert gas is discharged toward the first main surface Wa of the substrate W from a gas discharge port in the center of the lower surface of the shield plate 6 (i.e., the lower end port of the gas flow path 3g). In FIG. 6, the flow direction of the inert gas is schematically indicated by an arrow directly below the shield plate 6. The heater 34g may heat the inert gas to a temperature of, for example, 60°C or higher, 70°C or higher, or 80°C or higher. The temperature of the inert gas may be, for example, the temperature of the inert gas at the gas discharge port of the gas flow path 3g. The flow rate adjustment valve 33g may adjust the flow rate of the inert gas to, for example, 10 L / min or higher and 300 L / min or lower.

[0091] In FIG. 6( a), the downward movement of the shielding plate 6 is indicated by a block arrow next to the shielding plate 6. Here, the movement driver 35i lowers the nozzle 3i and the shielding plate 6 together while inert gas is being ejected from the gas flow path 3g. When the shielding plate 6 descends to the drying position, as shown in FIG. 6( b), the gap between the shielding plate 6 and the first main surface Wa of the substrate W can be narrowed. That is, the gap between the shielding plate 6 and the substrate W during the drying process can be narrower than the gap between the shielding plate 6 and the substrate W during the drying liquid supply process. This increases the flow rate of the inert gas flowing radially outward from the periphery of the shielding plate 6 and the substrate W during the drying process. The gap between the lower surface of the shielding plate 6 and the first main surface Wa of the substrate W during the drying process is set to, for example, a few millimeters (e.g., 5 mm) or less.

[0092] The substrate holding unit 2 may increase the rotation speed of the substrate W monotonically and non-decreasingly without reducing it during the transition from the drying liquid supplying step to the drying step and at the beginning of the drying step. The substrate holding unit 2 may rotate the substrate W at a rotation speed of, for example, 800 rpm or more and 2500 rpm or less, or may rotate the substrate W at a rotation speed of 800 rpm or more and 1500 rpm or less. Furthermore, the substrate holding unit 2 may gradually (for example, in steps) increase the rotation speed of the substrate W during or after the shielding plate 6 is lowered.

[0093] The increased rotation speed can increase the amount of drying liquid scattered from the periphery of the substrate W. This allows the drying liquid to evaporate while keeping the film of drying liquid on the first main surface Wa thin. This allows the drying liquid to evaporate in a shorter time.

[0094] On the other hand, as the rotation speed of the substrate W increases, the heat medium is more likely to flow from the second main surface Wb of the substrate W through the periphery to the peripheral portion of the first main surface Wa. However, in the above example, the inert gas flows outward in the radial direction from between the shielding plate 6 and the substrate W at a high flow rate. This allows the inert gas to push the heat medium back outward in the radial direction. This makes it possible to suppress or prevent the heat medium from flowing around. In other words, the distance between the shielding plate 6 and the substrate W and the flow rate of the inert gas can be set to a level that sufficiently suppresses the heat medium from flowing around.

[0095] When the drying liquid has sufficiently evaporated, the substrate heating unit 40 stops heating the substrate W. As a specific example, the control unit 90 measures the elapsed time since the discharge of the drying liquid stopped, and determines whether the measured time is equal to or longer than a predetermined evaporation time. The evaporation time is set in advance to a time sufficient to dry the first main surface Wa of the substrate W. When the elapsed time is equal to or longer than the evaporation time, the control unit 90 switches the supply valve 42 from an open state to a closed state. This stops the supply of the heat medium to the second main surface Wb of the substrate W. In other words, heating of the substrate W by the substrate heating unit 40 stops.

[0096] Then, the control unit 90 stops the rotation of the substrate W, for example, when a predetermined drying time has elapsed that is sufficient for drying the second main surface Wb of the substrate W. Furthermore, the movement drive unit 35i raises the nozzle 3i and the shielding plate 6 together to the shielding standby position, and the guard lifting drive unit 71 lowers the guard 7 to the lower position.

[0097] Next, the substrate holder 2 releases the hold on the substrate W (step S7: hold releasing step).Then, the second transporter 122 carries the processed substrate W out of the processing unit 1.

[0098] As described above, the processing unit 1 can process the substrate W. Moreover, in this embodiment, after the supply of the drying liquid is stopped, the substrate heating part 40 heats the second main surface Wb of the substrate W (drying step, FIG. 6 ). Therefore, in the drying step, the drying liquid on the first main surface Wa of the substrate W can evaporate at a higher temperature.

[0099] 7 is a timing chart of the processing unit 1 and a diagram schematically illustrating an example of the change over time in the temperature of the first main surface Wa of the substrate W (hereinafter referred to as the substrate temperature). In the example of FIG. 7, at time t1, the control unit 90 switches the supply valve 32i and the supply valve 42 from a closed state to an open state. Therefore, at time t1, the nozzle 3i begins to discharge the drying liquid, and the nozzle 4 begins to discharge the high-temperature heat medium. This discharge of the drying liquid essentially starts the drying liquid supply step (step S5). Furthermore, the discharge of the heat medium causes the substrate temperature of the first main surface Wa of the substrate W to rise over time. The substrate temperature rises at a high rate to a certain extent, and then may rise gradually or converge.

[0100] 7, at time t2, which is later than time t1, the control unit 90 switches the supply valve 32i from the open state to the closed state. As a result, the discharge of the drying liquid stops at time t2. This cessation of the discharge of the drying liquid essentially ends the drying liquid supplying process.

[0101] On the other hand, in the example of FIG. 7 , the supply valve 42 remains open even after time t2. Therefore, during the evaporation time after time t2 (the time from time t2 to time t3 in FIG. 7 , which corresponds to the predetermined period), the nozzle 4 discharges the heat medium, and the substrate W continues to receive heat from the heat medium. Therefore, the substrate temperature of the first main surface Wa of the substrate W during the evaporation time can be made equal to or higher than the substrate temperature when the drying liquid was supplied. In the example of FIG. 7 , the temperature of the first main surface Wa of the substrate W increases after time t2. This is because no new drying liquid is supplied to the first main surface Wa of the substrate W after time t2. In other words, if drying liquid at a lower temperature than the heat medium is supplied to the first main surface Wa of the substrate W, the drying liquid would cool the substrate W. However, since the supply of the drying liquid has ended after time t2, the temperature of the substrate W increases. Therefore, the substrate temperature of the first main surface Wa of the substrate W during the evaporation time is higher than the substrate temperature of the first main surface Wa of the substrate W during the drying liquid supply process.

[0102] Since the temperature of the first main surface Wa of the substrate W can be considered to be approximately equal to the temperature of the drying liquid on the first main surface Wa, the temperature of the drying liquid during the evaporation period is also higher than the temperature of the drying liquid during the drying liquid supplying step. Furthermore, the higher the temperature of the drying liquid, the lower the surface tension of the drying liquid. As described above, since the temperature of the drying liquid during the evaporation period is high, the surface tension of the drying liquid during the evaporation period can be reduced. Furthermore, the evaporation rate of the drying liquid can also be improved.

[0103] Pattern collapse is more likely to occur as the surface tension of the drying liquid increases. Furthermore, pattern collapse is more likely to occur as the evaporation rate decreases. This is because the impulse of the surface tension acting on the pattern increases as the evaporation rate decreases. According to this embodiment, the evaporation rate can be increased while reducing the surface tension of the drying liquid, thereby effectively reducing the rate of pattern collapse.

[0104] 7 , at time t3, which is later than time t2, the control unit 90 switches the supply valve 42 from the open state to the closed state. As a result, the nozzle 4 stops discharging the heat medium at time t3. That is, the substrate heating unit 40 stops heating the second main surface Wb of the substrate W at time t3. Therefore, after time t3, the temperature of the first main surface Wa of the substrate W decreases over time.

[0105] In the above example, in the drying step (step S6), a high-temperature inert gas is supplied to the first main surface Wa of the substrate W. This can further increase the temperature of the drying liquid on the first main surface Wa of the substrate W, further promoting evaporation. This can further reduce the rate of pattern collapse. It can also make the temperature distribution of the drying liquid on the first main surface Wa of the substrate W uniform.

[0106] Furthermore, in the above example, the substrate holder 2 increases the rotation speed of the substrate W during the drying process. This increases the amount of drying liquid that splashes outward from the periphery of the substrate W, while further promoting evaporation of the drying liquid. In other words, evaporation of the drying liquid is promoted while thinning the film of drying liquid on the first main surface Wa through splashing. This further reduces the rate of pattern collapse.

[0107] In the above example, in the drying step, the movement driver 35i moves the shielding plate 6 to a drying position closer to the first main surface Wa than the shielding processing position. This makes it possible to narrow the gap between the shielding plate 6 and the substrate W and increase the flow rate of the inert gas flowing outward in the radial direction from between the shielding plate 6 and the substrate W. This makes it possible to suppress or prevent the heat medium from flowing around the periphery of the substrate W. This reduces the rate of pattern collapse at the periphery of the first main surface Wa of the substrate W and also suppresses particle adhesion to the periphery.

[0108] Conversely, in the drying liquid supply step, the shielding plate 6 is stopped at the blocking processing position, which is farther from the substrate W than the drying position. Therefore, even if the drying liquid ejected from the nozzle 3i bounces off the first main surface Wa of the substrate W, the possibility of the rebounded drying liquid adhering to the underside of the shielding plate 6 can be reduced. If the drying liquid adheres to the underside of the shielding plate 6, droplets of the adhering drying liquid may fall onto the first main surface Wa of the substrate W, for example, when the next substrate W is processed. This is undesirable as it may cause processing problems. If the shielding plate 6 is stopped at the blocking processing position in the drying liquid supply step as described above, the occurrence of such problems can be suppressed.

[0109] In the above example, the substrate heating unit 40 heats the second main surface Wb of the substrate W during the drying liquid supplying step, and continues to heat the second main surface Wb of the substrate W during the transition from the drying liquid supplying step to the drying step. In other words, the substrate heating unit 40 continues to heat the second main surface Wb of the substrate W throughout the drying liquid supplying step and the initial stage of the drying step. This allows the temperature of the first main surface Wa of the substrate W to be maintained higher at the start of the drying step (i.e., time t2). In other words, the temperature of the drying liquid can be increased from the start of the drying step. Therefore, the evaporation rate of the drying liquid can be increased more quickly during the drying step, and the pattern collapse rate can be more appropriately reduced.

[0110] Furthermore, in the drying liquid supplying step, the efficiency of replacing the rinsing liquid with the drying liquid can be improved by increasing the temperature of the drying liquid on the first main surface Wa of the substrate W. In other words, it is possible to prevent the rinsing liquid, which has a higher surface tension than the drying liquid, from remaining. This further reduces the rate of pattern collapse in the drying step.

[0111] Second Embodiment The configuration of the processing unit 1 according to the second embodiment is similar to that of the first embodiment, except for the specific configuration of the substrate heating section 40. FIG. 8 is a diagram schematically illustrating an example of the configuration of the substrate heating section 40 according to the second embodiment. In the example of FIG. 8, the substrate heating section 40 includes a nozzle 4, a common pipe 411, a first temperature pipe 412, a second temperature pipe 413, and a mixer 45. The downstream end of the common pipe 411 is connected to the nozzle 4, and the upstream end of the common pipe 411 is connected to the mixer 45. The downstream ends of the first temperature pipe 412 and the second temperature pipe 413 are also connected to the mixer 45. The upstream ends of the first temperature pipe 412 and the second temperature pipe 413 are connected to a heat medium supply source. A heat medium at a first medium temperature flows through the first temperature pipe 412, and a heat medium at a second medium temperature flows through the second temperature pipe 413. The second medium temperature is lower than the first medium temperature. Hereinafter, the heat medium at the first medium temperature flowing through the first temperature pipe 412 will also be referred to as the high-temperature heat medium, and the heat medium at the second medium temperature flowing through the second temperature pipe 413 will also be referred to as the low-temperature heat medium. In the example of FIG. 8 , a heater 44 is provided in the first temperature pipe 412. The heater 44 heats the high-temperature heat medium flowing through the first temperature pipe 412 so that the temperature of the heat medium becomes the first medium temperature. The second medium temperature may be room temperature. Alternatively, a heater (not shown) may be provided in the second temperature pipe 413 to heat the low-temperature heat medium to a second medium temperature higher than room temperature.

[0112] The mixer 45 mixes the high-temperature heat medium from the first temperature pipe 412 and the low-temperature heat medium from the second temperature pipe 413 at a variable mixing ratio and causes the mixed heat medium to flow into the common pipe 411. The mixing ratio of the mixer 45 is controlled by the control unit 90. In the example of FIG. 8 , the mixer 45 includes a multiple valve 451, a flow rate adjustment valve 452, and a flow rate adjustment valve 453. The flow rate adjustment valve 452 adjusts the flow rate of the high-temperature heat medium flowing through the first temperature pipe 412. The flow rate adjustment valve 453 adjusts the flow rate of the low-temperature heat medium flowing through the second temperature pipe 413. The flow rate adjustment valves 452 and 453 are controlled by the control unit 90. The control unit 90 adjusts the respective flow rates, thereby adjusting the mixing ratio. The multiple valve 451 switches between connection and disconnection between the common pipe 411 and the first temperature pipe 412 and between connection and disconnection between the common pipe 411 and the second temperature pipe 413. If the multiple valve 451 itself has a function of adjusting the flow rate, the flow rate adjustment valves 452 and 453 are not necessary.

[0113] 8, a supply valve 42 is provided in the common pipe 411. The supply valve 42 switches between opening and closing the common pipe 411. The supply valve 42 is controlled by the control unit 90.

[0114] <Example of Operation of Substrate Processing Apparatus> The operation of the processing unit 1 according to the second embodiment is as shown in FIG. 4 , which was referred to in the first embodiment. However, the specific operation of the substrate heating section 40 differs from that of the first embodiment. In the second embodiment, the substrate heating section 40 heats the substrate W in the drying step (step S6) with a second amount of heat per unit time that is greater than the first amount of heat per unit time in the drying liquid supply step (step S5). As a more specific example, the substrate heating section 40 supplies the substrate W in the drying step with a heat medium having a temperature higher than that of the heat medium supplied to the substrate W in the drying liquid supply step. Specifically, the substrate heating section 40 adjusts the mixing ratio of the high-temperature heat medium and the low-temperature heat medium, and supplies the heat medium having a temperature higher than that of the heat medium in the drying liquid supply step to the second main surface of the substrate W in the drying step.

[0115] 9 is a timing chart of the processing unit 1 according to the second embodiment, and a diagram schematically illustrating an example of the flow rate of the heat medium and the change in the temperature of the heat medium over time. In the example of FIG. 9, an example of the flow rate of the high-temperature heat medium is shown as graph G1, and an example of the flow rate of the low-temperature heat medium is shown as graph G2.

[0116] 9 , the flow rate of the high-temperature heat medium is constant from time t1 to time t3. Meanwhile, the flow rate of the low-temperature heat medium decreases at time t2. That is, the flow rate of the low-temperature heat medium during the evaporation time from time t2 to time t3 is smaller than the flow rate of the low-temperature heat medium during the drying liquid supplying step from time t1 to time t2. Therefore, the temperature of the heat medium discharged from the nozzle 4 during the evaporation time is higher than the temperature of the heat medium discharged from the nozzle 4 during the drying liquid supplying step.

[0117] In the second embodiment, the flow rates of the high-temperature and low-temperature heat medium are not limited to those described above as long as the temperature of the heat medium discharged from the nozzle 4 is higher in the drying step (step S6) than in the drying liquid supply step (step S5). In other words, the ratio of the flow rate of the high-temperature heat medium to the flow rate of the low-temperature heat medium (= flow rate of high-temperature heat medium / flow rate of low-temperature heat medium) is higher in the drying step than in the drying liquid supply step.

[0118] The temperature of the heat medium ejected from the nozzle 4 in the drying liquid supplying process may be adjusted to be lower than the boiling point bp of the drying liquid. When the drying liquid is isopropyl alcohol, the boiling point bp of the drying liquid is approximately 82.4 degrees Celsius. In this case, the temperature of the heat medium in the drying liquid supplying process may be adjusted to be lower than 82.4 degrees Celsius. As a specific example, the first medium temperature of the high-temperature heat medium is set to a value higher than the boiling point bp of the drying liquid (e.g., 85 degrees Celsius), and the second medium temperature of the low-temperature heat medium is set to a value lower than the boiling point pb of the drying liquid (e.g., room temperature). The mixer 45 then mixes the high-temperature heat medium and the low-temperature heat medium at a mixing ratio such that the temperature of the heat medium is lower than the boiling point bp of the drying liquid.

[0119] According to this, since the temperature of the heat medium discharged from the nozzle 4 is below the boiling point bp of the drying liquid, the drying liquid on the first main surface Wa of the substrate W is also below the boiling point bp. This makes it possible to more reliably prevent the drying liquid from boiling on the first main surface Wa of the substrate W while the drying liquid is being supplied. If the drying liquid on the first main surface Wa of the substrate W boils while the drying liquid is being supplied, many particles will adhere to the first main surface Wa of the substrate W. In this embodiment, it is possible to more reliably prevent such particle adhesion.

[0120] On the other hand, during the drying process, the discharge of drying liquid from the nozzle 3i is stopped. Therefore, even if the drying liquid on the first main surface Wa of the substrate W boils, it hardly causes particle adhesion. Therefore, the substrate heating unit 40 may adjust the temperature of the heat medium during the evaporation time from time t2 to time t3 to be equal to or higher than the boiling point bp of the drying liquid. In other words, the mixer 45 may adopt a mixing ratio that causes the temperature of the heat medium to be equal to or higher than the boiling point bp of the drying liquid. In the example of FIG. 9 , the flow rate of the low-temperature heat medium is set to zero.

[0121] The mixer 45 may gradually change the mixing ratio over time. For example, the mixer 45 may gradually change the mixing ratio during the time it takes for the shielding plate 6 to descend from the shielding processing position to the drying position.

[0122] As described above, in the second embodiment, the temperature of the heat medium in the drying step is higher than the temperature of the heat medium in the drying liquid supply step. This allows the temperatures of the substrate W and the drying liquid to be further increased in the drying step. This further increases the evaporation rate of the drying liquid in the drying step. This further reduces the rate of pattern collapse on the substrate W.

[0123] Conversely, the temperatures of the substrate W and the drying liquid in the drying liquid supplying step can be made lower than those in the drying step, which makes it possible to suppress or prevent boiling of the drying liquid on the first main surface Wa of the substrate W in the drying liquid supplying step, and to suppress adhesion of particles to the first main surface Wa.

[0124] In the above example, the substrate heating unit 40 changes the temperature of the heat medium discharged from the nozzle 4 by changing the mixing ratio of the mixer 45. This allows the temperature of the heat medium to be changed quickly. Therefore, in the early stage of the drying process, the temperature of the heat medium can be increased more quickly, and the evaporation rate of the drying liquid can be increased more quickly. This also makes it possible to further reduce the rate of pattern collapse.

[0125] Third Embodiment In the first and second embodiments, the substrate heating unit 40 starts heating the second main surface Wb of the substrate W at approximately the same time as the nozzle 3i starts discharging the drying liquid in the drying liquid supply step (step S5) (see FIGS. 7 and 9 ). However, this is not necessarily limited to this. The substrate heating unit 40 may start heating the second main surface Wb of the substrate W at a time later than the nozzle 3i starts discharging the drying liquid.

[0126] 10 is a timing chart of the processing unit 1 according to the third embodiment and a diagram schematically illustrating an example of temperature change of the first main surface Wa of the substrate W. In the example of FIG. 10, the control unit 90 switches the supply valve 32i from the closed state to the open state at time t1. As a result, the drying liquid begins to be discharged from the nozzle 3i toward the first main surface Wa of the substrate W. In other words, the drying liquid supplying step essentially begins at time t1. On the other hand, in the example of FIG. 10, the control unit 90 switches the supply valve 42 from the closed state to the open state at time t12, which is later than time t1. As a result, the high-temperature heat medium begins to be discharged from the nozzle 4 toward the second main surface Wb of the substrate W. In other words, the substrate heating unit 40 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 from the open state to the closed state. In other words, the drying liquid supplying step essentially ends at time t2.

[0127] In other words, during the drying liquid supply time T from time t1 to time t2, the substrate heating unit 40 does not heat the second main surface Wb of the substrate W during a predetermined early time T1 from time t1 to time t12, but heats the second main surface Wb of the substrate W during a predetermined late time T2 from time t12 to time t2. The drying liquid supply time T is set to, for example, 20 seconds or more, and as a specific example, may be set to approximately 40 seconds. The late time T2 is preset to a time sufficient to bring the temperature of the first main surface Wa of the substrate W at time t2 close to the boiling point of the drying liquid. For example, the late time T2 may be set to half or less of the drying liquid supply time T, or to one-third or less, one-quarter or less, or one-tenth or less of the drying liquid supply time T.

[0128] As described above, in the third embodiment, the substrate heating section 40 does not heat the substrate W during the previous time T1, but heats the second main surface Wb of the substrate W during the subsequent time T2. That is, the substrate heating section 40 heats the second main surface Wb of the substrate W only during the subsequent time T2. This shortens the operating time of the substrate heating section 40, thereby reducing the power consumption of the substrate processing apparatus 100. Furthermore, when the substrate heating section 40 supplies a high-temperature heat medium to the second main surface Wb of the substrate W, the amount of heat medium supplied can be reduced. When the heat medium is liquid, liquid saving can be achieved.

[0129] Fourth Embodiment The configuration of a processing unit 1 according to a fourth embodiment is similar to that of, for example, the second embodiment. In the fourth embodiment, in the drying liquid supply step (step S5), the substrate heating unit 40 sets the temperature of the heat medium to be equal to or higher than the boiling point bp of the drying liquid.

[0130] 11 is a timing chart of the processing unit 1 according to the fourth embodiment, and a diagram schematically illustrating an example of changes over time in the flow rate of the heat medium, the temperature of the heat medium, and the temperature of the first main surface Wa of the substrate W. In the example of FIG. 11 , in the drying liquid supply step (step S5), the temperature of the heat medium ejected from the nozzle 4 is higher than the boiling point bp of the drying liquid. When the drying liquid is isopropyl alcohol, the boiling point bp is 82.4°C, and the temperature of the heat medium is set to, for example, approximately 85°C. However, the temperature of the heat medium may be set below the boiling point of the heat medium. For example, when the heat medium is water, the temperature may be set to less than 90°C, 10°C lower than the boiling point (100°C). This allows compliance with SEMI standards.

[0131] In the drying liquid supply process, drying liquid having a lower temperature than the heat medium is ejected from the nozzle 3i. The low-temperature drying liquid that continuously lands on the first main surface Wa of the substrate W can cool the first main surface Wa of the substrate W. The cooling capacity of this drying liquid increases as the flow rate of the drying liquid increases. Therefore, the flow rate control valve 33i adjusts the flow rate of the drying liquid to a value at which the substrate temperature of the first main surface Wa of the substrate W is lower than the boiling point bp. Specifically, the flow rate of the drying liquid is preset to, for example, approximately 250 ml / min or higher. In the example of FIG. 11 , the substrate temperature is shown as the temperature at the center of the first main surface Wa of the substrate W. Because the high-temperature heat medium lands on the center of the second main surface Wb of the substrate W, the substrate temperature of the substrate W has a temperature distribution described below. That is, the substrate temperature is high at the center of the substrate W and decreases radially outward. Therefore, in the example of FIG. 11 , the highest value in the temperature distribution on the first main surface Wa of the substrate W is shown as the substrate temperature.

[0132] 11 , the substrate temperature in the drying liquid supplying step is below the boiling point bp of the drying liquid. When the drying liquid is isopropyl alcohol, the highest substrate temperature in the temperature distribution of the substrate W can be adjusted to, for example, about 80° C. or less. This more reliably prevents the drying liquid from boiling in the drying liquid supplying step. This in turn more reliably prevents particles from adhering to the first main surface Wa of the substrate W.

[0133] Moreover, in the fourth embodiment, the temperature of the heat medium in the drying liquid supplying step is equal to or higher than the boiling point bp. Therefore, in the drying liquid supplying step, the maximum value in the temperature distribution on 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 on the first main surface Wa of the substrate W in the drying liquid supplying step (i.e., the substrate temperature at the peripheral portion of the first main surface Wa) is, for example, 60 degrees Celsius or higher. In other words, the flow rate of the drying liquid can be set so that the substrate temperature on the first main surface Wa of the substrate W is 60 degrees Celsius or higher and lower than the boiling point bp of the drying liquid.

[0134] In the fourth embodiment, even during the transition from the drying liquid supplying step to the drying step, the nozzle 4 discharges the heat medium at or above the boiling point bp onto the second main surface Wb of the substrate W. As a result, at the start of the drying step (i.e., time t2), the substrate temperature of the second main surface Wb of the substrate W can be brought to a value closer to the boiling point bp of the drying liquid. This makes it possible to further increase the temperature of the drying liquid at the start of the drying step. In other words, the surface tension of the drying liquid can be quickly reduced, and the evaporation rate of the drying liquid can be quickly increased.

[0135] During the evaporation time in the drying process, the substrate temperature of at least a portion (e.g., the center) of the first main surface Wa of the substrate W may be equal to or higher than the boiling point bp of the drying liquid. In the example of FIG. 11 , the substrate temperature (maximum value) during the evaporation time is higher than the boiling point bp. That is, the temperature and flow rate of the heat medium are set so that the substrate temperature (maximum value) is equal to or higher than the boiling point bp. This can further reduce the surface tension of the drying liquid while further increasing the evaporation rate of the drying liquid. Since the substrate temperature decreases toward the periphery, the temperature of at least the periphery of the main surface of the substrate W is lower than the boiling point bp of the drying liquid. The drying liquid mainly flows outward on the first main surface Wa of the substrate W. That is, the drying liquid mainly flows in contact with the first main surface Wa of the substrate W, rather than flowing while floating above the first main surface Wa of the substrate W.

[0136] In the first to third embodiments, the substrate temperature of at least a part (e.g., the central part) of the first main surface Wa of the substrate W during the evaporation time may be equal to or higher than the boiling point bp of the drying liquid. In other words, in the first to third embodiments, the temperature and flow rate of the heat medium may be set so that the substrate temperature (maximum value) during the evaporation time is equal to or higher than the boiling point bp.

[0137] Fifth Embodiment In the above example, the processing unit 1 performs the chemical step (step S3), the rinsing step (step S4), the drying liquid supply step (step S5), and the drying step (step S6) in this order. However, this is not necessarily limited to this.

[0138] Fig. 12 is a flowchart showing a first example of the operation of the processing unit 1 according to the fifth embodiment. In the example of Fig. 12, the control unit 90 causes the processing unit 1 to perform processes from step S11 to step S19 in accordance with a preset processing procedure (recipe). Steps S11 to S15 are similar to steps S1 to S5, respectively. However, in step S15 (drying liquid supply step), the substrate heating unit 40 does not have to heat the substrate W.

[0139] Next, the processing unit 1 hydrophobizes the first main surface Wa of the substrate W (corresponding to step S16: hydrophobization process: liquid supply process). Specifically, the processing unit 1 includes a nozzle that ejects a hydrophobizing liquid, and ejects 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. The silicon-based hydrophobizing liquid is a hydrophobizing liquid that hydrophobizes silicon (Si) itself and compounds containing silicon. The hydrophobizing liquid is, for example, a silylation liquid that includes a liquid silylation agent (also called a silane coupling agent). The processing unit 1 stops ejecting the hydrophobizing liquid from the nozzle when the first main surface Wa of the substrate W has been sufficiently hydrophobized.

[0140] Next, the processing unit 1 executes steps S17 to S19, which are similar to steps S5 to S7, respectively.

[0141] As described above, in the first example described above, the drying step (step S18) is performed in the same manner as the drying step (step S6) in the first to fourth embodiments. This makes it possible to reduce the collapse rate of the pattern on the substrate W. Moreover, since the first main surface Wa of the substrate W is hydrophobized, the contact angle of the first main surface Wa can be reduced. This makes it possible to reduce the surface tension acting on the pattern, further reducing the collapse rate of the pattern.

[0142] FIG. 13 is a flowchart illustrating a second example of the operation of the processing unit 1 according to the fifth embodiment. In the example of FIG. 13 , the control unit 90 causes the processing unit 1 to perform steps S21 to S26 according to a preset processing procedure (recipe). Steps S21 to S26 are similar to steps S1 to S3 and steps S5 to S7, respectively. However, at the end of step S23 (chemical liquid step: corresponding to the liquid supply step), metal is exposed on the first main surface Wa of the substrate W. In the second example, step S24 (drying liquid supply step) is performed after step S23. Therefore, water is not supplied to the first main surface Wa of the substrate W. This prevents a reaction between metal and water, thereby avoiding problems caused by the reaction. Furthermore, in the second example described above, a drying step (step S25) is performed similarly to the drying step (step S6) in the first to fourth embodiments. This reduces the rate of pattern collapse on the substrate W.

[0143] Sixth Embodiment An example of the configuration of a substrate processing apparatus 100 according to the sixth embodiment is similar to that of the substrate processing apparatus 100 according to the first to fifth embodiments. However, a specific example of the shielding plate 6 differs from that of the shielding plate 6 according to the first to fifth embodiments. Fig. 14 is a diagram schematically showing a first example of the configuration of the shielding plate 6 according to the sixth embodiment. Hereinafter, the lower surface of the shielding plate 6 will be referred to as the lower surface 6a. A lower end opening (i.e., a gas discharge port) of a gas flow path 3g is formed in the center of the lower surface 6a of the shielding plate 6.

[0144] As shown in FIG. 14 , the gas flow path 3g includes a vertical flow path 3ga and an expanded-diameter flow path 3gb. The vertical flow path 3ga is located vertically above the expanded-diameter flow path 3gb and extends vertically. In the example of FIG. 14 , the inner circumferential surface of the hollow shaft 61 forms the outer circumferential surface of the vertical flow path 3ga. In other words, the vertical flow path 3ga is located inside the hollow shaft 61. In the example of FIG. 14 , the lower end opening (i.e., the discharge port) of the nozzle 3i is located above the lower end of the vertical flow path 3ga. Above the lower end opening of the nozzle 3i, the vertical flow path 3ga corresponds to a cylindrical space between the inner circumferential surface of the hollow shaft 61 and the outer circumferential surface of the nozzle 3i. Below the lower end opening of the nozzle 3i, the vertical flow path 3ga corresponds to a columnar space surrounded by the inner circumferential surface of the hollow shaft 61.

[0145] The lower end of the vertical flow passage 3ga is connected to the upper end of the expanded diameter flow passage 3gb. The size of the lower end opening of the expanded diameter flow passage 3gb (i.e., the lower end opening of the gas flow passage 3g) in a plan view is larger than the size of the vertical flow passage 3ga in a plan view. Here, as an example, the inner circumferential surface of the hollow shaft 61 has a shape that follows the side surface of a cylinder, and the lower end opening of the expanded diameter flow passage 3gb has a circular shape. In this case, the diameter (outer diameter) R2 of the vertical flow passage 3ga is smaller than the diameter R1 of the lower end opening of the expanded diameter flow passage 3gb.

[0146] In the example of Figure 14, the diameter of the expanding diameter flow path 3gb increases as it approaches the gas discharge port. The expanding diameter flow path 3gb is formed by the inner peripheral surface of the blocking plate 6, which is an inclined surface. The inner peripheral surface of the blocking plate 6 has a shape that follows the side surface of a truncated cone, for example, and its lower end periphery is connected to the lower surface 6a of the blocking plate 6. The lower end periphery forms the lower end opening (i.e., the gas discharge port) of the expanding diameter flow path 3gb.

[0147] 14, the diameter of the expanded diameter flow path 3gb may increase monotonically as it approaches the lower surface 6a of the blocking plate 6. Alternatively, the diameter of the expanded diameter flow path 3gb may increase stepwise (i.e., in a stepped manner) as it approaches the lower surface 6a of the blocking plate 6.

[0148] According to the sixth embodiment, the inert gas is also discharged from the lower end opening of the gas flow path 3g toward the first main surface Wa of the substrate W. Fig. 15 is a diagram schematically showing an example of how the inert gas is discharged. When the inert gas is discharged toward the first main surface Wa of the substrate W, the inert gas collides with the liquid film of the drying liquid on the first main surface Wa of the substrate W. This collision may cause the drying liquid to splash. In the sixth embodiment, the lower end opening of the gas flow path 3g is large, so that the splashed drying liquid is less likely to reach the lower surface 6a of the shielding plate 6.

[0149] A specific example of the operation of the processing unit 1 of the sixth embodiment may be the same as or different from the operation of the processing unit 1 according to the first to fifth embodiments. As an example, the processing unit 1 of the sixth embodiment operates according to the flowchart of FIG.

[0150] FIG. 16 is a diagram showing a first example of a timing chart for the processing unit 1 according to the sixth embodiment. The example of FIG. 16 illustrates an example of the change over time in the position of the shielding plate 6 and the change over time in the flow rate of the inert gas. In the example of FIG. 16, similar to the first to fifth embodiments, the movement driver 35i moves the shielding plate 6 from the shielding processing position P1 to the drying position P2 when stopping the supply of drying liquid (time t2). In the sixth embodiment, the gas flow path 3g of the shielding plate 6 has an expanded-diameter flow path 3gb. Therefore, as described above, even if the shielding plate 6 is moved closer to the first main surface Wa of the substrate W, adhesion of the drying liquid to the shielding plate 6 can be suppressed. For example, the drying position may be set at a position where the distance between the lower surface 6a of the shielding plate 6 and the first main surface Wa of the substrate W is 2 mm or less, or may be set at a position where the distance is 1 mm or less.

[0151] By narrowing the gap, the processing unit 1 can dry the substrate W more quickly. In other words, since the gap can be set narrow from the early stage of the drying process, the processing unit 1 can dry the substrate W with high drying performance from the early stage of the drying process. In particular, the drying performance in the early stage of the drying process has a strong influence on suppressing pattern collapse. Therefore, the processing unit 1 can further reduce the rate of pattern collapse.

[0152] 16 , the processing unit 1 may supply an inert gas to the first main surface Wa of the substrate W in the drying liquid supplying step (step S5). That is, the control unit 90 may open the supply valve 32g in the drying liquid supplying step. This allows the inert gas to be discharged from the lower end opening of the gas flow path 3g also in the drying liquid supplying step. This makes it possible to prevent volatile components of the drying liquid from remaining in the space between the shielding plate 6 and the substrate W. The flow rate of the inert gas in the drying liquid supplying step is set to, for example, 20 mL (milliliters) / min or less.

[0153] In the example of FIG. 16 , the processing unit 1 increases the flow rate of the inert gas when moving the shield plate 6 to the drying position P2 during the drying process. For example, the flow rate control valve 33g may increase the flow rate of the inert gas from 20 mL (milliliters) / min or less to 30 mL / min or more. In the example of FIG. 16 , the flow rate control valve 33g gradually increases the flow rate of the inert gas over time. The flow rate control valve 33g may increase the flow rate to 100 mL / min or more as the final flow rate of the inert gas during the drying process. The processing unit 1 may increase the flow rate to 150 mL / min or more, or may increase the flow rate to 200 mL / min or more.

[0154] As described above, the processing unit 1 increases the flow rate of the inert gas as the shield plate 6 descends to the drying position P2. Therefore, the processing unit 1 can dry the substrate W with high drying performance from the early stage of the drying process. Moreover, in the sixth embodiment, since the gas flow path 3g has the expanded-diameter flow path 3gb, even if the flow rate of the inert gas is increased and liquid splashing becomes more likely to occur, the liquid splashing is less likely to reach the shield plate 6. Therefore, adhesion of the drying liquid to the shield plate 6 can also be suppressed.

[0155] The flow rate control valve 33g may increase the flow rate of the inert gas in steps rather than in stages. That is, the flow rate control valve 33g may increase the flow rate of the inert gas to its final value at time t2. Even if the inert gas is supplied at a high flow rate from the beginning of the drying process, the gas flow path 3g has the enlarged-diameter flow path 3gb, so that liquid splashes are less likely to reach the shield plate 6. Furthermore, if the processing unit 1 supplies the inert gas at a high flow rate from the beginning of the drying process, the drying performance can be further improved. Therefore, the processing unit 1 can further reduce the pattern collapse rate.

[0156] FIG. 17 is a diagram schematically illustrating a second example of a timing chart for the processing unit 1 according to the sixth embodiment. In the example of FIG. 17 , at time t11 during the drying liquid supply process, the control unit 90 causes the movement drive unit 35i to lower the shielding plate 6. Specifically, in the example of FIG. 17 , the shielding plate 6 is located at a first shielding processing position P11 at the beginning of the drying liquid supply process. Then, at time t11, the movement drive unit 35i moves the shielding plate 6 from the first shielding processing position P11 to a second shielding processing position P12. The second shielding processing position P12 is closer to the first main surface Wa of the substrate W than the first shielding processing position P11 and farther from the first main surface Wa of the substrate W than the drying position P2 (first drying position P21 in the figure). In other words, the second shielding processing position P12 is located between the first shielding processing position P11 and the drying position P2. The first blocking processing position P11 and the second blocking processing position P12 are each an example of the blocking processing position P1. The second blocking processing position P12 may be set, for example, at a position where the distance between the blocking plate 6 and the substrate W is 10 mm or less, or may be set at a position where the distance is about 5 mm. The first blocking processing position P11 may be set, for example, at a position where the distance between the blocking plate 6 and the substrate W is 20 mm or more (e.g., about 30 mm).

[0157] As described above, in the example of Figure 17, in the drying liquid supply process, the processing unit 1 supplies drying liquid to the first main surface Wa of the substrate W with the blocking plate 6 positioned at the first blocking processing position P11, and then moves the blocking plate 6 to the second blocking processing position P12 while supplying the drying liquid.

[0158] Here, we will explain the case where the gas flow path 3g extends in a cylindrical shape. FIG. 18 shows an example of the state of the processing unit 1 during the drying liquid supply process. Here, the shield plate 6 is located at the second shield processing position P12. In the example of FIG. 18, the outlet portion of the gas flow path 3g below the outlet of the nozzle 3i extends vertically with a constant width. At the outlet portion, the inert gas flows through the space between the liquid column of drying liquid from the outlet of the nozzle 3i and the inner circumferential surface of the shield plate 6, and then flows through the space between the lower surface 6a of the shield plate 6 and the first main surface Wa of the substrate W. Because the outlet portion of the gas flow path 3g extends vertically with a constant width, the volume of this space is relatively small. Furthermore, when the shield plate 6 is located at the second shield processing position P12, the volume of the space between the shield plate 6 and the substrate W is also relatively small. Therefore, the cross-section of the inert gas flow path is small. Therefore, the pressure of the inert gas increases, and the liquid column of drying liquid is more susceptible to the influence of the inert gas flow. As a result, the liquid column of drying liquid may fluctuate. In Figure 18, the fluctuation of the liquid column of drying liquid is schematically shown by a wavy line. Due to such fluctuation of the drying liquid, the landing position on the first main surface Wa of the substrate W may fluctuate, or droplets may be scattered from the liquid column of drying liquid and adhere to the shielding plate 6.

[0159] 19 is a diagram showing an example of the processing unit 1 during the drying liquid supply step according to the sixth embodiment. In the example of FIG. 19, the gas flow path 3g has an expanded-diameter flow path 3gb. Therefore, the volume of the space between the liquid column of drying liquid from the nozzle 3i and the inner circumferential surface of the blocking plate 6 is relatively large. This allows the inert gas to flow at a position relatively far from the liquid column of drying liquid, thereby reducing the effect of the inert gas flow on the drying liquid. This reduces fluctuations in the liquid column of drying liquid.

[0160] In the above example, during the final period of the drying liquid supplying step (step S5), the shielding plate 6 is positioned at the second shielding processing position P12, which is closer to the drying position P2. Therefore, the movement distance of the shielding plate 6 can be shortened during the subsequent drying step (step S6). In other words, during the initial stage of the drying step, the shielding plate 6 only needs to move from the second shielding processing position P12 to the drying position P2, which is a shorter movement distance than the movement distance from the first shielding processing position P11 to the drying position P2. Therefore, the movement drive unit 35i can cause the shielding plate 6 to reach the drying position P2 at an earlier timing. This further improves the drying performance during the initial stage of the drying step.

[0161] The time t11 at which the blocking plate 6 starts to move toward the second blocking process position P12 may be later than the center of the drying liquid supply time. In other words, the time difference between time t11 and time t2 may be shorter than the time difference between time t1 and time t11.

[0162] In the example of FIG. 17 , at time t21 during the drying process, the control unit 90 controls the movement drive unit 35i to move the shielding plate 6 from the first drying position P21 to the second drying position P22. The second drying position P22 is closer to the first main surface Wa of the substrate W than the first drying position P21. The second drying position P22 may be a position that is 0.5 mm or less away from the first main surface Wa of the substrate W. Each of the first drying position P21 and the second drying position P22 is an example of the drying position P2. Time t21, at which the shielding plate 6 starts moving to the second drying position P22, may be, for example, after the drying liquid has substantially finished scattering from the periphery of the substrate W. In other words, the shielding plate 6 descends to the second drying position P22 after the drying liquid above the pattern on the substrate W has substantially been shaken off to the outside. This allows the drying liquid in the pattern on the substrate W to evaporate while the shielding plate 6 is positioned at the second drying position P22, thereby enabling the substrate W to be dried more quickly. The control unit 90 may cause the movement drive unit 35i to move the shielding plate 6 to the second drying position P22 when a predetermined time has elapsed since time t2. The time is set to be a time sufficient for the scattering of the drying liquid from the substrate W to substantially end.

[0163] 20 is a diagram showing a second example of the configuration of the shield plate 6 according to the sixth embodiment. In the second example, a gas nozzle 3gA is provided. Like the nozzle 3i, the gas nozzle 3gA is provided inside the hollow shaft 61. The gas nozzles 3gA are adjacent to each other in the horizontal direction. The gas nozzles 3gA extend vertically, and their lower end openings function as gas discharge ports. The upstream end of the gas nozzle 3gA is connected to the downstream end of a supply pipe 31gA. The upstream end of the supply pipe 31gA is connected to a gas supply source.

[0164] The supply pipe 31gA is provided with a supply valve 32gA, a flow rate adjustment valve 33gA, and a heater 34gA. The supply valve 32gA switches the supply pipe 31gA between on and off. The flow rate adjustment valve 33gA adjusts the flow rate of the inert gas flowing through the supply pipe 31gA. The heater 34gA heats the inert gas flowing through the supply pipe 31gA. The heater 34gA may be, for example, an electric resistance heater having an electric heating wire. The supply valve 32gA, the flow rate adjustment valve 33gA, and the heater 34gA are controlled by the control unit 90.

[0165] In the drying liquid supplying step (step S5), the control unit 90 may open the supply valve 32g and close the supply valve 32gA. As a result, in the drying liquid supplying step, inert gas is not discharged from the gas nozzle 3gA, but is discharged from the gas flow path 3g. Since inert gas is not discharged from the gas nozzle 3gA located close to the nozzle 3i, fluctuations of the liquid column of drying liquid caused by the inert gas can be suppressed. Meanwhile, in the drying step (step S6), the control unit 90 opens the supply valves 32g and 32gA. As a result, inert gas is discharged from the gas flow path 3g and the gas nozzle 3gA in the drying step. Therefore, the inert gas can be more appropriately supplied to the center of the substrate W. The above-mentioned flow rate value of the inert gas may be the sum of the flow rates of the inert gas flowing through the gas flow path 3g and the gas nozzle 3gA.

[0166] Although the substrate processing apparatus 100 and the substrate processing method have been described in detail above, the above description is merely an example in all respects, and this disclosure is not limited thereto. Furthermore, the various modifications described above can be combined and applied as long as they are not mutually inconsistent. It is understood that many modifications not illustrated can be envisioned without departing from the scope of this disclosure.

[0167] In the above example, a dedicated nozzle is provided for each fluid, but one nozzle may be shared by different types of fluids.

[0168] Furthermore, in the above example, the substrate heating section 40 supplies a heat medium to the second main surface Wb of the substrate W, but this is not necessarily limited to this. The substrate heating section 40 may include, for example, a heater provided at a position vertically facing the second main surface Wb of the substrate W. The heater may be, for example, an electric resistance heater including an electric heating wire, or an optical heater that outputs light for heating.

[0169] In the above example, the substrate heating unit 40 heats the second main surface Wb of the substrate W during the evaporation time from time t2 when the supply of drying liquid is stopped to time t3. However, the substrate heating unit 40 may interrupt heating during a part of the evaporation time.

[0170] 3g Gas flow path 3gb Expanded diameter flow path 6 Blocking plate P1 Blocking process position P11 First blocking process position P12 Second blocking process position P2 Drying position P21 First drying position P22 Second drying position S1, S11, S21 Holding process (step) S4, S16, S23 Liquid supplying process (step) S5, S17, S24 Drying liquid supplying process (step) S6, S18, S25 Drying process (step) T2 Post-delay time W Substrate Wa First main surface Wb Second main surface

Claims

1. 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 opposite to the first main surface; a liquid supplying step of supplying a processing liquid to the first main surface of the substrate; a drying liquid supplying step of supplying a drying liquid to the first main surface of the substrate after the liquid supplying step; and a drying step of heating the second main surface of the substrate for a predetermined period of time after the drying liquid supplying step to make the substrate temperature of the first main surface of the substrate equal to or higher than the substrate temperature in the drying liquid supplying step, thereby drying the substrate.

2. A substrate processing method according to claim 1, wherein the substrate temperature of at least a part of the first main surface of the substrate is set to a boiling point of the drying liquid or higher during the predetermined period.

3. A substrate processing method as defined in claim 1 or 2, comprising: in the drying liquid supplying step, heating the second main surface of the substrate with a first amount of heat per unit time; and in the specified period of the drying step, heating the second main surface of the substrate with a second amount of heat per unit time greater than the first amount of heat.

4. A substrate processing method according to claim 1 or 2, further comprising the step of supplying a heat medium to the second main surface of the substrate during the predetermined period.

5. A substrate processing method as claimed in claim 3, wherein in the drying liquid supplying step, a heat medium obtained by mixing a high-temperature heat medium and a low-temperature heat medium having a lower temperature than the high-temperature heat medium is supplied to the second main surface of the substrate, and the mixing ratio of the high-temperature heat medium and the low-temperature heat medium is adjusted to supply the heat medium having a higher temperature than the heat medium in the drying liquid supplying step to the second main surface of the substrate for at least the specified period of the drying step.

6. A substrate processing method according to claim 4, wherein the heat medium having a temperature equal to or higher than the boiling point of the drying liquid is supplied to the second main surface of the substrate during the predetermined period.

7. A substrate processing method as described in claim 4, wherein in the drying liquid supplying step, the heat medium having a temperature equal to or higher than the boiling point of the drying liquid is supplied to the second main surface of the substrate, while the drying liquid is supplied at a flow rate such that the substrate temperature of the first main surface of the substrate becomes lower than the boiling point.

8. A substrate processing method as described in claim 4, wherein the heat medium includes a liquid, and in the drying liquid supplying step, the drying liquid is supplied to the first main surface of the substrate while a shielding plate having an opposing surface facing the first main surface of the substrate is positioned at a shielding processing position, and during the specified period of the drying step, an inert gas is supplied toward the first main surface of the substrate from a gas outlet in the center of the shielding plate while the shielding plate is moved to a drying position closer to the first main surface than the shielding processing position.

9. A substrate processing method according to claim 8, further comprising the step of supplying heated inert gas to the first main surface of the substrate during the predetermined period.

10. A substrate processing method as described in claim 8, wherein in the drying liquid supply process, the inert gas is supplied to the first main surface of the substrate through a gas flow path inside the blocking plate having a flow path with an expanding diameter that expands toward the gas outlet, and the flow rate of the inert gas is increased while the blocking plate is moved from the blocking processing position to the drying position.

11. A substrate processing method as described in claim 10, wherein, in the drying liquid supplying step, the drying liquid is supplied to the first main surface of the substrate while the blocking plate is positioned at a first blocking processing position which is one of the blocking processing positions, and then, while supplying the drying liquid, the blocking plate is moved to a second blocking processing position which is one of the blocking processing positions and is closer to the first main surface of the substrate than the first blocking processing position.

12. A substrate processing method according to claim 1 or 2, wherein the substrate is rotated at a rotation speed during the predetermined period of the drying step that is higher than the rotation speed of the substrate during the drying liquid supplying step.

13. A substrate processing method according to claim 1 or 2, wherein, in the drying liquid supply step, the second main surface of the substrate is heated only during a latter period of a drying liquid supply time during which the drying liquid is supplied.

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