KR20220133831A - Substrate processing method, substrate processing apparatus and pre-drying processing liquid - Google Patents

Abstract

A pre-drying processing solution, which is a solution containing a sublimable material that changes into a gas without passing through a liquid and a solvent that dissolves the sublimable material, is supplied to the surface of a substrate on which a pattern is formed. Thereafter, by evaporating the solvent from the pre-drying processing liquid on the surface of the substrate, a solidified body containing the sublimable material is formed on the surface of the substrate. Thereafter, the solidified body is removed from the surface of the substrate by sublimation. A value obtained by multiplying the ratio of the thickness of the solidified body to the height of the pattern by one hundred is greater than 76 and less than 219.

Description

Substrate processing method, substrate processing apparatus, and drying pretreatment liquid

This application claims priority based on Japanese Patent Application No. 2018-119092 filed on June 22, 2018 and Japanese Patent Application No. 2019-050214 filed on March 18, 2019, the entire contents of these applications is hereby incorporated by reference.

The present invention relates to a substrate processing method and a substrate processing apparatus for processing a substrate, and a drying pretreatment solution supplied to the surface of the substrate before drying the surface of the substrate. The substrate to be processed includes, for example, a semiconductor wafer, a substrate for a flat panel display (FPD) such as a liquid crystal display device or an organic EL (electroluminescence) display device, a substrate for an optical disk, a substrate for a magnetic disk, a substrate for a magneto-optical disk, Substrates for photomasks, ceramic substrates, substrates for solar cells, and the like are included.

In manufacturing processes, such as a semiconductor device and a liquid crystal display device, a process as needed is performed with respect to board|substrates, such as a semiconductor wafer and the glass substrate for liquid crystal display devices. Such processing includes supplying a processing liquid such as a chemical liquid or a rinse liquid to the substrate. After the processing liquid is supplied, the processing liquid is removed from the substrate and the substrate is dried. In a single-wafer substrate processing apparatus that processes substrates one by one, spin drying of drying the substrate is performed by removing the liquid adhering to the substrate by high-speed rotation of the substrate.

When the pattern is formed on the surface of the substrate, when the substrate is dried, a force resulting from the surface tension of the processing liquid adhering to the substrate is applied to the pattern, and the pattern may collapse. As a countermeasure, a method of supplying a liquid with low surface tension, such as IPA (isopropyl alcohol) to the substrate, or supplying a hydrophobizing agent that makes the contact angle of the liquid with respect to the pattern close to 90 degrees to the substrate is employed. However, even if IPA or a hydrophobic agent is used, the collapse force for breaking the pattern does not become zero. Therefore, depending on the strength of the pattern, even if such countermeasures are taken, it may not be possible to sufficiently prevent the pattern from collapsing. have.

In recent years, attention has been paid to sublimation drying as a technique for preventing pattern collapse. For example, JP2012-243869A discloses a substrate processing method and substrate processing apparatus for performing sublimation drying. In the sublimation drying described in JP2012-243869A, a solution of a sublimable material is supplied to the upper surface of a substrate, so that DIW on the substrate is replaced with a solution of the sublimable material. Thereafter, the solvent of the sublimable substance is dried to precipitate the sublimable substance. Thereby, a film made of a solid sublimable material is formed on the upper surface of the substrate. Paragraph 0028 of JP2012-243869A states, "The film thickness "t" of the sublimable material is preferably made as thin as possible as long as it sufficiently covers the convex portion 101 of the pattern. ' There is a note. After the film of the solid sublimable material is formed, the substrate is heated. Thereby, the sublimable material on the substrate is sublimed and removed from the substrate.

In general, sublimation drying has a lower rate of pattern collapse than conventional drying methods such as spin drying in which a liquid is removed by high-speed rotation of a substrate or IPA drying using IPA. However, when the intensity|strength of a pattern is extremely low, even if sublimation-drying is implemented, the collapse of a pattern may not fully be prevented. According to the study of the present inventors, it was found that one of the causes is the thickness of the solidified body containing the sublimable substance. According to JP2012-243869A, "the film thickness "t" of the sublimable material is preferably made as thin as possible as long as it sufficiently covers the convex portion 101 of the pattern. ', and the thickness of the film made of a sublimable material is not sufficiently considered.

It is an object of the present invention to provide a substrate processing method, substrate processing apparatus, and drying pretreatment solution capable of reducing pattern collapse occurring when a substrate is dried by sublimation drying.

In one embodiment of the present invention, a dry pretreatment solution, which is a solution containing a sublimable material that changes to a gas without passing through a liquid and a solvent that melts with the sublimable material, is supplied to the surface of the substrate on which the pattern is formed. A drying pretreatment solution supply step, a solidified body forming step of forming a solidified body including the sublimable material on the surface of the substrate by evaporating the solvent from the drying pretreatment solution on the surface of the substrate, and the solidified body and a sublimation step of removing from the surface of the substrate by sublimating, wherein the value obtained by multiplying the ratio of the thickness of the solidified body to the height of the pattern by one hundred times is greater than 76 and less than 219. .

According to this method, the drying pretreatment liquid containing the sublimable substance corresponding to a solute and a solvent is supplied to the surface of the board|substrate on which the pattern was formed. Then, the solvent is evaporated from the dry pretreatment solution. Thereby, a solidified body containing the sublimable substance is formed on the surface of the substrate. After that, the solidified body on the substrate is changed into a gas without going through a liquid. Thereby, the solidified material is removed from the surface of the substrate. Therefore, compared with the conventional drying method, such as spin drying, the collapse rate of a pattern can be reduced.

Upon evaporation of the solvent from the dry pretreatment liquid, a solid comprising a sublimable material is formed on the surface of the substrate. If the value obtained by multiplying the ratio of the thickness of the solidified body with respect to the height of the pattern by one hundred times is defined as the embedding rate, the embedding rate at the time when the solidified body is formed exceeds 76 and is less than 219. When the embedding rate is outside this range, the number of collapses of the pattern increases depending on the strength of the pattern. Conversely, if the embedding ratio is within this range, the number of collapses of the pattern can be reduced even if the strength of the pattern is low. Therefore, even if the intensity|strength of a pattern is low, the collapse rate of a pattern can be reduced.

In the said embodiment, at least one of the following characteristics may be added to the said substrate processing method.

The sublimable material includes at least one of camphor and naphthalene.

The solvent includes at least one of IPA (isopropyl alcohol), acetone, and PGEE (propylene glycol monoethyl ether).

The solvent is IPA, and the mass percent concentration of the sublimable substance in the drying pretreatment liquid is greater than 0.62 and less than 2.06.

The solvent is acetone, and the mass percent concentration of the sublimable substance in the drying pretreatment liquid exceeds 0.62 and is 0.96 or less.

The solvent is PGEE, and the mass percent concentration of the sublimable substance in the drying pretreatment liquid exceeds 3.55 and is 6.86 or less.

The drying pretreatment liquid supplied to the surface of the substrate in the drying pretreatment liquid supply process includes the sublimable material including a hydrophobic group, the solvent, a hydrophobic group and a hydrophilic group, and has a higher hydrophilicity than the sublimable material. A solution containing a substance.

According to this method, in addition to the sublimable material and the solvent, the drying pretreatment liquid containing the adsorbent material is supplied to the surface of the substrate on which the pattern is formed. Then, the solvent is evaporated from the dry pretreatment solution. Thereby, a solidified body containing the sublimable substance is formed on the surface of the substrate. After that, the solidified body on the substrate is changed into a gas without going through a liquid. Thereby, the solidified material is removed from the surface of the substrate. Therefore, compared with the conventional drying method, such as spin drying, the collapse rate of a pattern can be reduced.

A sublimable substance is a substance containing a hydrophobic group in a molecule|numerator. An adsorption substance is a substance containing a hydrophobic group and a hydrophilic group in a molecule|numerator. The hydrophilicity of the adsorbent material is higher than that of the sublimable material. Even if the surface of the pattern is either hydrophilic or hydrophobic, or even if a hydrophilic portion and a hydrophobic portion are included in the surface of the pattern, the adsorbed substance in the drying pretreatment solution is adsorbed to the surface of the pattern.

Specifically, when the surface of the pattern is hydrophilic, the hydrophilic group of the adsorption material in the drying pretreatment solution is attached to the surface of the pattern, and the hydrophobic group of the sublimable material in the drying pretreatment solution is attached to the hydrophobic group of the adsorption material. Thereby, the sublimable material is retained on the surface of the pattern through the adsorbent material. When the surface of the pattern is hydrophobic, at least a hydrophobic group of the sublimable material is attached to the surface of the pattern. Therefore, even if the surface of the pattern is either hydrophilic or hydrophobic, or even if a hydrophilic portion and a hydrophobic portion are included in the surface of the pattern, the sublimable material is maintained on or near the surface of the pattern before evaporation of the solvent.

When the sublimable material is hydrophilic and the surface of the pattern is hydrophilic, the sublimable material is attracted to the surface of the pattern by electrical attraction. On the other hand, when the sublimable material is hydrophobic and the surface of the pattern is hydrophilic, since such an attractive force is weak or does not occur, it is difficult for the sublimable material to adhere to the surface of the pattern. Further, in addition to the fact that the sublimable material is hydrophobic and the surface of the pattern is hydrophilic, it is conceivable that a sufficient amount of the sublimable material does not enter between the patterns when the spacing between the patterns is extremely narrow. Such a phenomenon also occurs when the sublimable material is hydrophilic and the surface of the pattern is hydrophobic.

When the solvent is evaporated in a state where the sublimable material is not present on or near the surface of the pattern, a collapsing force is applied to the pattern from the solvent in contact with the surface of the pattern, and the pattern may collapse. If the solvent is evaporated in a state in which a sufficient amount of the sublimable material is not present between the patterns, the gap between the patterns is not filled with a solidified material and the pattern collapses. Placing the sublimable material on or near the surface of the pattern before evaporating the solvent can reduce such collapse. Thereby, the collapse rate of a pattern can be reduced.

Any one of a hydroxyl group (a hydroxyl group, a hydroxyl group), a carboxy group (COOH), an amino group (NH2), and a carbonyl group ( _CO ) may be sufficient as a hydrophilic group, and other than these may be sufficient as them. The hydrophobic group may be any one of a hydrocarbon group, an alkyl group (C _n H _2n+1 ), a cycloalkyl group (C _n H _2n+1 ), and a phenyl group (C ₆ H ₅ ), or may be other than these groups.

The adsorption material is a material having sublimability.

According to this method, not only the sublimable substance but also the adsorption substance has sublimability. The adsorbed material changes from a solid to a gas at room temperature or pressure without going through a liquid. When at least a part of the surface of the pattern is hydrophilic, the solvent evaporates while the adsorbed material in the drying pretreatment liquid is adsorbed to the surface of the pattern. The adsorbent material changes from a liquid to a solid at the surface of the pattern. Thereby, a coagulated body comprising an adsorbent material and a sublimable material is formed. Then, the solid of the adsorbent material changes to a gas without passing through the liquid at the surface of the pattern. Therefore, it is possible to reduce the collapse force compared to the case of vaporizing the liquid on the surface of the pattern.

The concentration of the adsorbent in the drying pretreatment solution is lower than the concentration of the solvent in the drying pretreatment solution.

According to this method, a dry pretreatment liquid having a low concentration of an adsorbent is supplied to the surface of the substrate. When at least a part of the surface of the pattern is hydrophilic, a hydrophilic group of the adsorption material is attached to the surface of the pattern, and a monomolecular film of the adsorption material is formed along the surface of the pattern. When the concentration of the adsorbent material is high, a plurality of monomolecular films are stacked, and a laminated film of the adsorbent material is formed along the surface of the pattern. In this case, the sublimable material is held on the surface of the pattern through the laminated film of the adsorbent material. When the layered film of the adsorbent material is thick, the sublimable material entering between the patterns decreases. Therefore, by lowering the concentration of the adsorbent material, more sublimable materials can be introduced between the patterns.

When at least a part of the surface of the pattern is hydrophilic, the concentration of the adsorption material in the drying pretreatment liquid may be a value at which a monomolecular film of the adsorption material is formed on the surface of the pattern, or a value exceeding this. In the former case, the sublimable material is retained on the surface of the pattern through the monolayer of the adsorbent material. Therefore, even if at least a part of the surface of the pattern is hydrophilic, the sublimable material can be disposed in the vicinity of the surface of the pattern. In addition, since only a monomolecular film of the thinnest adsorption material is interposed between the sublimable material and the pattern, a sufficient amount of the sublimable material can be introduced between the patterns.

The sublimable material has a higher hydrophobicity than the adsorbent material. The solubility of the sublimable material in oil is higher than the solubility of the adsorbent material in oil. In other words, the solubility of the sublimable material in water is lower than the solubility of the adsorbent material in water.

According to this method, a drying pretreatment liquid containing a sublimable material having a higher hydrophobicity than an adsorption material is supplied to the surface of the substrate. Since any of the sublimable material and the adsorbing material contains a hydrophobic group, both the sublimable material and the adsorbing material may be attached to the surface of the pattern when at least a portion of the surface of the pattern is hydrophobic. However, since the affinity of the sublimable material and the pattern is higher than that of the adsorbing material and the pattern, more sublimable materials than the adsorbing material adhere to the surface of the pattern. This allows more sublimable material to adhere to the surface of the pattern.

Another embodiment of the present invention provides a dry pretreatment solution supplying a dry pretreatment solution, which is a solution containing a sublimable material that changes into a gas without going through a liquid and a solvent that melts with the sublimable material, to the surface of a substrate on which a pattern is formed. a unit, a solidified body forming unit for forming a solidified body comprising the sublimable material on the surface of the substrate by evaporating the solvent from the drying pretreatment liquid on the surface of the substrate; and a sublimation unit removing from the surface of the substrate, wherein a value obtained by multiplying a ratio of a thickness of the solidified body to a height of the pattern by one hundred times is greater than 76 and less than 219. According to this structure, the same effect as the above-mentioned substrate processing method can be exhibited.

Another embodiment of the present invention is a drying pretreatment liquid supplied to the surface of the substrate before drying the surface of the substrate on which the pattern is formed, and a sublimable material that changes to a gas without going through a liquid, and the sublimable material When a solidified body containing the sublimable material is formed on the surface of the substrate by evaporating the solvent from the drying pretreatment solution on the surface of the substrate, the solidified body with respect to the height of the pattern To provide a dry pretreatment solution, in which the concentration of the sublimable material is adjusted so that a value obtained by multiplying the ratio of the thickness of is greater than 76 and less than 219. According to this structure, the same effect as the above-mentioned substrate processing method can be exhibited.

The above-mentioned or still another objective in this invention, the characteristic, and an effect will become clear by description of embodiment described next with reference to an accompanying drawing.

1A is a schematic diagram of a substrate processing apparatus according to a first embodiment of the present invention as viewed from above.
1B is a schematic diagram of the substrate processing apparatus viewed from the side.
2 is a schematic diagram horizontally viewed inside a processing unit provided in the substrate processing apparatus.
3 is a schematic diagram illustrating a dry pretreatment liquid supply unit provided in the substrate processing apparatus.
Fig. 4 is a block diagram showing the hardware of the control device.
5 is a process chart for explaining an example of processing of the substrate according to the first embodiment.
Fig. 6A is a schematic diagram showing a state of the substrate when the substrate shown in Fig. 5 is being processed.
Fig. 6B is a schematic diagram showing a state of the substrate when the substrate shown in Fig. 5 is being processed.
Fig. 6C is a schematic diagram showing a state of the substrate when the substrate shown in Fig. 5 is being processed.
7 is a graph showing an example of an image in which the thickness of a liquid film of a drying pretreatment liquid on a substrate is reduced by evaporation of a solvent.
8 is a graph showing an example of the relationship between the initial concentration of the sublimable substance and the thickness of the solidified body.
Fig. 9 is a table showing an example of the embedding rate and the pattern collapse rate obtained when a plurality of samples in which patterns having the same shape and strength were formed were processed while changing the initial concentration of camphor.
It is a line graph which shows the relationship between the density|concentration of camphor in FIG. 9, and the collapse rate of a pattern.
11 : is a line graph which shows the relationship between the embedding rate in FIG. 9, and the collapse rate of a pattern.
12A and 12B are schematic diagrams for explaining a mechanism assumed for a phenomenon in which the collapse rate of the pattern increases when the solidified body is too thick.
13A and 13B are schematic diagrams for explaining a mechanism assumed for a phenomenon in which the collapse rate of the pattern increases when the solidified body is too thin.
14 is a table showing an example of a collapse rate of a pattern obtained when a plurality of samples in which a pattern having the same shape and strength is formed is processed while changing the initial concentration of camphor.
15 : is a table which shows an example of the collapse rate of the pattern obtained when the several samples in which the pattern with the same shape and intensity|strength were formed were processed changing the initial concentration of camphor.
16 : is a table which shows an example of the collapse rate of the pattern obtained when the several samples in which the pattern with the same shape and intensity|strength were formed were processed while changing the initial concentration of camphor.
It is a line graph which shows the relationship between the density|concentration of camphor in FIG. 14, and the collapse rate of a pattern.
Fig. 18 is a line graph showing the relationship between the concentration of camphor in Fig. 15 and the collapse rate of the pattern.
19 is a line graph showing the relationship between the concentration of camphor in FIG. 16 and the collapse rate of the pattern.
Fig. 20 is a graph in which the broken lines of Figs. 17 to 19 are superimposed.
21 is a schematic diagram horizontally viewed inside a processing unit included in the substrate processing apparatus according to the second embodiment.
22 is a process chart for explaining an example of processing of the substrate according to the second embodiment.
23A is a cross-sectional view of a substrate for explaining a phenomenon assumed to occur on the surface of a pattern to which a drying pretreatment liquid is supplied.
23B is a cross-sectional view of a substrate for explaining this phenomenon.
23C is a cross-sectional view of a substrate for explaining this phenomenon.
23D is a cross-sectional view of a substrate for explaining this phenomenon.
23E is a cross-sectional view of a substrate for explaining this phenomenon.
23F is a cross-sectional view of a substrate for explaining this phenomenon.

In the following description, the atmospheric pressure in the substrate processing apparatus 1 is maintained at atmospheric pressure (for example, 1 atmosphere or a value in the vicinity) in the clean room in which the substrate processing apparatus 1 is installed, unless otherwise specified. assume that there is

1A is a schematic diagram of a substrate processing apparatus 1 according to a first embodiment of the present invention as viewed from above. FIG. 1B is a schematic diagram of the substrate processing apparatus 1 viewed from the side.

As shown to FIG. 1A, the substrate processing apparatus 1 is a single-wafer type apparatus which processes disk-shaped board|substrates W, such as a semiconductor wafer, one by one. The substrate processing apparatus 1 includes a load port LP holding a carrier C for accommodating a substrate W, and a substrate W conveyed from the carrier C on the load port LP as a processing liquid or A plurality of processing units 2 that process with a processing fluid such as a processing gas, a transport robot that transports a substrate W between the processing unit 2 and a carrier C on a load port LP, and a substrate processing apparatus A control device (3) for controlling (1) is provided.

The transfer robot includes an indexer robot IR for carrying in and unloading the substrate W with respect to the carrier C on the load port LP, and the loading and unloading of the substrate W with respect to the plurality of processing units 2 . It includes a center robot (CR) that performs The indexer robot IR transfers the substrate W between the load port LP and the center robot CR, and the center robot CR transfers the substrate W between the indexer robot IR and the processing unit 2 W) is returned. The center robot CR includes a hand H1 that supports the substrate W, and the indexer robot IR includes a hand H2 that supports the substrate W.

The plurality of processing units 2 form a plurality of towers TW arranged around the center robot CR in a plan view. 1A shows an example in which four towers TW are formed. The center robot CR can access any tower TW. As shown in FIG. 1B , each tower TW includes a plurality of (for example, three) processing units 2 stacked vertically.

FIG. 2 is a schematic diagram horizontally viewed inside the processing unit 2 provided in the substrate processing apparatus 1 .

The processing unit 2 is a wet processing unit 2w that supplies a processing liquid to the substrate W. The processing unit 2 includes a box-shaped chamber 4 having an internal space and a vertical rotation axis A1 passing through the central portion of the substrate W while horizontally holding one substrate W in the chamber 4 . ) includes a spin chuck 10 that rotates around, and a cylindrical processing cup 21 that surrounds the spin chuck 10 around a rotation axis A1.

The chamber 4 contains the box-shaped partition 5 in which the carry-in/out port 5b through which the board|substrate W passes was provided, and the shutter 7 which opens and closes the carry-in/out port 5b. The FFU 6 (fan filter unit) is arrange|positioned on the air outlet 5a provided in the upper part of the partition 5. As shown in FIG. The FFU 6 always supplies clean air (air filtered by the filter) into the chamber 4 from the air outlet 5a. The gas in the chamber 4 is discharged from the chamber 4 through an exhaust duct 8 connected to the bottom of the processing cup 21 . Thereby, a down flow of clean air is always formed in the chamber 4 . The flow rate of the exhaust discharged to the exhaust duct 8 is changed according to the opening degree of the exhaust valve 9 disposed in the exhaust duct 8 .

The spin chuck 10 includes a disk-shaped spin base 12 held in a horizontal orientation, a plurality of chuck pins 11 above the spin base 12 for holding the substrate W in a horizontal orientation, , a spin shaft 13 extending downward from the central portion of the spin base 12, and a spin motor 14 for rotating the spin base 12 and the plurality of chuck pins 11 by rotating the spin shaft 13; include The spin chuck 10 is not limited to a clamping chuck that contacts the outer circumferential surface of the substrate W with the plurality of chuck pins 11, and the back surface (lower surface) of the substrate W, which is a non-device forming surface. It may be a vacuum chuck that holds the substrate W horizontally by adsorbing it to the upper surface 12u of the spin base 12 .

The processing cup 21 includes a plurality of guards 24 receiving the processing liquid discharged outward from the substrate W, and a plurality of cups 23 receiving the processing liquid guided downward by the plurality of guards 24 . and a cylindrical outer wall member 22 surrounding the plurality of guards 24 and the plurality of cups 23 . Fig. 2 shows an example in which four guards 24 and three cups 23 are provided, and the outermost cup 23 is integrated with the third guard 24 from the top.

The guard 24 includes a cylindrical portion 25 surrounding the spin chuck 10, and an annular ceiling portion 26 extending obliquely upward from the upper end of the cylindrical portion 25 toward the rotation axis A1. do. The plurality of ceiling portions 26 are vertically overlapped, and the plurality of cylindrical portions 25 are arranged concentrically. The annular upper end of the ceiling portion 26 corresponds to the upper end 24u of the guard 24 surrounding the substrate W and the spin base 12 in plan view. The plurality of cups 23 are arranged below the plurality of cylindrical portions 25 , respectively. The cup 23 forms an annular infusion groove for receiving the treatment liquid guided downward by the guard 24 .

The processing unit 2 includes a guard raising/lowering unit 27 for individually raising/lowering the plurality of guards 24 . The guard raising/lowering unit 27 positions the guard 24 at any position from an upper position to a lower position. 2 shows a state in which the two guards 24 are arranged at the upper position and the remaining two guards 24 are arranged at the lower position. The upper position is a position in which the upper end 24u of the guard 24 is arranged above the holding position in which the substrate W held by the spin chuck 10 is arranged. The lower position is a position where the upper end 24u of the guard 24 is disposed below the holding position.

When supplying the processing liquid to the rotating substrate W, at least one guard 24 is disposed at an upper position. In this state, when the processing liquid is supplied to the substrate W, the processing liquid supplied to the substrate W is shaken off around the substrate W. The removed processing liquid collides with the inner surface of the guard 24 horizontally opposed to the substrate W, and is guided to the cup 23 corresponding to the guard 24 . Accordingly, the processing liquid discharged from the substrate W is collected in the processing cup 21 .

The processing unit 2 includes a plurality of nozzles that discharge the processing liquid toward the substrate W held by the spin chuck 10 . The plurality of nozzles includes a chemical liquid nozzle 31 that discharges a chemical liquid toward the upper surface of the substrate W, a rinse liquid nozzle 35 that discharges a rinse liquid toward the upper surface of the substrate W, and It includes a dry pretreatment liquid nozzle 39 for discharging the drying pretreatment liquid toward the upper surface, and a replacement liquid nozzle 43 for discharging the replacement liquid toward the upper surface of the substrate W.

The chemical liquid nozzle 31 may be a horizontally movable scan nozzle in the chamber 4 or a fixed nozzle fixed to the partition 5 of the chamber 4 . The same applies to the rinse liquid nozzle 35 , the dry pretreatment liquid nozzle 39 , and the replacement liquid nozzle 43 . In FIG. 2 , the chemical liquid nozzle 31 , the rinse liquid nozzle 35 , the dry pretreatment liquid nozzle 39 , and the replacement liquid nozzle 43 are scan nozzles, and the movement of four nozzles corresponding to these four nozzles respectively An example in which the unit is installed is shown.

The chemical liquid nozzle 31 is connected to a chemical liquid pipe 32 that guides the chemical liquid to the chemical liquid nozzle 31 . When the chemical liquid valve 33 interposed in the chemical liquid pipe 32 is opened, the chemical liquid is continuously discharged downward from the discharge port of the chemical liquid nozzle 31 . The chemical liquid discharged from the chemical liquid nozzle 31 is sulfuric acid, nitric acid, hydrochloric acid, hydrofluoric acid, phosphoric acid, acetic acid, aqueous ammonia, hydrogen peroxide solution, organic acid (eg, citric acid, oxalic acid, etc.), organic alkali (eg, TMAH: tetra The liquid containing at least 1 of methylammonium hydroxide etc.), surfactant, and a corrosion inhibitor may be sufficient, and liquid other than this may be sufficient.

Although not shown, the chemical liquid valve 33 includes an internal flow path through which the chemical solution flows, a valve body provided with an annular valve seat surrounding the internal flow path, a valve body movable with respect to the valve seat, and the valve body and an actuator for moving the valve body between a closed position in contact with the valve body and an open position away from the valve seat. The same is true for other valves. An actuator may be a pneumatic actuator or an electric actuator, and actuators other than these may be sufficient as an actuator. The control device 3 opens and closes the chemical liquid valve 33 by controlling the actuator.

The chemical liquid nozzle 31 is connected to a nozzle moving unit 34 that moves the chemical liquid nozzle 31 in at least one of a vertical direction and a horizontal direction. The nozzle moving unit 34 is located at a processing position where the chemical liquid discharged from the chemical liquid nozzle 31 is supplied to the upper surface of the substrate W, and the chemical liquid nozzle 31 is located around the processing cup 21 in a plan view The chemical liquid nozzle 31 is horizontally moved between the standby positions.

The rinse liquid nozzle 35 is connected to a rinse liquid pipe 36 that guides the rinse liquid to the rinse liquid nozzle 35 . When the rinse liquid valve 37 interposed in the rinse liquid pipe 36 is opened, the rinse liquid is continuously discharged downward from the discharge port of the rinse liquid nozzle 35 . The rinse liquid discharged from the rinse liquid nozzle 35 is, for example, pure water (deionized water: DIW (Deionized Water)). The rinsing liquid may be any one of carbonated water, electrolytic ionized water, hydrogen water, ozone water, and hydrochloric acid water having a dilution concentration (eg, about 10 to 100 ppm).

The rinse liquid nozzle 35 is connected to a nozzle moving unit 38 that moves the rinse liquid nozzle 35 in at least one of a vertical direction and a horizontal direction. The nozzle moving unit 38 includes a processing position at which the rinse liquid discharged from the rinse liquid nozzle 35 is supplied to the upper surface of the substrate W, and the rinse liquid nozzle 35 of the treatment cup 21 in a plan view. The rinse liquid nozzle 35 is moved horizontally between the standby positions located on the periphery.

The dry pretreatment liquid nozzle 39 is connected to a dry pretreatment liquid pipe 40 that guides the treatment liquid to the dry pretreatment liquid nozzle 39 . When the drying pretreatment liquid valve 41 interposed in the drying pretreatment liquid pipe 40 is opened, the drying pretreatment liquid is continuously discharged downward from the discharge port of the drying pretreatment liquid nozzle 39 . Similarly, the replacement liquid nozzle 43 is connected to the replacement liquid pipe 44 which guides the replacement liquid to the replacement liquid nozzle 43 . When the replacement liquid valve 45 interposed in the replacement liquid pipe 44 is opened, the replacement liquid is continuously discharged downward from the discharge port of the replacement liquid nozzle 43 .

The drying pretreatment liquid is a solution containing a sublimable substance corresponding to a solute, and a solvent to be fused with the sublimable substance. The sublimable substance may be a substance that changes from a solid to a gas without passing through a liquid at normal temperature (synonymous with room temperature) or normal pressure (pressure in the substrate processing apparatus 1, for example, 1 atm or a value thereof). Such a substance may be sufficient as a solvent, and the substance other than this may be sufficient as it. That is, the drying pretreatment liquid may contain two or more types of substances that change from solid to gas at room temperature or normal pressure without passing through the liquid.

Sublimable substances include, for example, alcohols such as 2-methyl-2-propanol (another name: tert-butyl alcohol, t-butyl alcohol, tert-butyl alcohol) and cyclohexanol, fluorinated hydrocarbon compounds, 1,3 , 5-trioxane (alias: metaformaldehyde), camphor (alias: camphor, camphor), naphthalene, iodine, and cyclohexane may be used, or substances other than these may be used.

The solvent is, for example, pure water, IPA, HFE (hydrofluoroether), acetone, PGMEA (propylene glycol monomethyl ether acetate), PGEE (propylene glycol monoethyl ether, 1-ethoxy-2-propanol), ethylene At least one selected from the group consisting of glycol and hydrofluorocarbon may be sufficient.

Hereinafter, an example in which the sublimable substance is camphor and the solvent is any one of IPA, acetone, and PGEE will be described. The vapor pressure of IPA is higher than that of camphor. Similarly, the vapor pressures of acetone and PGEE are higher than those of camphor. The vapor pressure of acetone is higher than the vapor pressure of IPA, and the vapor pressure of IPA is higher than the vapor pressure of PGEE. The freezing point of camphor (solidification point at 1 atm. The same applies hereafter) is 175 ~ 177 ℃. Even if the solvent is any one of IPA, acetone, and PGEE, the coagulation point of camphor is higher than the boiling point of the solvent. The freezing point of camphor is higher than that of the dry pretreatment solution. The freezing point of the drying pretreatment liquid is lower than room temperature (a value of 23° C. or its vicinity). The substrate processing apparatus 1 is arranged in a clean room maintained at room temperature. Therefore, even if the drying pretreatment liquid is not heated, the drying pretreatment liquid can be maintained as a liquid. The solidification point of the drying pretreatment liquid may be room temperature or more.

As will be described later, the replacement liquid is supplied to the upper surface of the substrate W covered with the liquid film of the rinsing liquid, and the drying pretreatment liquid is supplied to the upper surface of the substrate W covered with the liquid film of the replacement liquid. The replacement liquid is a liquid that melts with both the rinse liquid and the dry pretreatment liquid. Substitutes are, for example, IPA or HFE. The replacement liquid may be a mixture of IPA and HFE, or may contain at least one of IPA and HFE and components other than these. IPA and HFE are liquids that mix with both water and fluorinated hydrocarbon compounds.

When the replacement liquid is supplied to the upper surface of the substrate W covered with the liquid film of the rinse liquid, most of the rinse liquid on the substrate W is pushed out by the replacement liquid and discharged from the substrate W. The remaining trace amount of the rinse solution is dissolved in the replacement solution and diffuses into the replacement solution. The diffused rinse liquid is discharged from the substrate W together with the replacement liquid. Accordingly, the rinsing solution on the substrate W can be efficiently replaced with the replacement solution. For the same reason, the replacement liquid on the substrate W can be efficiently replaced with the drying pretreatment liquid. Thereby, the rinse liquid contained in the drying pretreatment liquid on the board|substrate W can be reduced.

The dry pretreatment liquid nozzle 39 is connected to a nozzle moving unit 42 that moves the dry pretreatment liquid nozzle 39 in at least one of a vertical direction and a horizontal direction. The nozzle moving unit 42 includes a processing position where the dry pretreatment liquid discharged from the drying pretreatment liquid nozzle 39 is supplied to the upper surface of the substrate W, and a treatment cup ( 21), the drying pretreatment liquid nozzle 39 is moved horizontally between the standby positions located on the periphery.

Similarly, the replacement liquid nozzle 43 is connected to the nozzle moving unit 46 which moves the replacement liquid nozzle 43 in at least one of a vertical direction and a horizontal direction. The nozzle moving unit 46 includes a processing position at which the replacement liquid discharged from the replacement liquid nozzle 43 is supplied to the upper surface of the substrate W, and the replacement liquid nozzle 43 of the treatment cup 21 in plan view. The replacement liquid nozzle 43 is moved horizontally between the standby positions located on the periphery.

The processing unit 2 includes a blocking member 51 disposed above the spin chuck 10 . 2 shows an example in which the blocking member 51 is a disk-shaped blocking plate. The blocking member 51 includes a disk portion 52 horizontally disposed above the spin chuck 10 . The blocking member 51 is horizontally supported by a cylindrical support shaft 53 extending upwardly from the central portion of the disk portion 52 . The center line of the disk part 52 is arrange|positioned on the rotation axis line A1 of the board|substrate W. As shown in FIG. The lower surface of the disk part 52 corresponds to the lower surface 51L of the blocking member 51 . The lower surface 51L of the blocking member 51 is an opposing surface facing the upper surface of the substrate W. As shown in FIG. The lower surface 51L of the blocking member 51 is parallel to the upper surface of the substrate W, and has an outer diameter equal to or larger than the diameter of the substrate W.

The blocking member 51 is connected to a blocking member raising/lowering unit 54 that vertically elevates and lowers the blocking member 51 . The blocking member raising/lowering unit 54 positions the blocking member 51 at any position from the upper position (the position shown in FIG. 2 ) to the lower position. In the lower position, the lower surface 51L of the blocking member 51 is on the upper surface of the substrate W to a height at which a scan nozzle such as the chemical liquid nozzle 31 cannot enter between the substrate W and the blocking member 51. It is a close proximity location. The upper position is a spaced apart position where the blocking member 51 is retracted to a height at which the scan nozzle can enter between the blocking member 51 and the substrate W.

The plurality of nozzles include a central nozzle 55 that discharges a processing fluid such as a processing liquid or a processing gas downward through an upper central opening 61 that is opened from the central portion of the lower surface 51L of the blocking member 51 . . The center nozzle 55 extends vertically along the rotation axis A1. The central nozzle 55 is disposed in a through hole penetrating the central portion of the blocking member 51 up and down. The inner peripheral surface of the blocking member 51 surrounds the outer peripheral surface of the central nozzle 55 at intervals in the radial direction (direction orthogonal to the rotation axis A1). The center nozzle 55 moves up and down together with the blocking member 51 . The discharge port of the central nozzle 55 for discharging the processing liquid is disposed above the upper central opening 61 of the blocking member 51 .

The center nozzle 55 is connected to the upper gas pipe 56 which guides the inert gas to the center nozzle 55 . The substrate processing apparatus 1 may be provided with the upper temperature controller 59 which heats or cools the inert gas discharged from the center nozzle 55 . When the upper gas valve 57 interposed in the upper gas pipe 56 is opened, the inert gas is discharged at a flow rate corresponding to the opening degree of the flow rate control valve 58 that changes the flow rate of the inert gas, the outlet of the central nozzle 55 . It is continuously discharged downward from the The inert gas discharged from the center nozzle 55 is nitrogen gas. The inert gas may be a gas other than nitrogen gas such as helium gas or argon gas.

The inner peripheral surface of the blocking member 51 and the outer peripheral surface of the center nozzle 55 form a cylindrical upper gas flow path 62 extending vertically. The upper gas flow path 62 is connected to an upper gas pipe 63 that leads the inert gas to the upper central opening 61 of the blocking member 51 . The substrate processing apparatus 1 may include an upper temperature controller 66 that heats or cools the inert gas discharged from the upper central opening 61 of the blocking member 51 . When the upper gas valve 64 interposed in the upper gas pipe 63 is opened, the inert gas is supplied to the upper side of the shut-off member 51 at a flow rate corresponding to the opening degree of the flow control valve 65 that changes the flow rate of the inert gas. It is continuously discharged downward from the central opening 61 . The inert gas discharged from the upper central opening 61 of the blocking member 51 is nitrogen gas. The inert gas may be a gas other than nitrogen gas such as helium gas or argon gas.

The plurality of nozzles include a lower surface nozzle 71 that discharges the processing liquid toward the center of the lower surface of the substrate W. The lower surface nozzle 71 includes a nozzle disk portion disposed between the upper surface 12u of the spin base 12 and the lower surface of the substrate W, and a nozzle cylindrical portion extending downward from the nozzle disk portion. The discharge port of the lower surface nozzle 71 is opened in the upper surface center part of the nozzle disc part. When the substrate W is held by the spin chuck 10 , the discharge port of the lower surface nozzle 71 faces the center portion of the lower surface of the substrate W up and down.

The lower surface nozzle 71 is connected to the heating fluid pipe 72 which guides the lower surface nozzle 71 to hot water (pure water hotter than room temperature) which is an example of a heating fluid. The pure water supplied to the lower surface nozzle 71 is heated by the lower heater 75 interposed in the heating fluid pipe 72 . When the heating fluid valve 73 interposed in the heating fluid pipe 72 is opened, the hot water flows upward from the discharge port of the lower surface nozzle 71 at a flow rate corresponding to the opening degree of the flow rate control valve 74 that changes the flow rate of the hot water. is continuously discharged. Thereby, hot water is supplied to the lower surface of the board|substrate W.

The lower surface nozzle 71 is further connected to a cooling fluid pipe 76 that guides cold water (pure water at a lower temperature than room temperature), which is an example of the cooling fluid, to the lower surface nozzle 71 . The pure water supplied to the lower surface nozzle 71 is cooled by the cooler 79 interposed in the cooling fluid pipe 76 . When the cooling fluid valve 77 interposed in the cooling fluid pipe 76 is opened, the cold water flows upward from the discharge port of the lower surface nozzle 71 at a flow rate corresponding to the opening degree of the flow control valve 78 for changing the flow rate of the cold water. is continuously discharged. Thereby, cold water is supplied to the lower surface of the board|substrate W.

The outer peripheral surface of the lower surface nozzle 71 and the inner peripheral surface of the spin base 12 form a cylindrical lower gas flow path 82 extending vertically. The lower gas flow path 82 includes a lower central opening 81 that opens at the central portion of the upper surface 12u of the spin base 12 . The lower gas flow path 82 is connected to a lower gas pipe 83 that leads the inert gas to the lower central opening 81 of the spin base 12 . The substrate processing apparatus 1 may include a lower temperature controller 86 that heats or cools the inert gas discharged from the lower central opening 81 of the spin base 12 . When the lower gas valve 84 interposed in the lower gas pipe 83 is opened, the inert gas is supplied to the lower side of the spin base 12 at a flow rate corresponding to the opening degree of the flow control valve 85 that changes the flow rate of the inert gas. It is continuously discharged upward from the central opening 81 .

The inert gas discharged from the lower central opening 81 of the spin base 12 is nitrogen gas. The inert gas may be a gas other than nitrogen gas such as helium gas or argon gas. When the substrate W is held by the spin chuck 10 , when the lower central opening 81 of the spin base 12 discharges nitrogen gas, the nitrogen gas is transferred to the lower surface of the substrate W and the spin base 12 . ) flows radially in all directions between the upper surface 12u. Thereby, the space between the substrate W and the spin base 12 is filled with nitrogen gas.

Next, the drying pretreatment liquid supply unit is demonstrated.

3 is a schematic diagram illustrating a dry pretreatment liquid supply unit provided in the substrate processing apparatus 1 .

The substrate processing apparatus 1 includes a dry pretreatment liquid supply unit that supplies the dry pretreatment liquid to the dry pretreatment liquid nozzle 39 through the dry pretreatment liquid pipe 40 .

The dry pretreatment liquid supply unit includes a first tank 87A for storing the dry pretreatment liquid, a first circulation pipe 88A for circulating the dry pretreatment liquid in the first tank 87A, and a first tank 87A within the first tank 87A. A first pump 89A for sending the dry pretreatment liquid to the first circulation pipe 88A, and a first individual pipe 90A for guiding the dry pretreatment liquid in the first circulation pipe 88A to the dry pretreatment liquid pipe 40 ) includes The dry pretreatment liquid supply unit further includes a first on/off valve 91A for opening and closing the inside of the first individual pipe 90A, and a pre-drying treatment liquid supplied from the first individual pipe 90A to the dry pretreatment liquid pipe 40 . A first flow rate control valve 92A for changing the flow rate of the liquid is included.

The dry pretreatment liquid supply unit includes a second tank 87B for storing the dry pretreatment liquid, a second circulation pipe 88B for circulating the dry pretreatment liquid in the second tank 87B, and a second tank 87B. A second pump 89B for sending the dry pretreatment liquid to the second circulation pipe 88B, and a second individual pipe 90B for guiding the dry pretreatment liquid in the second circulation pipe 88B to the dry pretreatment liquid pipe 40 ) includes The drying pretreatment liquid supply unit further includes a second on-off valve 91B for opening and closing the inside of the second individual pipe 90B, and a pre-drying treatment liquid supplied from the second individual pipe 90B to the dry pretreatment liquid pipe 40 . A second flow control valve 92B for changing the flow rate of the liquid is included.

The concentration of the dry pretreatment liquid in the first tank 87A (concentration of the sublimable substance contained in the dry pretreatment liquid) is different from the concentration of the dry pretreatment liquid in the second tank 87B. Therefore, when the first on/off valve 91A and the second on/off valve 91B are opened, the dry pretreatment liquids having different concentrations are mixed with each other in the drying pretreatment liquid pipe 40, and the uniformly mixed dry pretreatment liquid is dried pretreatment It is discharged from the liquid nozzle (39). In addition, when the opening degree of at least one of the 1st flow control valve 92A and the 2nd flow control valve 92B is changed, the density|concentration of the dry pretreatment liquid discharged from the dry pretreatment liquid nozzle 39 is changed.

The control device 3 is a first on/off valve 91A, a second on/off valve 91B, a first flow control valve 92A, and a second flow rate based on the concentration of the dry pretreatment liquid specified in a recipe to be described later. The opening degree of the regulating valve 92B is set. For example, when the concentration of the dry pretreatment liquid specified in the recipe matches the concentration of the dry pretreatment liquid in the first tank 87A, the first on-off valve 91A is opened and the second on-off valve 91B is opened. is closed When the concentration of the dry pretreatment liquid specified in the recipe is between the concentration of the dry pretreatment liquid in the first tank 87A and the concentration of the dry pretreatment liquid in the second tank 87B, the first on-off valve 91A and the second Both of the 2 on-off valves 91B are opened, and the opening degree of the 1st flow control valve 92A and the 2nd flow control valve 92B is adjusted. Thereby, the density|concentration of the dry pretreatment liquid discharged from the drying pretreatment liquid nozzle 39 approaches the density|concentration of the dry pretreatment liquid designated by the recipe.

4 is a block diagram showing hardware of the control device 3 .

The control device 3 is a computer including a computer main body 3a and a peripheral device 3b connected to the computer main body 3a. The computer main body 3a includes a CPU 93 (central processing unit) that executes various instructions and a main memory 94 that stores information. The peripheral device 3b includes an auxiliary storage device 95 for storing information such as a program P, a reading device 96 for reading information from the removable medium M, and other devices such as a host computer and the like. and a communication device 97 for communicating.

The control device 3 is connected to the input device 98 and the display device 99 . The input device 98 is operated when an operator such as a user or a person in charge of maintenance inputs information into the substrate processing apparatus 1 . The information is displayed on the screen of the display device 99 . The input device 98 may be any one of a keyboard, a pointing device, and a touch panel, or devices other than these. A touch panel display serving as the input device 98 and the display device 99 may be provided in the substrate processing apparatus 1 .

The CPU 93 executes the program P stored in the auxiliary storage device 95 . The program P in the auxiliary storage device 95 may be pre-installed in the control device 3 or sent to the auxiliary storage device 95 from the removable medium M through the reading device 96 . Alternatively, it may be transmitted from an external device such as a host computer to the auxiliary storage device 95 via the communication device 97 .

The auxiliary storage device 95 and the removable medium M are nonvolatile memories that hold storage even when power is not supplied. The auxiliary storage device 95 is, for example, a magnetic storage device such as a hard disk drive. The removable medium M is, for example, an optical disk such as a compact disk or a semiconductor memory such as a memory card. The removable medium M is an example of a computer-readable recording medium in which the program P is recorded. The removable medium M is a non-transitory tangible recording medium.

The auxiliary storage device 95 stores a plurality of recipes. A recipe is information which prescribes|regulates the process content of the board|substrate W, process conditions, and a process sequence. A plurality of recipes differ from each other in at least one of the processing contents of the substrate W, processing conditions, and processing order. The control apparatus 3 controls the substrate processing apparatus 1 so that the board|substrate W is processed according to the recipe designated by the host computer. Each of the following processes is performed when the control apparatus 3 controls the substrate processing apparatus 1 . In other words, the control device 3 is programmed to execute each of the following steps.

Next, an example of the processing of the substrate W according to the first embodiment will be described.

The substrate W to be processed is, for example, a semiconductor wafer such as a silicon wafer. The surface of the board|substrate W corresponds to the device formation surface in which devices, such as a transistor and a capacitor, are formed. The substrate W may be a substrate W in which a pattern P1 (refer to FIG. 6A) is formed on the surface of the substrate W, which is a pattern formation surface, or the pattern P1 is formed on the surface of the substrate W, It may be the board|substrate W which is not present. In the latter case, the pattern P1 may be formed in a chemical solution supply process described later.

5 : is a process chart for demonstrating an example of the process of the board|substrate W which concerns on 1st Embodiment. 6A to 6C are schematic diagrams showing the state of the substrate W when the processing of the substrate W shown in FIG. 5 is being performed.

In the following, reference is made to FIGS. 2 and 5 . 6A to 6C are referred to as appropriate.

When the board|substrate W is processed by the substrate processing apparatus 1, the carrying-in process (step S1 of FIG. 5) of carrying in the board|substrate W into the chamber 4 is performed.

Specifically, in a state in which the blocking member 51 is located at the upper position, all the guards 24 are located at the lower position, and all the scan nozzles are located at the standby position, the center robot CR (refer to FIG. 1 ) ) moves the hand H1 into the chamber 4 while supporting the substrate W with the hand H1. Then, the center robot CR places the substrate W on the hand H1 on the plurality of chuck pins 11 with the surface of the substrate W facing upward. Thereafter, the plurality of chuck pins 11 are pressed against the outer peripheral surface of the substrate W, and the substrate W is gripped. The center robot CR places the substrate W on the spin chuck 10 and then withdraws the hand H1 from the inside of the chamber 4 .

Next, the upper gas valve 64 and the lower gas valve 84 are opened, and the upper central opening 61 of the shut-off member 51 and the lower central opening 81 of the spin base 12 control the discharge of nitrogen gas. start Thereby, the space between the substrate W and the blocking member 51 is filled with nitrogen gas. Similarly, the space between the substrate W and the spin base 12 is filled with nitrogen gas. On the other hand, the guard lifting unit 27 raises the at least one guard 24 from the lower position to the upper position. Thereafter, the spin motor 14 is driven to start the rotation of the substrate W (step S2 in Fig. 5). Thereby, the substrate W rotates at the liquid supply speed.

Next, a chemical solution supply process (step S3 in FIG. 5 ) of supplying a chemical solution to the upper surface of the substrate W and forming a chemical liquid film covering the entire upper surface of the substrate W is performed.

Specifically, in a state in which the blocking member 51 is positioned at the upper position and the at least one guard 24 is positioned at the upper position, the nozzle moving unit 34 moves the chemical liquid nozzle 31 from the standby position to the processing position. move to Thereafter, the chemical liquid valve 33 is opened, and the chemical liquid nozzle 31 starts discharging the chemical liquid. When a predetermined time elapses after the chemical liquid valve 33 is opened, the chemical liquid valve 33 is closed and discharge of the chemical liquid is stopped. Thereafter, the nozzle moving unit 34 moves the chemical liquid nozzle 31 to the standby position.

The chemical liquid discharged from the chemical liquid nozzle 31 collides with the upper surface of the substrate W rotating at the liquid supply speed, and then flows outward along the upper surface of the substrate W by centrifugal force. Therefore, the chemical liquid is supplied to the entire upper surface of the substrate W, and a liquid film of the chemical that covers the entire upper surface of the substrate W is formed. When the chemical liquid nozzle 31 is discharging the chemical liquid, the nozzle moving unit 34 may move the liquid landing position so that the liquid landing position of the chemical with respect to the upper surface of the substrate W passes through the central portion and the outer peripheral portion. , the liquid landing position may be stopped at the central portion.

Next, a rinse liquid supply process (step S4 in FIG. 5 ) of supplying pure water, which is an example of a rinse liquid, to the upper surface of the substrate W and washing the chemical liquid on the substrate W is performed.

Specifically, in a state in which the blocking member 51 is positioned at the upper position and the at least one guard 24 is positioned at the upper position, the nozzle moving unit 38 processes the rinse liquid nozzle 35 in the standby position. move to position Thereafter, the rinse liquid valve 37 is opened, and the rinse liquid nozzle 35 starts discharging the rinse liquid. Before the discharge of pure water is started, the guard raising/lowering unit 27 may vertically move the at least one guard 24 in order to switch the guard 24 receiving the liquid discharged from the substrate W. When a predetermined time elapses after the rinse liquid valve 37 is opened, the rinse liquid valve 37 is closed, and discharge of the rinse liquid is stopped. Thereafter, the nozzle moving unit 38 moves the rinse liquid nozzle 35 to the standby position.

The pure water discharged from the rinse liquid nozzle 35 collides with the upper surface of the substrate W rotating at the liquid supply speed, and then flows outward along the upper surface of the substrate W by centrifugal force. The chemical liquid on the substrate W is replaced with pure water discharged from the rinse liquid nozzle 35 . Thereby, the liquid film of pure water which covers the whole upper surface of the board|substrate W is formed. When the rinse liquid nozzle 35 is discharging pure water, the nozzle moving unit 38 may move the liquid landing position so that the liquid landing position of the pure water with respect to the upper surface of the substrate W passes through the central portion and the outer peripheral portion, or from the central portion The liquid landing position may be stopped.

Next, a replacement solution supply process (step S5 in FIG. 5 ) of supplying a replacement solution that is fused with both the rinse solution and the drying pretreatment solution to the upper surface of the substrate W, and replacing the pure water on the substrate W with the replacement solution is done

Specifically, in a state in which the blocking member 51 is positioned at the upper position and the at least one guard 24 is positioned at the upper position, the nozzle moving unit 46 processes the replacement liquid nozzle 43 in the standby position. move to position Thereafter, the replacement liquid valve 45 is opened, and the replacement liquid nozzle 43 starts discharging the replacement liquid. Before the discharging of the replacement liquid is started, the guard raising/lowering unit 27 may vertically move the at least one guard 24 in order to switch the guard 24 that receives the liquid discharged from the substrate W. When a predetermined time elapses after the replacement liquid valve 45 is opened, the replacement liquid valve 45 is closed and discharge of the replacement liquid is stopped. Thereafter, the nozzle moving unit 46 moves the replacement liquid nozzle 43 to the standby position.

The replacement liquid discharged from the replacement liquid nozzle 43 collides with the upper surface of the substrate W rotating at the liquid supply speed, and then flows outward along the upper surface of the substrate W by centrifugal force. The pure water on the substrate W is replaced with the replacement liquid discharged from the replacement liquid nozzle 43 . Thereby, the liquid film of the substitution liquid which covers the whole upper surface of the board|substrate W is formed. When the replacement liquid nozzle 43 is discharging the replacement liquid, the nozzle moving unit 46 may move the liquid landing position so that the liquid landing position of the replacement liquid with respect to the upper surface of the substrate W passes through the central portion and the outer peripheral portion, You may stop the liquid landing position in the center part. In addition, after the liquid film of the replacement liquid covering the entire upper surface of the substrate W is formed, while the discharge of the replacement liquid to the replacement liquid nozzle 43 is stopped, the substrate W is moved at a paddle speed (for example, 20 rpm exceeding 0) It may be rotated at the following speed).

Next, a drying pretreatment liquid supply process (step S6 in FIG. 5 ) of supplying the drying pretreatment liquid to the upper surface of the substrate W and forming a liquid film of the drying pretreatment liquid on the substrate W is performed.

Specifically, in a state in which the blocking member 51 is positioned at the upper position and the at least one guard 24 is positioned at the upper position, the nozzle moving unit 42 moves the drying pretreatment liquid nozzle 39 from the standby position. move to the processing position. After that, the drying pretreatment liquid valve 41 is opened, and the drying pretreatment liquid nozzle 39 starts discharging the drying pretreatment liquid. Before the discharge of the drying pretreatment liquid is started, the guard lifting unit 27 may vertically move the at least one guard 24 in order to switch the guard 24 receiving the liquid discharged from the substrate W. . When a predetermined time elapses after the drying pretreatment liquid valve 41 is opened, the drying pretreatment liquid valve 41 is closed, and discharging of the drying pretreatment liquid is stopped. Thereafter, the nozzle moving unit 42 moves the drying pretreatment liquid nozzle 39 to the standby position.

The dry pretreatment liquid discharged from the drying pretreatment liquid nozzle 39 collides with the upper surface of the substrate W rotating at the liquid supply speed, and then flows outward along the upper surface of the substrate W by centrifugal force. The replacement liquid on the substrate W is replaced with the dry pretreatment liquid discharged from the dry pretreatment liquid nozzle 39 . Thereby, the liquid film of the drying pretreatment liquid which covers the whole upper surface of the board|substrate W is formed. When the drying pretreatment liquid nozzle 39 is discharging the drying pretreatment liquid, the nozzle moving unit 42 moves the liquid landing position so that the liquid landing position of the dry pretreatment liquid with respect to the upper surface of the substrate W passes through the central portion and the outer peripheral portion. You may make it make it, and you may stop the liquid landing position in the center part.

Next, a part of the drying pretreatment liquid on the substrate W is removed, and while maintaining the state in which the entire upper surface of the substrate W is covered with the liquid film of the drying pretreatment liquid, the film thickness (liquid film) of the drying pretreatment liquid on the substrate W A film thickness reduction process (step S7 in FIG. 5) of reducing the thickness of .

Specifically, in the state where the blocking member 51 is located at the lower position, the spin motor 14 maintains the rotation speed of the substrate W at the film thickness reduction speed. The film thickness reduction rate may be the same as or different from the liquid supply rate. The drying pretreatment liquid on the substrate W is discharged outward from the substrate W by centrifugal force even after the discharge of the drying pretreatment liquid is stopped. Therefore, the thickness of the liquid film of the drying pretreatment liquid on the board|substrate W reduces. When the drying pretreatment liquid on the substrate W is discharged to a certain extent, the discharge amount of the drying pretreatment liquid from the substrate W per unit time is reduced to zero or substantially zero. Thereby, the thickness of the liquid film of the drying pretreatment liquid on the substrate W is stabilized at a value corresponding to the rotation speed of the substrate W.

Next, a solidified body forming process (step in FIG. 5) of solidifying the dry pretreatment liquid on the substrate W, and forming a solidifying body 101 (refer to FIG. 6b ) containing a sublimable material on the substrate W S8) is performed.

Specifically, in a state in which the blocking member 51 is positioned at the lower position, the spin motor 14 maintains the rotational speed of the substrate W as the solidified body formation speed. The solidified body formation rate may be the same as or different from the liquid supply rate. Further, the upper gas valve 57 is opened to start discharging nitrogen gas to the center nozzle 55 . In addition to or instead of opening the upper gas valve 57 , the opening degree of the flow control valve 65 may be changed to increase the flow rate of the nitrogen gas discharged from the upper central opening 61 of the shut-off member 51 .

When the rotation of the substrate W at the rate of solidification is started, evaporation of the drying pretreatment liquid is accelerated, and a part of the drying pretreatment liquid on the substrate W is evaporated. Since the vapor pressure of the solvent is higher than the vapor pressure of the sublimable material corresponding to the solute, the solvent evaporates at an evaporation rate greater than the evaporation rate of the sublimable material. Accordingly, while the concentration of the sublimable substance is gradually increased, the film thickness of the drying pretreatment solution is gradually decreased. The freezing point of the drying pretreatment liquid rises with an increase in the concentration of the sublimable substance. As can be seen by comparing FIGS. 6A and 6B , when the freezing point of the drying pretreatment liquid reaches the temperature of the drying pretreatment liquid, solidification of the drying pretreatment liquid starts, and the solidification film covering the entire upper surface of the substrate W A corresponding solidified body 101 is formed.

Next, a sublimation process (step S9 in Fig. 5) of sublimating the solidified body 101 on the substrate W and removing it from the upper surface of the substrate W is performed.

Specifically, in the state where the blocking member 51 is located at the lower position, the spin motor 14 maintains the rotation speed of the substrate W at the sublimation speed. The sublimation rate may be the same as or different from the liquid supply rate. In addition, when the upper gas valve 57 is closed, the upper gas valve 57 is opened, and the discharge of nitrogen gas to the center nozzle 55 is started. In addition to or instead of opening the upper gas valve 57 , the opening degree of the flow control valve 65 may be changed to increase the flow rate of the nitrogen gas discharged from the upper central opening 61 of the shut-off member 51 . When a predetermined time elapses after the rotation of the substrate W at the sublimation speed is started, the spin motor 14 stops and the rotation of the substrate W is stopped (step S10 in Fig. 5).

When the rotation of the substrate W at the sublimation rate, etc. is started, the sublimation of the solidified body 101 on the substrate W starts, and the gas containing the sublimable material is transferred to the solidified body 101 on the substrate W. arises from The gas (gas containing a sublimable substance) generated from the solidified body 101 radially flows through the space between the substrate W and the blocking member 51 , and is discharged from above the substrate W . And when a certain amount of time passes after the start of sublimation, as shown in FIG. 6C, all the solidified bodies 101 are removed from the board|substrate W. As shown in FIG.

Next, the carrying-out process (step S11 in FIG. 5) of carrying out the board|substrate W from the chamber 4 is performed.

Specifically, the blocking member lifting unit 54 raises the blocking member 51 to the upper position, and the guard lifting unit 27 lowers all the guards 24 to the lower position. Further, the upper gas valve 64 and the lower gas valve 84 are closed, and the upper central opening 61 of the blocking member 51 and the lower central opening 81 of the spin base 12 prevent nitrogen gas from being discharged. stop Thereafter, the center robot CR moves the hand H1 into the chamber 4 . The center robot CR supports the substrate W on the spin chuck 10 with the hand H1 after the plurality of chuck pins 11 release the grip of the substrate W. Thereafter, the center robot CR retracts the hand H1 from the inside of the chamber 4 while supporting the substrate W with the hand H1 . Thereby, the processed board|substrate W is carried out from the chamber 4 .

7 is a graph showing an example of an image in which the thickness of the liquid film of the drying pretreatment liquid on the substrate W is reduced by evaporation of the solvent.

In FIG. 7 , the thickness of the liquid film when the initial concentration of the sublimable material is a reference concentration is indicated by a solid line, and the thickness of the liquid film when the initial concentration of the sublimable material is low is indicated by a dashed-dotted line, and the sublimable material The thickness of the liquid film when the initial concentration of is high is shown by the dashed-dotted line. The reference concentration is higher than the low concentration and lower than the high concentration. The initial concentration of the sublimable substance means the concentration of the sublimable substance in the drying pretreatment solution before being supplied to the substrate W.

If the concentration of the sublimable substance in the drying pretreatment liquid is the same, the thickness T1 (refer to FIG. 6B ) of the solidified body 101 formed on the substrate W is It depends on the film thickness (thickness of the liquid film) of the drying pretreatment liquid. That is, when the film thickness of the drying pretreatment liquid is large, a thick solidified body 101 is formed, and when the film thickness of the drying pretreatment liquid is small, a thin solidified body 101 is formed. Therefore, by changing the film thickness of the drying pretreatment liquid, the thickness (T1) of the solidified body 101 can be changed.

When the rotation speed of the substrate W is increased, the drying pretreatment liquid is discharged from the substrate W by centrifugal force, and the film thickness of the drying pretreatment liquid on the substrate W is reduced. At this time, when the gas is discharged toward the upper surface of the substrate W, the pressure of the gas is applied to the drying pretreatment liquid, and the film thickness of the drying pretreatment liquid on the substrate W is further reduced. However, if the film thickness is reduced to a certain extent, the flow rate in the liquid film is extremely reduced. Therefore, even if the rotation speed or the gas flow rate is increased, the film thickness does not change significantly. Conversely, if the rotational speed or the flow rate of the gas is too large, the upper surface of the substrate W is partially exposed from the liquid film.

Therefore, even if the rotation speed of the substrate W or the flow rate of the gas is changed, the film thickness of the drying pretreatment liquid before forming the solidified body 101 cannot be extremely thin, and the extremely thin solidified body 101 cannot be formed. can't Therefore, an extremely thin solidified body 101 (for example, a solidified body 101 of 1 μm or less having a thickness exceeding 0) covering the entire upper surface of the substrate W is formed, or an ultra-thin range (for example, For example, in the case of changing the thickness T1 of the solidified body 101 within the range of 1 µm or less exceeding 0), the initial concentration of the sublimable substance must be changed.

7 , the film thickness of the drying pretreatment solution before evaporating the solvent is constant regardless of the initial concentration of the sublimable substance. Moreover, as shown in FIG. 7, if the temperature of the drying pretreatment liquid is the same, the concentration of the sublimable substance when the precipitation of the solidified body 101 starts is constant regardless of the initial concentration of the sublimable substance. When the solvent is evaporated to form the solidified body 101, the concentration of the sublimable material is gradually increased, and the film thickness of the drying pretreatment solution is gradually decreased. The freezing point of the drying pretreatment liquid rises with an increase in the concentration of the sublimable substance. When the freezing point of the drying pretreatment liquid reaches the temperature of the drying pretreatment liquid, solidification of the drying pretreatment liquid starts, and a solidified body 101 is formed on the substrate W.

As shown in FIG. 7 , when the initial concentration of the sublimable substance is the reference concentration, the solidified body 101 of the reference thickness Tr is formed. When the initial concentration of the sublimable material is low, since the amount of the sublimable material contained in the drying pretreatment solution is small, the solidified body 101 thinner than the reference thickness Tr is formed. When the initial concentration of the sublimable material is high, since the amount of the sublimable material contained in the drying pretreatment solution is large, the solidified body 101 thicker than the reference thickness Tr is formed. Therefore, by controlling the initial concentration of the sublimable material, it is possible to change the thickness (T1) of the solidified body 101 within the ultra-thin range.

8 is a graph showing an example of the relationship between the initial concentration of the sublimable substance and the thickness T1 of the solidified body 101 . In FIG. 8, vol% has shown the volume percent density|concentration. When the drying pretreatment liquid changes to the solid 101, the color of the material on the substrate W changes from transparent to non-transparent. When the film thickness of the transparent dry pretreatment liquid is measured by spectral interferometry, if the non-transparent solidified body 101 is formed, the measured value changes. The value immediately before this change is shown in FIG. 8 as the thickness T1 of the solidified body 101 .

In Fig. 8, when the initial concentration of the sublimable material is 0.5 vol%, the thickness T1 of the solidified material 101 is about 100 μm, and when the initial concentration of the sublimable material is 1.23 vol%, the solidified material 101 ) had a thickness (T1) of about 200 μm. The initial concentration of the sublimable material and the thickness (T1) of the solidified body 101 are generally in direct proportion, and when the initial concentration of the sublimable material increases, the thickness (T1) of the solidified body 101 is a constant ratio is increasing with Therefore, if the initial concentration of the sublimable material is changed, the thickness T1 of the solidified body 101 can be changed within the ultra-thin range.

9 is a table showing an example of the embedding rate and the collapse rate of the pattern P1 obtained when a plurality of samples in which the pattern P1 having the same shape and strength is formed is processed while changing the initial concentration of camphor. FIG. 10 : is a line graph which shows the relationship between the density|concentration of camphor in FIG. 9, and the collapse rate of the pattern P1.

9 and 10 show the collapse rate of the pattern P1 when the sublimable substance is camphor and the solvent is IPA. In the measurement conditions 1-1 to 1-13 shown in FIGS. 9 and 10 , the conditions other than the initial concentration of camphor are the same. The wt% in FIG. 9 represents the mass percent concentration. This is the same in other figures such as FIG. 14 .

The collapse rate of the pattern P1 is a value obtained by multiplying the ratio of the number of the collapsed patterns P1 to the total number of the patterns P1 by one hundred times. The embedding ratio is a value obtained by multiplying the ratio of the thickness T1 (refer to FIG. 6b) of the solidified body 101 to the height Hp (refer to FIG. 6B) of the pattern P1 by one hundred times. That is, the embedding rate is calculated|required by the formula of ((thickness (T1) of solidified body 101/height (Hp) of pattern P1) x 100).

As shown in the measurement condition 1-1 of FIG. 9 , when the initial concentration of camphor was 0.52 wt%, the collapse rate of the pattern P1 was 83.5%.

As shown in the measurement conditions 1-2 of FIG. 9 , when the initial concentration of camphor was 0.62 wt%, the collapse rate of the pattern P1 was 83.1%.

As shown in the measurement conditions 1-3 of FIG. 9 , when the initial concentration of camphor was 0.69 wt%, the collapse rate of the pattern P1 was 76.2%.

As shown in the measurement conditions 1-4 of FIG. 9, when the initial concentration of camphor was 0.78 wt%, the collapse rate of the pattern P1 was 36.1%.

As shown in the measurement conditions 1-13 of FIG. 9, when the initial concentration of camphor was 7.76 wt%, the collapse rate of the pattern P1 was 91.0%.

As shown in the measurement conditions 1-12 of FIG. 9, when the initial concentration of camphor was 4.03 wt%, the collapse rate of the pattern P1 was 91.7%.

As shown in the measurement conditions 1-11 of FIG. 9, when the initial concentration of camphor was 2.06 wt%, the collapse rate of the pattern P1 was 87.0%.

As shown in the measurement conditions 1-10 of FIG. 9, when the initial concentration of camphor was 1.55 wt%, the collapse rate of the pattern P1 was 46.8%.

As can be seen from FIGS. 9 and 10 , when the initial concentration of camphor increases from 0.62 wt% to 0.69 wt%, the rate of collapse of the pattern P1 is decreasing (measurement condition 1-2 → measurement condition 1). -3). In addition, when the initial concentration of camphor increases from 0.69 wt% to 0.78 wt%, the rate of collapse of the pattern P1 is sharply decreased (measurement condition 1-3 → measurement condition 1-4).

On the other hand, when the initial concentration of camphor decreases from 2.06 wt% to 1.55 wt%, the rate of collapse of the pattern P1 is sharply reduced (measurement condition 1-11 → measurement condition 1-10).

Therefore, the initial concentration of camphor exceeds 0.62 wt%, preferably less than 2.06 wt%, and more preferably 0.78 wt% or more and less than 2.06 wt%.

In the range where the initial concentration of camphor exceeds 0.62 wt% and is less than 2.06 wt%, the collapse rate of the pattern P1 is less than 87.0%.

In the range where the initial concentration of camphor is 0.78 wt% or more and 1.55 wt% or less, the collapse rate of the pattern P1 is 46.8% or less.

In the range where the initial concentration of camphor is 0.89 wt% or more and 1.24 wt% or less, the collapse rate of the pattern P1 is 17.6% or less. The collapse rate of the pattern P1 was the lowest when the initial concentration of camphor was 0.89 wt%, and was 8.32%.

Accordingly, the initial concentration of camphor may be 0.78 wt% or more and 1.55 wt% or less, or 0.89 wt% or more and 1.24 wt% or less.

11 : is a line graph which shows the relationship between the embedding rate in FIG. 9, and the collapse rate of the pattern P1.

As shown in the measurement condition 1-1 of FIG. 9, when the embedding rate was 65%, the collapse rate of the pattern P1 was 83.5%.

As shown in the measurement conditions 1-2 of FIG. 9, when the embedding rate was 76%, the collapse rate of the pattern P1 was 83.1%.

As shown in the measurement conditions 1-3 of FIG. 9, when the embedding rate was 83%, the collapse rate of the pattern P1 was 76.2%.

As shown in the measurement conditions 1-4 of FIG. 9, when the embedding rate was 91 %, the collapse rate of the pattern P1 was 36.1 %.

As shown in the measurement conditions 1-13 of FIG. 9, when the embedding rate was 797 %, the collapse rate of the pattern P1 was 91.0 %.

As shown in the measurement conditions 1-12 of FIG. 9, when the embedding rate was 418 %, the collapse rate of the pattern P1 was 91.7 %.

As shown in the measurement conditions 1-11 of FIG. 9, when the embedding rate was 219%, the collapse rate of the pattern P1 was 87.0%.

As shown in the measurement conditions 1-10 of FIG. 9, when the embedding rate was 168%, the collapse rate of the pattern P1 was 46.8%.

As can be seen from FIGS. 9 and 11 , when the embedding rate is increased from 76% to 83%, the collapse rate of the pattern P1 is decreasing (measurement condition 1-2→measurement condition 1-3). In addition, when the embedding rate is increased from 83% to 91%, the collapse rate of the pattern P1 is rapidly decreasing (measurement condition 1-3 → measurement condition 1-4).

On the other hand, when the embedding rate decreases from 219% to 168%, the collapse rate of the pattern P1 is rapidly decreasing (measurement condition 1-11 → measurement condition 1-10).

Therefore, it is preferable that it is more than 76 %, and it is preferable that it is less than 219 %, and, as for an embedding rate, it is more preferable that they are 83 % or more and less than 219 %.

In the range where the embedding rate exceeds 76% and is less than 219%, the collapse rate of the pattern P1 is less than 87.0%.

In the range where the embedding rate is 91% or more and 168% or less, the collapse rate of the pattern P1 is 46.8% or less.

In the range where the embedding rate is 102% or more and 138% or less, the collapse rate of the pattern P1 is 17.6% or less. The collapse rate of the pattern P1 was the lowest when the embedding rate was 102%, and was 8.32%.

Therefore, 91 % or more and 168 % or less may be sufficient as an embedding rate, and 102 % or more and 138 % or less may be sufficient as it.

As described above, the initial concentration of camphor is preferably greater than 0.62 wt% and less than 2.06 wt%. As shown in Fig. 9, when the initial concentration of camphor is 0.62 wt%, the embedding rate is 76%. When the initial concentration of camphor is 2.06 wt%, the buying rate is 219%. Accordingly, in this example, when the initial concentration of camphor is set to a value within a preferred range, the embedding rate is automatically set to a value within the preferred range.

12A and 12B are schematic diagrams for explaining the mechanism assumed for the phenomenon in which the collapse rate of the pattern P1 increases when the solidified body 101 is too thick. 13A and 13B are schematic diagrams for explaining a mechanism assumed for a phenomenon in which the collapse rate of the pattern P1 increases when the solidified body 101 is too thin.

As shown in FIG. 11, when the solidified body 101 is too thick (when embedding rate is too high), the collapse rate of the pattern P1 will become high. Also, even if the thickness T1 of the solidified body 101 is smaller than the height Hp of the pattern P1, the collapse rate of the pattern P1 may be low, but if the solidified body 101 is too thin (the embedding rate is too low), the rate of collapse of the pattern P1 is high. Hereinafter, a mechanism assumed for such a phenomenon will be described.

First, when the solidification body 101 is too thick, the mechanism assumed for the phenomenon that the collapse rate of the pattern P1 becomes high is demonstrated.

When the evaporation of IPA contained in the drying pretreatment solution proceeds, the concentration of camphor in the drying pretreatment solution gradually increases, and the coagulation point of the drying pretreatment solution gradually rises. When the freezing point of the drying pretreatment liquid reaches the temperature of the drying pretreatment liquid, coagulation of the drying pretreatment liquid starts, and a coagulated body 101 including camphor is formed on the substrate W.

When the embedding rate is 100% or more, that is, when the thickness T1 (refer to FIG. 6b) of the solidified body 101 is greater than or equal to the height Hp (refer to FIG. 6b) of the pattern P1, the solidified 101 is Before formation, the drying pretreatment liquid exists not only between the patterns P1 but also above the patterns P1. In the substrate W, such as a semiconductor wafer, since the space|interval of the adjacent two convex-shaped patterns P1 is narrow, the solidification point of the drying pretreatment liquid located between the patterns P1 falls. Therefore, the freezing point of the drying pretreatment liquid located between the patterns P1 is lower than the freezing point of the drying pretreatment liquid located above the patterns P1.

If the solidification point of the drying pretreatment liquid located above the pattern P1 is higher than the freezing point of the drying pretreatment liquid located between the patterns P1, the solidification of the drying pretreatment liquid starts at a position other than between the patterns P1. . Specifically, as shown in Fig. 12A, the crystal nuclei of camphor are generated in the surface layer of the drying pretreatment solution, that is, in the liquid layer located in the range from the top surface (liquid level) of the drying pretreatment solution to the top surface of the pattern P1. and the crystal nuclei grow gradually. And when a certain amount of time passes, the entire surface layer of the drying pretreatment liquid hardens and becomes the solidified body 101 .

Here, if the solidification point of the dry pretreatment liquid located between the patterns P1 is lower than the freezing point of the dry pretreatment liquid located above the pattern P1, as shown in FIG. In some cases, the drying pretreatment liquid does not solidify and remains liquid. In this case, an interface between a solid (solidified body 101) and a liquid (dry pretreatment liquid) is formed in the vicinity of the pattern P1. 12B shows a state in which an unclear interface of a solid and a liquid is located between the patterns P1.

Solids and liquids have different surface free energies. When an indistinct interface between a solid (solidified body 101) and a liquid (dry pretreatment liquid) is located between the patterns P1, a force due to the Laplace pressure is applied to the pattern P1. At this time, the force applied to the pattern P1 increases as the solidified body 101 thickens. Therefore, when the solidified body 101 is too thick, the collapsing force which collapses the pattern P1 exceeds the intensity|strength of the pattern P1, and the collapse rate of the pattern P1 becomes high. It is considered that the collapse rate of the pattern P1 rises by such a mechanism.

Next, the mechanism assumed for the phenomenon that the collapse rate of the pattern P1 becomes low even when the embedding rate is less than 100% will be described.

When the solidified body 101 is formed, the upper surface (liquid level) of the drying pretreatment liquid gradually approaches the lower end of the pattern P1 as the evaporation of the IPA proceeds. When the thickness T1 of the solidified body 101 is significantly smaller than the height Hp of the pattern P1, as shown in FIG. 13A, before the entire drying pretreatment liquid solidifies, the upper surface of the drying pretreatment liquid is It moves between two adjacent convex-shaped patterns P1. That is, the interface between the gas and the liquid (dry pretreatment liquid) moves between the patterns P1. Therefore, it is considered that the force resulting from the surface tension of the drying pretreatment liquid is applied to the pattern P1, and the pattern P1 collapses. And as shown to FIG. 13B, it is thought that the solidified body 101 is formed in the state which the pattern P1 collapsed.

Even when the thickness T1 of the solidified body 101 is slightly smaller than the height Hp of the pattern P1, it is considered that the interface between the gas and the liquid can move between the patterns P1. However, in this case, it is considered that camphor crystal nuclei have already been formed between the patterns P1, and the crystal nuclei are enlarged to some extent. In this case, the inclination of the pattern P1 is regulated by the large crystal nuclei, and the collapse of the pattern P1 becomes difficult to occur. By such a mechanism, even if the thickness T1 of the solidified body 101 is somewhat smaller than the height Hp of the pattern P1, it is considered that the collapse rate of the pattern P1 is reduced.

As mentioned above, even if the solidified body 101 is too thick or too thin, the collapse rate of the pattern P1 falls. In other words, in reducing the collapse rate of the pattern P1 of the substrate W after drying, the thickness of the solidified body 101 has an appropriate range. For example, when the solidified body 101 is set to a value within the range described with reference to FIG. 9 , the collapse rate of the pattern P1 of the substrate W after drying can be reduced. Thereby, the board|substrate W can be dried, suppressing the collapse rate of the pattern P1.

Next, the measurement result when another sample is used is demonstrated.

14 to 16 are tables showing an example of the collapse rate of the pattern P1 obtained when a plurality of samples in which the pattern P1 having the same shape and strength is formed is processed while changing the initial concentration of camphor.

14 shows the collapse rate of the pattern P1 when the sublimable material is camphor and the solvent is IPA, FIG. 15 shows the pattern P1 when the sublimable material is camphor and the solvent is acetone The rate of collapse is shown, and Fig. 16 shows the rate of collapse of the pattern P1 when the sublimable substance is camphor and the solvent is PGEE.

In the measurement condition 2-1 to the measurement condition 2-5 shown in FIG. 14, the conditions other than the initial concentration of camphor are the same. Similarly, in the measurement condition 3-1 to the measurement condition 3-13 shown in Fig. 15, the conditions other than the initial concentration of camphor are the same, and in the measurement condition 4-1 to the measurement condition 4-8 shown in Fig. 16, camphor Conditions other than the initial concentration of is the same.

In the measurement of FIGS. 14-16, the same sample was used. The intensity of the pattern P1 of the sample used for the measurement of FIGS. 14 to 16 is different from the intensity of the pattern P1 of the sample used for the measurement of FIG. 9 . Therefore, although both of FIGS. 9 and 14 show the collapse rate of the pattern P1 when the sublimable material is camphor and the solvent is IPA, since the strength of the pattern P1 used for measurement is different, the figure It is not possible to simply compare the collapse rates shown in 9 and FIG. 14 .

FIG. 17 : is a line graph which shows the relationship between the density|concentration of camphor in FIG. 14, and the collapse rate of the pattern P1. 18 : is a line graph which shows the relationship between the density|concentration of camphor in FIG. 15, and the collapse rate of the pattern P1. 19 : is a line graph which shows the relationship between the density|concentration of camphor in FIG. 16, and the collapse rate of the pattern P1.

First, with reference to FIGS. 14 and 17, an example of the relationship between the initial concentration of camphor when the solvent is IPA, and the collapse rate of the pattern P1 is demonstrated.

As shown in the measurement condition 2-1 of FIG. 14 , when the initial concentration of camphor was 0.89 wt%, the collapse rate of the pattern P1 was 91.7%.

As shown in the measurement condition 2-2 of FIG. 14 , when the initial concentration of camphor was 0.96 wt%, the collapse rate of the pattern P1 was 58.4%.

As shown in the measurement conditions 2-3 of FIG. 14 , when the initial concentration of camphor was 1.13 wt%, the collapse rate of the pattern P1 was 37.3.

As shown in the measurement conditions 2-4 of FIG. 14 , when the initial concentration of camphor was 1.38 wt%, the collapse rate of the pattern P1 was 50.6%.

As shown in the measurement conditions 2-5 of FIG. 14 , when the initial concentration of camphor was 1.55 wt%, the collapse rate of the pattern P1 was 95.3%.

As can be seen from FIGS. 14 and 17 , when the initial concentration of camphor increases from 0.89 wt% to 0.96 wt%, the rate of collapse of the pattern P1 is sharply decreased (measurement condition 2-1 → measurement). condition 2-2). Even when the initial concentration of camphor decreased from 1.55 wt% to 1.38 wt%, the rate of collapse of the pattern P1 was sharply decreased (measurement condition 2-5 → measurement condition 2-4).

In the range where the initial concentration of camphor is 0.96 wt% or more and 1.38 wt% or less, the collapse rate of the pattern P1 is 58.4% or less. Therefore, when the solvent is IPA, the initial concentration of camphor exceeds 0.89 wt%, preferably less than 1.55 wt%, and more preferably 0.96 wt% or more and 1.38 wt% or less.

Next, an example of the relationship between the initial concentration of camphor when the solvent is acetone and the rate of collapse of the pattern P1 will be described with reference to FIGS. 15 and 18 .

As shown in the measurement condition 3-3 of FIG. 15 , when the initial concentration of camphor was 0.62 wt%, the collapse rate of the pattern P1 was 86.6%.

As shown in the measurement conditions 3-4 of FIG. 15 , when the initial concentration of camphor was 0.69 wt%, the collapse rate of the pattern P1 was 60.2%.

As shown in the measurement conditions 3-9 of FIG. 15 , when the initial concentration of camphor was 1.04 wt%, the collapse rate of the pattern P1 was 99.7%.

As shown in the measurement conditions 3-8 of FIG. 15 , when the initial concentration of camphor was 0.96 wt%, the collapse rate of the pattern P1 was 82.2%.

As shown in the measurement conditions 3-7 of FIG. 15 , when the initial concentration of camphor was 0.89 wt%, the collapse rate of the pattern P1 was 76.4%.

As can be seen from FIGS. 15 and 18 , when the initial concentration of camphor increases from 0.62 wt% to 0.69 wt%, the rate of collapse of the pattern P1 is sharply decreased (measurement condition 3-3 → measurement). condition 3-4). Even when the initial concentration of camphor decreased from 1.04 wt% to 0.96 wt%, the rate of collapse of the pattern P1 rapidly decreased (measurement condition 3-9 → measurement condition 3-8).

However, in the range where the initial concentration of camphor is 0.96 wt% or more and 1.04 wt% or less, the collapse rate of the pattern P1 is not so low. When the initial concentration of camphor decreased from 0.96 wt% to 0.89 wt% (measurement condition 3-8 → measurement condition 3-7), not only the rate of collapse of the pattern (P1) rapidly decreased, but also the pattern (P1) ) is relatively low. Therefore, when the solvent is acetone, the initial concentration of camphor is preferably greater than 0.62 wt% and less than or equal to 0.96 wt%.

Next, with reference to FIGS. 16 and 19, an example of the relationship between the initial concentration of camphor when the solvent is PGEE, and the collapse rate of the pattern P1 is demonstrated.

As shown in the measurement condition 4-3 of FIG. 16, when the initial concentration of camphor was 3.06 wt%, the collapse rate of the pattern P1 was 98.9%.

As shown in the measurement conditions 4-4 of FIG. 16 , when the initial concentration of camphor was 3.55 wt%, the collapse rate of the pattern P1 was 88.3%.

As shown in the measurement conditions 4-5 of FIG. 16, when the initial concentration of camphor was 4.23 wt%, the collapse rate of the pattern P1 was 79.4%.

As shown in the measurement conditions 4-8 of FIG. 16, when the initial concentration of camphor was 9.95 wt%, the collapse rate of the pattern P1 was 99.5%.

As shown in the measurement conditions 4-7 of FIG. 16, when the initial concentration of camphor was 6.86 wt%, the collapse rate of the pattern P1 was 62.1%.

As shown in the measurement conditions 4-6 of FIG. 16, when the initial concentration of camphor was 5.23 wt%, the collapse rate of the pattern P1 was 57.5%.

As can be seen from FIGS. 15 and 18 , when the initial concentration of camphor increases from 3.06 wt% to 3.55 wt% (measurement condition 4-3 → measurement condition 4-4), the collapse rate of the pattern P1 is Although it decreases rapidly, the collapse rate of the pattern P1 is not very low in this range. When the initial concentration of camphor increases from 3.55 wt% to 4.23 wt% (measurement condition 4-4 → measurement condition 4-5), not only the rate of collapse of pattern (P1) is rapidly decreasing, but also pattern (P1) has a relatively low decay rate.

In addition, when the initial concentration of camphor decreases from 9.95 wt% to 6.86 wt% (measurement condition 4-8 → measurement condition 4-7), the collapse rate of the pattern P1 decreases rapidly, but in this range, the pattern The case where the collapse rate of (P1) is not very low is included. That is, when the initial concentration of camphor is around 6.86 wt%, the rate of collapse of the pattern P1 is low, but when the initial concentration of camphor is around 9.95 wt%, the rate of collapse of the pattern P1 is high.

When the initial concentration of camphor decreases from 6.86 wt% to 5.23 wt% (measurement condition 4-7 → measurement condition 4-6), the rate of collapse of the pattern P1 is gradually decreasing. Therefore, when the solvent is PGEE, the initial concentration of camphor is preferably greater than 3.55 wt% and not more than 6.86 wt%.

Fig. 20 is a graph in which the broken lines of Figs. 17 to 19 are superimposed. In FIG. 20, the broken line IPA of FIG. 17 is shown with a solid line, the broken line (acetone) of FIG. 18 is shown with a broken line, and the broken line PGEE of FIG. 19 is shown with the dashed-dotted line.

When the solvent was IPA, when the initial concentration of camphor was 1.13 wt%, the collapse rate of the pattern (P1) was the lowest and was 37.3% (measurement condition 2-3).

When the solvent was acetone, when the initial concentration of camphor was 0.78 wt%, the collapse rate of the pattern (P1) was the lowest and was 57.6% (measurement conditions 3-5).

When the solvent was PGEE, when the initial concentration of camphor was 5.23 wt%, the collapse rate of the pattern (P1) was the lowest and was 57.5% (measurement conditions 4-6).

In other words, the initial concentration of camphor when the collapse rate of the pattern P1 is lowest is 0.78 wt % when the solvent is acetone, 1.13 wt % when the solvent is IPA, and 5.23 when the solvent is PGEE. wt%. Comparing with attention to these solvents, the initial concentration of camphor when the collapse rate of the pattern P1 is lowest increases as the vapor pressure of the solvent decreases. That is, if the solvent is easily evaporated, the concentration of the sublimable substance contained in the drying pretreatment liquid is not necessarily high. Conversely, if the solvent is difficult to evaporate, the concentration of the sublimable substance contained in the drying pretreatment liquid needs to be high.

In the present invention, by evaporating the solvent from the drying pretreatment liquid, it is necessary to form the solidified body 101 including the sublimable material on the surface of the substrate W, for example, depending on the vapor pressure of the sublimable material. You may perform the process of selecting

As described above, according to the measurement result of FIG. 9 , when the initial concentration of camphor is set to a value within a preferred range, the embedding rate is automatically set to a value within the preferred range. Therefore, also in the measurement of Figs. 14 to 16, if the initial concentration of camphor is set to a value within a preferred range, it is considered that the embedding rate is automatically set to a value within the preferred range. It is considered that the collapse rate of the pattern P1 fell by this.

However, depending on the shape and strength of the pattern P1, even if the initial concentration of camphor is set to a value within a preferable range, it is considered that the embedding rate is not necessarily set to a value within a preferable range. Similarly, depending on the shape and strength of the pattern P1, even if the embedding rate is set to a value within a preferred range, it is considered that the initial concentration of camphor is not necessarily set to a value within a preferred range.

As described above, in the first embodiment, a drying pretreatment liquid containing a sublimable substance and a solvent corresponding to a solute is supplied to the surface of the substrate W on which the pattern P1 is formed. Then, the solvent is evaporated from the dry pretreatment solution. Thereby, the solidified body 101 containing the sublimable substance is formed on the surface of the substrate W. Thereafter, the solidified body 101 on the substrate W is changed into a gas without passing through the liquid. Thereby, the solidified body 101 is removed from the surface of the substrate W. Therefore, compared with the conventional drying method, such as spin drying, the collapse rate of the pattern P1 can be reduced.

When the solvent is evaporated from the dry pretreatment solution, a solidified body 101 including a sublimable material is formed on the surface of the substrate (W). The embedding rate at the time of formation of the solidified body 101 exceeds 76 and is less than 219. As mentioned above, when the embedding rate is outside this range, the number of collapses of the pattern P1 will increase depending on the intensity|strength of the pattern P1. Conversely, when the embedding ratio is within this range, even if the strength of the pattern P1 is low, the number of collapses of the pattern P1 can be reduced. Therefore, even if the intensity|strength of the pattern P1 is low, the collapse rate of the pattern P1 can be reduced.

Next, the second embodiment will be described.

The main difference between the second embodiment and the first embodiment is that, in addition to the sublimable material and the solvent, the adsorbent material is included in the drying pretreatment liquid.

In the following FIGS. 21-23F, about the structure equivalent to the structure shown in FIGS. 1-20, the same reference numerals as in FIG. 1 are attached, and the description thereof is omitted.

21 is a schematic diagram horizontally viewed inside the processing unit 2 provided in the substrate processing apparatus 1 according to the second embodiment.

The plurality of nozzles of the processing unit 2 is a second chemical liquid nozzle 31b that discharges a chemical liquid different in kind from the chemical liquid discharged from the chemical liquid nozzle 31 corresponding to the first chemical liquid nozzle toward the upper surface of the substrate W. ) are further provided. The second chemical liquid nozzle 31b may be a horizontally movable scan nozzle in the chamber 4 or a fixed nozzle fixed to the partition 5 of the chamber 4 . 21 shows an example in which the second chemical liquid nozzle 31b is a scan nozzle.

The second chemical liquid nozzle 31b is connected to a second chemical liquid pipe 32b that guides the chemical liquid to the second chemical liquid nozzle 31b. When the second chemical liquid valve 33b interposed in the second chemical liquid pipe 32b is opened, the chemical is continuously discharged downward from the discharge port of the second chemical liquid nozzle 31b. If the type is different from the chemical liquid discharged from the chemical liquid nozzle 31, the chemical liquid discharged from the second chemical liquid nozzle 31b is sulfuric acid, nitric acid, hydrochloric acid, hydrofluoric acid, phosphoric acid, acetic acid, ammonia water, hydrogen peroxide solution, organic acid (eg, For example, a liquid containing at least one of citric acid, oxalic acid, etc.), an organic alkali (eg, TMAH: tetramethylammonium hydroxide, etc.), a surfactant, and a corrosion inhibitor, or a liquid other than this may be used.

The second chemical liquid nozzle 31b is connected to a nozzle moving unit 34b that moves the second chemical liquid nozzle 31b in at least one of a vertical direction and a horizontal direction. The nozzle moving unit 34b includes a processing position at which the chemical liquid discharged from the second chemical liquid nozzle 31b is supplied to the upper surface of the substrate W, and a processing cup 21 when the second chemical liquid nozzle 31b is viewed in a plan view. The second chemical liquid nozzle 31b is horizontally moved between standby positions positioned around the .

As described above, the drying pretreatment liquid contains an adsorbent material in addition to the sublimable material and the solvent. The drying pretreatment liquid is a solution containing a sublimable substance corresponding to a solute, a solvent that melts with the sublimable substance, and an adsorption substance adsorbed on the surface of the pattern P1 (refer to FIG. 23A ). The sublimable substance, the solvent, and the adsorption substance are substances of different kinds from each other. An adsorption substance is a substance which melt|dissolves with at least one of a sublimable substance and a solvent.

A solvent is a liquid of a soluble substance which melt|dissolves with a sublimable substance. The concentration of the dissolved substance in the drying pretreatment liquid is higher than the concentration of the sublimable substance in the drying pretreatment liquid, and is higher than the concentration of the adsorbed substance in the drying pretreatment liquid. The concentration of the adsorbed substance in the drying pretreatment liquid may be the same as the concentration of the sublimable substance in the drying pretreatment liquid, or may be different from the concentration of the sublimable substance in the drying pretreatment liquid.

The adsorbent material is an amphiphilic molecule containing both hydrophilic and hydrophobic groups. The adsorption substance may be a surfactant. As long as the types are different from the sublimable substance and the solvent, the adsorbed substance may be a substance (sublimable substance) that changes from a solid to a gas at room temperature or normal pressure without passing through a liquid, or may be a substance different from this. A hydrophobic substance or a hydrophilic substance may be sufficient as a sublimable substance, and an amphiphilic molecule|numerator may be sufficient as it. Similarly, a hydrophobic substance or a hydrophilic substance may be sufficient as a solvent, and an amphiphilic molecule|numerator may be sufficient as it.

When the sublimable substance is a hydrophilic substance or an amphiphilic molecule, the adsorbent substance may have a higher hydrophilicity than the sublimable substance. In other words, the solubility of the adsorbent substance in water may be higher than the solubility of the sublimable substance in water. When the sublimable material is a hydrophobic material or an amphiphilic molecule, the sublimable material may have a higher hydrophobicity than the adsorbed material. In other words, the solubility of the sublimable substance in oil may be higher than the solubility of the adsorbent substance in oil. These are the same also about a solvent.

When the surface of the pattern P1 is hydrophilic and the adsorption material has a higher hydrophilicity than the sublimable material, the adsorption material is more likely to be adsorbed on the surface of the pattern P1 than the sublimable material. The hydrophilic group of the adsorption material is attached to the surface of the pattern P1, and the sublimable material is attached to the hydrophobic group of the adsorption material attached to the surface of the pattern P1. When the surface of the pattern P1 is hydrophobic and the sublimable material has higher hydrophobicity than the adsorption material, the sublimable material is more likely to be adsorbed on the surface of the pattern P1 than the adsorption material. Therefore, even if the surface of the pattern P1 is either hydrophilic or hydrophobic, the sublimable material can be located on or near the surface of the pattern P1.

The freezing point of a sublimable substance is higher than room temperature. The solidification point of the sublimable substance may be higher than the boiling point of the solvent. The solidification point of the solvent is lower than room temperature. Room temperature may be sufficient as the freezing point of an adsorption substance, and may differ from room temperature. When the freezing point of the adsorbent material is higher than room temperature, the freezing point of the adsorbent material may be the same as the freezing point of the sublimable material or different from the freezing point of the sublimable material. The freezing point of the drying pretreatment liquid is lower than room temperature (a value of 23° C. or its vicinity). The solidification point of the drying pretreatment liquid may be room temperature or more.

The vapor pressure of the solvent is higher than the vapor pressure of the sublimable material and higher than the vapor pressure of the adsorbent material. The vapor pressure of the adsorbed substance may be the same as the vapor pressure of the sublimable substance, or may be different from the vapor pressure of the sublimable substance. The solvent evaporates from the drying pretreatment liquid at an evaporation rate greater than the evaporation rate of the sublimable material and the adsorbent material. The freezing point of the drying pretreatment liquid rises with evaporation of the solvent. When the freezing point of the drying pretreatment liquid rises to room temperature, the drying pretreatment liquid changes from a liquid to a solid. Thereby, the solidified body 101 containing a sublimable substance is formed.

Hereinafter, an example in which the sublimable substance is camphor, the solvent is IPA, and the adsorption substance is tert-butyl alcohol will be described. In the following description, the dry pretreatment liquid is a solution of camphor, IPA, and tert-butyl alcohol. Instead of camphor, naphthalene may be contained in the drying pretreatment liquid. Instead of IPA, acetone or PGEE may be contained in the drying pretreatment liquid. Instead of tert-butyl alcohol, cyclohexanol may be contained in the drying pretreatment liquid.

The molecule of camphor contains a hydrocarbon group which is a hydrophobic group and a carbonyl group which is a hydrophilic group. The molecule of IPA contains an alkyl group which is a hydrophobic group and a hydroxyl group which is a hydrophilic group. The molecule of tertiary butyl alcohol also contains an alkyl group which is a hydrophobic group and a hydroxyl group which is a hydrophilic group. IPA and tert-butyl alcohol are amphiphilic molecules. Although camphor is strictly an amphiphilic molecule, it is considered a hydrophobic substance because its solubility in water is significantly lower than that of tert-butyl alcohol. Camphor is more hydrophobic than tert-butyl alcohol.

In the 1st tank 87A and the 2nd tank 87B shown in FIG. 3, the density|concentration of an adsorption substance is the same, and the drying pretreatment liquid from which the density|concentration of a sublimable substance differs is stored. Therefore, even if the dry pretreatment liquid supplied from the first tank 87A is mixed with the dry pretreatment liquid supplied from the second tank 87B, the concentration of adsorbed substances in the mixed dry pretreatment liquid is 87A) and the concentration of the adsorbed material in the dry pretreatment liquid in the second tank 87B. The initial concentration of the sublimable substance in the drying pretreatment liquid in the first tank 87A and the second tank 87B may be set to the same value as in the first embodiment, or set to a value different from that in the first embodiment. may be set.

Next, an example of the processing of the substrate W according to the second embodiment will be described.

22 : is a process chart for demonstrating an example of the process of the board|substrate W which concerns on 2nd Embodiment. In the following, reference is made to FIGS. 21 and 22 .

In an example of the processing of the substrate W according to the second embodiment, steps S3-1 to S4-2 shown in FIG. 22 are performed instead of steps S3 to S4 shown in FIG. 5 . Steps other than these are the same as Step S1 to Step S2 and Step S5 to Step S11 shown in FIG. 5 . Accordingly, steps S3-1 to S4-2 will be described below.

Hereinafter, an example in which hydrofluoric acid and SC1 (a mixture of ammonia, hydrogen peroxide, and water) are sequentially supplied to the silicon wafer corresponding to the substrate W will be described. The native oxide film formed on the silicon wafer is removed from the silicon wafer by supply of hydrofluoric acid. Thereby, silicon is exposed on the surface of the pattern P1. After that, SC1 is supplied to the silicon wafer. Silicon exposed on the surface of the pattern P1 changes to silicon oxide upon contact with SC1. Thereby, the surface of the pattern P1 changes from hydrophobicity to hydrophilicity. Accordingly, the drying pretreatment liquid is supplied to the silicon wafer when the surface of the pattern P1 is hydrophilic.

As shown in Fig. 22, after the rotation of the substrate W is started (step S2 in Fig. 22), hydrofluoric acid, which is an example of a chemical solution, is supplied to the upper surface of the substrate W, and the entire upper surface of the substrate W is covered. A first chemical solution supply process (step S3-1 in FIG. 22) of forming a hydrofluoric acid liquid film is performed.

Specifically, in a state in which the blocking member 51 is positioned at the upper position and the at least one guard 24 is positioned at the upper position, the nozzle moving unit 34 moves the chemical liquid nozzle 31 from the standby position to the processing position. move to After that, the chemical liquid valve 33 is opened, and the chemical liquid nozzle 31 starts discharging the hydrofluoric acid. When a predetermined time elapses after the chemical liquid valve 33 is opened, the chemical liquid valve 33 is closed and the discharging of the hydrofluoric acid is stopped. Thereafter, the nozzle moving unit 34 moves the chemical liquid nozzle 31 to the standby position.

The hydrofluoric acid discharged from the chemical liquid nozzle 31 collides with the upper surface of the substrate W rotating at the liquid supply speed, and then flows outward along the upper surface of the substrate W by centrifugal force. For this reason, hydrofluoric acid is supplied to the entire upper surface of the substrate W, and a hydrofluoric acid liquid film covering the entire upper surface of the substrate W is formed. When the chemical liquid nozzle 31 is discharging the hydrofluoric acid, the nozzle moving unit 34 may move the liquid landing position so that the liquid landing position of the hydrofluoric acid with respect to the upper surface of the substrate W passes through the central portion and the outer peripheral portion, or liquid landing in the central portion The position may be stopped.

Next, a first rinse liquid supply process (step S4-1 in FIG. 22 ) of supplying pure water, which is an example of a rinse liquid, to the upper surface of the substrate W and washing the hydrofluoric acid on the substrate W is performed.

Specifically, in a state in which the blocking member 51 is positioned at the upper position and the at least one guard 24 is positioned at the upper position, the nozzle moving unit 38 processes the rinse liquid nozzle 35 in the standby position. move to position Thereafter, the rinse liquid valve 37 is opened, and the rinse liquid nozzle 35 starts discharging the rinse liquid. Before the discharge of pure water is started, the guard raising/lowering unit 27 may vertically move the at least one guard 24 in order to switch the guard 24 receiving the liquid discharged from the substrate W. When a predetermined time elapses after the rinse liquid valve 37 is opened, the rinse liquid valve 37 is closed, and discharge of the rinse liquid is stopped. Thereafter, the nozzle moving unit 38 moves the rinse liquid nozzle 35 to the standby position.

The pure water discharged from the rinse liquid nozzle 35 collides with the upper surface of the substrate W rotating at the liquid supply speed, and then flows outward along the upper surface of the substrate W by centrifugal force. The hydrofluoric acid on the substrate W is replaced with the pure water discharged from the rinse liquid nozzle 35 . Thereby, the liquid film of pure water which covers the whole upper surface of the board|substrate W is formed. When the rinse liquid nozzle 35 is discharging pure water, the nozzle moving unit 38 may move the liquid landing position so that the liquid landing position of the pure water with respect to the upper surface of the substrate W passes through the central portion and the outer peripheral portion, or from the central portion The liquid landing position may be stopped.

Next, a second chemical solution supply process (step S3-2 in Fig. 22) of supplying SC1, which is an example of a chemical solution, to the upper surface of the substrate W, and forming a liquid film of SC1 covering the entire upper surface of the substrate W is performed. All.

Specifically, in a state in which the blocking member 51 is positioned at the upper position and the at least one guard 24 is positioned at the upper position, the nozzle moving unit 34b moves the second chemical liquid nozzle 31b from the standby position. move to the processing position. Thereafter, the second chemical liquid valve 33b is opened, and the second chemical liquid nozzle 31b starts discharging SC1. When a predetermined time elapses after the second chemical liquid valve 33b is opened, the second chemical liquid valve 33b is closed and the discharge of SC1 is stopped. Thereafter, the nozzle moving unit 34b moves the second chemical liquid nozzle 31b to the standby position.

SC1 discharged from the second chemical liquid nozzle 31b collides with the upper surface of the substrate W rotating at the liquid supply speed, and then flows outward along the upper surface of the substrate W by centrifugal force. The pure water on the substrate W is replaced with SC1 discharged from the second chemical liquid nozzle 31b. Thereby, the liquid film of SC1 which covers the whole upper surface of the board|substrate W is formed. When the second chemical liquid nozzle 31b is discharging SC1, the nozzle moving unit 34b may move the liquid landing position so that the liquid landing position of SC1 with respect to the upper surface of the substrate W passes through the central portion and the outer peripheral portion, or the central portion You may stop the liquid landing position in

Next, a second rinse liquid supply process (step S4-2 in FIG. 22 ) of supplying pure water, which is an example of a rinse liquid, to the upper surface of the substrate W and washing SC1 on the substrate W is performed.

Specifically, in a state in which the blocking member 51 is positioned at the upper position and the at least one guard 24 is positioned at the upper position, the nozzle moving unit 38 processes the rinse liquid nozzle 35 in the standby position. move to position Thereafter, the rinse liquid valve 37 is opened, and the rinse liquid nozzle 35 starts discharging the rinse liquid. Before the discharge of pure water is started, the guard raising/lowering unit 27 may vertically move the at least one guard 24 in order to switch the guard 24 receiving the liquid discharged from the substrate W. When a predetermined time elapses after the rinse liquid valve 37 is opened, the rinse liquid valve 37 is closed, and discharge of the rinse liquid is stopped. Thereafter, the nozzle moving unit 38 moves the rinse liquid nozzle 35 to the standby position.

The pure water discharged from the rinse liquid nozzle 35 collides with the upper surface of the substrate W rotating at the liquid supply speed, and then flows outward along the upper surface of the substrate W by centrifugal force. SC1 on the substrate W is replaced with pure water discharged from the rinse liquid nozzle 35 . Thereby, the liquid film of pure water which covers the whole upper surface of the board|substrate W is formed. When the rinse liquid nozzle 35 is discharging pure water, the nozzle moving unit 38 may move the liquid landing position so that the liquid landing position of the pure water with respect to the upper surface of the substrate W passes through the central portion and the outer peripheral portion, or from the central portion The liquid landing position may be stopped.

After the second rinse solution supply step (step S4-2 in FIG. 22) is performed, the replacement solution and the drying pretreatment solution are applied to the substrate ( W) is sequentially supplied (step S5 to step S6 in FIG. 22), and the solidified body 101 (refer to FIG. 23E) on the surface of the substrate W is sublimated (step S7 to step S9 in FIG. 22). Thereafter, the substrate W is taken out from the chamber 4 (steps S10 to S11 in FIG. 22 ). Thereby, the processed board|substrate W is carried out from the chamber 4 .

Next, a phenomenon assumed to occur on the surface of the pattern P1 to which the drying pretreatment liquid is supplied will be described.

23A to 23F are cross-sectional views of the substrate W for explaining this phenomenon. 23A to 23E, tert-butyl alcohol is represented by TBA. 23A to 23C, the hydrophilic group of the tert-butyl alcohol molecule is indicated by a thick straight line, and the hydrophobic group of the tert-butyl alcohol molecule is indicated by a black circle.

As described above, in an example of the processing of the substrate W according to the second embodiment, hydrofluoric acid and SC1 are sequentially supplied to the silicon wafer corresponding to the substrate W. The surface of the pattern P1 changes to hydrophobicity by supply of hydrofluoric acid. Thereafter, the surface of the pattern P1 changes to hydrophilicity by the supply of SC1. Therefore, the dry pretreatment liquid containing camphor, IPA, and tert-butyl alcohol is supplied to the silicon wafer when the surface of the pattern P1 is hydrophilic.

Camphor is a substance that can be regarded as hydrophobic, and tert-butyl alcohol is an amphiphilic molecule containing a hydrophilic group and a hydrophobic group. As shown in FIG. 23A , since the surface of the pattern P1 is hydrophilic, the hydrophilic group of the tert-butyl alcohol molecule is attracted to the surface of the pattern P1. As a result, as shown in Fig. 23B, the hydrophilic group of the tert-butyl alcohol molecule is adsorbed to the surface of the pattern P1, and the thin film of tert-butyl alcohol is formed on the side surface Ps and the upper surface Pu of the pattern P1. ) is formed in

23B shows an example in which a monomolecular film of tert-butyl alcohol is formed along the surface of the pattern P1. As shown in Fig. 23C, in this example, the hydrophobic group of the camphor molecule is attached to the hydrophobic group of the tert-butyl alcohol molecule adsorbed on the surface of the pattern P1. When the laminated film of tert-butyl alcohol is formed along the surface of the pattern P1, the hydrophobic group of the camphor molecule is attached to the hydrophobic group of the tert-butyl alcohol molecule exposed on the surface layer of the laminated film. Thereby, camphor is held on the surface of the pattern P1 through the thin film of tert-butyl alcohol.

As shown in FIG. 23C , camphor molecules in the drying pretreatment solution adhere to camphor molecules held in a thin film of tert-butyl alcohol. By this phenomenon, many camphor molecules are retained on the side surface Ps of the pattern P1 through the molecular layer of tert-butyl alcohol. Therefore, as shown in Fig. 23D, a sufficient amount of camphor molecules enters between the patterns P1. In FIG. 23D, a thin film of tert-butyl alcohol is formed not only on the side surface Ps and the upper surface Pu of the pattern P1, but also on the bottom surface Pb of the recess formed between the two adjacent patterns P1. an example is shown.

In the IPA corresponding to the solvent, a thin film of tert-butyl alcohol is formed along the surface of the pattern (P1), and a plurality of camphor molecules are maintained on the surface of the pattern (P1) through the thin film of tert-butyl alcohol. evaporated from the dry pretreatment solution. As the IPA evaporates, the freezing point of the drying pretreatment solution rises, and the concentrations of camphor and tert-butyl alcohol rise. Thereby, as shown in FIG. 23E, the solidified body 101 containing camphor and tert-butyl alcohol is formed on the surface of the board|substrate W. As shown in FIG. Then, as shown in FIG. 23F, the solidified body 101 is vaporized and it removes from the surface of the board|substrate W. As shown in FIG.

According to the research of the present inventors, when processing the substrate W according to the second embodiment by using a plate-shaped sample made of silicon with the pattern P1 formed thereon instead of the substrate W, camphor, IPA, and When the solution of sherry butyl alcohol was used as the drying pretreatment solution, it was confirmed that the rate of collapse of the pattern P1 was lowered compared to the case where camphor and IPA solutions were used as the drying pretreatment solution. Although the concentration (volume percent concentration) of tert-butyl alcohol was changed in the range of 0.1 vol% to 10 vol%, a large difference was not seen in the collapse rate of the pattern (P1). Therefore, when tertiary butyl alcohol is added even in a small amount, the rate of collapse of the pattern P1 is reduced. The concentration of tert-butyl alcohol may be within the above range or may be outside the above range.

In the second embodiment, in addition to the effects according to the first embodiment, the following effects can be exhibited. Specifically, in the second embodiment, in addition to the sublimable substance and the solvent, the drying pretreatment liquid containing the adsorbent substance is supplied to the surface of the substrate W on which the pattern P1 is formed. Then, the solvent is evaporated from the dry pretreatment solution. Thereby, the solidified body 101 containing the sublimable substance is formed on the surface of the substrate W. Thereafter, the solidified body 101 on the substrate W is changed into a gas without passing through the liquid. Thereby, the solidified body 101 is removed from the surface of the substrate W. Therefore, compared with the conventional drying method, such as spin drying, the collapse rate of the pattern P1 can be reduced.

A sublimable substance is a substance containing a hydrophobic group in a molecule|numerator. An adsorption substance is a substance containing a hydrophobic group and a hydrophilic group in a molecule|numerator. The hydrophilicity of the adsorbent material is higher than that of the sublimable material. Even if the surface of the pattern (P1) is either hydrophilic or hydrophobic, or even if a hydrophilic part and a hydrophobic part are included in the surface of the pattern (P1), the adsorbed material in the drying pretreatment solution is the surface of the pattern (P1) is adsorbed to

Specifically, when the surface of the pattern (P1) is hydrophilic, the hydrophilic group of the adsorbed material in the drying pretreatment solution is attached to the surface of the pattern (P1), and the hydrophobic group of the sublimable material in the drying pretreatment solution is attached to the hydrophobic group of the adsorbed material do. Thereby, the sublimable material is held on the surface of the pattern P1 via the adsorbent material. When the surface of the pattern P1 is hydrophobic, at least a hydrophobic group of the sublimable material is attached to the surface of the pattern P1. Therefore, even if the surface of the pattern P1 is either hydrophilic or hydrophobic, or even if the hydrophilic part and the hydrophobic part are included in the surface of the pattern P1, the sublimable material is transferred to the pattern P1 before evaporation of the solvent. maintained on or near the surface of

When the sublimable material is hydrophilic and the surface of the pattern P1 is hydrophilic, the sublimable material is attracted to the surface of the pattern P1 by electrical attraction. On the other hand, when the sublimable material is hydrophobic and the surface of the pattern P1 is hydrophilic, since such an attractive force is weak or does not occur, it is difficult for the sublimable material to adhere to the surface of the pattern P1. In addition, in addition to that the sublimable material is hydrophobic and the surface of the pattern P1 is hydrophilic, when the interval between the patterns P1 is extremely narrow, a sufficient amount of the sublimable material does not enter between the patterns P1. can think These phenomena also occur when the sublimable material is hydrophilic and the surface of the pattern P1 is hydrophobic.

If the solvent is evaporated while the sublimable material is not present on or near the surface of the pattern P1, a collapsing force is applied to the pattern P1 from the solvent in contact with the surface of the pattern P1, and the pattern P1 may collapse. . If the solvent is evaporated in a state where a sufficient amount of sublimable material is not present between the patterns P1, the gap between the patterns P1 is not filled with the solidified body 101, and the pattern P1 collapses. have. If the sublimable material is disposed on or near the surface of the pattern P1 before evaporating the solvent, such collapse can be reduced. Thereby, the collapse rate of the pattern P1 can be reduced.

In the second embodiment, not only the sublimable substance but also the adsorption substance has sublimability. The adsorbed material changes from a solid to a gas at room temperature or pressure without going through a liquid. When at least a part of the surface of the pattern P1 is hydrophilic, the solvent evaporates while the adsorbed material in the drying pretreatment solution is adsorbed to the surface of the pattern P1. The adsorbent material changes from a liquid to a solid at the surface of the pattern P1. Thereby, the solidified body 101 containing the adsorbent material and the sublimable material is formed. Thereafter, the solid of the adsorbent material changes into a gas on the surface of the pattern P1 without passing through the liquid. Accordingly, the collapse force may be reduced compared to the case of vaporizing the liquid on the surface of the pattern P1.

In the second embodiment, a dry pretreatment liquid having a low concentration of an adsorbent is supplied to the surface of the substrate W. When at least a part of the surface of the pattern P1 is hydrophilic, a hydrophilic group of the adsorption material is attached to the surface of the pattern P1 , and a monomolecular film of the adsorption material is formed along the surface of the pattern P1 . When the concentration of the adsorbent material is high, a plurality of monomolecular films are stacked, and a laminated film of the adsorbent material is formed along the surface of the pattern P1 . In this case, the sublimable material is held on the surface of the pattern P1 through the laminated film of the adsorbent material. When the layered layer of the adsorbent material is thick, the sublimable material entering between the patterns P1 is reduced. Accordingly, by lowering the concentration of the adsorbent material, more sublimable material can be introduced between the patterns P1.

In the second embodiment, a drying pretreatment liquid containing a sublimable material having a higher hydrophobicity than the adsorption material is supplied to the surface of the substrate W. Since a hydrophobic group is included in any of the sublimable material and the adsorbing material, when at least a part of the surface of the pattern P1 is hydrophobic, both the sublimable material and the adsorbing material may be attached to the surface of the pattern P1 . However, since the affinity between the sublimable material and the pattern P1 is higher than that of the adsorption material and the pattern P1, more sublimable materials than the adsorption material adhere to the surface of the pattern P1. Thereby, more sublimable substances can be adhered to the surface of the pattern P1.

another embodiment

The present invention is not limited to the contents of the above-described embodiment, and various modifications are possible.

For example, in order to change the thickness T1 of the solidified body 101, you may change conditions other than the density|concentration of a drying pretreatment liquid. For example, in addition to or instead of the concentration of the drying pretreatment liquid, the temperature of the drying pretreatment liquid may be changed.

The pattern P1 is not limited to a single layer structure, and may have a layered structure. At least a part of the pattern P1 may be formed of a material other than silicon. For example, at least a part of the pattern P1 may be formed of a metal.

In an example of the treatment of the substrate W according to the first and second embodiments, in order to maintain the drying pretreatment liquid on the substrate W as a liquid, the freezing point of the drying pretreatment liquid is higher than the boiling point of the drying pretreatment liquid, and lower than the boiling point of the drying pretreatment liquid. At the liquid holding temperature, you may perform the temperature holding process of holding the dry pretreatment liquid on the board|substrate W.

When the rinse solution on the substrate W such as pure water can be replaced with the drying pretreatment solution, the drying pretreatment solution supply step is performed without performing the replacement solution supply step of replacing the rinse solution on the substrate W with the replacement solution. also be

In an example of the processing of the board|substrate W which concerns on 2nd Embodiment, the surface of the pattern P1 may be hydrophilic from the beginning, ie, before being carried into the substrate processing apparatus 1 . In this case, the second chemical solution supply step (step S3-2 in FIG. 22 ) and the second rinse solution supply step (step S4-2 in FIG. 22 ) may be omitted. Further, the chemical solution supplied to the substrate W in the first chemical solution supply step (step S3-1 in FIG. 22 ) may be a chemical solution other than hydrofluoric acid.

In an example of the treatment of the substrate W according to the second embodiment, when the drying pretreatment liquid is supplied to the surface of the substrate W, the surface of the pattern P1 may be hydrophobic. In this case, the surface of the pattern P1 may be hydrophobic from the beginning, and may change to hydrophobicity when the process of the board|substrate W is being performed.

In the second embodiment, unless the initial concentration of the sublimable substance (the concentration of the sublimable substance in the drying pretreatment liquid before being supplied to the substrate W) is changed, the first tank 87A shown in FIG. 3 and One of the second tanks 87B may be omitted.

In the second embodiment, the adsorbent material may be mixed with a solution of the sublimable material and the solvent outside the first tank 87A and the second tank 87B. In this case, the adsorbed material may be mixed before the solution of the sublimable material and the solvent is discharged from the drying pretreatment liquid nozzle 39 , and mixed after the solution of the sublimable material and the solvent is discharged from the dry pretreatment liquid nozzle 39 . may be In the latter case, the adsorption material may be mixed with a solution of a sublimable material and a solvent in a space between the drying pretreatment liquid nozzle 39 and the substrate W, and a solution of a sublimable material and a solvent on the upper surface of the substrate W may be mixed with

The blocking member 51 may include, in addition to the disk portion 52 , a cylindrical portion extending downward from the outer periphery of the disk portion 52 . In this case, when the blocking member 51 is disposed at the lower position, the substrate W held by the spin chuck 10 is surrounded by the cylindrical portion.

The blocking member 51 may rotate around the rotation axis A1 together with the spin chuck 10 . For example, the blocking member 51 may be placed on the spin base 12 so that it does not contact the substrate W. In this case, since the blocking member 51 is connected to the spin base 12 , the blocking member 51 rotates in the same direction as the spin base 12 at the same speed.

The blocking member 51 may be omitted. However, when supplying a liquid such as pure water to the lower surface of the substrate W, it is preferable that the blocking member 51 is provided. A droplet returning from the lower surface of the substrate W to the upper surface of the substrate W on the outer circumferential surface of the substrate W or a droplet returning to the inside from the processing cup 21 can be blocked by the blocking member 51 , This is because it is possible to reduce the amount of liquid mixed into the drying pretreatment liquid of the phase (W).

The substrate processing apparatus 1 is not limited to the apparatus which processes the disk-shaped board|substrate W, The apparatus which processes the polygonal board|substrate W may be sufficient.

The substrate processing apparatus 1 is not limited to a single-wafer type apparatus, A batch type apparatus which processes the several board|substrate W collectively may be sufficient.

Two or more of all the above-described configurations may be combined. Two or more of all the steps described above may be combined.

The dry pretreatment liquid nozzle 39 is an example of a dry pretreatment liquid supply unit. The center nozzle 55 and the spin motor 14 are an example of a solidified body forming unit. The center nozzle 55 and the spin motor 14 are also examples of the sublimation unit.

Although embodiments of the present invention have been described in detail, these are merely specific examples used to clarify the technical content of the present invention, and the present invention should not be construed as being limited to these specific examples, but the spirit and The scope is limited only by the appended claims.

Claims (12)

A drying pretreatment solution supplying step of supplying a drying pretreatment solution, which is a solution containing a sublimable material that changes to a gas without going through a liquid and a solvent that melts with the sublimable material, to the surface of the substrate on which the pattern is formed;
A solidified body forming step of forming a solidified body including the sublimable material on the surface of the substrate by evaporating the solvent from the drying pretreatment solution on the surface of the substrate;
a sublimation process of removing the solidified material from the surface of the substrate by sublimating;
A value obtained by multiplying the ratio of the thickness of the solidified body to the height of the pattern by one hundred times is greater than 76 and less than 219. The method according to claim 1,
The sublimable material comprises at least one of camphor and naphthalene. The method according to claim 1 or 2,
The solvent includes at least one of IPA (isopropyl alcohol), acetone, and PGEE (propylene glycol monoethyl ether). 4. The method of claim 3,
The solvent is IPA,
The mass percent concentration of the sublimable material in the drying pretreatment liquid is greater than 0.62 and less than 2.06. 4. The method of claim 3,
The solvent is acetone,
The mass percent concentration of the sublimable material in the drying pretreatment liquid is greater than 0.62 and less than or equal to 0.96. 4. The method of claim 3,
The solvent is PGEE,
The mass percent concentration of the sublimable material in the drying pretreatment liquid is greater than 3.55 and not more than 6.86. The method according to claim 1 or 2,
The drying pretreatment liquid supplied to the surface of the substrate in the drying pretreatment liquid supply process includes the sublimable material including a hydrophobic group, the solvent, a hydrophobic group and a hydrophilic group, and has a higher hydrophilicity than the sublimable material. A method of processing a substrate, wherein the solution is a solution comprising a substance. 8. The method of claim 7,
The adsorbent material is a material having sublimability. 8. The method of claim 7,
The concentration of the adsorbent in the drying pretreatment solution is lower than the concentration of the solvent in the drying pretreatment solution. 8. The method of claim 7,
wherein the sublimable material has higher hydrophobicity than the adsorbent material. A dry pretreatment liquid supply unit for supplying a dry pretreatment liquid, which is a solution containing a sublimable material that changes into a gas without going through a liquid and a solvent that melts with the sublimable material, to the surface of the substrate on which the pattern is formed;
a solidified body forming unit for forming a solidified body including the sublimable material on the surface of the substrate by evaporating the solvent from the drying pretreatment liquid on the surface of the substrate;
a sublimation unit for removing the solidified body from the surface of the substrate by sublimating;
The value obtained by multiplying the ratio of the thickness of the solidified body to the height of the pattern by one hundred times exceeds 76 and is less than 219, the substrate processing apparatus. As a drying pretreatment solution supplied to the surface of the substrate before drying the surface of the substrate on which the pattern is formed,
Sublimable substances that change to gas without going through liquid,
It contains a solvent that dissolves with the sublimable material,
When a solidified body including the sublimable material is formed on the surface of the substrate by evaporating the solvent from the drying pretreatment solution on the surface of the substrate, the ratio of the thickness of the solidified body to the height of the pattern is back The dry pretreatment liquid, wherein the concentration of the sublimable substance is adjusted so that the doubling value exceeds 76 and is less than 219.

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