Method for producing liquid containing sublimable substance, substrate drying method and substrate processing device

Abstract

The sublimable substance is selected based on whether the pattern surface is hydrophilic or hydrophobic. If the pattern surface is hydrophilic, a hydrophilic solvent is selected whose solubility in water is lower than that of the selected sublimable substance. If the pattern surface is hydrophobic, a hydrophobic solvent is selected whose solubility in oil is lower than that of the selected sublimable substance. The selected sublimable substance is dissolved in the selected solvent.

Description

Technical Field

[0001] This application claims priority based on Japanese Patent Application No. 2019-100140 filed on May 29, 2019, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a method for producing a liquid containing a sublimable substance, wherein the liquid containing the sublimable substance is removed from the substrate when the surface of a substrate having a pattern formed thereon is dried. The present invention also relates to a substrate drying method and a substrate processing apparatus for drying the substrate. Examples of substrates include semiconductor wafers, substrates for flat panel displays (FPDs) such as liquid crystal displays or organic electroluminescence (EL) displays, substrates for optical disks, magnetic disks, magneto-optical disks, photomask substrates, ceramic substrates, and substrates for solar cells. Background Art

[0003] During the manufacturing process of semiconductor devices and FPDs, substrates such as semiconductor wafers and FPD glass substrates are processed as needed. This processing involves supplying a treatment liquid, such as a chemical solution or rinse solution, to the substrate. After supplying the treatment liquid, the treatment liquid is removed from the substrate to dry it.

[0004] When the surface of the substrate is formed with a pattern, there is the following situation: when the substrate is dried, the force generated due to the surface tension of the treatment liquid attached to the substrate is applied to the pattern, so that the pattern collapses. As its countermeasure, a liquid with low surface tension such as IPA (isopropyl alcohol) is supplied to the substrate or a method in which a hydrophobic agent with a contact angle of the liquid relative to the pattern close to 90 degrees is supplied to the substrate. However, even if IPA or a hydrophobic agent is used, the collapse force that causes the pattern to collapse will not become zero, so according to the intensity of the pattern, there is a situation in which the pattern collapse cannot be fully prevented even if these countermeasures are performed.

[0005] In recent years, sublimation drying has attracted considerable attention as a technology for preventing pattern collapse. For example, Patent Document 1 discloses a substrate drying method and substrate processing apparatus that perform sublimation drying. Patent Document 1 discloses dissolving ammonium fluorosilicate, a sublimable substance (solute), in pure water (DIW) or in a mixture of DIW and IPA (isopropyl alcohol); and dissolving camphor or naphthalene, a sublimable substance (solute), in an alcohol such as IPA.

[0006] Patent Document 1 also discloses the following: After forming a pattern on a SiN film, a solution of a sublimable substance is supplied to a substrate; and after forming a pattern on a photoresist film, a solution of a sublimable substance is supplied to the substrate. After the solution of the sublimable substance is supplied to the substrate, a film containing the solid sublimable substance is formed. The substrate is then transferred from a liquid handling unit to a hot plate unit. The hot plate unit heats the substrate to a temperature higher than the sublimation temperature of the sublimable substance. This causes the sublimable substance to sublime and be removed from the substrate.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2018-139331 Summary of the Invention

[0010] Problems to be solved by the invention

[0011] According to the studies conducted by the present inventors, it has been found that in order to reduce the collapse rate of a pattern during sublimation drying, it is also important to consider the affinity between the solvent and the pattern.

[0012] Specifically, if the solvent has a high affinity for the surface of the pattern, it is easy to keep the solvent on the surface of the pattern. Therefore, there is a situation where a lot of solvent remains between the patterns after the solidified film containing the sublimable substance is formed. For example, it is believed that if the surface of the pattern is hydrophilic and the hydrophilicity of the solvent is high, a lot of solvent remains between the patterns after the solidified film is formed. In this case, it is believed that in a state where the space between the patterns is filled with a liquid containing a solvent, a solidified film is formed above the pattern (refer to Figure 8B ).

[0013] After the solidified film is formed, if the liquid containing the solvent remains between the patterns, the force generated by the surface tension of the solvent is applied to the patterns. If the strength of the pattern is low, even such a force will cause the pattern to collapse. Therefore, the solvent is also required to have a low affinity for the surface of the pattern. Patent Document 1 does not consider this aspect at all. That is, the inventors have discovered a new problem, that is, if the liquid containing the sublimable substance contains a solvent with an inappropriate affinity for the pattern, it is impossible to fully reduce the collapse rate of the pattern.

[0014] Therefore, an object of the present invention is to provide a method for producing a liquid containing a sublimable substance, the method being capable of producing a liquid containing a sublimable substance that includes a solvent having an appropriate affinity for a pattern. Another object of the present invention is to provide a substrate drying method and substrate processing apparatus that can dry a substrate using the liquid containing a sublimable substance.

[0015] Means used to solve problems

[0016] One embodiment of the present invention provides a method for manufacturing a liquid containing a sublimable substance, wherein the method comprises: a sublimable substance selection step of selecting a sublimable substance based on whether the surface of the pattern is hydrophilic or hydrophobic; a solvent selection step of selecting a hydrophilic solvent having a lower solubility in water than the sublimable substance selected in the sublimable substance selection step when the surface of the pattern is hydrophilic; and selecting a hydrophobic solvent having a lower solubility in oil than the sublimable substance selected in the sublimable substance selection step when the surface of the pattern is hydrophilic; and a dissolving step of dissolving the sublimable substance selected in the sublimable substance selection step in the solvent selected in the solvent selection step.

[0017] In this method, a liquid containing a sublimable substance and a solvent is produced. The liquid containing the sublimable substance is supplied to the surface of a substrate formed with a pattern and then removed from the substrate. The substrate is thereby dried. When removing the liquid containing the sublimable substance from the substrate, for example, the solvent is evaporated from the liquid containing the sublimable substance on the surface of the substrate. This forms a cured film containing the sublimable substance on the surface of the substrate. The cured film is then sublimated and removed from the surface of the substrate. Thus, the liquid containing the sublimable substance is removed from the substrate.

[0018] When the surface of the pattern is hydrophilic, the liquid containing the sublimable substance contains a solvent with a lower solubility in water than the sublimable substance. If the surface of the pattern is hydrophilic and the solvent is highly hydrophilic, the solvent is easily retained on the surface of the pattern, so a large amount of solvent remains between the patterns after the cured film is formed. In this case, the collapse force that causes the pattern to collapse is applied from the solvent to the pattern. If a solvent with low hydrophilicity is used, the amount of solvent remaining between the patterns after the cured film is formed can be reduced to zero or near zero.

[0019] If the surface of the pattern is hydrophobic, the liquid containing the sublimable substance contains a solvent with a lower solubility in oil than the sublimable substance. If the surface of the pattern is hydrophobic and the solvent is highly hydrophobic, the solvent is easily retained on the surface of the pattern, so a large amount of solvent remains between the patterns after the cured film is formed. In this case, the collapse force that causes the pattern to collapse is applied from the solvent to the pattern. If a less hydrophobic solvent is used, the amount of solvent remaining between the patterns after the cured film is formed can be reduced to zero or near zero.

[0020] In this way, regardless of whether the pattern surface is hydrophilic or hydrophobic, the solvent contained in the liquid containing a sublimable substance has a lower affinity for the pattern surface than the sublimable substance contained in the liquid containing a sublimable substance. Consequently, the amount of solvent remaining between the patterns after the cured film is formed can be reduced, thereby reducing the collapse force applied to the pattern during or after the cured film is formed. Consequently, it is possible to produce a liquid containing a sublimable substance that can dry a substrate with a low pattern collapse rate, regardless of whether the pattern surface is hydrophilic or hydrophobic.

[0021] In the above embodiment, at least one of the following features may be added to the method for producing the liquid containing a sublimable substance.

[0022] The method for manufacturing a liquid containing a sublimable substance further includes: a property judgment step, wherein when the surface of the pattern includes a hydrophilic portion and a hydrophobic portion and the upper end portion of the side surface of the pattern is hydrophilic, the surface of the pattern is considered to be hydrophilic before selecting the sublimable substance and the solvent; and when the surface of the pattern includes the hydrophilic portion and the hydrophobic portion and the upper end portion of the side surface of the pattern is hydrophobic, the surface of the pattern is considered to be hydrophobic before selecting the sublimable substance and the solvent.

[0023] In this method, if the surface of a pattern includes hydrophilic and hydrophobic portions, the pattern surface is considered hydrophilic if the upper end of the side surface of the pattern is hydrophilic. If the surface of a pattern includes hydrophilic and hydrophobic portions, the pattern surface is considered hydrophobic if the upper end of the side surface of the pattern is hydrophobic. In other words, whether the pattern surface is hydrophilic or hydrophobic is determined based on the properties of the upper end of the side surface of the pattern.

[0024] When a liquid surface (the interface between gas and liquid) forms between two adjacent convex patterns, a collapsing force due to surface tension is applied to the pattern. This collapsing force increases as the distance from the base of the pattern to the liquid surface increases. Therefore, even if a liquid surface forms between two adjacent convex patterns, the collapsing force applied to the pattern is weak as long as the distance from the base (bottom) of the pattern to the liquid surface is short.

[0025] If the pattern surface contains both hydrophilic and hydrophobic portions, and the upper end of the pattern's side surface is hydrophilic, treating the pattern surface as hydrophobic will result in the solvent surface forming at the upper end of the pattern's side surface after the cured film is formed, potentially exerting a significant collapse force on the pattern. If the pattern surface is treated as hydrophilic, even if the solvent surface forms between the pattern elements, it will be located at the base of the pattern. This shortens the distance from the base of the pattern to the liquid surface.

[0026] For similar reasons, when the pattern surface includes hydrophilic and hydrophobic portions, and the upper end of the side surface of the pattern is hydrophobic, if the pattern surface is considered hydrophobic, even if the solvent liquid surface forms between the patterns, the distance from the base of the pattern to the liquid surface can be shortened. This makes it possible to produce a liquid containing a sublimable substance that weakens the collapse force applied to the pattern and reduces the collapse rate of the pattern.

[0027] Another embodiment of the present invention provides a substrate drying method, which includes: a liquid supplying step containing a sublimable substance, supplying a liquid containing a sublimable substance produced by a method for producing a liquid containing a sublimable substance to a surface of a substrate; a cured film forming step, forming a cured film containing the sublimable substance on the surface of the substrate by evaporating a solvent from the liquid containing the sublimable substance on the surface of the substrate; and a sublimation step, removing the cured film from the surface of the substrate by sublimating the cured film.

[0028] In this method, a liquid containing a sublimable substance, which is equivalent to a solute, and a solvent, is supplied to the surface of a substrate on which a pattern is formed. The solvent is then evaporated from the liquid containing the sublimable substance. This forms a solidified film containing the sublimable substance on the surface of the substrate. The solidified film on the substrate is then converted into a gas without passing through the liquid. This allows the solidified film to be removed from the surface of the substrate. Therefore, compared to conventional drying methods such as spin drying, the collapse rate of the pattern can be reduced.

[0029] Another embodiment of the present invention provides a substrate drying method for drying a surface of a substrate having a pattern formed thereon, wherein the method comprises: a sublimation substance selection step of selecting a sublimation substance based on whether the surface of the pattern is hydrophilic or hydrophobic; a solvent selection step of selecting a hydrophilic solvent having a lower solubility in water than the sublimation substance selected in the sublimation substance selection step when the surface of the pattern is hydrophilic, and selecting a hydrophobic solvent having a lower solubility in oil than the sublimation substance selected in the sublimation substance selection step when the surface of the pattern is hydrophobic; and a dissolving step of dissolving the sublimation substance in the sublimation substance by dissolving the sublimation substance in the sublimation substance. The sublimable substance selected in the substance selection step is dissolved in the solvent selected in the solvent selection step to produce a sublimable substance-containing liquid containing the sublimable substance and the solvent; a sublimable substance-containing liquid supplying step is to supply the sublimable substance-containing liquid produced in the dissolving step to the surface of the substrate; a cured film forming step is to form a cured film containing the sublimable substance on the surface of the substrate by evaporating the solvent from the sublimable substance-containing liquid on the surface of the substrate; and a sublimation step is to remove the cured film from the surface of the substrate by sublimating the cured film.

[0030] In this method, a liquid containing a sublimable substance, which contains a sublimable substance equivalent to a solute and a solvent, is manufactured and supplied to the surface of a substrate formed with a pattern. The solvent is then evaporated from the liquid containing the sublimable substance. This forms a solidified film containing the sublimable substance on the surface of the substrate. The solidified film on the substrate is then converted into a gas without passing through the liquid. This allows the solidified film to be removed from the surface of the substrate. Therefore, compared to conventional drying methods such as spin drying, the collapse rate of the pattern can be reduced.

[0031] When the surface of the pattern is hydrophilic, the liquid containing the sublimable substance contains a solvent with a lower solubility in water than the sublimable substance. If the surface of the pattern is hydrophilic and the solvent is highly hydrophilic, the solvent is easily retained on the surface of the pattern, so a large amount of solvent remains between the patterns after the cured film is formed. In this case, the collapse force that causes the pattern to collapse is applied from the solvent to the pattern. If a solvent with low hydrophilicity is used, the amount of solvent remaining between the patterns after the cured film is formed can be reduced to zero or near zero.

[0032] If the surface of the pattern is hydrophobic, the liquid containing the sublimable substance contains a solvent with a lower solubility in oil than the sublimable substance. If the surface of the pattern is hydrophobic and the solvent is highly hydrophobic, the solvent is easily retained on the surface of the pattern, so after the solidified film is formed, a large amount of solvent remains between the pattern. In this case, the collapse force that causes the pattern to collapse is applied from the solvent to the pattern. If a solvent with low hydrophobicity is used, the amount of solvent remaining between the pattern after the solidified film is formed can be reduced to zero or near zero.

[0033] In this way, regardless of whether the pattern surface is hydrophilic or hydrophobic, the solvent contained in the liquid containing the sublimable substance has a lower affinity for the pattern surface than the sublimable substance contained in the liquid containing the sublimable substance. Consequently, the amount of solvent remaining between the patterns after the cured film is formed can be reduced, thereby reducing the collapse force applied to the pattern during or after the cured film is formed. Consequently, regardless of whether the pattern surface is hydrophilic or hydrophobic, the substrate can be dried with a low pattern collapse rate.

[0034] In the embodiment, at least one of the following features may be added to the substrate drying method.

[0035] The substrate drying method also includes: a property judgment step, when the surface of the pattern includes a hydrophilic portion and a hydrophobic portion and the upper end portion of the side surface of the pattern is hydrophilic, before selecting the sublimable substance and the solvent, the surface of the pattern is considered to be hydrophilic; when the surface of the pattern includes the hydrophilic portion and the hydrophobic portion and the upper end portion of the side surface of the pattern is hydrophobic, before selecting the sublimable substance and the solvent, the surface of the pattern is considered to be hydrophobic.

[0036] In this method, if the surface of a pattern includes hydrophilic and hydrophobic portions, the pattern surface is considered hydrophilic if the upper end of the side surface of the pattern is hydrophilic. If the surface of a pattern includes hydrophilic and hydrophobic portions, the pattern surface is considered hydrophobic if the upper end of the side surface of the pattern is hydrophobic. In other words, whether the pattern surface is hydrophilic or hydrophobic is determined based on the properties of the upper end of the side surface of the pattern.

[0037] If a liquid surface (the interface between gas and liquid) forms between two adjacent convex patterns, a collapsing force due to surface tension is applied to the pattern. This collapsing force increases as the distance from the base of the pattern to the liquid surface increases. Therefore, even if a liquid surface forms between two adjacent convex patterns, the collapsing force applied to the pattern is weak as long as the distance from the base (bottom) of the pattern to the liquid surface is short.

[0038] If the pattern surface contains both hydrophilic and hydrophobic portions, and the upper end of the pattern's side surface is hydrophilic, treating the pattern surface as hydrophobic will result in the solvent surface forming at the upper end of the pattern's side surface after the cured film is formed, potentially exerting a significant collapse force on the pattern. If the pattern surface is treated as hydrophilic, even if the solvent surface forms between the pattern elements, it will be located at the base of the pattern. This shortens the distance from the base of the pattern to the liquid surface.

[0039] For similar reasons, if the pattern surface includes hydrophilic and hydrophobic portions, and the upper end of the side surface of the pattern is hydrophobic, then if the pattern surface is considered hydrophobic, even if the solvent liquid surface forms between the patterns, the distance from the base of the pattern to the liquid surface can be shortened. This can reduce the collapse force applied to the pattern and thus reduce the collapse rate of the pattern.

[0040] Another embodiment of the present invention provides a substrate processing device for drying a surface of a substrate having a pattern formed thereon, wherein the device comprises: a sublimation substance selecting unit for selecting a sublimation substance based on whether the surface of the pattern is hydrophilic or hydrophobic; a solvent selecting unit for selecting a hydrophilic solvent having a lower solubility in water than the sublimation substance selected by the sublimation substance selecting unit when the surface of the pattern is hydrophilic, and for selecting a hydrophobic solvent having a lower solubility in oil than the sublimation substance selected by the sublimation substance selecting unit when the surface of the pattern is hydrophobic; and a dissolving unit for dissolving the sublimation substance by dissolving the sublimation substance selected by the sublimation substance selecting unit. The sublimable substance selected by the substance selection unit dissolves in the solvent selected by the solvent selection unit to produce a sublimable substance-containing liquid containing the sublimable substance and the solvent; the sublimable substance-containing liquid supply unit supplies the sublimable substance-containing liquid produced by the dissolving unit to the surface of the substrate; the cured film forming unit evaporates the solvent from the sublimable substance-containing liquid on the surface of the substrate to form a cured film containing the sublimable substance on the surface of the substrate; and the sublimation unit removes the cured film from the surface of the substrate by sublimating the cured film. This configuration can achieve the same effects as the substrate drying method.

[0041] Whether the pattern surface is hydrophilic or hydrophobic can be determined based on the surface properties (hydrophilicity or hydrophobicity) of the pattern when the liquid containing the sublimable substance first contacts the substrate surface. For example, if a chemical solution is supplied to the substrate surface before the liquid containing the sublimable substance is supplied, the surface properties of the pattern may change from one of hydrophilicity and hydrophobicity to the other. In such cases, the sublimable substance and solvent can be selected based on the surface properties of the pattern after the chemical solution is supplied.

[0042] If the selected sublimation substance is insoluble or poorly soluble in the selected solvent, the dissolution step may include an amphiphilic molecule addition step, in which the selected sublimation substance, the selected solvent, and an amphiphilic molecule containing both a hydrophilic group and a hydrophobic group are mixed to dissolve the selected sublimation substance in the selected solvent. The dissolution unit may also include an amphiphilic molecule addition unit, in which the selected sublimation substance, the selected solvent, and an amphiphilic molecule containing both a hydrophilic group and a hydrophobic group are mixed to dissolve the selected sublimation substance in the selected solvent. In these cases, the solvent dissolves in the amphiphilic molecule, and the sublimation substance dissolves in the mixture of the solvent and the amphiphilic molecule. Therefore, even if the sublimation substance is insoluble or poorly soluble in the solvent, a liquid containing the sublimation substance and the solvent can be produced.

[0043] The sublimation material selection step may also be a step in which, when the surface of the pattern is hydrophilic, the sublimation material containing a hydrophilic group is selected; and when the surface of the pattern is hydrophobic, the sublimation material containing a hydrophobic group is selected. The sublimation material selection unit may also be a unit in which, when the surface of the pattern is hydrophilic, the sublimation material containing a hydrophilic group is selected; and when the surface of the pattern is hydrophobic, the sublimation material containing a hydrophobic group is selected. In these cases, a liquid containing a sublimation material having a high affinity for the surface of the pattern can be produced. Therefore, the amount of solvent remaining between the patterns after the cured film is formed can be further reduced.

[0044] The above and other objects, features, and effects of the present invention will become more apparent from the following description of the embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1A This is a schematic diagram of a substrate processing apparatus according to a first embodiment of the present invention as viewed from above.

[0046] Figure 1B This is a schematic diagram of a substrate processing apparatus viewed from the side.

[0047] Figure 2 This is a schematic diagram showing the interior of a processing unit included in a substrate processing apparatus when viewed horizontally.

[0048] Figure 3 This is a schematic diagram showing a liquid supply unit containing a sublimable substance included in the substrate processing apparatus.

[0049] Figure 4(a) and (b) are cross-sectional views showing examples of cross sections of substrates processed by the substrate processing apparatus.

[0050] Figure 5 It is a block diagram showing the hardware of the control device.

[0051] Figure 6 This is a process diagram for explaining an example of processing of a substrate by a substrate processing apparatus.

[0052] Figure 7A This is a schematic diagram for explaining the following phenomenon, which is assumed to be Figure 6 This phenomenon occurs during the period from supplying a liquid containing a sublimable substance to the upper surface of the substrate to removing a cured film from the upper surface of the substrate in the treatment of the substrate shown.

[0053] Figure 7B This is a schematic diagram for explaining this phenomenon.

[0054] Figure 7C This is a schematic diagram for explaining this phenomenon.

[0055] Figure 7D This is a schematic diagram for explaining this phenomenon.

[0056] Figure 7E This is a schematic diagram for explaining this phenomenon.

[0057] Figure 7F This is a schematic diagram for explaining this phenomenon.

[0058] Figure 8A This is a schematic diagram for explaining the following phenomenon, which is assumed to be Figure 6 This phenomenon occurs during the period from supplying a liquid containing a sublimable substance to the upper surface of the substrate to removing a cured film from the upper surface of the substrate in the treatment of the substrate shown.

[0059] Figure 8B This is a schematic diagram for explaining this phenomenon.

[0060] Figure 8C This is a schematic diagram for explaining this phenomenon.

[0061] Figure 8D This is a schematic diagram for explaining this phenomenon.

[0062] Figure 9 This is a schematic diagram showing a liquid supply unit containing a sublimable substance included in a substrate processing apparatus according to a second embodiment of the present invention.

[0063] Figure 10 It is used for Figure 6 FIG. 1 is a process diagram for explaining another example of the process of supplying a liquid containing a sublimable substance shown in FIG. DETAILED DESCRIPTION

[0064] In the following description, unless otherwise specified, the atmospheric pressure in the substrate processing apparatus 1 is assumed to be maintained at the atmospheric pressure in the clean room where the substrate processing apparatus 1 is installed (eg, 1 atmosphere or a value close thereto).

[0065] Figure 1A This is a schematic diagram of the substrate processing apparatus 1 according to the first embodiment of the present invention as viewed from above. Figure 1B It is a schematic diagram of the substrate processing apparatus 1 as viewed from the side.

[0066] like Figure 1A As shown, a substrate processing apparatus 1 is a single-wafer apparatus that processes circular substrates W, such as semiconductor wafers, one by one. The apparatus 1 includes a load port LP that holds a carrier CA that stores the substrates W; multiple processing units 2 that process the substrates W transferred from the carrier CA on the load port LP using a processing fluid such as a processing liquid or a processing gas; a transfer robot that transfers the substrates W between the carrier CA on the load port LP and the processing units 2; and a control unit 3 that controls the apparatus 1.

[0067] The transport robots include an indexing robot IR, which loads and unloads substrates W into and out of carriers CA on load ports LP, and a central robot CR, which loads and unloads substrates W into and out of multiple processing units 2. The indexing robot IR transports substrates W between the load ports LP and the central robot CR, while the central robot CR transports substrates W between the indexing robot IR and the processing units 2. The central robot CR includes a hand H1 that supports the substrates W, and the indexing robot IR includes a hand H2 that supports the substrates W.

[0068] The plurality of processing units 2 form a plurality of towers TW arranged around the center robot CR in a plan view. Figure 1A An example is shown in which four towers TW are formed. The central robot CR can approach any of the towers TW. Figure 1B As shown, each tower TW includes a plurality (eg, three) of processing units 2 stacked one above the other.

[0069] like Figure 1A As shown, the substrate processing apparatus 1 includes multiple (e.g., four) fluid cartridges FB that house fluid devices such as valves. The four fluid cartridges FB correspond to four towers TW, respectively. Liquid within the cartridge CC is supplied via any of the fluid cartridges FB to all processing units 2 included in the tower TW corresponding to that cartridge FB. The cartridge CC of the substrate processing apparatus 1 can be positioned around the outer wall 1a of the substrate processing apparatus 1 or located underground within the clean room where the substrate processing apparatus 1 is installed.

[0070] Figure 2 It is a schematic diagram showing the interior of the processing unit 2 included in the substrate processing apparatus 1 when viewed horizontally.

[0071] The processing unit 2 is a wet processing unit 2w that supplies processing liquid to a substrate W. The processing unit 2 includes a box-shaped chamber 4 having an internal space, a spin chuck 10 that holds a substrate W horizontally within the chamber 4 while rotating the substrate W about a vertical rotation axis A1 passing through the center of the substrate W, and a cylindrical processing cup 21 that surrounds the spin chuck 10 about the rotation axis A1.

[0072] The chamber 4 includes a box-shaped partition wall 5 provided with a loading and unloading port 5b for the substrate W to pass through, and a baffle 7 for opening and closing the loading and unloading port 5b. The FFU6 (fan filter unit) is arranged above the air supply port 5a provided on the upper part of the partition wall 5. The FFU6 always supplies clean air (air that has been filtered by the filter) into the chamber 4 from the air supply port 5a. The gas in the chamber 4 passes through the exhaust pipe 8 connected to the bottom of the processing cup 21 and is discharged from the chamber 4. As a result, a downward flow of clean air is always formed in the chamber 4. The flow rate of the exhaust gas discharged from the exhaust pipe 8 changes according to the opening of the exhaust valve 9 arranged in the exhaust pipe 8.

[0073] The spin chuck 10 includes a disk-shaped spin base 12 held horizontally, a plurality of chuck pins 11 above the spin base 12 that hold the substrate W horizontally, a rotation shaft 13 extending downward from the center of the spin base 12, and a rotation motor 14 that rotates the spin base 12 and the plurality of chuck pins 11 by rotating the rotation shaft 13. The spin chuck 10 is not limited to a clamping chuck in which the plurality of chuck pins 11 contact the outer circumference of the substrate W. It may also be a vacuum chuck that holds the substrate W horizontally by adsorbing the back surface (lower surface) of the substrate W, which is the non-device forming surface, against the upper surface 12u of the spin base 12.

[0074] The processing cup 21 includes a plurality of shields 24 for receiving processing liquid discharged from the substrate W, a plurality of cups 23 for receiving processing liquid guided downward by the shields 24 , and a cylindrical outer wall member 22 surrounding the shields 24 and the cups 23 . Figure 2 An example is shown in which four protective covers 24 and three cups 23 are provided, and the outermost cup 23 is integrated with the third protective cover 24 from the top.

[0075] The protective cover 24 includes a cylindrical portion 25 that surrounds the rotary chuck 10 and an annular top portion 26 that extends obliquely upward from the upper end of the cylindrical portion 25 toward the rotation axis A1. Multiple top portions 26 overlap each other, and the multiple cylindrical portions 25 are arranged in a concentric circle. The top portion 26 is annular in shape, and its upper end corresponds to the upper end 24u of the protective cover 24 that surrounds the substrate W and the rotating base 12 when viewed from above. Multiple cups 23 are respectively arranged below the multiple cylindrical portions 25. The cups 23 form an annular liquid receiving tank that receives the processing liquid guided downward by the protective cover 24.

[0076] The processing unit 2 includes a shield lift unit 27 for lifting each of the plurality of shields 24. The shield lift unit 27 positions the shields 24 at any position within a range from an upper position to a lower position. Figure 2 The figure shows a state where two protective covers 24 are arranged in an upper position and the remaining two protective covers 24 are arranged in a lower position. The upper position is when the upper ends 24u of the protective covers 24 are arranged above the holding position of the substrate W held by the spin chuck 10. The lower position is when the upper ends 24u of the protective covers 24 are arranged below the holding position.

[0077] When supplying processing liquid to the rotating substrate W, at least one protective cover 24 is positioned in the upper position. In this position, when processing liquid is supplied to the substrate W, the processing liquid is flung outward from the substrate W. The flung processing liquid collides with the inner surface of the protective cover 24, which is positioned horizontally opposite the substrate W, and is guided into the cup 23 corresponding to the protective cover 24. Thus, the processing liquid discharged from the substrate W is collected in the cup 23.

[0078] The processing unit 2 includes a plurality of nozzles for ejecting a processing liquid toward a substrate W held on a spin chuck 10. The plurality of nozzles include a chemical liquid nozzle 31 for ejecting a chemical liquid toward the upper surface of the substrate W, a rinse liquid nozzle 35 for ejecting a rinse liquid toward the upper surface of the substrate W, a liquid nozzle 39 for ejecting a liquid containing a sublimable substance toward the upper surface of the substrate W, and a replacement liquid nozzle 43 for ejecting a replacement liquid toward the upper surface of the substrate W.

[0079] The chemical liquid nozzle 31 may be a scanning nozzle that can move horizontally within the chamber 4 or a fixed nozzle fixed to the partition wall 5 of the chamber 4. The same applies to the rinse liquid nozzle 35, the liquid nozzle 39 containing the sublimable substance, and the replacement liquid nozzle 43. Figure 2 The example shown is as follows: the chemical liquid nozzle 31 , the rinse liquid nozzle 35 , the liquid nozzle 39 containing a sublimable substance, and the replacement liquid nozzle 43 are scanning nozzles, and four nozzle moving units corresponding to these four nozzles are provided.

[0080] The chemical nozzle 31 is connected to a chemical piping 32 that guides the chemical liquid to the chemical nozzle 31. When a chemical valve 33, located on the chemical piping 32, is opened, the chemical liquid is continuously ejected downward from the discharge port of the chemical nozzle 31. The chemical liquid ejected from the chemical nozzle 31 may include at least one of sulfuric acid, nitric acid, hydrochloric acid, hydrofluoric acid, phosphoric acid, acetic acid, aqueous ammonia, aqueous hydrogen peroxide, an organic acid (e.g., citric acid, oxalic acid), an organic base (e.g., TMAH: tetramethylammonium hydroxide), a surfactant, and an anticorrosive agent, or may be any other liquid.

[0081] Although not shown, the liquid medicine valve 33 includes a valve body with an annular valve seat through which the liquid medicine passes; a valve body that is movable relative to the valve seat; and an actuator that moves the valve body between a closed position, in which the valve body contacts the valve seat, and an open position, in which the valve body separates from the valve seat. The same applies to other valves. The actuator can be a pneumatic actuator, an electric actuator, or other types. The control device 3 controls the actuator to open and close the liquid medicine valve 33.

[0082] 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 moves the chemical liquid nozzle 31 horizontally between a processing position, where the chemical liquid ejected from the chemical liquid nozzle 31 is supplied to the upper surface of the substrate W, and a standby position, where the chemical liquid nozzle 31 is positioned around the processing cup 21 when viewed from above.

[0083] Rinse liquid nozzle 35 is connected to a rinse liquid pipe 36 that guides rinse liquid to rinse liquid nozzle 35. When rinse liquid valve 37, installed in rinse liquid pipe 36, is opened, rinse liquid is continuously ejected downward from the nozzle of rinse liquid nozzle 35. The rinse liquid ejected from rinse liquid nozzle 35 is, for example, pure water (deionized water: DIW). Alternatively, the rinse liquid may be any of carbonated water, electrolytically ionized water, hydrogen water, ozone water, and hydrochloric acid water at a diluted concentration (e.g., approximately 10 to 100 ppm).

[0084] The rinsing liquid nozzle 35 is connected to a nozzle moving unit 38 that moves the rinsing liquid nozzle 35 in at least one of a vertical direction and a horizontal direction. The nozzle moving unit 38 moves the rinsing liquid nozzle 35 horizontally between a processing position, where the rinsing liquid ejected from the rinsing liquid nozzle 35 is supplied to the upper surface of the substrate W, and a standby position, where the rinsing liquid nozzle 35 is located around the processing cup 21 when viewed from above.

[0085] The sublimable liquid nozzle 39 is connected to a sublimable liquid piping 40 that guides the treatment liquid to the sublimable liquid nozzle 39. When a sublimable liquid valve 41, mounted on the sublimable liquid piping 40, is opened, the sublimable liquid is continuously ejected downward from the ejection port of the sublimable liquid nozzle 39. Similarly, the replacement liquid nozzle 43 is connected to a replacement liquid piping 44 that guides the replacement liquid to the replacement liquid nozzle 43. When a replacement liquid valve 45, mounted on the replacement liquid piping 44, is opened, the replacement liquid is continuously ejected downward from the ejection port of the replacement liquid nozzle 43.

[0086] The liquid containing a sublimable substance is a solution containing a sublimable substance corresponding to a solute and a solvent that is compatible with the sublimable substance. The liquid containing a sublimable substance may further contain substances other than the sublimable substance and the solvent. The sublimable substance may also be a substance that directly transforms from a solid to a gas without passing through a liquid at normal temperature (synonymous with room temperature) or normal pressure (the pressure within the substrate processing apparatus 1, such as 1 atmosphere or a value close thereto).

[0087] The freezing point of the liquid containing the sublimable substance (the freezing point at 1 atmosphere. The same shall apply hereinafter) is lower than room temperature (e.g., 23°C or a value in the vicinity thereof). The substrate processing apparatus 1 is arranged in a clean room maintained at room temperature. Therefore, even if the liquid containing the sublimable substance is not heated, the liquid containing the sublimable substance can be maintained as a liquid. The freezing point of the sublimable substance is higher than the freezing point of the liquid containing the sublimable substance. The freezing point of the sublimable substance is higher than room temperature. At room temperature, the sublimable substance is solid. The freezing point of the sublimable substance may also be higher than the boiling point of the solvent. The vapor pressure of the solvent is higher than the vapor pressure of the sublimable substance.

[0088] The sublimable substance may be, for example, an alcohol such as 2-methyl-2-propanol (also known as tert-butyl alcohol, t-butyl alcohol, tertiary butyl alcohol) or cyclohexanol, a hydrofluorocarbon, 1,3,5-trioxane (also known as trioxymethylene), camphor (also known as camphre, camphor), naphthalene, and iodine, or may be a substance other than these.

[0089] The solvent may be, for example, at least one selected from the group consisting of pure water, IPA, methanol, HFE (hydrofluoroether), acetone, PGMEA (propylene glycol monomethyl ether acetate), PGEE (propylene glycol monoethyl ether, 1-ethoxy-2-propanol), and ethylene glycol. IPA has a higher vapor pressure and a lower surface tension than water.

[0090] As described later, a replacement liquid is supplied to the upper surface of the substrate W covered by the liquid film of the rinsing liquid, and a liquid containing a sublimable substance is supplied to the upper surface of the substrate W covered by the liquid film of the replacement liquid. The replacement liquid can be any liquid as long as it is compatible with both the rinsing liquid and the liquid containing a sublimable substance. An example of the replacement liquid is IPA (liquid). The replacement liquid can also be a mixture of IPA and HFE, or other liquids.

[0091] If a replacement liquid is supplied to the upper surface of the substrate W covered by the liquid film of the rinsing liquid, most of the rinsing liquid on the substrate W is washed away by the replacement liquid and discharged from the substrate W. The remaining trace amount of rinsing liquid dissolves in the replacement liquid and diffuses in the replacement liquid. The diffused rinsing liquid is discharged from the substrate W together with the replacement liquid. Therefore, the rinsing liquid on the substrate W can be efficiently replaced with the replacement liquid. For the same reason, the replacement liquid on the substrate W can be efficiently replaced with a liquid containing a sublimable substance. As a result, the rinsing liquid contained in the liquid containing a sublimable substance on the substrate W can be reduced.

[0092] The liquid nozzle 39 containing a sublimable substance is connected to a nozzle moving unit 42 that moves the liquid nozzle 39 in at least one of a vertical direction and a horizontal direction. The nozzle moving unit 42 moves the liquid nozzle 39 containing a sublimable substance horizontally between a processing position, where the liquid containing a sublimable substance ejected from the liquid nozzle 39 is supplied to the upper surface of the substrate W, and a standby position, where the liquid nozzle 39 containing a sublimable substance is located around the processing cup 21 in a plan view.

[0093] Similarly, the replacement fluid nozzle 43 is connected to a nozzle moving unit 46 that moves the replacement fluid nozzle 43 in at least one of a vertical direction and a horizontal direction. The nozzle moving unit 46 moves the replacement fluid nozzle 43 horizontally between a processing position, where the replacement fluid ejected from the replacement fluid nozzle 43 is supplied to the upper surface of the substrate W, and a standby position, where the replacement fluid nozzle 43 is positioned around the processing cup 21 when viewed from above.

[0094] The processing unit 2 includes a blocking member 51 disposed above the spin chuck 10 . Figure 2An example is shown in which the barrier member 51 is a circular barrier plate. The barrier member 51 includes a circular plate portion 52 horizontally arranged above the spin chuck 10. The barrier member 51 is horizontally supported by a cylindrical support shaft 53 extending upward from the center of the circular plate portion 52. The center line of the circular plate portion 52 is arranged on the rotation axis A1 of the substrate W. The lower surface of the circular plate portion 52 corresponds to the lower surface 51L of the barrier member 51. The lower surface 51L of the barrier member 51 is the facing surface facing the upper surface of the substrate W. The lower surface 51L of the barrier member 51 is parallel to the upper surface of the substrate W and has an outer diameter greater than the diameter of the substrate W.

[0095] The blocking member 51 is connected to a blocking member lifting unit 54 that vertically lifts and lowers the blocking member 51. The blocking member lifting unit 54 positions the blocking member 51 from the upper position ( Figure 2 The barrier member 51 may be positioned at any position within a range from the upper position (shown in FIG. 1 ) to the lower position. The lower position is a close position where the lower surface 51L of the barrier member 51 is brought close to the upper surface of the substrate W to a height where a scanning nozzle such as the liquid medicine nozzle 31 cannot enter between the substrate W and the barrier member 51. The upper position is a separated position where the barrier member 51 is retracted to a height where a scanning nozzle can enter between the barrier member 51 and the substrate W.

[0096] The plurality of nozzles include a central nozzle 55, which ejects a processing fluid such as a processing liquid or a processing gas downward through an upper central opening 61 opened in the central portion of the lower surface 51L of the barrier member 51. The central nozzle 55 extends up and down along the rotation axis A1. The central nozzle 55 is arranged in a through hole that passes through the central portion of the barrier member 51 from top to bottom. The inner peripheral surface of the barrier member 51 surrounds the outer peripheral surface of the central nozzle 55 at intervals in the radial direction (in a direction perpendicular to the rotation axis A1). The central nozzle 55 rises and falls together with the barrier member 51. The nozzle of the central nozzle 55 that ejects the processing fluid is arranged above the upper central opening 61 of the barrier member 51.

[0097] The central nozzle 55 is connected to an upper gas pipe 56 that guides inert gas to the central nozzle 55. The substrate processing apparatus 1 may also include an upper temperature regulator 59 that heats or cools the inert gas ejected from the central nozzle 55. When the upper gas valve 57 installed in the upper gas pipe 56 is opened, the inert gas is continuously ejected downward from the ejection port of the central nozzle 55 at a flow rate corresponding to the opening of the flow control valve 58, which changes the flow rate of the inert gas. The inert gas ejected from the central nozzle 55 is nitrogen. The inert gas may also be a gas other than nitrogen, such as helium or argon.

[0098] The inner circumferential surface of the barrier member 51 and the outer circumferential surface of the central nozzle 55 form a cylindrical upper gas flow path 62 extending up and down. The upper gas flow path 62 is connected to an upper gas pipe 63 that guides the inert gas to the upper central opening 61 of the barrier member 51. The substrate processing device 1 may also have an upper temperature regulator 66 that heats or cools the inert gas ejected from the upper central opening 61 of the barrier member 51. If the upper gas valve 64 installed on the upper gas pipe 63 is opened, the inert gas is continuously ejected downward from the upper central opening 61 of the barrier member 51 at a flow rate corresponding to the opening of the flow regulating valve 65 that changes the flow rate of the inert gas. The inert gas ejected from the upper central opening 61 of the barrier member 51 is nitrogen. The inert gas may also be a gas other than nitrogen, such as helium or argon.

[0099] The multiple nozzles include a lower surface nozzle 71 that discharges processing liquid toward the center of the lower surface of the substrate W. The lower surface nozzle 71 comprises a nozzle disc portion positioned between the upper surface 12u of the spin base 12 and the lower surface of the substrate W, and a nozzle tubular portion extending downward from the nozzle disc portion. The discharge port of the lower surface nozzle 71 opens in the center of the upper surface of the nozzle disc portion. When the substrate W is held on the spin chuck 10, the discharge port of the lower surface nozzle 71 faces the center of the lower surface of the substrate W vertically.

[0100] The lower surface nozzle 71 is connected to a heating fluid pipe 72 that guides warm water (pure water with a temperature higher than room temperature), an example of a heating fluid, to the lower surface nozzle 71. The pure water supplied to the lower surface nozzle 71 is heated by a heater 75 installed in the heating fluid pipe 72. When a heating fluid valve 73 installed in the heating fluid pipe 72 is opened, warm water is continuously ejected upward from the ejection port of the lower surface nozzle 71 at a flow rate corresponding to the opening of a flow control valve 74, which changes the flow rate of the warm water. This supplies warm water to the lower surface of the substrate W.

[0101] The lower surface nozzle 71 is further connected to a cooling fluid pipe 76 that guides cold water (pure water with a temperature lower than room temperature), an example of a cooling fluid, to the lower surface nozzle 71. The pure water supplied to the lower surface nozzle 71 is cooled by a cooler 79 installed in the cooling fluid pipe 76. When a cooling fluid valve 77 installed in the cooling fluid pipe 76 is opened, cold water is continuously ejected upward from the ejection port of the lower surface nozzle 71 at a flow rate corresponding to the opening of a flow control valve 78, which changes the flow rate of the cold water. This supplies cold water to the lower surface of the substrate W.

[0102] The outer peripheral surface of the lower surface nozzle 71 and the inner peripheral surface of the rotating base 12 form a cylindrical lower gas flow path 82 extending up and down. The lower gas flow path 82 includes a lower central opening 81 opened in the central portion of the upper surface 12u of the rotating base 12. The lower gas flow path 82 is connected to a lower gas piping 83 that guides the inert gas to the lower central opening 81 of the rotating base 12. The substrate processing apparatus 1 may also include a lower temperature regulator 86 that heats or cools the inert gas ejected from the lower central opening 81 of the rotating base 12. If the lower gas valve 84 installed in the lower gas piping 83 is opened, the inert gas is continuously ejected upward from the lower central opening 81 of the rotating base 12 at a flow rate corresponding to the opening degree of the flow adjustment valve 85 that changes the flow rate of the inert gas.

[0103] The inert gas ejected from the lower central opening 81 of the spin base 12 is nitrogen. The inert gas may also be a gas other than nitrogen, such as helium or argon. When nitrogen is ejected from the lower central opening 81 of the spin base 12 while the substrate W is held on the spin chuck 10, the nitrogen flows radially in all directions between the lower surface of the substrate W and the upper surface 12u of the spin base 12. As a result, the space between the substrate W and the spin base 12 is filled with nitrogen.

[0104] Next, the liquid supply unit 99 containing the sublimable substance will be described.

[0105] Figure 3 Schematic diagram showing a liquid supply unit 99 containing a sublimable substance included in the substrate processing apparatus 1 . Figure 4 1 is a cross-sectional view illustrating an example of a cross section of a substrate W processed by the substrate processing apparatus 1 .

[0106] like Figure 3 As shown, the substrate processing apparatus 1 includes a liquid supply unit 99 containing a sublimable substance for supplying a liquid containing a sublimable substance to a substrate W held by a spin chuck 10. The liquid nozzle 39 containing a sublimable substance, the liquid pipe 40 containing a sublimable substance, and the liquid valve 41 containing a sublimable substance are included in the liquid supply unit 99 containing a sublimable substance.

[0107] The liquid supply unit 99 containing a sublimable substance includes a raw liquid tank 87 for storing a liquid containing a sublimable substance equivalent to a raw liquid, a circulation pipe 88 for circulating the liquid containing a sublimable substance in the raw liquid tank 87, a pump 89 for transferring the liquid containing a sublimable substance in the raw liquid tank 87 to the circulation pipe 88, and an individual pipe 90 for guiding the liquid containing a sublimable substance in the circulation pipe 88 to the liquid pipe containing a sublimable substance 40. The liquid supply unit 99 containing a sublimable substance further includes an on-off valve 91 for opening and closing the interior of the individual pipe 90, and a flow rate regulating valve 92 for varying the flow rate of the liquid containing a sublimable substance supplied from the individual pipe 90 to the liquid pipe containing a sublimable substance 40.

[0108] The liquid supply unit 99 containing a sublimable substance includes a diluent tank 93, which stores a diluent for diluting the liquid containing a sublimable substance. The diluent may be, for example, a solvent having the same name as the solvent contained in the liquid containing a sublimable substance in the original liquid tank 87. The diluent supply unit includes a circulation pipe 94 for circulating the diluent in the diluent tank 93, a pump 95 for transferring the diluent from the diluent tank 93 to the circulation pipe 94, and a separate pipe 96 for directing the diluent in the circulation pipe 94 to the liquid pipe 40 containing a sublimable substance. The diluent supply unit also includes an on-off valve 97 for opening and closing the interior of the separate pipe 96, and a flow control valve 98 for adjusting the flow rate of the diluent supplied from the separate pipe 96 to the liquid pipe 40 containing a sublimable substance.

[0109] When the on-off valve 91 is opened, the liquid containing the sublimable substance is supplied to the liquid piping 40 containing the sublimable substance at a flow rate corresponding to the opening of the flow control valve 92. When the on-off valve 97 is opened, the diluent is supplied to the liquid piping 40 containing the sublimable substance at a flow rate corresponding to the opening of the flow control valve 98. When both the on-off valve 91 and the on-off valve 97 are opened, the liquid containing the sublimable substance supplied from the stock liquid tank 87 and the diluent supplied from the diluent tank 93 are mixed and diluted in the liquid piping 40 containing the sublimable substance. The diluted liquid containing the sublimable substance is then ejected from the liquid nozzle 39 containing the sublimable substance.

[0110] The control device 3 sets the openings of the on-off valve 91, the flow control valve 92, the on-off valve 97, and the flow control valve 98 based on the concentration of the liquid containing a sublimable substance (sublimable substance concentration) specified by a recipe (described later). For example, when the concentration of the liquid containing a sublimable substance specified by the recipe matches the concentration of the liquid containing a sublimable substance in the stock liquid tank 87, the on-off valve 91 is opened and the on-off valve 97 is closed. When the concentration of the liquid containing a sublimable substance specified by the recipe is lower than the concentration of the liquid containing a sublimable substance in the stock liquid tank 87, both the on-off valve 91 and the on-off valve 97 are opened, and the openings of the flow control valve 92 and the flow control valve 98 are adjusted. This allows the concentration of the liquid containing a sublimable substance ejected from the liquid nozzle 39 containing a sublimable substance to approach the concentration of the liquid containing a sublimable substance specified by the recipe.

[0111] The liquid containing the sublimable substance is selected according to the substrate W to be processed by the substrate processing apparatus 1 and is stored in the raw liquid tank 87 before starting the processing of the substrate W in the substrate processing apparatus 1. Figure 4 ) is hydrophilic, a sublimation substance containing a hydrophilic group and a hydrophilic solvent having a lower solubility in water than the sublimation substance are selected. In the case where the surface of the pattern P1 formed on the surface of the substrate W is hydrophobic, a sublimation substance containing a hydrophobic group and a hydrophobic solvent having a lower solubility in oil than the sublimation substance are selected. Then, the selected sublimation substance is dissolved in the selected solvent. Thus, a liquid containing the selected sublimation substance and the solvent is manufactured. The dissolution of the sublimation substance in the solvent can be carried out in the stock liquid tank 87 or in a tank different from the stock liquid tank 87.

[0112] The liquid containing the sublimable substance in the original liquid tank 87 may contain two or more sublimable substances, or may contain two or more solvents. The liquid containing the sublimable substance in the original liquid tank 87 may further contain substances other than the sublimable substance and the solvent. For example, the liquid containing the sublimable substance may contain amphiphilic molecules containing both hydrophilic and hydrophobic groups. In this case, the solvent may not be a substance containing both hydrophilic and hydrophobic groups in its molecule, such as alcohol.

[0113] If the surface of pattern P1 is hydrophilic and the liquid containing a sublimable substance contains two or more sublimable substances, at least one of the sublimable substances may contain a hydrophilic group. In this case, the solubility of the solvent in water is lower than that of the sublimable substance containing a hydrophilic group. If the surface of pattern P1 is hydrophilic and the liquid containing a sublimable substance contains two or more solvents, it is preferable that the solubility of all solvents in water is lower than that of the sublimable substance containing a hydrophilic group.

[0114] If the surface of pattern P1 is hydrophobic and the liquid containing a sublimable substance contains two or more sublimable substances, at least one of the sublimable substances needs to contain a hydrophobic group. In this case, the solubility of the solvent in the oil is lower than the solubility of the sublimable substance containing a hydrophobic group in the oil. If the surface of pattern P1 is hydrophobic and the liquid containing a sublimable substance contains two or more solvents, it is preferable that the solubility of all solvents in the oil is lower than the solubility of the sublimable substance containing a hydrophobic group in the oil.

[0115] If the surface of pattern P1 is hydrophilic, the liquid containing the sublimable substance can be a solution containing camphor, tert-butyl alcohol, and IPA, or a solution containing camphor, IPA, a first solute, a second solute, and a first solvent, or a solution other than these. Specific examples of the first solute, the second solute, and the first solvent are described below. If the surface of pattern P1 is hydrophobic, the liquid containing the sublimable substance can be a solution containing camphor and IPA, or a solution containing camphor and methanol, or a solution other than these. Camphor is a sublimable substance containing a methyl group, an example of a hydrophobic group, in its molecule. Tert-butyl alcohol is a sublimable substance containing a methyl group, an example of a hydrophobic group, and a hydroxyl group, an example of a hydrophilic group, in its molecule.

[0116] The first solute and the second solute are each a separate substance. The first solute and the second solute are different substances. The first solute and the second solute each have at least one of an amino group, a hydroxyl group, and a carbonyl group.

[0117] The first solute and the second solute are each any one of phthalic anhydride, caffeine, melamine, 1,4-benzoquinone, camphor, hexamethylenetetramine, hexahydro-1,3,5-trimethyl-1,3,5-triazine, 1-adamantanol, 1,4-diazabicyclo[2.2.2]octane, borneol, (-)-borneol, (±)-isoborneol, 1,2-cyclohexanedione, 1,3-cyclohexanedione, 1,4-cyclohexanedione, 3-methyl-1,2-cyclopentanedione, (±)-camphorquinone, (-)-camphorquinone, (+)-camphorquinone, and 1-adamantanamine.

[0118] The first solvent may not contain pure water, or may contain pure water and one or more substances other than pure water. The first solvent may also contain an organic solvent. The organic solvent may be a single substance or a mixture of two or more substances.

[0119] Examples of organic solvents include: alcohols such as methanol (MeOH), ethanol (EtOH), and isopropyl alcohol (IPA); alkanes such as hexane, heptane, and octane; ethers such as ethyl butyl ether, dibutyl ether, and tetrahydrofuran (THF); lactic acid esters such as methyl lactate and ethyl lactate (EL); aromatic hydrocarbons such as benzene, toluene, and xylene; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-heptanone, cyclopentanone, and cyclohexanone; amides such as N,N-dimethylacetamide and N-methylpyrrolidone; lactones such as γ-butyrolactone, etc.

[0120] Examples of the ethers include, among others, ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate and ethylene glycol monoethyl ether acetate; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether (PGME) and propylene glycol monoethyl ether (PGEE); and propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monoethyl ether acetate.

[0121] like Figure 4 As shown in (a), if the entire surface area of pattern P1, that is, the entire area of the upper surface Pu of pattern P1 and the entire area of the side surface Ps of pattern P1, have the same properties, then the surface of pattern P1 is determined to be hydrophilic as long as any part of the surface of pattern P1 is hydrophilic. If the entire surface area of pattern P1 has the same properties, then the surface of pattern P1 is determined to be hydrophobic as long as any part of the surface of pattern P1 is hydrophobic. In this case, if the contact angle of water with respect to the surface of pattern P1 is, for example, 60 degrees or less, then the surface of pattern P1 is determined to be hydrophilic. If the entire surface area of pattern P1 has the same properties, pattern P1 can be either a single-layer film or a laminated film.

[0122] On the other hand, Figure 4 As shown in (b), if the surface of pattern P1 includes both hydrophilic and hydrophobic portions and the upper end Px of side surface Ps of pattern P1 is hydrophilic, the surface of pattern P1 is considered hydrophilic. If the surface of pattern P1 includes both hydrophilic and hydrophobic portions and the upper end Px of side surface Ps of pattern P1 is hydrophobic, the surface of pattern P1 is considered hydrophobic. That is, if the surface of pattern P1 includes both hydrophilic and hydrophobic portions, the properties of the upper end Px of side surface Ps of pattern P1 determine whether the surface of pattern P1 is hydrophilic or hydrophobic.

[0123] Figure 5 2 is a block diagram showing the hardware of the control device 3 .

[0124] The control device 3 is a computer comprising a main computer 3a and peripheral devices 3d connected to the main computer 3a. The main computer 3a includes a CPU 3b (central processing unit) that executes various commands and a main storage device 3c that stores information. The peripheral devices 3d include an auxiliary storage device 3e that stores information such as programs P, a reader 3f that reads information from removable media RM, and a communication device 3g that communicates with other devices such as a host computer.

[0125] The control device 3 is connected to an input device and a display device. The input device is operated when an operator, such as a user or maintenance personnel, inputs information into the substrate processing apparatus 1. The information is displayed on a screen of the display device. The input device can be any of a keyboard, a pointing device, and a touch panel, or other devices. A touch panel display that serves as both an input device and a display device can also be provided in the substrate processing apparatus 1.

[0126] The CPU 3b executes the program P stored in the auxiliary storage device 3e. The program P in the auxiliary storage device 3e may be a program pre-installed in the control device 3, a program transferred to the auxiliary storage device 3e from the removable medium RM via the reading device 3f, or a program transferred to the auxiliary storage device 3e from an external device such as a host computer via the communication device 3g.

[0127] The auxiliary storage device 3e and removable medium RM are nonvolatile memories that retain stored data even when power is off. The auxiliary storage device 3e is, for example, a magnetic storage device such as a hard disk drive. The removable medium RM is, for example, an optical disk such as a CD (compact disk) or a semiconductor memory such as a memory card. The removable medium RM is an example of a computer-readable recording medium that stores the program P. The removable medium RM is a non-transitory, tangible recording medium.

[0128] The auxiliary storage device 3e stores multiple processing programs. A processing program is information that specifies the processing details, processing conditions, and processing sequence for substrates W. Each of the multiple processing programs differs from the others in at least one of the processing details, processing conditions, and processing sequence for the substrates W. The control device 3 controls the substrate processing apparatus 1 so that substrates W are processed according to the processing program specified by the host computer. The control device 3 is programmed to execute the following steps.

[0129] Figure 61 is a process diagram for explaining an example of processing of a substrate W by the substrate processing apparatus 1. Figure 2 and Figure 6 .

[0130] The substrate W to be processed is, for example, a semiconductor wafer such as a silicon wafer. The surface of the substrate W corresponds to a device forming surface for forming devices such as transistors or capacitors. The substrate W may be a substrate having a pattern P1 formed on the pattern forming surface, i.e., the surface of the substrate W (see Figure 7A ) may be a substrate W having no pattern P1 formed on the surface of the substrate W. In the latter case, the pattern P1 may be formed in the chemical solution supplying step described later.

[0131] When the substrate W is processed by the substrate processing apparatus 1, a loading step ( Figure 6 Step S1).

[0132] Specifically, when the blocking member 51 is in the upper position, all the protective covers 24 are in the lower position, and all the scanning nozzles are in the standby position, the central robot CR (refer to Figure 1A ) While supporting the substrate W with its hand H1, the central robot CR moves the hand H1 into the chamber 4. The central robot CR then places the substrate W on the hand H1 onto the chuck pins 11 with the surface of the substrate W facing upward. The chuck pins 11 are then pressed against the outer circumference of the substrate W, thereby gripping the substrate W. After the central robot CR places the substrate W on the spin chuck 10, the hand H1 retreats from the interior of the chamber 4.

[0133] Next, the upper gas valve 64 and the lower gas valve 84 are opened, and nitrogen gas begins to be ejected from the upper central opening 61 of the barrier member 51 and the lower central opening 81 of the rotating base 12. As a result, the space between the substrate W and the barrier member 51 is filled with nitrogen gas. Similarly, the space between the substrate W and the rotating base 12 is filled with nitrogen gas. On the other hand, the protective cover lifting unit 27 raises at least one protective cover 24 from the lower position to the upper position. Thereafter, the rotation motor 14 is driven to start the rotation of the substrate W ( Figure 6 Step S2). Thus, the substrate W is rotated at the liquid supply speed.

[0134] Next, the liquid medicine supply process is carried out ( Figure 6 In step S3), in this chemical liquid supply process, the chemical liquid is supplied to the upper surface of the substrate W to form a chemical liquid film covering the entire area of the upper surface of the substrate W.

[0135] Specifically, with the barrier member 51 in the upper position and at least one protective cover 24 in the upper position, the nozzle moving unit 34 moves the liquid medicine nozzle 31 from the standby position to the processing position. The liquid medicine valve 33 is then opened, and the liquid medicine nozzle 31 begins to spray the liquid medicine. After a predetermined time has passed since the liquid medicine valve 33 was opened, the liquid medicine valve 33 is closed, stopping the spraying of the liquid medicine. The nozzle moving unit 34 then moves the liquid medicine nozzle 31 to the standby position.

[0136] After the chemical liquid ejected from the chemical nozzle 31 collides with the upper surface of the substrate W, which is rotating at the liquid supply speed, it is then drawn outward along the upper surface of the substrate W by centrifugal force. Consequently, the chemical liquid is supplied to the entire upper surface of the substrate W, forming a chemical liquid film that covers the entire upper surface of the substrate W. As the chemical liquid nozzle 31 ejects the chemical liquid, the nozzle moving unit 34 can move the chemical liquid's landing position relative to the upper surface of the substrate W, either through the center and the periphery, or by keeping the landing position stationary at the center.

[0137] Next, the rinse liquid supply process is performed ( Figure 6 In step S4), in the rinse liquid supply process, pure water as an example of the rinse liquid is supplied to the upper surface of the substrate W, thereby rinsing the chemical liquid on the substrate W.

[0138] Specifically, when the blocking member 51 is in the upper position and at least one protective cover 24 is in the upper position, the nozzle moving unit 38 moves the rinsing liquid nozzle 35 from the standby position to the processing position. Then, the rinsing liquid valve 37 is opened, and the rinsing liquid nozzle 35 starts to spray the rinsing liquid. Before starting to spray pure water, the protective cover lifting unit 27 may also vertically move at least one protective cover 24 in order to switch the protective cover 24 that receives the liquid discharged from the substrate W. If a specified time has passed after the rinsing liquid valve 37 is opened, the rinsing liquid valve 37 is closed, thereby stopping the spraying of the rinsing liquid. Then, the nozzle moving unit 38 moves the rinsing liquid nozzle 35 to the standby position.

[0139] After the pure water ejected from the rinse liquid nozzle 35 collides with the upper surface of the substrate W, which is rotating at the liquid supply speed, it is centrifugally forced to flow outward along the upper surface of the substrate W. The chemical liquid on the substrate W is replaced by the pure water ejected from the rinse liquid nozzle 35. This forms a liquid film of pure water covering the entire upper surface of the substrate W. While the rinse liquid nozzle 35 ejects pure water, the nozzle moving unit 38 can move the landing position of the pure water relative to the upper surface of the substrate W, such that the landing position passes through the center and the periphery, or the landing position remains stationary at the center.

[0140] Next, the replacement fluid supply process is performed ( Figure 6In step S5), in the replacement liquid supply process, a replacement liquid that is compatible with both the rinse liquid and the liquid containing the sublimable substance is supplied to the upper surface of the substrate W, and the pure water on the substrate W is replaced by the replacement liquid.

[0141] Specifically, with the barrier member 51 in the upper position and at least one protective cover 24 in the upper position, the nozzle moving unit 46 moves the replacement fluid nozzle 43 from the standby position to the processing position. The replacement fluid valve 45 is then opened, causing the replacement fluid nozzle 43 to begin discharging the replacement fluid. Before discharging the replacement fluid begins, the protective cover lifting unit 27 may vertically move at least one protective cover 24 to switch the protective cover 24 that receives the liquid discharged from the substrate W. After a predetermined time has passed since the replacement fluid valve 45 was opened, the replacement fluid valve 45 is closed, thereby stopping the discharging of the replacement fluid. The nozzle moving unit 46 then moves the replacement fluid nozzle 43 to the standby position.

[0142] After the replacement liquid ejected from the replacement liquid nozzle 43 collides with the upper surface of the substrate W rotating at the liquid supply speed, it flows outward along the upper surface of the substrate W due to centrifugal force. The pure water on the substrate W is replaced by the replacement liquid ejected from the replacement liquid nozzle 43. Thus, a liquid film of the replacement liquid covering the entire area of the upper surface of the substrate W is formed. When the replacement liquid nozzle 43 ejects the replacement liquid, the nozzle moving unit 46 can move the landing position of the replacement liquid relative to the upper surface of the substrate W in a manner that the landing position passes through the central part and the peripheral part, or can make the landing position stationary in the central part. In addition, after the liquid film of the replacement liquid covering the entire area of the upper surface of the substrate W is formed, the replacement liquid nozzle 43 can stop ejecting the replacement liquid while the substrate W is rotated at a liquid covering speed (for example, a speed greater than 0 and less than 20 rpm).

[0143] Next, a liquid supply step containing a sublimable substance is performed ( Figure 6 In step S6), in the liquid supplying process containing the sublimable substance, the liquid containing the sublimable substance is supplied to the upper surface of the substrate W, and a liquid film of the liquid containing the sublimable substance is formed on the substrate W.

[0144] Specifically, with the barrier member 51 in the upper position and at least one protective cover 24 in the upper position, the nozzle moving unit 42 moves the liquid nozzle 39 containing a sublimable substance from the standby position to the processing position. The liquid valve 41 containing a sublimable substance is then opened, causing the liquid nozzle 39 containing a sublimable substance to begin discharging the liquid containing the sublimable substance. Before discharging the liquid containing the sublimable substance, the protective cover lifting unit 27 may also vertically move at least one protective cover 24 to switch the protective cover 24 that receives the liquid discharged from the substrate W. After a predetermined time has passed since the liquid valve 41 containing a sublimable substance was opened, the liquid valve 41 containing a sublimable substance is closed, thereby stopping the discharging of the liquid containing the sublimable substance. The nozzle moving unit 42 then moves the liquid nozzle 39 containing a sublimable substance to the standby position.

[0145] After the liquid containing a sublimate ejected from the liquid nozzle 39 collides with the upper surface of the substrate W rotating at the liquid supply speed, it is caused to flow outward along the upper surface of the substrate W due to centrifugal force. The replacement liquid on the substrate W is replaced by the liquid containing a sublimate ejected from the liquid nozzle 39 . As a result, a liquid film of the liquid containing a sublimate is formed that covers the entire upper surface of the substrate W. When the liquid containing a sublimate ejected from the liquid nozzle 39 , the nozzle moving unit 42 can move the landing position of the liquid containing a sublimate relative to the upper surface of the substrate W so that the landing position passes through the center and the periphery, or can keep the landing position stationary at the center.

[0146] Next, the film thickness reduction step ( Figure 6 In step S7), in this film thickness reducing process, a portion of the liquid containing the sublimable substance on the substrate W is removed, while maintaining the entire upper surface area of the substrate W covered by the liquid film of the liquid containing the sublimable substance, the film thickness of the liquid containing the sublimable substance on the substrate W (the thickness of the liquid film) is reduced.

[0147] Specifically, when the blocking member 51 is in the lower position, the rotary motor 14 maintains the rotation speed of the substrate W at the film thickness reduction speed. The film thickness reduction speed may be equal to or different from the liquid supply speed. After the liquid containing the sublimation substance on the substrate W stops being ejected, it is also discharged outward from the substrate W by centrifugal force. Therefore, the thickness of the liquid film of the liquid containing the sublimation substance on the substrate W is reduced. If the liquid containing the sublimation substance on the substrate W is discharged to a certain extent, the amount of liquid containing the sublimation substance discharged from the substrate W per unit time is reduced to zero or to approximately zero. As a result, the thickness of the liquid film of the liquid containing the sublimation substance on the substrate W is stabilized at a value corresponding to the rotation speed of the substrate W.

[0148] Next, a cured film forming step ( Figure 6 In step S8), in this solidified film forming step, the solvent is evaporated from the liquid containing the sublimable substance on the substrate W, thereby forming a solidified film SF containing the sublimable substance on the substrate W (see Figure 7B ).

[0149] Specifically, with the barrier member 51 in the lower position, the rotation motor 14 maintains the rotation speed of the substrate W at the cured film formation speed. The cured film formation speed may be equal to or different from the liquid supply speed. Furthermore, the upper gas valve 57 is opened, causing the central nozzle 55 to begin ejecting nitrogen gas. Alternatively or in addition to opening the upper gas valve 57, the opening of the flow control valve 65 may be adjusted to increase the flow rate of nitrogen gas ejected from the upper central opening 61 of the barrier member 51.

[0150] When substrate W begins rotating at a solidified film formation speed, for example, the evaporation of the liquid containing the sublimable substance is accelerated, causing a portion of the liquid containing the sublimable substance on substrate W to evaporate. Because the vapor pressure of the solvent is higher than the vapor pressure of the sublimable substance corresponding to the solute, the solvent evaporates at a rate greater than the evaporation rate of the sublimable substance. Consequently, the concentration of the sublimable substance gradually increases while the film thickness of the liquid containing the sublimable substance gradually decreases. The freezing point of the liquid containing the sublimable substance rises as the concentration of the sublimable substance increases. When the freezing point of the liquid containing the sublimable substance coincides with the temperature of the liquid containing the sublimable substance, the liquid containing the sublimable substance begins to solidify, forming a solidified solid film SF covering the entire upper surface of substrate W.

[0151] Next, the sublimation process is carried out ( Figure 6 In step S9), in this sublimation process, the cured film SF on the substrate W is sublimated and removed from the upper surface of the substrate W.

[0152] Specifically, when the barrier member 51 is in the lower position, the rotary motor 14 maintains the rotation speed of the substrate W at the sublimation speed. The sublimation speed may be equal to or different from the liquid supply speed. Furthermore, when the upper gas valve 57 is closed, the upper gas valve 57 is opened to cause the central nozzle 55 to start spraying nitrogen. In addition to or instead of opening the upper gas valve 57, the opening of the flow regulating valve 65 may be changed to increase the flow rate of nitrogen sprayed from the upper central opening 61 of the barrier member 51. If a specified time has passed after the substrate W starts to rotate at the sublimation speed, the rotary motor 14 is stopped, thereby stopping the rotation of the substrate W ( Figure 6 Step S10).

[0153] When the substrate W begins to rotate at a sublimation speed, for example, the cured film SF on the substrate W begins to sublime, thereby generating a gas containing a sublimable substance from the cured film SF on the substrate W. The gas generated from the cured film SF (gas containing a sublimable substance) flows radially in the space between the substrate W and the barrier member 51 and is exhausted from above the substrate W. After a certain period of time has passed since the start of sublimation, the cured film SF is completely removed from the substrate W.

[0154] Next, a carry-out process ( Figure 6 Step S11).

[0155] Specifically, the barrier member lifting unit 54 raises the barrier member 51 to the upper position, and the protective cover lifting unit 27 lowers all the protective covers 24 to the lower position. Furthermore, the upper gas valve 64 and the lower gas valve 84 are closed, so that the upper central opening 61 of the barrier member 51 and the lower central opening 81 of the rotating base 12 stop spraying nitrogen. Then, the central robot CR causes the hand H1 to enter the chamber 4. After the plurality of chuck pins 11 release the grip of the substrate W, the central robot CR supports the substrate W on the rotating chuck 10 with the hand H1. Then, the central robot CR supports the substrate W with the hand H1 while retracting the hand H1 from the inside of the chamber 4. In this way, the processed substrate W is moved out of the chamber 4.

[0156] Figures 7A to 7F This is a schematic diagram for explaining the following phenomenon, which is assumed to be Figure 6 The phenomenon shown in FIG. 1 is caused during the period from when the liquid containing the sublimable substance is supplied to the upper surface of the substrate W to when the cured film SF is removed from the upper surface of the substrate W in the processing of the substrate W.

[0157] The following describes a case where the entire surface area of pattern P1 is hydrophilic and the liquid containing the sublimable substance contains a sublimable substance containing a hydrophilic group and IPA as a solvent. In the following description, the solubility of the sublimable substance containing a hydrophilic group in water is assumed to be greater than the solubility of IPA in water.

[0158] like Figure 7A As shown in FIG, the liquid containing the sublimable substance is supplied to the upper surface of the substrate W while the substrate W is rotating and the upper surface of the substrate W is covered with a liquid film of the replacement liquid. Figure 7B As shown, the replacement liquid is discharged from between the patterns P1, and the spaces between the patterns P1 are filled with the liquid containing the sublimable substance. Figure 7C Graph 1 shows the distribution of the sublimable substance in the liquid containing the sublimable substance supplied to the upper surface of the substrate W. Figure 7C In the figure, ○ is used to represent a sublimable substance.

[0159] A single IPA molecule contains a hydroxyl group, an example of a hydrophilic group, and two methyl groups, an example of a hydrophobic group. Therefore, IPA experiences an attractive force pulling it toward the surface of pattern P1, while also experiencing a repulsive force pulling it away from the surface. Furthermore, sublimable substances containing hydrophilic groups have a higher affinity for the surface of pattern P1 than IPA. Therefore, it is believed that IPA is less likely to remain on the surface of pattern P1 than sublimable substances.

[0160] like Figure 7D As shown, after the upper surface of the substrate W is covered with a liquid film containing a sublimable substance, the solvent is evaporated from the liquid containing a sublimable substance on the substrate W. When the solvent evaporates, the concentration of the sublimable substance increases. The freezing point of the liquid containing a sublimable substance increases with the increase in the concentration of the sublimable substance. If the freezing point of the liquid containing a sublimable substance is consistent with the temperature of the liquid containing a sublimable substance, then Figure 7E As shown in FIG, the liquid containing the sublimable substance begins to solidify, thereby forming a solidified film SF corresponding to a solidified body covering the entire upper surface of the substrate W. Then, as shown in FIG. Figure 7F As shown, the cured film SF is sublimated and removed from the upper surface of the substrate W.

[0161] When the solidified film SF is formed, the solvent is introduced from the main body of the liquid film containing the sublimable substance (see Figure 7C ), that is, the liquid layer in the range from the upper surface (liquid surface) of the liquid film containing the sublimable substance to the upper surface Pu of the pattern P1 evaporates, thereby increasing the concentration of the sublimable substance in the main part of the liquid film. The IPA contained in the liquid containing the sublimable substance located between the patterns P1 moves to the main part of the liquid film and is released into the air from the upper surface of the liquid containing the sublimable substance. As a result, not only the concentration of the sublimable substance above the pattern P1 increases, but also the concentration of the sublimable substance between the patterns P1 increases. Therefore, it is considered that Figure 7E As shown, after the solidified film SF is formed, the IPA liquid is discharged from between the patterns P1, so that the space between two adjacent convex patterns P1 is filled with the solidified film SF.

[0162] Figures 8A to 8D This is a cross-sectional view of a substrate W for explaining the following phenomenon, which is assumed to be Figure 6 The phenomenon shown in FIG. 1 is caused during the period from when the liquid containing the sublimable substance is supplied to the upper surface of the substrate W to when the cured film SF is removed from the upper surface of the substrate W in the processing of the substrate W.

[0163] Hereinafter, the case where the entire surface area of the pattern P1 is hydrophilic and the liquid containing the sublimable substance contains a sublimable substance containing a hydrophilic group and methanol as a solvent will be described. Except that the solvent is methanol instead of IPA, the processing conditions of the substrate W are the same as those of the reference Figures 7A to 7F The same processing conditions are used for the substrate W. In the following description, the solubility of the sublimable substance containing a hydrophilic group in water is assumed to be smaller than the solubility of methanol in water.

[0164] With reference Figures 7A to 7F Similarly to the processing of the substrate W described above, a liquid containing a sublimable substance, including methanol as a solvent, is supplied to the upper surface of the substrate W while the substrate W is rotating and the upper surface of the substrate W is covered with a liquid film of the replacement liquid. As a result, the replacement liquid is discharged from between the patterns P1, and the space between the patterns P1 is filled with the liquid containing the sublimable substance. Figure 8A The state where the space between the patterns P1 is filled with the sublimable substance-containing liquid containing the sublimable substance and the solvent (methanol) is shown.

[0165] A single methanol molecule contains a hydroxyl group, an example of a hydrophilic group, and a methyl group, an example of a hydrophobic group. Therefore, methanol experiences an attractive force pulling it toward the surface of pattern P1, while also experiencing a repulsive force pulling it away from the surface. However, compared to IPA, methanol contains fewer methyl groups per molecule. Therefore, it is thought that methanol is more likely to remain on the surface of pattern P1 than IPA. Furthermore, sublimable substances containing hydrophilic groups have a lower affinity for the surface of pattern P1 than methanol. Therefore, it is thought that methanol is more likely to remain on the surface of pattern P1 than sublimable substances.

[0166] When the cured film SF is formed, the methanol contained in the liquid containing the sublimable substance between the patterns P1 moves to the main body of the liquid film containing the sublimable substance (see Figure 8A ) and is released into the air from the upper surface of the liquid containing the sublimable substance. However, because the force holding methanol on the surface of pattern P1 is relatively strong, methanol is difficult to escape from between patterns P1. Consequently, the concentration of the sublimable substance in the liquid containing the sublimable substance between patterns P1 is unlikely to increase. Therefore, it is believed that methanol may remain between patterns P1 after the main portion of the liquid film transforms into the solidified film SF. Figure 8B An example is shown in which a cured film SF is formed over the pattern P1 and the space between the patterns P1 is filled with methanol.

[0167] exist Figure 8B In the case of the example shown, Figure 8CAs shown in FIG, after the solidified film SF is sublimated, methanol still remains between the patterns P1. The methanol remaining between the patterns P1 evaporates and disappears from the substrate W. However, before the methanol disappears from the substrate W, a methanol liquid surface (interface between gas and liquid) is formed between two adjacent convex patterns P1, and a collapse force that collapses the pattern P1 is applied from the methanol to the pattern P1. If the strength of the pattern P1 is low, as shown in FIG. Figure 8D As shown, the pattern P1 collapses due to such a collapse force.

[0168] Thus, if the surface of pattern P1 is hydrophilic and the solvent is highly hydrophilic, the solvent will not be expelled from between patterns P1 during the formation of cured film SF, but will remain there. This will cause the solvent to exert a collapsing force on pattern P1, causing it to collapse. Similarly, if the surface of pattern P1 is hydrophobic and the solvent is highly hydrophobic, the solvent will not be expelled from between patterns P1 during the formation of cured film SF, but will remain there. This will cause the solvent to exert a collapsing force on pattern P1, causing it to collapse. Therefore, if the solvent is selected without considering its affinity for pattern P1, the strength of pattern P1 will cause the pattern P1 to collapse.

[0169] As described above, in this embodiment, a liquid containing a sublimable substance, which contains a sublimable substance serving as a solute and a solvent, is supplied to the surface of a substrate W on which a pattern P1 is formed. The solvent is then evaporated from the liquid containing the sublimable substance. This results in the formation of a solidified film SF containing the sublimable substance on the surface of the substrate W. The solidified film SF on the substrate W is then converted to a gas without passing through the liquid. This removes the solidified film SF from the surface of the substrate W. Consequently, the collapse rate of the pattern P1 can be reduced compared to conventional drying methods such as spin drying.

[0170] If the surface of pattern P1 is hydrophilic, the liquid containing the sublimable substance contains a solvent with a lower solubility in water than the sublimable substance. If the surface of pattern P1 is hydrophilic and the solvent is highly hydrophilic, the solvent is easily retained on the surface of pattern P1. Consequently, a significant amount of solvent remains between patterns P1 after the formation of cured film SF. In this case, the collapsing force causing pattern P1 to collapse is applied from the solvent to pattern P1. Using a less hydrophilic solvent can reduce the amount of solvent remaining between patterns P1 after the formation of cured film SF to zero or near zero.

[0171] If the surface of pattern P1 is hydrophobic, the liquid containing the sublimable substance contains a solvent with a lower solubility in oil than the sublimable substance. If the surface of pattern P1 is hydrophobic and the solvent is highly hydrophobic, the solvent is easily retained on the surface of pattern P1. Consequently, a significant amount of solvent remains between patterns P1 after the formation of cured film SF. In this case, the collapsing force causing pattern P1 to collapse is applied from the solvent to pattern P1. Using a less hydrophobic solvent can reduce the amount of solvent remaining between patterns P1 after the formation of cured film SF to zero or near zero.

[0172] In this way, regardless of whether the surface of pattern P1 is hydrophilic or hydrophobic, the solvent contained in the liquid containing a sublimable substance has a lower affinity for the surface of pattern P1 than the sublimable substance contained in the liquid containing a sublimable substance. Consequently, the amount of solvent remaining between patterns P1 after the formation of the cured film SF can be reduced, thereby reducing the collapse force applied to pattern P1 during or after the formation of the cured film SF. Consequently, regardless of whether the surface of pattern P1 is hydrophilic or hydrophobic, the substrate W can be dried with a low collapse rate of pattern P1.

[0173] In this embodiment, if the surface of pattern P1 includes both hydrophilic and hydrophobic portions, the surface of pattern P1 is considered hydrophilic if the upper end Px of side surface Ps of pattern P1 is hydrophilic. If the surface of pattern P1 includes both hydrophilic and hydrophobic portions, the surface of pattern P1 is considered hydrophobic if the upper end Px of side surface Ps of pattern P1 is hydrophobic. In other words, whether the surface of pattern P1 is hydrophilic or hydrophobic is determined based on the properties of the upper end Px of side surface Ps of pattern P1.

[0174] When a liquid surface (the interface between gas and liquid) forms between two adjacent convex patterns P1, a collapsing force due to surface tension is applied to pattern P1. This collapsing force increases as the distance from the base of pattern P1 to the liquid surface increases. Therefore, even if a liquid surface forms between two adjacent convex patterns P1, the collapsing force applied to pattern P1 is weak if the distance from the base (bottom) of pattern P1 to the liquid surface is short.

[0175] If the surface of pattern P1 contains both hydrophilic and hydrophobic portions, and the upper end Px of side surface Ps of pattern P1 is hydrophilic, then if the surface of pattern P1 is considered hydrophobic, the solvent liquid surface will form at the upper end Px of side surface Ps of pattern P1 after the cured film SF is formed, potentially exerting a large collapsing force on pattern P1. If the surface of pattern P1 is considered hydrophilic, even if the solvent liquid surface forms between patterns P1, it will be located at the base of pattern P1. This shortens the distance from the base of pattern P1 to the liquid surface.

[0176] For similar reasons, if the surface of pattern P1 includes both hydrophilic and hydrophobic portions, and the upper end Px of side surface Ps of pattern P1 is hydrophobic, then if the surface of pattern P1 is considered hydrophobic, even if a solvent liquid surface forms between patterns P1, the distance from the base of pattern P1 to the liquid surface can be shortened. This reduces the collapsing force applied to pattern P1, thereby reducing the collapse rate of pattern P1.

[0177] Next, a second embodiment will be described.

[0178] The second embodiment is mainly different from the first embodiment in that the liquid containing the sublimable substance is produced immediately before the liquid containing the sublimable substance is supplied to the substrate W.

[0179] In the following Figures 9 and 10 In the figure 1~ Figure 8D The same reference numerals as those in FIG. 1 and the like are given to the structures equivalent to those shown, and their description is omitted.

[0180] Figure 9 Schematic diagram showing a liquid supply unit 99 containing a sublimable substance included in a substrate processing apparatus 1 according to a second embodiment of the present invention.

[0181] The liquid supply unit 99 containing sublimable substances includes a first raw liquid tank 87A for storing liquid containing sublimable substances and a second raw liquid tank 87B for storing liquid containing sublimable substances. The liquid in the first raw liquid tank 87A contains a sublimable substance containing a hydrophilic group. The liquid in the second raw liquid tank 87B contains a sublimable substance containing a hydrophobic group. At least one component of the liquid in the first raw liquid tank 87A and the liquid in the second raw liquid tank 87B is different from each other. The liquid in the first raw liquid tank 87A can also be a molten liquid of the sublimable substance. If the concentration of the sublimable substance is high, the liquid in the first raw liquid tank 87A can be a solution containing a sublimable substance and a solvent, or it can contain a substance other than a solvent and a sublimable substance. The same is true for the liquid in the second raw liquid tank 87B.

[0182] The liquid supply unit 99 for a sublimable substance includes a first dilution liquid tank 93A storing a solvent and a second dilution liquid tank 93B storing a solvent. The solvent in the first dilution liquid tank 93A and the solvent in the second dilution liquid tank 93B differ from each other in at least one component. The solvent in the first dilution liquid tank 93A can be a molten solvent, an aqueous solution of the solvent, or can contain substances other than water and solvents. The same applies to the solvent in the second dilution liquid tank 93B. The solvent in the first dilution liquid tank 93A and the solvent in the second dilution liquid tank 93B can also be alcohol.

[0183] The liquid in the first raw liquid tank 87A is transported to the circulation pipe 88A by the pump 89A and returns from the circulation pipe 88A to the first raw liquid tank 87A. The liquid in the second raw liquid tank 87B is transported to the circulation pipe 88B by the pump 89B and returns from the circulation pipe 88B to the second raw liquid tank 87B. The circulation pipe 88A is connected to the individual pipe 90A equipped with an on-off valve 91A and a flow regulating valve 92A. The circulation pipe 88B is connected to the individual pipe 90B equipped with an on-off valve 91B and a flow regulating valve 92B. The downstream ends of the individual pipes 90A and 90B are connected to the liquid pipe 40 containing the sublimable substance via the mixing valve 100.

[0184] The solvent in the first diluent tank 93A is transported to a circulation pipe 94A by a pump 95A and then returned from the circulation pipe 94A to the first diluent tank 93A. The solvent in the second diluent tank 93B is transported to a circulation pipe 94B by a pump 95B and then returned from the circulation pipe 94B to the second diluent tank 93B. The circulation pipe 94A is connected to a separate pipe 96A equipped with an on / off valve 97A and a flow control valve 98A. The circulation pipe 94B is connected to a separate pipe 96B equipped with an on / off valve 97B and a flow control valve 98B. The downstream ends of the separate pipes 96A and 96B are connected to the liquid pipe 40 containing the sublimable substance via a mixing valve 100.

[0185] The mixing valve 100 includes an individual flow path 101, an individual flow path 102, an individual flow path 103, and an individual flow path 104, which are respectively connected to the individual pipes 90A, 90B, 96A, and 96B. The mixing valve 100 also includes a first check valve V1 that prevents backflow of liquid in the individual flow path 101, a second check valve V2 that prevents backflow of liquid in the individual flow path 102, a third check valve V3 that prevents backflow of liquid in the individual flow path 103, a fourth check valve V4 that prevents backflow of liquid in the individual flow path 104, and a collecting flow path 105 connected to the downstream ends of the individual flow paths 101, 102, 103, and 104.

[0186] The opening and closing of on-off valves 91A, 91B, 97A, and 97B, as well as the opening degrees of flow control valves 92A, 92B, 98A, and 98B are controlled by the control device 3. When on-off valve 91A is opened, the liquid containing the sublimable substance in the first raw liquid tank 87A is supplied to the mixing valve 100 at a flow rate corresponding to the opening degree of flow control valve 92A. The same applies when on-off valves 91B, 97A, and 97B are opened.

[0187] When at least one of on-off valves 91A and 91B, and at least one of on-off valves 97A and 97B, is opened, a liquid containing a sublimable substance and a solvent are supplied to mixing valve 100 and mixed within collecting flow path 105 of mixing valve 100. As a result, the liquid containing a sublimable substance is diluted with the solvent, thereby producing a liquid containing a sublimable substance. The liquid containing a sublimable substance produced by mixing valve 100 is supplied from sublimable substance-containing liquid piping 40 to sublimable substance-containing liquid nozzle 39 and ejected from sublimable substance-containing liquid nozzle 39 toward the upper surface of substrate W.

[0188] If the surface of pattern P1 is hydrophilic, a sublimable substance containing a hydrophilic group is mixed with a solvent having a lower solubility in water than the sublimable substance within mixing valve 100. Specifically, control device 3 opens on-off valve 91A and on-off valve 97A or on-off valve 97B. If the surface of pattern P1 is hydrophobic, a sublimable substance containing a hydrophobic group is mixed with a solvent having a lower solubility in oil than the sublimable substance within mixing valve 100. Specifically, control device 3 opens on-off valve 91B and on-off valve 97A or on-off valve 97B.

[0189] When the liquid containing the sublimable substance is supplied to the substrate W, at least one of the on-off valves 91A and 91B, and at least one of the on-off valves 97A and 97B, is opened. The multiple valves to be opened may also be specified by a processing program. When information for determining whether the surface of the pattern P1 is hydrophilic or hydrophobic is input to the control device 3, the control device 3 may also select the multiple valves to be opened. Such information may include, for example, information indicating the material of the surface of the pattern P1 or information indicating the type of liquid supplied to the substrate W before the liquid containing the sublimable substance is supplied.

[0190] Furthermore, if the liquid containing the sublimable substance contains a substance other than the sublimable substance (e.g., a solvent), opening at least one of on-off valves 91A and 91B, and at least one of on-off valves 97A and 97B, dilutes the liquid containing the sublimable substance with the solvent. In this case, the substance other than the sublimable substance may be a solvent with the same name as the dilution solvent, or may be a substance different from the dilution solvent. In the latter case, dilution of the liquid containing the sublimable substance with the solvent reduces the concentration of the substance other than the sublimable substance to a value at which the effect of the substance on the processing of the substrate W can be ignored.

[0191] Figure 10 It is used for Figure 6 FIG. 1 is a process diagram for explaining another example of the process of supplying a liquid containing a sublimable substance shown in FIG.

[0192] In the substrate processing apparatus 1 of the second embodiment, similarly to the first embodiment, Figure 6 The steps shown.

[0193] In the liquid supply process containing sublimable substances ( Figure 6 In step S6), the control device 3 determines whether the liquid nozzle 39 containing the sublimable substance should be made to eject the liquid containing the sublimable substance ( Figure 10 Step S21). In the case where no ejection is required (in Figure 10 If the answer is No in step S21, the control device 3 determines again whether the liquid containing the sublimable substance should be ejected after a predetermined time (returning to step S21). Figure 10 Step S21).

[0194] In the case of needing to spray liquid containing sublimable substances (in Figure 10 If the answer is Yes in step S21 of , the control device 3 opens at least one of the on-off valve 91A and the on-off valve 91B and at least one of the on-off valve 97A and the on-off valve 97B. Figure 10 Thus, the liquid containing the sublimable substance is mixed with the solvent, thereby producing the liquid containing the sublimable substance in the mixing valve 100. Then, the liquid containing the sublimable substance is ejected from the liquid nozzle 39 containing the sublimable substance.

[0195] After the start of ejection of the liquid containing the sublimable substance, the control device 3 determines whether a predetermined time ( Figure 10 Step S23). If the specified time has not passed (in Figure 10 If the answer is No in step S23 of the control unit 3, the control unit 3 will again determine whether the predetermined time has passed (return to Figure 10 Step S23). When the prescribed time has passed (in Figure 10 If the answer is Yes in step S23, the control device 3 closes the plurality of valves opened in step S22. Figure 10 Step S24). Thus, the mixing of the liquid containing the sublimable substance and the solvent and the ejection of the liquid containing the sublimable substance are stopped.

[0196] Other implementations

[0197] The present invention is not limited to the contents of the above-described embodiment, and various modifications are possible.

[0198] For example, in the first embodiment, there may be provided: a hydrophilic tank for storing a hydrophilic liquid containing a sublimable substance to be supplied to the substrate W when the surface of the storage pattern P1 is hydrophilic; and a hydrophobic tank for storing a hydrophobic liquid containing a sublimable substance to be supplied to the substrate W when the surface of the storage pattern P1 is hydrophilic.

[0199] In this case, regardless of whether the surface of pattern P1 is hydrophilic or hydrophobic, an appropriate liquid containing a sublimable substance can be supplied to substrate W, thereby reducing the collapse rate of pattern P1. Whether to supply a hydrophilic liquid containing a sublimable substance or a hydrophobic liquid containing a sublimable substance to substrate W can be specified by a processing program or selected by control device 3 based on information input to control device 3.

[0200] In the first embodiment, the liquid containing a sublimable substance supplied from the raw liquid tank 87 may be mixed with the diluent supplied from the diluent tank 93 at a location other than the liquid pipe 40 containing a sublimable substance. For example, the liquid containing a sublimable substance may be mixed with the diluent inside at least one of a pipe other than the liquid pipe 40 containing a sublimable substance, a valve such as the mixing valve 100, and the liquid nozzle 39 containing a sublimable substance. The liquid containing a sublimable substance may also be mixed with the diluent on the upper surface of the substrate W.

[0201] Similarly, in the second embodiment, the liquid containing a sublimable substance supplied from at least one of the first stock liquid tank 87A and the second stock liquid tank 87B may be mixed with the solvent supplied from at least one of the first dilution liquid tank 93A and the second dilution liquid tank 93B at a location other than the mixing valve 100. For example, the liquid containing a sublimable substance may be mixed with the solvent inside at least one of a valve other than the mixing valve 100, a piping, and a liquid nozzle 39 containing a sublimable substance. The liquid containing a sublimable substance may also be mixed with the solvent on the upper surface of the substrate W. Solid sublimable substances may also be dissolved in the solvent within the box CC.

[0202] The cured film SF may be removed by a processing unit 2 different from the wet processing unit 2w. The processing unit 2 for removing the cured film SF may be part of the substrate processing apparatus 1 or may be part of a substrate processing apparatus different from the substrate processing apparatus 1. In other words, the substrate processing apparatus 1 including the wet processing unit 2w and the substrate processing apparatus including the processing unit 2 for removing the cured film SF may be provided in the same substrate processing system, and the substrate W may be transferred from the substrate processing apparatus 1 to another substrate processing apparatus before the cured film SF is removed.

[0203] When the rinsing liquid on the substrate W, such as pure water, can be replaced with a liquid containing a sublimable substance, the liquid supplying step containing a sublimable substance may be performed instead of the replacement liquid supplying step of replacing the rinsing liquid on the substrate W with the replacement liquid.

[0204] The blocking member 51 may also rotate about the rotation axis A1 together with the spin chuck 10. For example, the blocking member 51 may be placed on the rotating base 12 so as not to come into contact with the substrate W. In this case, the blocking member 51 is coupled to the rotating base 12, so that the blocking member 51 and the rotating base 12 rotate in the same direction and at the same speed.

[0205] The blocking member 51 may be omitted. However, when a liquid such as pure water is supplied to the lower surface of the substrate W, it is preferable to provide the blocking member 51. This is because the blocking member 51 can block liquid droplets that flow along the outer circumference of the substrate W from the lower surface of the substrate W to the upper surface of the substrate W, or liquid droplets that bounce inward from the processing cup 21, thereby reducing the amount of liquid that mixes with the liquid containing the sublimable substance on the substrate W.

[0206] The substrate processing apparatus 1 is not limited to an apparatus for processing disc-shaped substrates W, and may also be an apparatus for processing polygonal substrates W.

[0207] All of the above structures may be combined with two or more of them. All of the above steps may be combined with two or more of them.

[0208] The control device 3 is an example of a sublimable substance selection unit and a solvent selection unit. The sublimable substance-containing liquid supply unit 99 is an example of a sublimable substance-containing liquid supply unit. The spin chuck 10 and the center nozzle 55 are an example of a solidified film forming unit. The spin chuck 10 and the center nozzle 55 are also an example of a sublimation unit. The sublimable substance-containing liquid pipe 40 and the mixing valve 100 are an example of a dissolution unit.

[0209] The embodiments of the present invention have been described in detail, but these are only specific examples for illustrating the technical content of the present invention. The present invention should not be limited to these specific examples. The spirit and scope of the present invention are limited only by the appended claims.

[0210] Description of Reference Numerals

[0211] 1: Substrate processing equipment,

[0212] 3: Control device (sublimable substance selection unit, solvent selection unit),

[0213] 10: Rotary chuck (cured film forming unit, sublimation unit),

[0214] 40: Liquid piping containing sublimable substances (dissolving unit),

[0215] 55: Center nozzle (cured film forming unit, sublimation unit),

[0216] 99: Liquid supply unit containing sublimable substance (Liquid supply unit containing sublimable substance),

[0217] 100: Mixing valve (dissolving unit),

[0218] P1: Pattern,

[0219] Ps: The side of the pattern,

[0220] Px: The upper end of the side of the pattern,

[0221] SF: Cured film,

[0222] W: substrate.

Claims

1. A method for producing a liquid containing a sublimable substance, wherein the liquid containing a sublimable substance is removed from a substrate when the surface of the substrate having a pattern is dried, include: a sublimation material selection step of selecting a sublimation material containing a hydrophilic group when the surface of the pattern is hydrophilic, and selecting a sublimation material containing a hydrophobic group when the surface of the pattern is hydrophobic; a solvent selection step of selecting a hydrophilic solvent having a lower solubility in water than the sublimation substance selected in the sublimation substance selection step when the surface of the pattern is hydrophilic, and selecting a hydrophobic solvent having a lower solubility in oil than the sublimation substance selected in the sublimation substance selection step when the surface of the pattern is hydrophilic; as well as The dissolving step is to dissolve the sublimable substance selected in the sublimable substance selecting step in the solvent selected in the solvent selecting step.

2. The method for producing a liquid containing a sublimable substance according to claim 1, wherein Further including: The property judgment process is as follows: when the surface of the pattern includes a hydrophilic portion and a hydrophobic portion and the upper end portion of the side surface of the pattern is hydrophilic, the surface of the pattern is considered to be hydrophilic before selecting the sublimable substance and the solvent; when the surface of the pattern includes the hydrophilic portion and the hydrophobic portion and the upper end portion of the side surface of the pattern is hydrophobic, the surface of the pattern is considered to be hydrophobic before selecting the sublimable substance and the solvent.

3. A substrate drying method, wherein: include: a liquid supplying step containing a sublimable substance, supplying the liquid containing a sublimable substance produced by the method for producing a liquid containing a sublimable substance according to claim 1 or 2 to the surface of the substrate; a cured film forming step of forming a cured film containing a sublimable substance on the surface of the substrate by evaporating a solvent from the liquid containing a sublimable substance on the surface of the substrate; as well as The sublimation step is to remove the cured film from the surface of the substrate by sublimating the cured film.

4. A substrate processing apparatus for drying a surface of a substrate on which a pattern is formed, wherein: include: a sublimation material selection unit for selecting a sublimation material containing a hydrophilic group when the surface of the pattern is hydrophilic, and for selecting a sublimation material containing a hydrophobic group when the surface of the pattern is hydrophobic; a solvent selection unit for selecting a hydrophilic solvent having a smaller solubility in water than the sublimation substance selected by the sublimation substance selection unit when the surface of the pattern is hydrophilic, and for selecting a hydrophobic solvent having a smaller solubility in oil than the sublimation substance selected by the sublimation substance selection unit when the surface of the pattern is hydrophilic; a dissolving unit for producing a sublimable substance-containing liquid containing the sublimable substance and the solvent by dissolving the sublimable substance selected by the sublimable substance selecting unit in the solvent selected by the solvent selecting unit; a liquid supply unit containing a sublimable substance, supplying the liquid containing the sublimable substance produced by the dissolving unit to the surface of the substrate; a cured film forming unit for forming a cured film containing the sublimable substance on the surface of the substrate by evaporating the solvent from the liquid containing the sublimable substance on the surface of the substrate; as well as The sublimation unit removes the cured film from the surface of the substrate by sublimating the cured film.

Images