Substrate processing method

Abstract

To provide a substrate treatment method capable of removing an altered resist film from a substrate within a short time while reducing the burden of treatment of liquid waste.SOLUTION: A substrate treatment method includes: bringing a resist film 902 on a rotating substrate 901 into contact with an ozone-containing aqueous solution 920 to form a crack in the resist film 902; impregnating an ammonia-containing aqueous solution 930 into the rotating substrate 901 through the crack in the resist film 902 to give a swelling effect to the resist film 902, the ammonia-containing aqueous solution containing ammonia at a higher concentration compared with the ozone-containing aqueous solution 920; spraying, by means of a spray nozzle above the substrate 901, droplets of the ammonia-containing aqueous solution 930 onto a portion of the resist film 902 on the rotating substrate 901, the portion having been given the swelling effect, to separate the resist film 902 from the substrate 901; and moving the spray nozzle such that a radial position of the spray nozzle is shifted above the substrate 901.SELECTED DRAWING: Figure 14

Description

Technical Field

[0001] The present invention relates to a substrate processing method, and more particularly to a substrate processing method for removing a resist film from a substrate.

Background Art

[0002] After processing using a resist film is performed on a substrate, in many cases, the resist film is removed from the substrate. For the purpose of performing this process, a method of supplying a sulfuric acid / hydrogen peroxide mixture (SPM) as a cleaning liquid onto the substrate surface has been widely used conventionally. However, in recent years, a substrate processing method that does not use SPM has been demanded because of the large burden of waste liquid treatment.

[0003] According to Japanese Patent Application Laid-Open No. 2010-153442 (Patent Document 1), a substrate processing method for removing a resist film on a wafer is disclosed. As an example, it is described that a resist film is removed by supplying a mixture of aqueous ammonia and ozone water to the wafer. According to this publication, it is claimed that the resist can be removed at a high speed.

[0004] According to Japanese Patent Application Laid-Open No. 2001-144006 (Patent Document 2), it has been proposed to etch a resist film by supplying ozone-dissolved water and an ozone decomposition catalyst solution onto the resist film formed on a semiconductor wafer. As a method shown as a preferred example, first, aqueous ammonia as an ozone decomposition catalyst solution is discharged onto the wafer. Next, ozone-dissolved water is discharged onto the wafer. Thereby, the ozone-dissolved water is discharged onto the wafer surface in a state where the entire wafer surface is covered with the ozone decomposition catalyst solution. According to this publication, it is claimed that the etching time can be shortened because ozone can be instantaneously decomposed on the wafer surface.

[0005] According to Japanese Patent Application Laid-Open No. 2001-203182 (Patent Document 3), a method for cleaning the surface of an article is disclosed. Specifically, an aqueous base solution and an aqueous ozone solution are simultaneously supplied to the surface of an article whose surface is contaminated with deposits. At that time, the surface is continuously brought into contact with fresh aqueous base solution and aqueous ozone solution. Thereby, ozone is decomposed on the surface. Thereby, the deposits are removed. According to this publication, it is claimed that an excellent cleaning effect can be obtained without using a special physical action that may damage the surface of the article, such as high-pressure jet injection.

[0006] According to Japanese Patent Application Laid-Open No. 4-179225 (Patent Document 4), a cleaning method is disclosed. In this publication, as one aspect of the cleaning method, it is described that an object to be cleaned is immersed in a cleaning liquid containing ammonia or amines and hydrogen peroxide and / or ozone and irradiated with ultraviolet rays. According to this publication, it is claimed that, as an effect, heating equipment for the chemical solution is unnecessary.

[0007] According to Japanese Patent Application Laid-Open No. 2003-234323 (Patent Document 5), a substrate processing method for removing organic substances has been proposed. This organic substance is a reaction product formed on the surface of a substrate by dry etching using a resist as a mask. According to this substrate processing method, the organic substance is swollen by supplying a removing liquid toward the surface of the substrate. Next, by rotating the substrate, the removing liquid adhering to the substrate is removed. Next, the residue of the organic substance swollen as described above is peeled off. This peeling is performed by supplying a cleaning medium toward the surface of the substrate. Examples of the removing liquid include a liquid containing an organic alkali solution. Examples of the cleaning medium include warm water. As a reason for removing the removing liquid adhering to the substrate before supplying the cleaning medium, it is explained that, by avoiding the phenomenon that strong alkali is generated by mixing the two, the time required for the treatment for removing this strong alkali is made unnecessary.

Prior Art Documents

Patent Documents

[0008] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2010 - 153442 [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2001 - 144006 [Patent Document 3] Japanese Unexamined Patent Application Publication No. 2001 - 203182 [Patent Document 4] Japanese Unexamined Patent Application Publication No. Hei 4 - 179225 [Patent Document 5] Japanese Unexamined Patent Application Publication No. 2003 - 234323 [Summary of the Invention] [Problems to be Solved by the Invention]

[0009] The technologies of the above Patent Documents 1 to 3 are intended to accelerate the decomposition of the resist film by promoting the action of ozone. According to the study by the present inventors, if an attempt is made to remove the resist film mainly relying only on the decomposition action, the processing time will become long.

[0010] The technology of the above Patent Document 4 is intended to remove a resist or the like by ultraviolet irradiation in a mixed solution of several chemical solutions. Since the functions of each chemical solution are deactivated after mixing, in this technology, the sufficient expression of the functions of each chemical solution is likely to be hindered. Therefore, the required processing time is likely to be long.

[0011] According to the technology of the above Patent Document 5, peeling is promoted by swelling the resist film. However, according to the study by the present inventors, there is still a large room for improvement in the degree of progress of swelling. Therefore, there is still a large room for improvement in reducing the processing time.

[0012] The present invention has been made to solve the above - mentioned problems, and its object is to provide a substrate processing method capable of removing a resist film from a substrate in a short time while suppressing the burden of waste liquid treatment. [Means for Solving the Problems]

[0013] In order to solve the above problems, one aspect is a substrate processing method for removing a deteriorated resist film from a substrate, comprising: (a) discharging an ozone-containing aqueous solution onto the rotating substrate and bringing the ozone-containing aqueous solution into contact with the resist film on the substrate to form cracks in the resist film; (b) permeating an ammonia-containing aqueous solution containing ammonia at a higher concentration than the ozone-containing aqueous solution through the cracks formed in the resist film in step (a) into the rotating substrate to exert a swelling action on the resist film; (c) spraying droplets of the ammonia-containing aqueous solution from a spray nozzle above the substrate onto the portion of the resist film that has been swollen in step (b) to peel the resist film from the substrate; and (d) moving the position of the spray nozzle radially above the substrate.

Advantages of the Invention

[0014] According to the above aspect, the ammonia-containing aqueous solution is brought into contact with the portion of the resist film that has already been in contact with the ozone-containing aqueous solution. Since the portion that has already been in contact with the ozone-containing aqueous solution has already been subjected to the decomposition action by ozone, it is likely to be subjected to the swelling action by the ammonia-containing aqueous solution. Thereby, the progress of the swelling of the resist film is promoted. Therefore, the resist film can be removed in a short time in the subsequent process. In addition, the ozone-containing aqueous solution and the ammonia-containing aqueous solution have a smaller burden on waste liquid treatment than SPM. From the above, the resist film can be removed from the substrate in a short time while suppressing the burden of waste liquid treatment.

Brief Description of the Drawings

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Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals and their descriptions will not be repeated.

[0017] <Substrate Processing Apparatus> First, an example of a substrate processing apparatus applicable to Embodiments 1 to 6 described below will be explained. In each embodiment, it is not necessary to use all the functions of the substrate processing apparatus described below. Therefore, in each embodiment, unnecessary mechanisms of the substrate processing apparatus may be omitted.

[0018] FIG. 1 is a top view schematically showing the configuration of the substrate processing apparatus according to Embodiment 1 of the present invention. Each of FIGS. 2 and 3 is a schematic cross-sectional view taken along line II-II and line III-III of FIG. 1. In the figure, a wafer 901 (substrate) to be processed by the substrate processing apparatus is also shown. A resist film (not shown in FIGS. 1 to 3) is provided on the wafer 901 before processing. This resist film is removed by substrate processing by the substrate processing apparatus. The substrate processing apparatus includes a support unit 10, a discharge unit 30, and a spray unit 40.

[0019] The support unit 10 includes a rotation shaft 16, a spin base 13, a chuck 12, a back surface nozzle 11, a warm water supply source 101, a deionized water supply source 102, a valve 111, and a valve 112. The rotation shaft 16 is rotated by a motor (not shown). The spin base 13 is attached to the rotation shaft 16. The chuck 12 is attached near the outer edge of the spin base 13 and fixes the wafer 901. With these configurations, the wafer 901 is rotatably supported (see arrow SP) by the support unit 10. The back surface nozzle 11 discharges a fluid, particularly a liquid, onto the back surface of the wafer 901. An opening OP is provided in the spin base 13 so as not to interfere with this discharge. The warm water supply source 101 supplies warm water to the back surface nozzle 11 via the valve 111. The deionized water supply source 102 supplies deionized water to the back surface nozzle 11 via the valve 112.

[0020] The ejection unit 30 includes an ejection nozzle 31, an arm 32, a rotating shaft 33, an actuator 34, an ozone water supply unit 301, an additive supply unit 302, an SC1 supply unit 303, a deionized water supply unit 304, valves 311, 312, 313, 314, a liquid pipe 320, and a heater 331. The ejection nozzle 31 is connected to the liquid pipe 320 and ejects the liquid supplied from the liquid pipe 320 onto the wafer 901. The arm 32 connects between the ejection nozzle 31 and the rotating shaft 33. The rotation angle of the rotating shaft 33 is adjusted by the actuator 34. With these configurations, the ejection nozzle 31 can perform a scanning operation (see FIG. 1) approximately along the radial direction of the wafer 901.

[0021] The ozone water supply unit 301 supplies ozone water to the liquid pipe 320 via the valve 311. The additive supply unit 302 supplies an additive to the liquid pipe 320 via the valve 312. The additive may be a liquid. The SC1 supply unit 303 supplies an SC1 (Standard Clean 1) cleaning liquid to the liquid pipe 320 via the valve 313. The SC1 cleaning liquid is a mixture of ammonia water, hydrogen peroxide water, and water. The deionized water supply unit 304 supplies deionized water to the liquid pipe 320 via the valve 314.

[0022] The heater 331 is for heating the ozone water from the ozone water supply unit 301. The heater 331 is preferably attached between the valve 311 and the liquid pipe 320. Here, the valve 311 may be the one closest to the liquid pipe 320 among at least one valve attached between the ozone water supply unit 301 and the liquid pipe 320. The heater 331 may be arranged upstream or downstream of the junction where the pipes from the additive supply unit 302, the SC1 supply unit 303, and the deionized water supply unit 304 merge among the pipes between the ozone water supply unit 301 and the liquid pipe 320. In the former case, only the ozone water can be selectively heated, and in the latter case, the mixed liquid can be heated. The heater 331 is, for example, a lamp heater or an LED heater.

[0023] The spraying unit 40 includes a spray nozzle 41, an arm 42, a rotating shaft 43, an actuator 44, an ammonia water supply unit 401, a hydrogen peroxide water supply unit 402, an SC1 cleaning liquid supply unit 403, a gas supply unit 409, a valve 411, a valve 412, a valve 413, and a valve 419. The spray nozzle 41 is a nozzle that ejects a two-fluid of the liquid supplied from the liquid pipe 420 and the gas supplied from the gas pipe 429, that is, a two-fluid nozzle. It is preferable that a flow of the gas and the droplets dispersed therein is generated by mixing the two fluids with each other.

[0024] The arm 42 connects between the spray nozzle 41 and the rotating shaft 43. The rotation angle of the rotating shaft 43 is adjusted by the actuator 44. With these configurations, the spray nozzle 41 can perform a scanning operation (see FIG. 1) approximately along the radial direction of the wafer 901.

[0025] The ammonia water supply unit 401 supplies ammonia water to the liquid pipe 420 via the valve 411. The temperature of the supplied ammonia water is preferably equal to or higher than room temperature and equal to or lower than 40°C. The hydrogen peroxide water supply unit 402 supplies hydrogen peroxide water to the liquid pipe 420 via the valve 412. The temperature of the supplied hydrogen peroxide water is preferably equal to or higher than room temperature and equal to or lower than 80°C. The SC1 cleaning liquid supply unit 403 supplies the SC1 cleaning liquid to the liquid pipe 420 via the valve 413. The gas supply unit 409 supplies gas to the gas pipe 429 via the valve 419. The gas supplied from the gas supply unit 409 may be an inert gas, for example, nitrogen (N 2 ) gas.

[0026] FIG. 4 is a cross-sectional view showing an example of the configuration of the spray nozzle 41 (FIG. 3). The spray nozzle 41 has a liquid nozzle portion 41L, a gas nozzle portion 41G, and a gas inlet 41i in order to perform spraying from the spray port OS.

[0027] The liquid nozzle portion 41L has a through hole HL. One end of the through hole HL is connected to the liquid pipe 20, and the other end of the through hole HL reaches the spray port OS.

[0028] The gas nozzle part 41G has an annular hole HG that surrounds the liquid nozzle part 41L. The annular hole HG is connected to the gas inlet 41i and reaches the spray port OS. The extension direction of the outlet part of the annular hole HG (see the dashed arrow in the figure) and the extension direction of the outlet part of the through hole HL (see the solid arrow in the figure) are arranged to intersect below the spray nozzle 41. With this configuration, the gas discharged from the gas nozzle part 41G collides with the liquid discharged from the liquid nozzle part 41L. Thereby, a flow AS of the gas and the droplets dispersed therein is generated.

[0029] In the above description, the case where the mechanism for the scanning operation of the discharge nozzle 31 and the mechanism for the scanning operation of the spray nozzle 41 are provided separately has been described. As a modification, a common scanning mechanism may be provided for the scanning operations of both the discharge nozzle 31 and the spray nozzle 41. In other words, the discharge nozzle 31 and the spray nozzle 41 may be attached to a single common arm capable of a scanning operation. In this case, it is preferable that the discharge nozzle 31 and the spray nozzle 41 are attached so that the region directly receiving the discharge from the discharge nozzle 31 and the region directly receiving the spray from the spray nozzle 41 are separated from each other. Thereby, it is possible to prevent the fluid reaching the wafer 901 from the discharge nozzle 31 and the fluid reaching the wafer 901 from the spray nozzle 41 from interfering with each other unnecessarily in the middle of the path. Even when the discharge nozzle 31 and the spray nozzle 41 can operate independently in a scanning manner as shown in FIG. 1, for the above reasons, it is preferable that the two scanning operations are controlled so that the region directly receiving the discharge from the discharge nozzle 31 and the region directly receiving the spray from the spray nozzle 41 are kept separated from each other.

[0030] <Embodiment 1> FIG. 5 is a flowchart schematically showing the substrate processing method in the first embodiment from the viewpoint of the processing at the portion P1 (FIG. 6) of the resist film 902. Each of FIGS. 6 to 9 is a partial cross-sectional view schematically showing the first to fourth steps of the substrate processing method in the first embodiment.

[0031] Referring to FIG. 6, first, a wafer 901 provided with a resist film 902 including a portion P1 is prepared. Note that the resist film 902 may have a pattern shape (not shown) on the wafer 901. Further, the resist film 902 may be one that has been altered by being used as, for example, an etching mask or an implantation mask. Usually, removal of the resist film due to this alteration becomes more difficult.

[0032] Referring to FIG. 7, in step T21 (FIG. 5), an ozone-containing aqueous solution 920 is brought into contact with at least the portion P1 of the resist film 902. For this purpose, the ozone-containing aqueous solution 920 is ejected toward the wafer 901. The portion P1 of the resist film 902 that has come into contact with the ozone-containing aqueous solution 920 undergoes a decomposition action by ozone. Specifically, the C (carbon)-C bonds in the resist film 902 are cleaved by ozone radicals. Due to this decomposition action of the ozone-containing aqueous solution 920, it is preferable that cracks are formed in the resist film 902. In other words, it is preferable to apply the decomposition action by the ozone-containing aqueous solution 920 to the resist film 902 until cracks occur in the resist film 902. Here, the ozone-containing aqueous solution 920 preferably does not substantially contain aqueous ammonia, and preferably does not substantially contain hydrogen peroxide solution. For example, it may be a simple ozone water produced by dissolving ozone in deionized water.

[0033] Referring to FIG. 8, next, in step T31 (FIG. 5), an ammonia-containing aqueous solution is brought into contact with the portion P1 of the resist film 902. For this purpose, the ammonia-containing aqueous solution is ejected toward the wafer 901. Specifically, droplets 930S of the ammonia-containing aqueous solution are brought into contact with the portion P1. The ammonia-containing aqueous solution contains ammonia at a higher concentration than the ozone-containing aqueous solution 920. Note that, as described above, the ozone-containing aqueous solution 920 may not contain ammonia. The resist film 902 that has come into contact with the ammonia-containing aqueous solution contains NH in the ammonia-containing aqueous solution 4It is affected by the swelling action of OH. This swelling action preferably involves the intrusion of the ammonia-containing aqueous solution into the cracks of the resist film 902 formed in the above step T21.

[0034] In addition, in other parts on the wafer 901, when the ammonia-containing aqueous solution comes into contact with the ozone-containing aqueous solution 920 (Fig. 7) that was provided in step T21, the decomposition action by ozone in the ozone-containing aqueous solution 920 may be temporarily activated. Also, the ammonia-containing aqueous solution may contain hydrogen peroxide water, whereby the above swelling action is enhanced and the above decomposition action is temporarily more activated.

[0035] As described above, step T21 and step T31 are performed. Thereafter, the combination of step T21 and step T31 may be repeated any number of times.

[0036] Referring to Fig. 9, next, in step T32 (Fig. 5), the portion P1 of the resist film 902 is separated (peeled off) from the wafer 901 by physical cleaning. Here, physical cleaning mainly refers to cleaning based on mechanical action. This physical cleaning process preferably includes a step of blowing gas onto the wafer 901, and more preferably a step of spraying droplets 930S of the ammonia-containing aqueous solution onto the wafer 901 by the gas. The gas is preferably an inert gas, for example, N 2 gas.

[0037] By performing the above step T21, step T31, and step T32 (Fig. 5) on the portion of the resist film 902 to be peeled off, the desired portion (typically all) of the resist film 902 is peeled off. Thereby, the peeling process of the resist film 902 is completed.

[0038] Each of step T21, step T31, and step T32 (FIG. 5) does not need to be simultaneously performed on the entire resist film 902, and may be performed at any timing on each part of the resist film 902. This will be described below by taking as an example the substrate processing using the substrate processing apparatus (FIGS. 1 to 3) described above.

[0039] FIG. 10 is a flowchart schematically showing the substrate processing method according to Embodiment 1 from the viewpoint of the operation of the substrate processing apparatus (FIGS. 1 to 3). Each of FIGS. 11 to 18 is a top view schematically showing the first to eighth operations of the substrate processing apparatus according to Embodiment 1. In FIGS. 11 to 18, for the substrate processing apparatus (FIGS. 1 to 3), only the positions of the discharge nozzle 31 and the spray nozzle 41 are shown by dots, and the illustration of other configurations is omitted.

[0040] Referring to FIG. 11, a wafer 901 (FIG. 6) provided with a resist film 902 having a portion P1 is attached to the substrate processing apparatus (FIGS. 1 to 3). The wafer 901 is rotated (see the arrow SP in the figure). Along with this, the position of the portion P1 rotates around the center of the wafer 901. The number of revolutions per minute is, for example, about 800 rpm.

[0041] Referring to FIG. 12, in step S20 (FIG. 10), ozone water as the ozone-containing aqueous solution 920 (FIG. 7) starts to be discharged from the discharge nozzle 31. At this time, the discharge nozzle 31 is preferably arranged near the center of the wafer 901. The ozone-containing aqueous solution 920 spreads outward on the wafer 901 by centrifugal force. The ozone concentration of the ozone water is preferably set to a sufficiently high concentration from the viewpoints of shortening the time required for peeling the resist film 902 and suppressing unnecessary etching of the wafer 901 as the base of the resist film 902, for example, about 100 ppm. The discharge amount of the ozone water is preferably 3 liters / minute or less. The ozone water as the ozone-containing aqueous solution 920 may be heated by the heater 331 (FIG. 2) in the pipe away from the wafer 901 between the ozone water supply unit 301 (FIG. 2) and the discharge nozzle 31. This heating may be continued while the ozone-containing aqueous solution 920 is being discharged. Note that the ozone-containing aqueous solution 920 may be heated on the wafer 901 instead of or together with the heating in the above-described pipe. For this purpose, a heater that radiates heat toward the upper surface of the wafer 901 may be provided in the substrate processing apparatus. This heater may be separated from the pipe. Instead of or together with that, as will be described later, the wafer 901 may be heated by warm water (or other heated liquid) from the back surface nozzle 11 (FIG. 3). Thereby, the liquid on the wafer 901 is also heated. In the first embodiment, the step of bringing the ozone-containing aqueous solution 920 into contact with the portion P1 in step S20 is performed by supplying the ozone-containing aqueous solution 920 from the discharge nozzle 31 to the wafer 901 without supplying the ammonia-containing aqueous solution from the spray nozzle 41 to the wafer 901.

[0042] Referring to FIG. 13, as a result of the ozone-containing aqueous solution 920 spreading as described above, the ozone-containing aqueous solution 920 is brought into contact with the portion P1 (FIG. 5: step T21). Further, as shown in the drawing, the ozone-containing aqueous solution 920 preferably covers the entire upper surface of the wafer 901.

[0043] Referring to FIG. 14, in step S30 (FIG. 10), ammonium peroxide (a mixture of aqueous ammonia and aqueous hydrogen peroxide), as an aqueous solution containing ammonia, is used as a gas N 2 is used to be sprayed from the spray nozzle 41. In other words, droplets 930S (FIG. 8) of ammonium peroxide are sprayed. Thereby, the aqueous ammonia-containing solution 930 is locally supplied onto the wafer 901 in the vicinity of the spray nozzle 41. During this spraying, the discharge of the ozone-containing aqueous solution 920 from the discharge nozzle 31 may be continued. The spraying amount is preferably 20 milliliters per minute or more and 300 milliliters per minute or less. The number of revolutions per minute of the wafer 901 in step S30 may be lower than the number of revolutions per minute in step S20 described above, for example, about 500 rpm.

[0044] By receiving the spraying, the ozone-containing aqueous solution 920 is substantially excluded from the vicinity region (the region directly receiving the spraying) of the spray nozzle 41 on the upper surface of the wafer 901. Also, the ammonia-containing aqueous solution 930 that has spread to the outside of this vicinity region mixes with the ozone-containing aqueous solution 920. Note that at the time shown in FIG. 14, the portion P1 has not yet come into contact with the ammonia-containing aqueous solution 930.

[0045] In the above process, ozone water from the discharge nozzle 31 and ammonium peroxide (aqueous ammonia and aqueous hydrogen peroxide) from the spray nozzle 41 are supplied onto the wafer 901. The ratio (volume ratio) of aqueous ammonia and aqueous hydrogen peroxide may be about the same. In that case, the ratio (volume ratio) of ozone water:aqueous ammonia:aqueous hydrogen peroxide is, for example, about 2000:10:10 under the condition where ozone water is relatively large, and about 500:125:125 under the condition where ozone water is relatively small. The aqueous ammonia mentioned here has a concentration of about 28% by weight, for example, and the aqueous hydrogen peroxide has a concentration of about 30% by weight, for example. Note that instead of ammonium peroxide, an ammonia-containing aqueous solution that does not contain aqueous hydrogen peroxide may be used, for example, aqueous ammonia may be used.

[0046] Referring to FIG. 15, as the wafer 901 rotates, when the position of the portion P1 in plan view (the field of view of FIG. 15) sufficiently approaches the position of the spray nozzle 41, the portion P1 comes into contact with the ammonia-containing aqueous solution 930 (FIG. 5: step T31).

[0047] Referring to FIG. 16, as the wafer 901 rotates, when the position of the portion P1 in plan view (the field of view of FIG. 16) is sufficiently away from the position of the spray nozzle 41, the portion P1 comes into contact with the ozone-containing aqueous solution 920 again (FIG. 5: step T21). By repeating this operation, the processes of FIGS. 15 and 16 corresponding to step T21 and step T31 (FIG. 5) may be repeated a plurality of times.

[0048] Referring to FIG. 17, when the position of the spray nozzle 41 for discharging the ammonia-containing aqueous solution, i.e., the scan operation, is shifted to some extent from the position of the portion P1 in the radial direction, the spraying of the ammonia-containing aqueous solution is not provided to the portion P1. Instead, the spraying of the ammonia-containing aqueous solution is provided to another portion P2. Thereby, the same process as the process in the portion P1 is also performed in the portion P2.

[0049] Referring to FIG. 18, with the rescan operation of the spray nozzle 41, the spraying of the ammonia-containing aqueous solution from the spray nozzle 41 is again provided to the portion P1. This spraying causes the collision of the droplets 930S (FIG. 9) with the resist film 902. In other words, it causes the collision of the aerosol flow of the droplets 930S with the resist film 902. Therefore, this spraying acts as physical cleaning on the resist film 902. By this physical cleaning, the portion P1 is separated (peeled off) from the wafer 901.

[0050] With the scanning operation of the spray nozzle 41, the portion P2 (FIG. 17) is similarly separated. This scanning operation is preferably performed such that the ammonia-containing aqueous solution 930 is discharged to the peripheral portion of the wafer 901 for a longer time than to the central portion of the wafer 901. In other words, the spray nozzle 41 that discharges the ammonia-containing aqueous solution 930 is preferably positioned above the peripheral portion of the wafer 901 for a longer time than above the central portion of the wafer 901. For example, compared with the arrangement of the spray nozzle 41 shown in FIG. 17, the arrangement of the spray nozzle 41 shown in FIG. 18 is maintained for a longer time. In the latter case, the spray nozzle 41 is arranged more on the peripheral side in the radial direction than in the former case.

[0051] As described above, the process of peeling the entire resist film 902 (FIG. 6) is completed.

[0052] In the above description, the scanning operation of the spray nozzle 41 has been described. However, for example, as shown by the arrow SN (FIGS. 14 to 18), the discharge nozzle 31 may also perform a scanning operation. When both the spray nozzle 41 and the discharge nozzle 31 perform a scanning operation, the relative positions of the spray nozzle 41 and the discharge nozzle 31 may be constant or may vary. In the former case, a common mechanism for the scanning operation can be used, and in the latter case, the degree of freedom for optimizing the scanning operation is increased.

[0053] Here, it is preferable that the discharge nozzle 31 is positioned closer to the center of the wafer 901 than the spray nozzle 41 in at least a part of the period during which liquid is supplied from both the discharge nozzle 31 and the spray nozzle 41. More preferably, the discharge nozzle 31 is positioned closer to the center of the wafer 901 than the spray nozzle 41 in more than half of the above period. The discharge nozzle 31 may always be positioned closer to the center of the wafer 901 than the spray nozzle 41 during the above period. Thereby, the range in which the ozone-containing aqueous solution 920 from the discharge nozzle 31 spreads due to centrifugal force is likely to include the position of the spray nozzle 41 in the radial direction. Therefore, the probability that the region in contact with the ozone-containing aqueous solution 920 receives spraying from the spray nozzle 41 is increased.

[0054] The period during which liquid is supplied from both the discharge nozzle 31 and the spray nozzle 41 described above may be a period during which liquid is discharged from the discharge nozzle 31 and the spray nozzle 41 simultaneously, and instead of or together with this, it may be a period during which liquid is alternately supplied from the discharge nozzle 31 and the spray nozzle 41 at short intervals so that the liquid from both nozzles sufficiently coexists on the wafer 901.

[0055] Also, during the above processing, warm water may be supplied from the back surface nozzle 11 (Figs. 2 and 3) onto the back surface of the wafer 901. Thereby, the temperature of the wafer 901 during processing can be raised. For example, warm water at about 80°C is discharged at about 2 liters / min.

[0056] Next, in step S80, the discharge nozzle 31 discharges deionized water. Thereby, the wafer 901 is washed with water. During this process, deionized water may be supplied from the back surface nozzle 11 (Figs. 2 and 3) onto the back surface of the wafer 901. Also, during this process, the spraying from the spray nozzle 41 may be stopped. The number of revolutions per minute of the wafer 901 in step S80 may be higher than the number of revolutions per minute in step S30 described above, for example, about 800 rpm.

[0057] Next, in step S90, the discharge of deionized water from the discharge nozzle 31 and the back surface nozzle 11 is stopped, and the wafer 901 is rotated at a high speed, for example, about 2500 rpm. Thereby, the liquid on the wafer 901 is removed by centrifugal force. That is, the wafer 901 is dried. This drying process may include a process of discharging a volatile liquid such as isopropyl alcohol from the discharge nozzle 31, and thereby the generation of watermarks can be suppressed.

[0058] Thus, the operation (Fig. 10) of the substrate processing apparatus (Figs. 1 to 3) is completed.

[0059] According to this embodiment, an ammonia-containing aqueous solution 930 (FIG. 14) is brought into contact with a portion P1 (FIG. 13) of the resist film 902 (FIG. 6) that has already been in contact with the ozone-containing aqueous solution 920 (FIG. 7). Since the portion P1 has been previously subjected to the decomposition action of ozone, it is likely to be subjected to the swelling action of the ammonia-containing aqueous solution 930. As a result, the progress of the swelling of the resist film 902 is promoted. Therefore, the resist film 902 can be removed in a short time in subsequent processes. Also, the ozone-containing aqueous solution 920 and the ammonia-containing aqueous solution 930 have a smaller burden on waste liquid treatment compared to SPM. From the above, the resist film 902 can be removed from the wafer 901 in a short time while suppressing the burden of waste liquid treatment.

[0060] In addition, if an attempt is made to decompose the entire resist film relying on the decomposition action of ozone, if the thickness of the resist film is relatively large, the processing time will become extremely long. This is particularly a problem in single-wafer substrate processing. In this embodiment, instead of the entire resist film being decomposed, the residue of the swollen resist film 902 is peeled off (see FIG. 9). As a result, it is not necessary to progress the decomposition of the resist film until the entire resist film disappears. Therefore, processing in a short time as described above becomes possible.

[0061] The step of bringing the ozone-containing aqueous solution 920 into contact (FIG. 13) is performed by discharging the ozone-containing aqueous solution 920 from a discharge nozzle 31 (FIGS. 1 and 2) toward the wafer 901. Thereby, the ozone-containing aqueous solution 920 can be handled by a method suitable for single-wafer substrate processing.

[0062] The step of bringing the ammonia-containing aqueous solution 930 into contact (FIG. 15) is performed by discharging the ammonia-containing aqueous solution 930 from a spray nozzle 41 (FIGS. 1 and 3) toward the wafer 901. Thereby, the ammonia-containing aqueous solution 930 can be handled by a method suitable for single-wafer substrate processing.

[0063] The step of discharging the ammonia-containing aqueous solution 930 (Figs. 17 and 18) includes the step of moving the spray nozzle 41 that discharges the ammonia-containing aqueous solution 930, specifically, the step of performing a scanning operation. Thereby, at each time point, while locally and intensively supplying the ammonia-containing aqueous solution 930 onto the wafer 901, the ammonia-containing aqueous solution 930 can be supplied over a wide range on the wafer 901 by the movement of the spray nozzle 41. Therefore, the peeling treatment can be performed over a wide range on the wafer 901 while locally enhancing the peeling action.

[0064] The step of moving the spray nozzle 41 is preferably performed such that the ammonia-containing aqueous solution 930 is discharged for a longer time to the peripheral portion of the wafer 901 than to the central portion of the wafer 901. Thereby, the non-uniformity of the supply amount of the ammonia-containing aqueous solution 930 (Figs. 17 and 18) on the wafer 901 can be suppressed. Therefore, the treatment can proceed more evenly on the wafer 901.

[0065] Among the resist films 902, the portion P1 that has already come into contact with the ammonia-containing aqueous solution 930 by the step of bringing the ammonia-containing aqueous solution 930 into contact (Fig. 13) is separated from the wafer 901 by physical cleaning (Fig. 9). Since the resist film 902 has already been sufficiently swollen by the swelling step (Fig. 8), it is easily peeled off by physical cleaning. Therefore, the resist film 902 can be peeled off in a shorter time.

[0066] Physical cleaning (Fig. 9) includes the step of spraying a gas from the spray nozzle 41 (Figs. 1 and 3) onto the wafer 901. Thereby, compared with the case where a fluid consisting only of a liquid or a fluid containing a solid is sprayed, damage to the wafer 901 can be suppressed while ensuring sufficient cleaning power.

[0067] The step of blowing gas onto the wafer 901 includes the step of spraying droplets 930S (Figs. 8 and 9) of an ammonia-containing aqueous solution onto the wafer 901 with the gas. Thereby, the droplets 930S dispersed in the gas collide with the wafer 901. In the step of Fig. 8, due to the gas pressure, the ammonia-containing aqueous solution is pushed deeper into the resist film 902. Therefore, swelling is more likely to progress even in the deep part of the resist film 902. Further, from the portion of the upper surface of the wafer 901 directly hit by the gas flow, the ozone-containing aqueous solution 920 is removed by the gas pressure. Thereby, it is prevented that the swelling action of the ammonia-containing aqueous solution 930 is inhibited by the action of ozone in this portion. Therefore, the progress of swelling can be promoted. Also, in the step of Fig. 9, since the droplets 930S are included in the gas flow, the effect of physical cleaning can be enhanced.

[0068] The gas is preferably an inert gas. Thereby, unnecessary chemical reactions between the gas and the wafer 901 can be avoided.

[0069] The step of bringing the ozone-containing aqueous solution 920 into contact (Fig. 7) preferably includes the step of forming cracks in the resist film 902 with the ozone-containing aqueous solution 920. Thereby, the ammonia-containing aqueous solution 930 (Fig. 15) can penetrate from the cracks. Therefore, the swelling (see Fig. 8) of the resist film 902 by the ammonia-containing aqueous solution 930 can be promoted.

[0070] The ammonia-containing aqueous solution 930 preferably contains hydrogen peroxide. Thereby, the swelling (see Fig. 8) of the resist film 902 by the ammonia-containing aqueous solution 930 can be promoted. Also, the ammonia-containing aqueous solution 930 (Fig. 15) sprayed from the spray nozzle 41 spreads on the wafer 901 and is mixed into the ozone-containing aqueous solution 920. Thereby, the decomposition action of the resist film 902 by the ozone-containing aqueous solution 920 can be activated.

[0071] The step of bringing the ozone-containing aqueous solution 920 into contact (FIG. 12) includes a step of supplying the ozone-containing aqueous solution 920 to the wafer 901 without supplying the ammonia-containing aqueous solution 930 (FIG. 14) to the wafer 901 (FIG. 10: step S20). Thereby, a large amount of the ozone-containing aqueous solution 920 can be supplied to the wafer 901 before the action of the ammonia-containing aqueous solution 930. Therefore, before step S30 (FIG. 10), the decomposition action of the resist film 902 (FIG. 7) by ozone can be sufficiently applied in advance.

[0072] The step of bringing the ozone-containing aqueous solution 920 into contact (FIGS. 12 to 18) may include a step of heating the ozone-containing aqueous solution 920 in a pipe separated from the wafer 901. Thereby, the decomposition action of the resist film 902 (FIG. 7) by the ozone-containing aqueous solution 920 can be enhanced.

[0073] The step of bringing the ozone-containing aqueous solution into contact (FIGS. 12 to 18) may include a step of heating the ozone-containing aqueous solution 920 on the wafer 901. Thereby, while enhancing the decomposition action of the resist film 902 (FIG. 7) by the ozone-containing aqueous solution 920 by heating, compared with the case where the ozone-containing aqueous solution 920 is heated before being applied onto the wafer 901 (for example, when heated by the heater 331 (FIG. 2)), the deactivation of ozone due to the passage of time after heating can be suppressed.

[0074] <Embodiment 2> FIG. 19 is a flowchart schematically showing the substrate processing method in the present Embodiment 2 from the viewpoint of the operation of the substrate processing apparatus (FIGS. 1 to 3). This flow corresponds to the flow in Embodiment 1 with step S20 (FIG. 10) omitted. Therefore, hereinafter, only the differences related to this omission will be described, and the description of the same features as those in Embodiment 1 will be omitted.

[0075] Each of FIGS. 20 to 22 is a top view schematically showing the first to third operations of the substrate processing apparatus according to the second embodiment. In FIGS. 20 to 22, for the substrate processing apparatus (FIGS. 1 to 3), only the positions of the discharge nozzle 31 and the spray nozzle 41 are shown by dots, and the illustration of other configurations is omitted.

[0076] Referring to FIG. 20, first, a wafer 901 (FIG. 6) provided with a resist film 902 having portions P1a and P1b is attached to the substrate processing apparatus (FIGS. 1 to 3). The wafer 901 is rotated (see the arrow SP in the figure). Accordingly, the positions of the portions P1a and P1b rotate around the center of the wafer 901. In step S30 (FIG. 19), ozone water as the ozone-containing aqueous solution 920 (FIG. 7) starts to be discharged from the discharge nozzle 31. Almost simultaneously, ammonia perhydrate (a mixed solution of ammonia water and hydrogen peroxide water) as the ammonia-containing aqueous solution 930 starts to be sprayed from the spray nozzle 41 using N 2 as a gas.

[0077] Referring to FIG. 21, the portion P1a first comes into contact with the ozone-containing aqueous solution 920 instead of the ammonia-containing aqueous solution 930. This is the same as in the case of the portion P1 (FIG. 13). Therefore, the treatment of the portion P1a is almost the same as the treatment of the portion P1 in the first embodiment. On the other hand, the portion P1b first comes into contact with the ammonia-containing aqueous solution 930 instead of the ozone-containing aqueous solution 920.

[0078] Referring to FIG. 22, next, the portion P1b comes into contact with the ozone-containing aqueous solution 920 for the first time. In other words, step T21 (FIG. 5) for the portion P1b is performed. The subsequent treatment of the portion P1b is almost the same as the treatment of the portion P1. That is, except that the portion P1b first comes into contact with the ammonia-containing aqueous solution 930 instead of the ozone-containing aqueous solution 920, the same treatment as that of the portion P1 is performed on the portion P1b.

[0079] According to this embodiment, unlike the case of Embodiment 1 (FIG. 12), the step of bringing the ozone-containing aqueous solution into contact (FIG. 20) is performed by supplying the ozone-containing aqueous solution 920 to the wafer 901 while supplying the ammonia-containing aqueous solution 930 to the wafer 901. As a result, step S20 (FIG. 10: Embodiment 1) can be omitted. In this embodiment, although it is difficult to supply a large amount of the ozone-containing aqueous solution 920 to the wafer 901 before the action of the ammonia-containing aqueous solution 930, by sufficiently supplying the ozone-containing aqueous solution 920 thereafter, an effect substantially the same as that of Embodiment 1 can be obtained.

[0080] <Embodiment 3> FIG. 23 is a flowchart schematically showing the substrate processing method in this Embodiment 3 from the viewpoint of the operation of the substrate processing apparatus (FIGS. 1 to 3). In this embodiment, prior to step S20 (FIG. 10: Embodiment 1), the resist film 902 (FIG. 6) is irradiated with ultraviolet rays (UV). The wavelength of the ultraviolet rays is preferably 190 nm or less, for example, 172 nm. The irradiation with ultraviolet rays may be performed using an apparatus different from the substrate processing apparatus (FIGS. 1 to 3). Note that for other configurations, since they are substantially the same as the configuration of Embodiment 1 described above, the same reference numerals are given to the same or corresponding elements, and the description thereof will not be repeated. As a modification, step S10 (FIG. 23) may be performed prior to step S30 (FIG. 19: Embodiment 2).

[0081] According to this embodiment, by the irradiation with ultraviolet rays, at the time when the ammonia-containing aqueous solution 930 (FIG. 15) is supplied, the decomposition of the resist film 902 (see FIG. 7) can be made in a more advanced state. Specifically, cracks can be more surely formed in the resist film 902. Therefore, the swelling of the resist film by the ammonia-containing aqueous solution 930 (see FIG. 8) can be promoted. Thus, the resist film 902 can be removed in a shorter time.

[0082] <Embodiment 4> FIG. 24 is a flowchart schematically showing the substrate processing method in Embodiment 4 from the viewpoint of the operation of the substrate processing apparatus (FIGS. 1 to 3). In this embodiment, step S50 is performed between step S30 and step S80. In step S50, while the discharge nozzle 31 discharges the SC1 cleaning liquid or deionized water, the spray nozzle 41 sprays the SC1 cleaning liquid. Thereby, the wafer 901 is cleaned. The flow rate of the discharge nozzle 31 is, for example, about 500 milliliters per minute, and the flow rate of the spray nozzle 41 is, for example, about 100 milliliters per minute. The number of revolutions per minute of the wafer 901 in step S80 may be approximately the same as the number of revolutions per minute in step S30 described above, for example, about 500 rpm. During this process, the SC1 cleaning liquid or deionized water may be supplied from the back surface nozzle 11 (FIGS. 2 and 3) onto the back surface of the wafer 901. Regarding the other configurations, since they are substantially the same as any of the above-described Embodiments 1 to 3, the same reference numerals are assigned to the same or corresponding elements, and the description thereof will not be repeated.

[0083] <Embodiment 5> FIG. 25 is a flowchart schematically showing the substrate processing method in Embodiment 5 from the viewpoint of the operation of the substrate processing apparatus (FIGS. 1 to 3). In this embodiment, first, steps S10 and S20 are performed in the same manner as in Embodiment 3 (FIG. 23).

[0084] FIG. 26 is a partial cross-sectional view schematically showing a step of the substrate processing method in the fifth embodiment. After the above step, in step S25 (FIG. 25), a mixed solution 930L of ozone water and an additive is discharged from a discharge nozzle 31 (FIG. 2). In other words, both a valve 311 and a valve 312 (FIG. 2) are opened. The additive contains aqueous ammonia and hydrogen peroxide water. This mixed solution contains ammonia at a higher concentration than the ozone-containing aqueous solution 920 (FIG. 7). Note that, as described above, the ozone-containing aqueous solution 920 may not contain ammonia. By supplying the mixed solution 930L in step S25, both a decomposition action and a swelling action on the resist film 902 occur. The decomposition action by ozone in the ozone-containing aqueous solution is temporarily more activated by mixing aqueous ammonia and hydrogen peroxide water. Although the temporarily increased activity decreases with the passage of time, the influence of the decrease in activity is suppressed by sufficiently supplying a new mixed solution from the discharge nozzle 31.

[0085] Next, in step S35 (FIG. 25), as in the case of step S30 (FIG. 10: first embodiment), ammonia peroxide is sprayed from a spray nozzle 41. By this physical cleaning by spraying (FIG. 9), the resist film 902 is separated from the wafer 901. During this spraying, the discharge of the above mixed solution from the discharge nozzle 31 is continued. By receiving the spraying, the above mixed solution is substantially removed from the vicinity region of the spray nozzle 41 on the upper surface of the wafer 901. In addition, the ammonia-containing aqueous solution 930 that has spread to the outside of this vicinity region is mixed with the above mixed solution, whereby the ozone in the mixed solution 930L is more activated.

[0086] The subsequent steps are the same as those in the third embodiment (FIG. 23), and thus the description thereof is omitted. In this embodiment, instead of step S30 (FIG. 23), steps S25 and S35 are performed. Such a replacement of steps may be made not only for the third embodiment but also for the other above-described embodiments.

[0087] In this embodiment, in step S25 (FIG. 25), the liquid discharged from the discharge nozzle 31 contains ozone water, ammonia water, and hydrogen peroxide water. As a result, both the decomposition action by ozone activated by ammonia water and hydrogen peroxide water and the swelling action by ammonia water can be obtained simultaneously. Thereby, the resist film 902 can be removed from the wafer 901 in a short time.

[0088] <Embodiment 6> FIG. 27 is a flowchart schematically showing the substrate processing method in Embodiment 6 of the present invention from the viewpoint of the operation of the substrate processing apparatus (FIGS. 1 to 3). In this embodiment, the physical cleaning step (FIG. 9) in step S35 (FIG. 25: Embodiment 5) described above is omitted. In order to compensate for the omission of physical cleaning, the contact with the mixed liquid in step S25 (FIG. 26) is performed for a longer time. Since this mixed liquid contains ammonia water, it is a kind of ammonia-containing aqueous solution.

[0089] FIG. 28 is a flowchart schematically showing the substrate processing method in Embodiment 6 of the present invention from the viewpoint of the processing of one part of the resist film. FIG. 29 is a partial cross-sectional view schematically showing one step of the substrate processing method in Embodiment 6 of the present invention.

[0090] In step U10 (FIG. 28), cracks are formed in the resist film 902 (FIGS. 6 and 7). This step U10 (FIG. 28) can be implemented by steps S10 and S20 (FIG. 27) as the operations of the substrate processing apparatus.

[0091] Referring to FIG. 29, next, in step U11 (FIG. 28), the mixed liquid 930L, particularly the ammonia water contained therein, is infiltrated into the interface between the wafer 901 and the resist film 902 through the cracks. Thereby, the resist film 902 is peeled off from the wafer 901.

[0092] According to this embodiment, although the time required for step S25 is slightly longer than that in Embodiment 5, the resist film 902 can be peeled off from the wafer 901 without using physical cleaning (see FIG. 29). Therefore, when prioritizing the omission of physical cleaning, Embodiment 6 is preferably used, and when prioritizing the shortening of the processing time, the aforementioned Embodiment 5 is preferably used. According to an experimental example by the present inventors, the time required for peeling the resist film was about 4 minutes in the case of Embodiment 5 and about 6 minutes in the case of Embodiment 6. As a modification, step S50 (FIG. 24: Embodiment 4) may be performed between step S25 and step S80.

[0093] Although the present invention has been described in detail, the above description is illustrative in all aspects and the present invention is not limited thereto. Innumerable modifications that are not illustrated can be assumed without departing from the scope of the present invention. Each configuration described in the above embodiments and each modification can be appropriately combined or omitted as long as they do not conflict with each other.

[0094] <Appendix> This specification includes the disclosure of the following aspects.

[0095] A first aspect is a substrate processing method including a step of bringing an ozone-containing aqueous solution into contact with a resist film on a substrate, and a step of bringing an ammonia-containing aqueous solution containing ammonia at a higher concentration than the ozone-containing aqueous solution into contact with a portion of the resist film that has already been in contact with the ozone-containing aqueous solution in the step of bringing the ozone-containing aqueous solution into contact.

[0096] A second aspect is the substrate processing method according to the first aspect, wherein the step of bringing the ozone-containing aqueous solution into contact is performed by discharging the ozone-containing aqueous solution toward the substrate.

[0097] A third aspect is the substrate processing method according to the first or second aspect, wherein the step of bringing the ammonia-containing aqueous solution into contact is performed by discharging the ammonia-containing aqueous solution toward the substrate.

[0098] Aspect 4 is the substrate processing method of Aspect 3, wherein the step of discharging the ammonia-containing aqueous solution includes a step of moving a nozzle for discharging the ammonia-containing aqueous solution.

[0099] Aspect 5 is the substrate processing method of Aspect 4, wherein the step of moving the nozzle is performed such that the ammonia-containing aqueous solution is discharged for a longer time to the peripheral portion of the substrate than to the central portion of the substrate.

[0100] Aspect 6 is the substrate processing method according to any one of Aspects 1 to 5, further comprising a step of separating, from the substrate by physical cleaning, a portion of the resist film that has already been in contact with the ammonia-containing aqueous solution by the step of bringing the ammonia-containing aqueous solution into contact therewith.

[0101] Aspect 7 is the substrate processing method of Aspect 6, wherein the physical cleaning includes a step of blowing a gas onto the substrate.

[0102] Aspect 8 is the substrate processing method of Aspect 7, wherein the step of blowing a gas onto the substrate includes a step of spraying the ammonia-containing aqueous solution onto the substrate with the gas.

[0103] Aspect 9 is the substrate processing method according to Aspect 7 or 8, wherein the gas is an inert gas.

[0104] Aspect 10 is the substrate processing method according to any one of Aspects 1 to 5, wherein the step of bringing the ozone-containing aqueous solution into contact therewith includes a step of forming cracks in the resist film with the ozone-containing aqueous solution.

[0105] Aspect 11 is the substrate processing method of Aspect 10, wherein the step of bringing the ammonia-containing aqueous solution into contact therewith includes a step of peeling the resist film from the substrate by allowing the ammonia-containing aqueous solution to penetrate to the interface between the substrate and the resist film through the cracks formed by the step of forming cracks in the resist film.

[0106] Aspect 12 is a substrate processing method according to any one of Aspects 1 to 11, wherein the ammonia-containing aqueous solution contains hydrogen peroxide.

[0107] Aspect 13 is a substrate processing method according to any one of Aspects 1 to 12, further comprising a step of irradiating the resist film with ultraviolet light before the step of bringing the ozone-containing aqueous solution into contact.

[0108] Aspect 14 is a substrate processing method according to any one of Aspects 1 to 13, wherein the step of bringing the ozone-containing aqueous solution into contact includes a step of supplying the ozone-containing aqueous solution to the substrate without supplying the ammonia-containing aqueous solution to the substrate.

[0109] Aspect 15 is a substrate processing method according to any one of Aspects 1 to 14, wherein the step of bringing the ozone-containing aqueous solution into contact includes a step of heating the ozone-containing aqueous solution in a pipe separated from the substrate.

[0110] Aspect 16 is a substrate processing method according to any one of Aspects 1 to 15, wherein the step of bringing the ozone-containing aqueous solution into contact includes a step of heating the ozone-containing aqueous solution on the substrate.

[0111] According to the first aspect described above, the ammonia-containing aqueous solution is brought into contact with the portion of the resist film that has already come into contact with the ozone-containing aqueous solution. Since the portion that has already come into contact with the ozone-containing aqueous solution has been previously subjected to the decomposition action by ozone, it is susceptible to the swelling action by the ammonia-containing aqueous solution. As a result, the progress of the swelling of the resist film is promoted. Therefore, the resist film can be removed in a short time in the subsequent process. Also, the ozone-containing aqueous solution and the ammonia-containing aqueous solution have a smaller burden on waste liquid treatment compared to SPM. From the above, the resist film can be removed from the substrate in a short time while suppressing the burden of waste liquid treatment.

Explanation of Reference Numerals

[0112] 11 Back surface nozzle 31 Discharge nozzle 41 Spray nozzle 901 Wafer (substrate) 331 Heater 902 Resist film 920 Aqueous solution containing ozone 930 Aqueous solution containing ammonia 930L Mixture 930S Droplet

Claims

1. A substrate processing method for removing a resist film from a substrate, comprising: (a) discharging an ozone-containing aqueous solution onto the rotating substrate to bring the ozone-containing aqueous solution into contact with the resist film on the substrate, thereby forming cracks in the resist film; (b) spraying droplets of an ammonia-containing aqueous solution from a spray nozzle above the substrate onto the rotating substrate, so that the ammonia-containing aqueous solution having a higher concentration of ammonia than the ozone-containing aqueous solution penetrates through the cracks formed in the resist film in step (a), thereby swelling the resist film; (c) spraying droplets of the ammonia-containing aqueous solution from the spray nozzle above the substrate onto the portion of the resist film that has been swollen in step (b), thereby peeling the resist film from the substrate; (d) in each of steps (b) and (c), moving the position of the spray nozzle radially above the substrate; and in step (a), the ozone-containing aqueous solution is discharged onto the rotating substrate so as to cover the entire upper surface of the substrate; in steps (b) and (c), the spray nozzle locally sprays droplets of the ammonia-containing aqueous solution onto the substrate while the discharge of the ozone-containing aqueous solution is continued; steps (b) and (c) are a substrate processing method in which droplets of the ammonia-containing aqueous solution are sprayed onto a local area on the substrate by causing the ammonia-containing aqueous solution to collide with a gas, and the ozone-containing aqueous solution is temporarily removed from the local area by the pressure of the gas.

2. The substrate processing method according to claim 1, wherein the rotation speed of the substrate in step (a) is higher than the rotation speed of the substrate in step (b).

3. The substrate processing method according to claim 1 or 2, further comprising, after step (d), discharging an SC1 cleaning solution, which is a mixture of ammonia water, hydrogen peroxide water, and water, from a discharge nozzle above the rotating substrate while the spray nozzle sprays the SC1 cleaning solution to clean the substrate.

4. The substrate processing method according to claim 1, wherein the step (d) is performed such that the ammonia-containing aqueous solution is discharged to the peripheral portion of the substrate for a longer time than the central portion of the substrate.

5. The substrate processing method according to any one of claims 1 to 4, wherein the ammonia-containing aqueous solution is ammonia perhydrate which is a mixed solution of only ammonia water and hydrogen peroxide water.

6. The substrate processing method according to any one of claims 1 to 5, further comprising a step of irradiating ultraviolet rays to the resist film before the step (a).

7. The substrate processing method according to any one of claims 1 to 6, wherein the step (a) includes a step of supplying an ozone-containing aqueous solution to the substrate without supplying an ammonia-containing aqueous solution to the substrate.

8. The substrate processing method according to any one of claims 1 to 7, wherein the step (a) includes a step of heating an ozone-containing aqueous solution in a pipe away from the substrate.

9. The substrate processing method according to any one of claims 1 to 8, wherein the step (a) includes a step of heating an ozone-containing aqueous solution on the substrate.

10. With the rotation of the substrate, the step (a) and the step (b) are repeated. After the repetition, the substrate processing method according to any one of claims 1 to 9, wherein the spray nozzle is moved in the radial direction in the step (b).

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