Substrate processing method, substrate processing apparatus, and computer program product

Abstract

This invention provides a substrate processing method, a substrate processing apparatus, and a computer program product that can suppress deviations in etching amount during liquid processing using a mixture of fluid and processing liquid. The substrate processing apparatus includes: a fluid supply unit supplying a fluid containing pressurized pure water vapor or mist; a processing liquid supply unit supplying a processing liquid containing at least sulfuric acid; a nozzle connected to the fluid supply unit and the processing liquid supply unit; and a temperature detection unit detecting the temperature of the processing liquid supplied to the nozzle. The substrate processing method performed using this apparatus includes: a processing liquid discharge step, supplying processing liquid from the processing liquid supply unit to the nozzle and discharging the processing liquid from the nozzle to the substrate; and a mixed fluid discharge step, after the processing liquid discharge step, when the temperature of the processing liquid detected by the temperature detection unit reaches a specified temperature, supplying fluid from the processing liquid supply unit to the nozzle and discharging the mixed fluid formed by mixing the fluid and the processing liquid from the nozzle to the substrate.

Description

Technical Field

[0001] This invention relates to substrate processing methods, substrate processing apparatus, and computer program products. Background Technology

[0002] In the manufacturing process of semiconductor devices, there is a known technique for removing resist films and other materials from a substrate by supplying SPM (sulfuric acid peroxide) to a substrate such as a semiconductor wafer. Patent Document 1 describes a method of supplying SPM to the substrate after mixing it with pure water vapor in order to improve processing efficiency.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent document 1: Japanese Patent Application Publication No. 2023-87757. Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] This invention provides a technique for suppressing deviations in etching amount during liquid treatment using a mixture of fluid and processing liquid.

[0008] Technical means for solving problems

[0009] According to one aspect of the present invention, a substrate processing method is provided using a substrate processing apparatus, wherein the substrate processing apparatus includes: a substrate holding section for holding a substrate; a fluid supply section for supplying a fluid comprising pressurized pure water vapor or mist; a processing liquid supply section for supplying a processing liquid comprising at least sulfuric acid; a nozzle connected to the fluid supply section and the processing liquid supply section for mixing the fluid with the processing liquid and discharging it to the substrate; and a temperature detection section for detecting the temperature of the processing liquid supplied from the processing liquid supply section to the nozzle, the substrate processing method including: a processing liquid discharge step, supplying the processing liquid from the processing liquid supply section to the nozzle and discharging the processing liquid from the nozzle to the substrate; and a mixed fluid discharge step, after the processing liquid discharge step, when the temperature of the processing liquid detected by the temperature detection section reaches a specified temperature, supplying the fluid from the processing liquid supply section to the nozzle and discharging the mixed fluid formed by mixing the fluid with the processing liquid from the nozzle to the substrate.

[0010] Invention Effects

[0011] According to one aspect of the present invention described above, deviations in the etching amount can be suppressed. Attached Figure Description

[0012] Figure 1This is a schematic top view showing the overall structure of a substrate processing system as one embodiment of a substrate processing apparatus.

[0013] Figure 1A It indicates assembly at Figure 1 A schematic top view of a configuration example of the processing unit of a substrate processing system.

[0014] Figure 2 yes Figure 1 A schematic side view of the substrate processing device.

[0015] Figure 3 This is a diagram showing the structure of the nozzle used for SPM discharge. It is a cross-sectional view obtained by cutting the nozzle with a plane orthogonal to its length direction.

[0016] Figure 4 For along Figure 3 A cross-sectional view of the nozzle along line IV-IV.

[0017] Figure 5 It is along Figure 3 A cross-sectional view of the nozzle with the VV line.

[0018] Figure 6 Viewed from below Figures 3-5 A schematic top view of the nozzle shown.

[0019] Figure 7 This diagram illustrates an example of a piping system that supplies SPM and steam to nozzles used for SPM discharge.

[0020] Figure 8 This is a flowchart illustrating an example of a series of processes performed on a single wafer.

[0021] Figure 9 It means Figure 8 The flowchart shows an example of a detailed sequence of SPM processing steps.

[0022] Figure 10 This is a schematic side view illustrating an example of SPM liquid being discharged from a nozzle.

[0023] Figure 11 This is a schematic side view illustrating an example of a situation where a mixture of SPM liquid and vapor is discharged from a nozzle.

[0024] Explanation of reference numerals in the attached figures

[0025] 102 Substrate Holding Section

[0026] 141 Nozzle

[0027] 201 Fluid Supply Department

[0028] 202 Processing Fluid Supply Department

[0029] 2052 Temperature Detection Department. Detailed Implementation

[0030] Hereinafter, with reference to the accompanying drawings, a substrate processing apparatus (substrate processing system) for implementing the present invention and a substrate processing method performed thereon (hereinafter referred to as "Embodiments") will be described in detail. However, the present invention is not limited to these embodiments. Furthermore, the various embodiments can be appropriately combined without contradicting the processing content. In the following embodiments, the same reference numerals are used to label the same parts, and repeated descriptions are omitted.

[0031] Furthermore, in the embodiments shown below, expressions such as "certain," "orthogonal," "perpendicular," or "parallel" are sometimes used, but these expressions do not need to be strictly "certain," "orthogonal," "perpendicular," or "parallel." That is, deviations in manufacturing precision, setting precision, etc., are allowed for the aforementioned expressions.

[0032] Furthermore, in the accompanying figures mentioned below, for ease of understanding, an orthogonal coordinate system is sometimes shown, defining mutually orthogonal X-axis, Y-axis, and Z-axis directions, with the positive Z-axis direction set as the vertically upward direction. Additionally, the direction of rotation about the vertical axis is sometimes referred to as the θ direction.

[0033] In the semiconductor device manufacturing process, a photoresist film is formed in a prescribed pattern on a substrate such as a semiconductor wafer. This photoresist film is then used as a mask to perform etching, ion implantation, and other treatments on the substrate. After treatment, the unwanted photoresist film is removed from the wafer.

[0034] SPM treatment is used as a method for removing resist films. SPM treatment involves supplying a high-temperature SPM (Sulfuric Acid Hydrogen Peroxide Mixture) solution (also known as "sulfuric acid hydrogen peroxide"), obtained by mixing sulfuric acid and an aqueous solution of hydrogen peroxide, to the resist film. Furthermore, the efficiency of SPM treatment can be improved by using a mixture of pressurized pure water (deionized water) vapor (hereinafter referred to as "vapor") and the SPM solution.

[0035] Furthermore, the substrate processing apparatus of the present invention can also be applied to liquid processing other than SPM processing. Specifically, the substrate processing apparatus of the present invention can be applied to liquid processing using a processing solution containing at least sulfuric acid.

[0036] "A treatment solution containing at least sulfuric acid" other than SPM solution can include, for example, treatment solutions that react with sulfuric acid (heating or etchant addition), specifically, dilute sulfuric acid (a mixture of sulfuric acid and water), a mixture of sulfuric acid and ozone water, etc. Alternatively, "a treatment solution containing at least sulfuric acid" can also be sulfuric acid itself.

[0037] [Overall structure of the substrate processing system]

[0038] First, refer to Figure 1 The general structure of a substrate processing system 1 according to one embodiment of the substrate processing apparatus will be described. Figure 1 This is a diagram showing a schematic structure of the substrate processing system 1 according to the first embodiment. Hereinafter, in order to clarify the positional relationships, the X-axis, Y-axis and Z-axis are defined as mutually orthogonal, and the positive direction of the Z-axis is set as the vertical upward direction.

[0039] like Figure 1 As shown, the substrate processing system 1 (an example of a substrate processing apparatus) includes an infeed / outfeed station 2 and a processing station 3.

[0040] The feed-in / feed-out station 2 includes a carrier placement section 11 and a transport section 12. Multiple carriers C (e.g., FOUP) are placed in the carrier placement section 11. In each carrier C, multiple substrates (in this embodiment, semiconductor wafers W (hereinafter, for simplicity, simply referred to as "wafer W")) are stored at equal intervals in the vertical direction in a horizontal orientation.

[0041] The substrate transport device 13 and the transfer section 14 are provided inside the transport section 12. The substrate transport device 13 is composed of a multi-axis transport robot or a multi-joint transport robot. The substrate transport device 13 uses a fork-shaped wafer holder as an end effector to hold the wafer and transport the wafer W between the carrier C and the transfer section 14.

[0042] The processing station 3 includes a conveying unit 15 and multiple processing units 16.

[0043] A substrate transport device 17 is provided inside the transport section 15. The substrate transport device 17 is composed of a multi-axis transport robot or a multi-joint transport robot. The substrate transport device 17 uses a fork-shaped wafer holder as an end effector to hold the wafer and transport the wafer W between the processing unit 16 and the transfer section 14.

[0044] The processing unit 16 performs liquid processing by supplying a processing fluid (such as SPM liquid in the example described below) to the wafer W fed by the substrate transport device 17.

[0045] The wafer W housed in the carrier C is taken out by the substrate transport device 13 of the transport section 12 and sent to the transfer section 14. The wafer W is then taken out by the substrate transport device 17 of the transport section 15 and sent to the processing unit 16. The wafer that has been processed by the processing unit 16 returns to the original carrier C along the reverse path described above.

[0046] Substrate processing system 1 includes control device 4 (only in...) Figure 1 (As shown in the diagram). The control device 4 is capable of controlling the operation of all operable components included in the substrate processing system 1. The control device 4 is, for example, a computer, including a control and arithmetic unit 18 and a storage unit 19. The storage unit 19 stores programs that control various processes executed in the substrate processing system 1 (including a processing scheme that determines the sequence of processes). The control and arithmetic unit 18 controls the operation of the substrate processing system 1 by reading and executing the programs stored in the storage unit 19. The control and arithmetic unit 18 may be a CPU (Central Processing Unit) or one or more circuits.

[0047] Furthermore, the aforementioned program can also be recorded on a computer-readable storage medium and installed from that storage medium into the storage unit 19 of the control device 4. The computer-readable storage medium can be, for example, any one or a combination of two or more of the following: hard disk (HD), floppy disk (FD), optical disk (CD), magneto-optical disk (MO), memory card, RAM (Random Access Memory), ROM (Read Only Memory), and SSD (Solid State Drive).

[0048] <Structure of the Processing Unit>

[0049] Next, refer to Figure 1A An example of the structure of a processing unit 16 assembled in a substrate processing system 1 is described. The processing unit 16 includes a chamber 101, a substrate holding portion 102, a cup portion 103, a first supply mechanism 104, a second supply mechanism 105, and a nozzle cleaning mechanism 106. Furthermore, the processing unit 16 includes: a vapor supply unit 201, which is a fluid supply unit supplying a fluid containing pressurized pure water vapor or mist; an SPM supply unit 202, which is a processing liquid supply unit supplying a processing solution containing at least sulfuric acid; a rinsing liquid supply unit 203; and a replacement liquid supply unit 204. The processing unit 16 removes the resist film formed on the surface of a substrate such as a semiconductor wafer (hereinafter referred to as "wafer W").

[0050] The substrate holding portion 102 includes: a circular plate-shaped main body portion 121 with a diameter larger than that of the wafer W; a plurality of gripping portions 122 disposed on the periphery of the upper surface of the main body portion 121; a support member 123 supporting the main body portion 121; and a drive portion 124 for rotating the support member 123. In addition, the number of gripping portions 122 is not limited to the number shown in the figure.

[0051] The substrate holding portion 102 holds the wafer W by gripping the peripheral portion of the wafer W using a plurality of gripping portions 122. Thus, the wafer W is held horizontally with its surface slightly separated from the upper surface of the main body portion 121. As described above, a resist film serving as a removal target film (or etching target film) is formed on the surface (upper surface) of the wafer W.

[0052] In the example shown, a substrate holding part 102, referred to as a mechanical chuck, is used to hold the periphery of the wafer W using multiple gripping parts 122. However, a vacuum chuck that holds the back of the wafer W by adsorption can be used instead.

[0053] The cup body 103 is arranged to surround the substrate holding part 102. At the bottom of the cup body 103, there is a drain port 131 for discharging the processing liquid supplied to the wafer W to the outside of the chamber 101 and an exhaust port 132 for exhausting the atmosphere inside the chamber 101.

[0054] The first supply mechanism 104 includes: a nozzle 141; a first arm 142 extending horizontally and supporting the nozzle 141 from above; and a first rotation and lifting mechanism 143 that rotates and lifts the first arm 142. The first rotation and lifting mechanism 143 enables the first arm 142 to be positioned at a processing position above the wafer W. Figure 1 (as shown by the dashed line) and the standby position on the outer side of the chip W ( Figure 1 It moves between (as shown by the solid line in the middle).

[0055] Nozzle 141 is a strip-shaped nozzle that extends in a straight line along the horizontal direction. Nozzle 141 has a length that is the same as the radius of wafer W. When positioned in the processing position, the leading end of nozzle 141 in the longitudinal direction is located above the center of wafer W, and the base end of nozzle 141 in the longitudinal direction is located above the periphery of wafer W.

[0056] Nozzle 141 is connected to steam supply unit 201 via steam supply path 211 equipped with on / off valve 212. Additionally, nozzle 141 is connected to SPM supply unit 202 via SPM supply path 221. Steam supply unit 201 supplies pressurized pure water (deionized water) vapor, i.e., mist, to nozzle 141 via steam supply path 211. SPM supply unit 202 supplies nozzle 141 with a mixture of sulfuric acid and hydrogen peroxide aqueous solution, i.e., SPM solution, via SPM supply path 221.

[0057] The following is for reference Figure 7 This section describes a structural example of a process fluid supply mechanism (steam supply unit 201 and SPM supply unit 202) that supplies steam and SPM liquid to nozzle 141.

[0058] SPM supply unit 202 includes sulfuric acid supply unit 2020, hydrogen peroxide aqueous solution supply unit 2040 and mixing unit 2050 for mixing sulfuric acid and hydrogen peroxide aqueous solution to generate SPM.

[0059] The sulfuric acid supply unit 2020 includes a tank 2021 for storing sulfuric acid, a circulation path 2022 connected to the tank 2021, and equipment such as a pump 2023, a heater 2024, and a filter 2025 installed in the circulation path 2022. For example, sulfuric acid is supplied to the tank 2021 as needed from a sulfuric acid supply source (not shown) provided as part of a plant facility. The pump 2023 creates a circulating flow of sulfuric acid from the tank 2021 to the circulation path 2022 and back to the tank 2021. The sulfuric acid circulates within the circulation path 2022 while being heated to a preset temperature (e.g., approximately 120°C) by the heater 2024.

[0060] A number of branch supply paths 2026 branch off from the circulation path 2022, the same number as the number of processing units 16 provided in the substrate processing system 1. Each branch supply path 2026 is assigned to a chamber 101. A flow meter 2027, a flow control valve 2028, and an on / off valve 2029 are provided in each branch supply path 2026. A return path 2030 branches off from the branch supply path 2026 between the flow control valve 2028 and the on / off valve 2029. An on / off valve 2031 is provided in the return path 2030.

[0061] The hydrogen peroxide aqueous solution supply unit 2040 has, for example, a main supply path 2041 connected to a hydrogen peroxide aqueous solution supply source 2043 provided as a plant unit. A number of branch supply paths 2042 branch from the main supply path 2041, the same number as the number of processing units 16, are assigned to one processing unit 16. A flow meter 2045, a flow control valve 2046, and an on / off valve 2047 are provided in each branch supply path 2042. The downstream end of the branch supply path 2042 of the hydrogen peroxide aqueous solution supply unit 2040 merges with a branch supply path 2026 for sulfuric acid. This merging section becomes the aforementioned mixing section 2050, and the branch supply path 2026 downstream of this mixing section 2050 becomes the aforementioned SPM supply path 221. A temperature sensor (temperature detection unit) 2052 is provided at the downstream end of the SPM supply path 221 (near the connection with the nozzle 141). A structure that promotes the mixing of sulfuric acid and hydrogen peroxide aqueous solution may also be provided in the mixing section 2050 or the SPM supply path 221 slightly downstream of the mixing section 2050, such as a pipeline mixer.

[0062] Between the mixing section 2050 and the on / off valve 2029, a discharge line 2032 branches off from the sulfuric acid supply branch path 2026. An on / off valve is installed on the discharge line 2032. This discharge line 2032 is used to discharge liquid retained in the SPM supply path 221. As detailed later, it is not used during normal operation when the unit is operated in a mode without pseudo-dispensing. The discharge line 2032 can be used to completely drain liquid from the SPM supply path 221 during unit maintenance or long-term unit shutdown.

[0063] Nozzle 141 discharges SPM liquid supplied from SPM supply unit 202, either alone or mixed with vapor supplied from vapor supply unit 201, into wafer W. The specific structure of nozzle 141 will be described later.

[0064] Furthermore, the second supply mechanism 105 includes: an auxiliary nozzle 151; a second arm 152 extending horizontally to support the auxiliary nozzle 151 from above; and a second rotation and lifting mechanism 153 that rotates and lifts the second arm 152. Using the second rotation and lifting mechanism 153, the second arm 152 can move the auxiliary nozzle 151 between a processing position above the wafer W and a standby position outside the wafer W.

[0065] The auxiliary nozzle 151 is connected to the steam supply unit 201 via the steam supply path 211. The steam supply unit 201 supplies steam to the auxiliary nozzle 151 via the steam supply path 211. Additionally, the auxiliary nozzle 151 is connected to the flushing fluid supply unit 203 via the flushing fluid supply path 231 and to the replacement fluid supply unit 204 via the replacement fluid supply path 241. The flushing fluid supply unit 203 supplies flushing fluid, in this example, pure water (deionized water), to the auxiliary nozzle 151 via the flushing fluid supply path 231. The replacement fluid supply unit 204 supplies replacement fluid, in this example, IPA (isopropanol), to the auxiliary nozzle 151 via the replacement fluid supply path 241.

[0066] The auxiliary nozzle 151 discharges steam supplied from the steam supply unit 201 to the wafer W via the steam supply path 211. Additionally, the auxiliary nozzle 151 discharges rinsing fluid supplied from the rinsing fluid supply unit 203 to the wafer W via the rinsing fluid supply path 231. Furthermore, the auxiliary nozzle 151 discharges replacement fluid supplied from the replacement fluid supply unit 204 to the wafer W via the replacement fluid supply path 241.

[0067] The nozzle cleaning mechanism 106 is positioned in the standby position of the nozzle 141. The nozzle cleaning mechanism 106 cleans the nozzle 141.

[0068] <Nose Structure>

[0069] Next, refer to Figures 3-6 The structure of nozzle 141 will be described. Figure 3 This is a cross-sectional view of a nozzle 141 of a configuration example, cut by a plane orthogonal to the length direction. Additionally, Figure 4 yes Figure 3 The sectional view along line IV-IV shown. Additionally... Figure 5 yes Figure 3 The VV line shown is a sectional view taken from the side. Additionally... Figure 6 This is a schematic top view of the nozzle 141 of the first embodiment, viewed from below. Additionally, in Figure 6 In the diagram, points represent regions where steam flows.

[0070] like Figure 3 As shown, nozzle 141 includes nozzle body 41, two first distribution paths 42, one second distribution path 43, and multiple outlet paths 44 (see reference). Figure 4 and Figure 5 Additionally, nozzle 141 includes a plurality of first discharge outlets 45 and a plurality of first discharge paths 46 (see reference). Figure 4 ) and multiple second discharge outlets 47 and multiple second discharge paths 48 (see reference) Figure 5 ).

[0071] The first distribution path 42 and the second distribution path 43 are formed inside the nozzle body 41. For example... Figure 4 and Figure 5 As shown, the first distribution path 42 and the second distribution path 43 extend along the length of the nozzle body 41. The first distribution path 42 is connected to the steam supply unit 201 via the steam supply path 211. In addition, the second distribution path 43 is connected to the SPM supply unit 202 via the SPM supply path 221.

[0072] like Figure 3 As shown, the second distribution path 43 is positioned on the centerline of the nozzle body 41 in cross-section (the line that bisects the nozzle body 41 to the left and right). Additionally, one of each of the two first distribution paths 42 is positioned on the left and right sides of the centerline of the nozzle body 41 in cross-section.

[0073] Multiple export paths 44 are located below the second allocation path 43. For example... Figures 3-5 As shown, multiple outlet paths 44 are flow paths disposed at the lower part of the nozzle body 41, extending downward in the vertical direction. The multiple outlet paths 44 are arranged at equal intervals along the length of the nozzle body 41, for example. Adjacent outlet paths 44 are separated by partitions. The cross-sectional shape of the outlet path 44 is, for example, rectangular. The cross-sectional shape of the outlet path 44 can also be circular or elliptical, etc.

[0074] The first row of outlets 45 opens on the inner side of the outlet path 44. Additionally, the second row of outlets 47 is positioned above the first row of outlets 45 and opens on the upper end face of the outlet path 44. (Example...) Figure 4 and Figure 5 As shown, a plurality of first outlets 45 and a plurality of second outlets 47 are arranged at equal intervals along the length of the nozzle body 41.

[0075] like Figures 3-6 As shown, nozzle 141 includes a plurality of first outlets 45 and a plurality of second outlets 47, and includes a plurality of outlet paths 44 communicating with two of the first outlets 45 and one of the second outlets 47. Furthermore, the number of first outlets 45 and second outlets 47 communicating with one outlet path 44 is not limited to [specific number missing]. Figures 3-6 The number shown. That is, the nozzle 141 may also include multiple outlet paths 44 communicating with at least one first outlet 45 and at least one second outlet 47.

[0076] Multiple first discharge outlets 45 are connected to a first distribution path 42 via multiple first discharge paths 46. In addition, multiple second discharge outlets 47 are connected to a second distribution path 43 via multiple second discharge paths 48.

[0077] Steam supplied from steam supply unit 201 to first distribution path 42 is distributed from first distribution path 42 to multiple first discharge paths 46, and discharged from multiple first discharge outlets 45 to corresponding multiple outlet paths 44. Additionally, SPM liquid supplied from SPM supply unit 202 to second distribution path 43 is distributed from second distribution path 43 to multiple second discharge paths 48, and discharged from multiple second discharge outlets 47 to corresponding multiple outlet paths 44.

[0078] The vapor discharged from the first outlet 45 and the SPM liquid discharged from the second outlet 47 mix near the upper end of the inlet of the outlet path 44 and are discharged towards the wafer W from the lower end of the outlet of the outlet path 44.

[0079] like Figure 6 As shown, the second outlet 47 is coaxially configured with the outlet path 44 when viewed from above. The second outlet 47 discharges SPM liquid in a direction along the central axis of the outlet path 44 (that is, the Z-axis direction). The first outlet 45 is configured to be oriented at a position offset from the central axis of the outlet path 44 when viewed from above. The first outlet 45 discharges vapor at a position offset from the central axis of the outlet path 44 when viewed from above. As a result, the vapor colliding with the inner surface of the outlet path 44 forms a swirling flow of vapor within the outlet path 44 and mixes with the SPM liquid discharged from the second outlet 47. In order to form a swirling flow of vapor within the outlet path 44, it is only necessary to make the vapor discharged from the first outlet 45 flow along the inner surface of the outlet path 44.

[0080] According to the nozzle 141 with the illustrated structure, steam and SPM liquid can be mixed efficiently, thereby enabling efficient increase of the temperature of the SPM liquid.

[0081] In addition, such as Figure 6 As shown, the central axis of the first outlet 45 is inclined relative to the direction of the normal N of the inner surface of the outlet path 44 when viewed from above. By inclining the central axis of the first outlet 45 relative to the normal N, a swirling flow of vapor can be easily formed within the outlet path 44 compared to the case where the central axis of the first outlet 45 is perpendicular to the inner surface of the outlet path 44. Furthermore, since the time that vapor remains in the outlet path 44 due to the swirling flow can be prolonged, the amount of vapor used for mixing vapor and SPM liquid can be suppressed.

[0082] The preferred structure of nozzle 141 Figures 3-6 The structure shown is not limited to this. It is acceptable as long as it is configured to allow the vapor and SPM liquid to be mixed substantially uniformly within the nozzle 141 and then the mixture of vapor and SPM liquid is discharged from the nozzle 141 to the wafer W.

[0083] In addition, Figure 7In this configuration, temperature sensor 2052 is disposed near nozzle 141 in SPM supply path 221, but is not limited thereto. Temperature sensor 2052 can be disposed in any location as long as it is positioned to detect the temperature of SPM before it is mixed with steam. For example, temperature sensor 2052 can also be configured to detect the temperature of SPM flowing in the second distribution path 43 within nozzle 141.

[0084] <Processing performed by the processing unit>

[0085] Next, refer to Figure 8 and Figure 9 The flowchart illustrates the processing performed on the wafer within processing unit 16. The processing described below is also included. Figure 1 It is executed under the control of the control device 4 shown.

[0086] First, the wafer W is fed into the processing unit (step S101). Specifically, the substrate transport device 17 of the transport unit 15 feeds the wafer W into the processing unit 16, and the wafer W is held by the substrate holding unit 102. Then, the substrate holding unit 102 starts to rotate at a predetermined speed. The wafer W continues to rotate (the speed may also change) until the series of processes performed on a single wafer W is completed.

[0087] Next, SPM treatment is performed on the wafer W (step S102). The first rotary lifting mechanism 143 moves the nozzle 141 from the standby position to the processing position above the wafer W. Then, SPM liquid, or a mixture of SPM liquid and vapor, is discharged from the nozzle 141 onto the surface of the wafer W. As a result, the resist film formed on the surface of the wafer W is removed. (See below for further details.) Figure 9 Describe the details of step S102.

[0088] An auxiliary nozzle 151 can also be used during SPM processing. When using the auxiliary nozzle 151, the second rotary lifting mechanism 153 positions the auxiliary nozzle 151 above the wafer W. Specifically, the auxiliary nozzle 151 is positioned at a location where insufficient vapor supply might occur if only the nozzle 141 is used, such as the outer periphery of the wafer W. Vapor is then discharged from the auxiliary nozzle 151 onto the surface of the wafer W. Thus, by using the auxiliary nozzle 151, vapor can be supplied more evenly to the entire surface of the wafer W. Therefore, the temperature of the SPM solution can rise more evenly across the entire surface of the wafer W.

[0089] When the SPM treatment in step S102 is completed, a rinsing process is performed (step S103). During the rinsing process, with the auxiliary nozzle 151 positioned above the center of the wafer W, a rinsing solution (in this case, DIW, or pure water) is supplied to the surface of the wafer W from the auxiliary nozzle 151. The rinsing solution supplied to the wafer W flows and diffuses towards the periphery of the wafer W under the centrifugal force accompanying the rotation of the wafer W, thus scattering outwards. As a result, any remaining SPM solution on the wafer W is rinsed away by the rinsing solution. During the rinsing process, the landing position of the rinsing solution can be moved between the center of the wafer and the periphery.

[0090] Next, a displacement process is performed (step S104). In the displacement process, a displacement fluid (IPA) is supplied from the auxiliary nozzle 151 to the center of the surface of the wafer W. The displacement fluid supplied to the wafer W flows towards the periphery of the wafer W under the action of centrifugal force accompanying the rotation of the wafer W, thereby replacing the rinsing fluid remaining on the wafer W.

[0091] Next, a drying process is performed (step S105). During the drying process, the rotational speed of the wafer W is increased while the displacement fluid is stopped. As a result, the displacement fluid remaining on the wafer W is discarded, and the wafer W is dried. Afterward, the rotation of the wafer W is stopped.

[0092] Next, the delivery process is performed (step S106). In the delivery process, the substrate delivery device 17 of the delivery unit 15 delivers the wafer W held in the substrate holding unit 102 to the processing unit 16. Through the above steps, a series of processes performed on a wafer W in association with the processing unit 16 are completed.

[0093] <Details of SPM processing>

[0094] Next, the details of the SPM process (step S102 above) in one embodiment will be described.

[0095] First, the nozzle 141 is moved from the standby position to the processing position above the wafer W. At this point, as a result of the back-suction process (described in detail later) performed after the previous processing, i.e., after step S214, most of the SPM supply path 221 is empty. The SPM liquid used in the previous processing remains in the section of the SPM supply path 221 from the mixing section 2050 to the slightly downstream side. Additionally, SPM liquid that was not completely removed during the back-suction process remains in the nozzle 141. The particularly empty sections of the SPM supply path 221 cool down due to heat dissipation as time passes since the end of the previous processing.

[0096] From this state, on-off valves 2029 and 2047 open, and on-off valve 2031 closes. On-off valve 2033 remains closed. As a result, sulfuric acid and hydrogen peroxide aqueous solution flow from branch supply paths 2026 and 2042 into mixing section 2050, where they mix to form SPM liquid, which then flows into SPM supply path 221. Additionally, the SPM liquid remaining in the aforementioned section of SPM supply path 221 is expelled by new SPM liquid. Consequently, only SPM liquid (SPM liquid not mixed with vapor) is discharged from nozzle 141 to the substrate (step S201).

[0097] exist Figure 10 The diagram schematically illustrates this state, with SPM liquid being discharged from each outlet path 44 of nozzle 141 toward the surface of wafer W. The SPM liquid landing on the rotating surface of wafer W covers the entire surface of wafer W. This situation, where only SPM liquid is discharged from nozzle 141 before the mixture of SPM liquid and vapor is discharged from nozzle 141, is also referred to as "Pre-SPM discharge". As the SPM liquid passes through SPM supply path 221, it is discharged from nozzle 141 to wafer W after losing heat to the cooled tubing and nozzle 141 that constitute SPM supply path 221. As time passes from the start of SPM liquid discharge from nozzle 141, the temperature of the tubing and nozzle 141 gradually rises, and thus the temperature of the SPM liquid discharged from nozzle 141 gradually approaches the desired temperature.

[0098] Simultaneously with the start of PreSPM discharge, the elapsed time from the start of PreSPM discharge, i.e., the PreSPM time, is measured (incrementally counted) (step S202). This measurement is performed using the timer function of the control device 4. For example, the time when the on / off valve 2029 is open can be considered as the PreSPM time. Other time measurements described later can also be measured based on the specified opening or closing times of the on / off valves.

[0099] Next, it is determined whether the measured PreSPM time exceeds the upper limit time (step S203). In addition, as long as the SPM supply source is working normally, the PreSPM time will almost never exceed the upper limit time.

[0100] If the determination in step S203 is "yes", it is determined that the processing of the mixed fluid cannot be expected under normal processing conditions in the future, and the process is transferred to remedial processing of the currently processed wafer W (step S205). In addition, an alarm is issued via the user interface to notify the operator that an anomaly has occurred (step S206).

[0101] The remedial treatment in step S205 is as follows. First, the supply of SPM liquid to nozzle 141 is stopped. Then, a rinsing process is performed (the same process as in step S103 above). After that, the same process as the displacement process S104 and drying process S105 above is performed. After that, the wafer W is inspected, and if the wafer W can be remedied, for example, the wafer W is subjected to SPM treatment again.

[0102] On the other hand, during the period when the judgment in step S203 is "no", the temperature of the SPM liquid detected by the temperature sensor 2052 is sampled at a preset sampling frequency, and the sampled temperature detection value is compared with the preset set temperature (step S204).

[0103] Furthermore, for example, if the temperature of the sulfuric acid supplied from the sulfuric acid supply unit 2020 (i.e., the temperature of the sulfuric acid circulating in the circulation path 2022) is 120°C, and the temperature of the hydrogen peroxide aqueous solution supplied from the hydrogen peroxide aqueous solution supply unit 2040 is room temperature, the set temperature may be, for example, 140°C (but is not limited to this).

[0104] When the sampled (detected) temperature value exceeds the set temperature ("Yes" in step S204), the measurement of PreSPM time ends (incrementing count), and the detected PreSPM time (i.e., the elapsed time from the start of PreSPM discharge (also called time "X")) is saved to the memory (e.g., the storage unit 19 of the control device 4) (step S207).

[0105] If the judgment in step S204 is "no", the process returns to step S203. That is, the loop consisting of steps S203 and S204 is repeated until the judgment in step S204 is "yes". If the judgment in step S204 is not "yes" even if the PreSPM time reaches the upper limit, an abnormality is determined as described above, the process exits the loop, and proceeds to steps S205 and S206 as described above.

[0106] When the detected SPM temperature exceeds the set temperature, the on / off valve 212 is immediately opened, and steam (pure water vapor) is supplied to nozzle 141 (step S208), and the elapsed time from the start of steam supply (steam supply time) is measured (counted) (step S209). The steam supplied to nozzle 141 mixes with the SPM liquid inside nozzle 141 to form a mixed fluid, which is then discharged from nozzle 141 to wafer W. Figure 11 The diagram schematically illustrates this state, with the mixed fluid M being discharged from each outlet path 44 of the nozzle 141 toward the surface of the wafer W. The mixed fluid M, falling onto the surface of the rotating wafer W, covers the entire surface of the wafer W. Thus, the etching of the object on the surface of the wafer W is performed rapidly.

[0107] Next, it is determined whether the measured vapor supply time (which is equivalent to the time for discharging the mixed fluid to the wafer W) has reached the set arrival time (step S210).

[0108] Once the steam supply time reaches the set arrival time, the on / off valve 212 is immediately closed, stopping the supply of steam to the nozzle 141 (step S211). As a result, only SPM liquid is discharged from the nozzle 141 to the wafer W again. The situation at this time is similar to... Figure 10 The PreSPM discharge shown is the same. The operation of discharging only the SPM liquid after discharging the mixture of SPM liquid and steam from nozzle 141 is also called "PostSPM discharge". The measurement (counting) of the PostSPM time, which is the elapsed time from the start of PostSPM discharge (i.e., the elapsed time from the cessation of steam supply), begins (step S212).

[0109] The sum of the measured PostSPM time and the PreSPM time recorded in the memory (the aforementioned time X) is compared with a preset time (step S213). When the sum reaches the preset time ("Yes" in step S213), the discharge of SPM from nozzle 141 is stopped by closing the on / off valves 2029 and 2047 (step S214). Simultaneously, while closing the on / off valve 2029, the on / off valve 2031 is opened, causing the high-temperature sulfuric acid drawn from the circulation path 2022 into the branch supply path 2026 to circulate back to the circulation path 2022 via the return path 2030, thereby preventing the temperature of the branch supply path 2026 from decreasing. Through the above steps, a series of SPM processes are performed on a wafer W. Figure 8 Step S102) ends. Afterwards, proceed to... Figure 8 The rinsing process in step S103.

[0110] Alternatively, a setting time related to the sum of the PostSPM time and the PreSPM time used in step S213 can be used as the upper limit time of the PreSPM time that becomes the judgment criterion in step S203.

[0111] In one example, when the device has a long standby time and the SPM liquid in the piping is quite cold, the PreSPM time, steam supply time, and PostSPM time are, for example, 10 seconds, 60 seconds, and 10 seconds. On the other hand, when the device processes the wafer W continuously (with shorter processing intervals), the PreSPM time, steam supply time, and PostSPM time are, for example, 5 seconds, 60 seconds, and 15 seconds.

[0112] Furthermore, after step S214, the aforementioned back-suction process is performed. The back-suction process is performed by opening the opening / closing valve 2033 after closing the opening / closing valves 2029 and 2047. As a result, any remaining undischarged SPM liquid in the nozzle 141 and SPM supply path 221 is discharged via the drainage path 2032 under gravity. Typically, the SPM liquid remains slightly downstream of the mixing section 2050 (…). Figure 7 The SPM is positioned slightly above the mixing section 2050 to allow for backflow treatment by emptying the downstream SPM supply path 221. Additionally, at this time, some SPM may remain in the nozzle 141 due to liquid interruption. This backflow treatment helps to suppress the amount of degraded SPM discharged to the wafer.

[0113] According to the above embodiments, the following advantageous effects can be obtained.

[0114] In the above embodiment, after the SPM liquid reaches a set temperature, vapor is mixed and discharged into the wafer as a mixed fluid of SPM liquid and vapor. Therefore, the temperature of the mixed fluid can be precisely managed to the desired temperature immediately after discharge, allowing the etching amount of the target film on the wafer to reach the desired value. Consequently, when multiple wafers are processed, deviations in etching amount can be suppressed, improving the inter-plane uniformity of etching amount. Furthermore, "inter-plane uniformity" refers to the degree of deviation (e.g., etching amount) in the processing results of each wafer W when multiple wafers W are processed identically.

[0115] Furthermore, in the above embodiments, there is a period during which only SPM solution is discharged to the wafer (specifically, the PreSPM and PostSPM times), during which the etch target film on the wafer is also etched. However, compared to the case where only the mixed fluid is discharged, the etching amount is significantly reduced when only SPM solution is discharged to the wafer. Therefore, even if only SPM solution is used before and / or after etching with the mixed fluid, the impact on the total etching amount is quite small. This can also be seen from an example of experimental results described below.

[0116] <An example of experimental results>

[0117] The following are experimental results comparing the etching amounts of the wafer under the conditions of only discharging SPM solution and discharging a mixed fluid. The etched film was SiN. The composition of the SPM solution was sulfuric acid:hydrogen peroxide aqueous solution = 10:1. The temperature of the sulfuric acid before mixing the hydrogen peroxide aqueous solution was set to 120°C. The etching time for both conditions 1 and 2 was 60 seconds.

[0118] (Condition 1) Only SPM liquid is supplied to nozzle 141, and only SPM liquid is discharged from nozzle 141 to the wafer. The etching depth is 0.06 nm at this time.

[0119] (Condition 2) In addition to supplying SPM liquid to nozzle 141 under the same conditions as in Condition 1, water vapor is also supplied to nozzle 141 at pressures of 28 kPa, 47 kPa, and 55 kPa, and the mixed fluid is discharged from nozzle 141 to the wafer. The etching depth is 0.39 nm at a water vapor pressure of 28 kPa, 0.51 nm at a water vapor pressure of 47 kPa, and 0.54 nm at a water vapor pressure of 55 kPa.

[0120] Based on the experimental results above, it is evident that even when PreSPM drainage (draining SPM liquid only onto wafer W) is performed before etching using a mixed fluid (e.g., condition 2), the impact on the total etching amount is quite small. It should be noted that during PreSPM drainage, the SPM liquid cooled within the piping is drained onto the substrate; therefore, the impact of PreSPM drainage on the total etching amount is even smaller than estimated based on the experimental results above. Furthermore, the PreSPM time is, for example, around 10 seconds, and the drainage time of the mixed fluid is, for example, around 60 seconds (these drainage times are only examples), further reducing the impact of PreSPM drainage on the total etching amount. Therefore, based on the required uniformity of etching amount between wafers (i.e., the allowable limit of deviation in etching amount between wafers), the etching amount based on PreSPM drainage can be ignored. That is, the PostSPM drainage performed in the above specific embodiment can be omitted.

[0121] However, when strict management of the uniformity of etching amount between wafers is desired, it is preferable to perform PostSPM discharge as described in the previously explained specific embodiment, so that the sum of the PreSPM time and PostSPM time becomes a preset set time. Although the etching amount during PreSPM discharge and PostSPM discharge is much smaller than the etching amount during discharge of the mixed fluid, by managing the sum of the PreSPM time and PostSPM time, the uniformity of etching amount between wafers can be further improved. In addition, it is possible to prevent the processing schedule (the time spent processing one wafer) from becoming disordered.

[0122] Strictly speaking, the temperature of the SPM solution during PreSPM discharge is lower than that during PostSPM discharge. Furthermore, the wafer temperature during PreSPM discharge is also lower than that during PostSPM discharge. Therefore, the etching rate during PostSPM discharge is slightly higher than that during PreSPM discharge. Consequently, the sum of PreSPM time + α × PostSPM time (where α is a constant, for example, from 1 to approximately 1.2) can be constant.

[0123] Alternatively, according to the above embodiment, the previously required pseudo-dispensing of SPM solution can be omitted. In conventional methods, heated sulfuric acid is used to remove SPM solution that has cooled due to stagnation in the piping connected to the nozzle during standby (the period from the end of dispensing SPM solution to the start of dispensing SPM solution to the next wafer), and then discharges it to a suitable pseudo-dispensing port. The pseudo-dispensing port is typically located below or near the nozzle's starting position. Afterwards, after dispensing the sulfuric acid from the piping via the drain line, the nozzle is moved to a processing position above the wafer, and then a mixture of SPM solution and water vapor is discharged onto the wafer. In this case, a small amount of processing fluid (SPM solution and sulfuric acid) is wasted. Additionally, there are waste liquid disposal costs. Furthermore, the time from the start of pseudo-dispensing to the start of dispensing the mixed fluid onto the wafer W is relatively long, thus reducing productivity.

[0124] In contrast, according to the above embodiment, the amount of waste, i.e., consumption, of the processing liquid can be reduced. In the above embodiment, during PreSPM discharge, the SPM liquid, which is at a temperature slightly lower than the set temperature, is supplied to the wafer without mixing with water vapor. As mentioned above, the etching amount during PreSPM discharge is much smaller than that during mixed fluid discharge, but some etching of the target film is still performed. Therefore, the SPM liquid is not completely wasted. In addition, in the above embodiment, the nozzle 141 can be moved to the processing position and processing can begin immediately after the wafer is placed in the substrate holding section. Therefore, the time wastage that may occur during false dispensing can be reduced, and the productivity of the apparatus can be improved.

[0125] The embodiments disclosed herein should be considered illustrative rather than restrictive in all respects. The above embodiments may be omitted, substituted, or modified in various ways without departing from the appended technical solutions and their spirit.

[0126] The substrate being processed is not limited to semiconductor wafers; it can also be any type of substrate used in the field of semiconductor device manufacturing, such as glass substrates or ceramic substrates.

Claims

1. A substrate processing method performed using a substrate processing apparatus, characterized in that: The substrate processing apparatus includes: Maintain the substrate holding portion of the substrate; A fluid supply unit that supplies a fluid containing pressurized pure water vapor or mist; The processing solution supply unit supplies processing solutions containing at least sulfuric acid; A nozzle, connected to the fluid supply unit and the treatment liquid supply unit, mixes the fluid and the treatment liquid and discharges them onto the substrate; and A temperature detection unit detects the temperature of the treatment fluid supplied from the treatment fluid supply unit to the nozzle. The substrate processing method includes: The processing liquid discharge step involves supplying the processing liquid from the processing liquid supply unit to the nozzle, and discharging the processing liquid from the nozzle to the substrate; and In the mixed fluid discharge step, after the processing liquid discharge step, when the temperature of the processing liquid detected by the temperature detection unit reaches a specified temperature, the fluid is supplied from the processing liquid supply unit to the nozzle, and the mixed fluid formed by mixing the fluid with the processing liquid is discharged from the nozzle to the substrate.

2. The substrate processing method as described in claim 1, characterized in that: It also includes an alarm issuing step, in which an alarm is issued if, during the processing liquid discharge step, the temperature of the processing liquid detected by the temperature detection unit has not reached a specified temperature even after a predetermined time has elapsed since the start of discharging the processing liquid into the substrate.

3. The substrate processing method as described in claim 2, characterized in that: It also includes a remedial treatment step, which, upon the issuance of the alarm, stops the discharge of the treatment liquid from the nozzle to the substrate and performs remedial treatment on the substrate.

4. The substrate processing method as described in claim 3, characterized in that: The remedial treatment steps include rinsing the substrate with DIW.

5. The substrate processing method as described in claim 1, characterized in that: The mixed fluid discharge step is performed for a preset time, and after the preset time has elapsed, the supply of fluid from the treatment fluid supply unit to the nozzle is stopped.

6. The substrate processing method as described in claim 5, characterized in that: It also includes a process fluid discharge step of continuing to supply the process fluid from the process fluid supply unit to the nozzle after stopping the supply of the fluid from the process fluid supply unit to the nozzle, and discharging the process fluid from the nozzle to the substrate.

7. The substrate processing method as described in claim 6, characterized in that: In the case where the process liquid discharge step prior to the mixed fluid discharge step is referred to as the first process liquid discharge step, and the process liquid discharge step following the mixed fluid discharge step is referred to as the second process liquid discharge step, The second treatment liquid discharge step is performed until the total time of the discharge of the treatment liquid in the first treatment liquid discharge step and the discharge time of the treatment liquid in the second treatment liquid discharge step reaches a preset time.

8. The substrate processing method as described in claim 7, characterized in that: The system also includes an alarm issuance step. In the first processing liquid discharge step, if the temperature of the processing liquid, as detected by the temperature detection unit, has not reached a specified temperature even after a predetermined time has elapsed since the processing liquid began discharging into the substrate, an alarm is issued. The preset time of the total time is used as the preset time as the criterion for issuing an alarm in the alarm issuing step.

9. The substrate processing method as described in claim 1, characterized in that: The treatment solution is a mixture of sulfuric acid and hydrogen peroxide aqueous solution.

10. A substrate processing apparatus, characterized by, include: Maintain the substrate holding portion of the substrate; A fluid supply unit that supplies a fluid containing pressurized pure water vapor or mist; The processing solution supply unit supplies processing solutions containing at least sulfuric acid; A nozzle, connected to the fluid supply unit and the treatment liquid supply unit, mixes the fluid and the treatment liquid and discharges them onto the substrate; A temperature detection unit detects the temperature of the treatment liquid supplied from the treatment liquid supply unit to the nozzle; and The control unit controls the operation of the substrate processing device. The control unit is configured to enable the substrate processing apparatus to execute a substrate processing method, the substrate processing method including: The processing liquid discharge step involves supplying the processing liquid from the processing liquid supply unit to the nozzle, and discharging the processing liquid from the nozzle to the substrate; and In the mixed fluid discharge step, after the processing liquid discharge step, when the temperature of the processing liquid detected by the temperature detection unit reaches a specified temperature, the fluid is supplied from the processing liquid supply unit to the nozzle, and the mixed fluid formed by mixing the fluid with the processing liquid is discharged from the nozzle to the substrate.

11. The substrate processing apparatus as claimed in claim 10, characterized in that: In the process fluid discharge step, if the temperature of the process fluid detected by the temperature detection unit does not reach the specified temperature even after a predetermined time has elapsed since the start of discharging the process fluid into the substrate, the control unit causes the substrate processing apparatus to perform an alarm issuing step.

12. The substrate processing apparatus as claimed in claim 11, characterized in that: When the alarm is issued, the control unit stops discharging the processing liquid from the nozzle to the substrate, causing the substrate processing device to perform a remedial processing step to remediate the substrate.

13. The substrate processing apparatus as described in claim 12, characterized in that: The remedial treatment steps include rinsing the substrate with DIW.

14. The substrate processing apparatus as described in claim 10, characterized in that: The mixed fluid discharge step is performed for a preset time, and after the preset time has elapsed, the supply of fluid from the treatment fluid supply unit to the nozzle is stopped.

15. The substrate processing apparatus as described in claim 14, characterized in that: After stopping the supply of fluid from the processing liquid supply unit to the nozzle, the control unit causes the substrate processing apparatus to perform a processing liquid discharge step of continuing to supply the processing liquid from the processing liquid supply unit to the nozzle and discharging the processing liquid from the nozzle to the substrate.

16. The substrate processing apparatus as described in claim 15, characterized in that: In the case where the process liquid discharge step prior to the mixed fluid discharge step is referred to as the first process liquid discharge step, and the process liquid discharge step following the mixed fluid discharge step is referred to as the second process liquid discharge step, The control unit causes the substrate processing apparatus to perform the second processing liquid discharge step until the total time of the discharge of the processing liquid in the first processing liquid discharge step and the discharge time of the processing liquid in the second processing liquid discharge step reaches a preset time.

17. The substrate processing apparatus as claimed in claim 16, characterized in that: In the first processing liquid discharge step, if the temperature of the processing liquid detected by the temperature detection unit has not reached a specified temperature even after a predetermined time has elapsed since the processing liquid began to be discharged from the substrate, the control unit causes the substrate processing apparatus to execute an alarm issuing step. The preset time of the total time is used as the preset time as the criterion for issuing an alarm in the alarm issuing step.

18. A computer program product comprising computer program instructions, characterised in that, When the computer program instructions are executed by the processor, they control the operation of the substrate processing device. The substrate processing apparatus includes: Maintain the substrate holding portion of the substrate; A fluid supply unit that supplies a fluid containing pressurized pure water vapor or mist; The processing solution supply unit supplies processing solutions containing at least sulfuric acid; A nozzle, connected to the fluid supply unit and the treatment liquid supply unit, mixes the fluid and the treatment liquid and discharges them onto the substrate; A temperature detection unit detects the temperature of the treatment fluid supplied from the treatment fluid supply unit to the nozzle; and Control Department By executing the computer program instructions, the control unit causes the substrate processing apparatus to perform a substrate processing method, which includes: The processing liquid discharge step involves supplying the processing liquid from the processing liquid supply unit to the nozzle, and discharging the processing liquid from the nozzle to the substrate; and In the mixed fluid discharge step, after the processing liquid discharge step, when the temperature of the processing liquid detected by the temperature detection unit reaches a specified temperature, the fluid is supplied from the processing liquid supply unit to the nozzle, and the mixed fluid formed by mixing the fluid with the processing liquid is discharged from the nozzle to the substrate.

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