Substrate processing method and substrate processing device

Abstract

The present invention provides a substrate processing method and a substrate processing device. The substrate processing method of the present invention includes a holding step, a preheating step, a releasing step, and a moving step. The holding step holds the substrate. The preheating step heats the central portion of the opposite surface, which is the surface of the substrate on the side opposite to the processed surface. The releasing step releases SPM, which is a mixture of sulfuric acid and hydrogen peroxide, to the peripheral portion of the processed surface after the preheating step. The moving step moves the release position of SPM from the peripheral portion to the central portion of the processed surface after the releasing step. The present invention can suppress deviation in substrate processing using SPM.

Description

Technical Field

[0001] The present invention relates to a substrate processing method and a substrate processing device. Background Art

[0002] Conventionally, there is a known technique for treating substrates such as semiconductor wafers and glass substrates using SPM as a mixture of sulfuric acid and hydrogen peroxide (see Patent Document 1). This technique utilizes the reaction heat generated by the reaction of sulfuric acid and hydrogen peroxide to treat the substrate.

[0003] Prior art literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2018-107455 Summary of the Invention

[0005] Technical problem to be solved by the invention

[0006] The present invention provides a technology capable of suppressing flapping of a substrate during substrate processing using an SPM.

[0007] Technical solutions to technical problems

[0008] A substrate processing method according to one embodiment of the present invention includes a holding step, a preheating step, a releasing step, and a moving step. The holding step holds the substrate. The preheating step heats the central portion of the opposite surface, which is the surface of the substrate opposite to the processed surface. The releasing step releases SPM, a mixture of sulfuric acid and hydrogen peroxide, toward the peripheral portion of the processed surface after the preheating step. The moving step moves the SPM release position from the peripheral portion to the central portion of the processed surface after the releasing step.

[0009] Effects of the Invention

[0010] According to the present invention, vibration of a substrate can be suppressed in substrate processing using an SPM. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a diagram showing the configuration of a substrate processing system according to the first embodiment.

[0012] Figure 2 It is a diagram showing the configuration of a processing unit according to the first embodiment.

[0013] Figure 3 It is a diagram showing the configuration of the SPM supply mechanism according to the first embodiment.

[0014] Figure 4This is a graph showing changes in the temperature difference between the center and the peripheral portion of the wafer when the SPM set to the release temperature of 110° C. is released under a plurality of different release conditions in the first embodiment.

[0015] Figure 5 This is a flowchart showing the steps of substrate processing performed by the processing unit of the first embodiment.

[0016] Figure 6 This is a flowchart showing the steps of the SPM process according to the first embodiment.

[0017] Figure 7 This is a diagram showing an example of the operation of the processing unit in the SPM process.

[0018] Figure 8 This is a diagram showing an example of the operation of the processing unit in the SPM process.

[0019] Figure 9 This is a diagram showing an example of the operation of the processing unit in the SPM process.

[0020] Figure 10 It is a diagram showing the configuration of an SPM supply mechanism according to a second embodiment.

[0021] Figure 11 This is a diagram showing an example of the relationship between the release position of SPM on the front surface of the wafer and the mixing ratio of SPM released to the back surface of the wafer.

[0022] Figure 12 It is a diagram showing the configuration of a processing unit according to the third embodiment.

[0023] Description of Reference Numerals

[0024] W chip

[0025] 1. Substrate processing system

[0026] 2 Entry and exit stations

[0027] 3 Processing Stations

[0028] 4 Control device

[0029] 16 processing units

[0030] 18 Control Department

[0031] 19 Storage

[0032] 30 substrate holding mechanism

[0033] 31. Maintaining part

[0034] 40 Front supply unit

[0035] 70 SPM supply mechanism

[0036] 80 Temperature Sensor

[0037] 90 Back supply unit. DETAILED DESCRIPTION

[0038] Hereinafter, with reference to the accompanying drawings, embodiments for implementing the substrate processing method and substrate processing apparatus of the present invention (hereinafter referred to as "embodiments") will be described in detail. The substrate processing method and substrate processing apparatus of the present invention are not limited to these embodiments. Furthermore, the various embodiments can be appropriately combined to the extent that the processing contents do not conflict. In the following embodiments, identical parts are denoted by identical reference numerals, and duplicate descriptions are omitted.

[0039] In addition, in order to facilitate understanding of the description, the various drawings referred to below may sometimes show a rectangular coordinate system in which the X-axis, Y-axis, and Z-axis are defined as being orthogonal to each other, with the positive direction of the Z-axis being the vertically upward direction. Furthermore, the direction of rotation about the vertical axis is referred to as the θ direction.

[0040] (First embodiment)

[0041] <Substrate processing system>

[0042] Figure 1 FIG. 1 is a diagram showing the configuration of a substrate processing system according to the first embodiment. Figure 1 As shown, the substrate processing system 1 includes a feeding station 2 and a processing station 3. The feeding station 2 and the processing station 3 are arranged adjacent to each other.

[0043] The loading and unloading station 2 includes a carrier placement unit 11 and a conveying unit 12. A plurality of carriers C for storing a plurality of substrates (hereinafter referred to as "wafers W") in a horizontal state are placed on the carrier placement unit 11.

[0044] The transport unit 12 is disposed adjacent to the carrier placement unit 11 and includes a substrate transport device 13 and a delivery unit 14 therein. The substrate transport device 13 includes a substrate holding mechanism for holding a wafer W. The substrate transport device 13 is movable in horizontal and vertical directions and rotatable about a vertical axis, and uses the substrate holding mechanism to transport wafers W between the carrier C and the delivery unit 14.

[0045] The processing station 3 is disposed adjacent to the conveying portion 12. The processing station 3 includes a conveying portion 15 and a plurality of processing units 16. The plurality of processing units 16 are disposed side by side on both sides of the conveying portion 15.

[0046] The transport unit 15 includes a substrate transport device 17 therein. The substrate transport device 17 includes a substrate holding mechanism for holding the wafer W. The substrate transport device 17 is movable in the horizontal and vertical directions and rotatable about a vertical axis, and uses the substrate holding mechanism to transport the wafer W between the interface 14 and the processing unit 16.

[0047] The processing unit 16 performs predetermined substrate processing on the wafer W transported by the substrate transport device 17 .

[0048] The substrate processing system 1 also includes a control device 4. The control device 4 is, for example, a computer and includes a control unit 18 and a storage unit 19. The storage unit 19 stores programs for controlling various processes performed in the substrate processing system 1. The control unit 18 controls the operation of the substrate processing system 1 by reading and executing the programs stored in the storage unit 19.

[0049] The above-mentioned program is a program stored in a computer-readable storage medium, and may be a program installed from the storage medium to the storage unit 19 of the control device 4. Examples of computer-readable storage media include a hard disk (HD), a floppy disk (FD), a compact disk (CD), a magneto-optical disk (MO), and a memory card.

[0050] In the substrate processing system 1 configured as described above, the substrate transport device 13 of the transport station 2 first removes a wafer W from the carrier C placed on the carrier placement portion 11 and places the removed wafer W on the delivery portion 14. The substrate transport device 17 of the processing station 3 removes the wafer W placed on the delivery portion 14 from the delivery portion 14 and transports it to the processing unit 16.

[0051] After being processed by the processing unit 16, the wafer W is transported from the processing unit 16 by the substrate transport device 17 and placed on the delivery unit 14. The processed wafer W placed on the delivery unit 14 is then returned to the carrier C of the carrier placement unit 11 by the substrate transport device 13.

[0052] <Composition of Processing Unit>

[0053] Below, refer to Figure 2 , describing the structure of the processing unit 16. Figure 2 It is a diagram showing the configuration of the processing unit 16 according to the first embodiment.

[0054] Figure 2 The illustrated processing unit 16 supplies SPM (Sulfuric Acid Hydrogen Peroxide Mixture), which is a mixed solution of sulfuric acid and hydrogen peroxide, to the front surface of the wafer W to remove, for example, a film formed on the front surface of the wafer W.

[0055] Processing unit 16 utilizes the strong oxidizing power of Caro's acid contained in the SPM and the heat of reaction between sulfuric acid and hydrogen peroxide to process wafer W. Caro's acid (H2SO5) is generated according to the reaction formula "H2SO4 + H2O2 → H2SO5 + H2O," and heat of reaction between sulfuric acid and hydrogen peroxide is generated during the formation of peroxymonosulfuric acid.

[0056] like Figure 2 As shown, the processing unit 16 includes a chamber 20 , a substrate holding mechanism 30 , a front supply unit 40 , a recovery cup 50 , a temperature sensor 80 , an SPM supply mechanism 70 , and a back supply unit 90 .

[0057] The chamber 20 houses a substrate holding mechanism 30, a front supply unit 40, a recovery cup 50, a temperature sensor 80, and a back supply unit 90. A fan filter unit (FFU) 21 is provided on the top of the chamber 20. The FFU 21 creates a downflow in the chamber 20.

[0058] The substrate holding mechanism 30 includes a holding portion 31, a support portion 32, and a drive portion 33. The holding portion 31 holds the wafer W horizontally. Specifically, the holding portion 31 has multiple gripping portions 31a, which grip the peripheral edge of the wafer W. The support portion 32 extends in the vertical direction, with its base portion rotatably supported by the drive portion 33 and its front end portion horizontally supporting the holding portion 31. The drive portion 33 rotates the support portion 32 about a vertical axis. The substrate holding mechanism 30 described above rotates the support portion 32 using the drive portion 33, thereby rotating the holding portion 31 supported by the support portion 32, thereby rotating the wafer W held by the holding portion 31.

[0059] The front supply unit 40 supplies SPM onto the wafer W. Specifically, the front supply unit 40 includes a nozzle 41 disposed above the wafer W, an arm 42 supporting the nozzle 41, and a moving mechanism 43 for moving the arm 42. The nozzle 41 is connected to an SPM supply mechanism 70 (described later), and releases the SPM supplied from the SPM supply mechanism 70 onto the front surface of the wafer W.

[0060] The recovery cup 50 is arranged to surround the holding portion 31 and collects SPM scattered from the wafer W due to the rotation of the holding portion 31. A drain port 51 is formed at the bottom of the recovery cup 50, and the processing liquid collected by the recovery cup 50 is discharged from the drain port 51 to the outside of the processing unit 16. In addition, an exhaust port 52 is formed at the bottom of the recovery cup 50 to discharge the gas supplied from the FFU 21 to the outside of the processing unit 16.

[0061] The temperature sensor 80 is disposed above the wafer W and acquires temperature information of the SPM on the wafer W.

[0062] The temperature sensor 80 irradiates infrared rays as the irradiation light. In addition, the temperature sensor 80 receives the reflected light from the front surface of the wafer W. The reflected light received by the temperature sensor 80 has a component reflected by the SPM present on the wafer W as the main component, and the intensity value of the reflected light can be collected as information on the SPM.

[0063] The temperature sensor 80 converts the intensity value of the received reflected light into a temperature value, and obtains a temperature distribution related to the planar region including the wafer W as temperature information. The obtained temperature information is continuously sent to the control unit 18 at a prescribed time interval (e.g., 1 second). The control unit 18 receives the temperature information sent from the temperature sensor 80 and stores it in the storage unit 19.

[0064] The back surface supply unit 90 is disposed, for example, in the hollow portion that penetrates the holding unit 31 and the support column unit 32 in the vertical direction. A flow path 91 extending in the vertical direction is formed inside the back surface supply unit 90, and the flow path 91 is connected to the SPM supply mechanism 70. The back surface supply unit 90 releases the SPM supplied from the SPM supply mechanism 70 from the discharge port 92 formed at the front end of the flow path 91 to the back surface of the wafer W.

[0065] <Configuration of the SPM Supply Mechanism>

[0066] Next, refer to Figure 3 to describe the configuration of the SPM supply mechanism 70. Figure 3 is a diagram showing the configuration of the SPM supply mechanism of the first embodiment.

[0067] As Figure 3 shown, the SPM supply mechanism 70 includes a sulfuric acid supply source 301, a sulfuric acid supply path 302, a temperature adjustment unit 303, and a valve 304 as a supply system for sulfuric acid (H2SO4). The sulfuric acid supply source 301 supplies sulfuric acid at room temperature (room temperature). The sulfuric acid supply path 302 connects the sulfuric acid supply source 301 to a mixing unit 308 described later. The temperature adjustment unit 303 is, for example, a heater that heats the sulfuric acid flowing in the sulfuric acid supply path 302. The valve 304 opens and closes the sulfuric acid supply path 302. In addition, the temperature adjustment unit 303 may include a cooling electronic device having a cooling function, etc.

[0068] In addition, the SPM supply mechanism 70 includes a hydrogen peroxide supply source 305, a hydrogen peroxide supply path 306, and a valve 307 as a supply system for hydrogen peroxide (H2O2). The hydrogen peroxide supply source 305 supplies hydrogen peroxide at room temperature (room temperature). The hydrogen peroxide supply path 306 connects the hydrogen peroxide supply source 305 and the mixing unit 308 described later, and allows the hydrogen peroxide supplied from the hydrogen peroxide supply source 305 to flow through. The valve 307 opens and closes the hydrogen peroxide supply path 306.

[0069] The SPM supply mechanism 70 also includes a mixing unit 308 and a switching unit 309. The mixing unit 308 mixes sulfuric acid supplied from the sulfuric acid supply path 302 and hydrogen peroxide supplied from the hydrogen peroxide supply path 306 at a predetermined mixing ratio to produce SPM as a mixed liquid. The produced SPM is supplied to the front supply unit 40 or the back supply unit 90 via the switching unit 309. The mixing unit 308 has a function of changing the mixing ratio based on instructions from the control unit 18.

[0070] The switching unit 309 switches the outflow destination of the SPM generated in the mixing unit 308. Specifically, the switching unit 309 can cause the SPM to flow to either the front supply unit 40 or the back supply unit 90, or to both the front supply unit 40 and the back supply unit 90.

[0071] <About Chip Vibration>

[0072] In wet processing of substrates using chemical solutions such as SPM, a so-called scan-in action, in which the release point of the chemical solution is moved from the periphery of the substrate toward the center, is preferred for improving in-plane uniformity. However, when SPM, heated to a high temperature (approximately 100-150°C) due to the heat of reaction between sulfuric acid and hydrogen peroxide, is released onto the periphery of the substrate, the periphery of the substrate expands due to thermal expansion, causing the entire substrate, gripped by the gripping portion 31a, to warp. As a result, the rotating substrate vibrates. When the substrate vibrates, there is a possibility of damage to the gripped portion of the substrate, for example. Furthermore, there is a possibility of notches forming in the gripping portion that grips the substrate, causing the substrate to move away from the gripping portion, resulting in interrupted processing. Furthermore, due to substrate vibration, it is difficult to uniformly supply the chemical solution to the front surface of the substrate, potentially reducing the in-plane uniformity of the wet processing. Therefore, under the current situation, a scan-out action is performed to move the release position from the center portion to the peripheral portion of the substrate.

[0073] Figure 4 This is a graph showing changes in the temperature difference between the center and the peripheral portion of the wafer W when the SPM set to the release temperature of 110° C. is released under a plurality of different release conditions. Figure 4 The hollow columns shown represent the experimental results when the release position of the SPM on the front surface of the wafer W is fixed at 80 mm, 100 mm, 120 mm, and 140 mm (peripheral portion) with the center of the wafer W being 0 mm. Figure 4 The shaded columns shown represent experimental results when the release position of the SPM on the front surface of the wafer W was swept out from 80 mm, 100 mm, 120 mm, and 140 mm.

[0074] like Figure 4 As shown, when the release position was fixed, the temperature difference ΔT (peripheral temperature - central temperature) exceeded 60°C at any release position, causing wafer W vibration. On the other hand, when the release position was swept out, the temperature difference ΔT was 42°C or less at any of the distances of 80 mm, 100 mm, 120 mm, and 140 mm, resulting in no wafer W vibration. These results indicate that wafer W vibration occurs when the temperature difference ΔT between the central and peripheral portions of wafer W exceeds 40°C.

[0075] Therefore, in the processing unit 16 of the first embodiment, substrate processing using SPM is performed under processing conditions in which the temperature difference ΔT between the center portion and the peripheral portion of the wafer W is 40° C. or less.

[0076] <Specific Operations of Processing Unit>

[0077] Below, refer to Figure 5 , describing the contents of the substrate processing performed by the processing unit 16 of this embodiment. Figure 5 1 is a flowchart showing the steps of substrate processing performed by the processing unit 16 according to the first embodiment. Figure 5 Each of the processing steps shown is executed according to the control of the control unit 18 .

[0078] First, in the processing unit 16, the wafer W is fed in (step S101). Specifically, the wafer transport device 17 (see Figure 1 ) The wafer W is fed into the chamber 20 of the processing unit 16 (refer to Figure 2 ) and held in the holding portion 31. Thereafter, the processing unit 16 rotates the holding portion 31 at a predetermined rotation speed (for example, 50 rpm).

[0079] Next, the SPM process is performed in the processing unit 16 (step S102). The details of the SPM process will be described later.

[0080] After the SPM treatment in step S102 is completed, a rinse process (step S103) is performed in the processing unit 16. During this rinse process, a rinse liquid (e.g., DIW (deionized water)) is supplied to the wafer W from a rinse liquid supply unit (not shown). The DIW supplied to the wafer W spreads across the front surface of the wafer W due to the centrifugal force associated with the rotation of the wafer W. As a result, the SPM remaining on the wafer W is washed away by the DIW. Alternatively, during the rinse process, after supplying the wafer W with DIW heated to a temperature below the SPM temperature, the wafer W may be supplied with DIW at room temperature. This can suppress sudden temperature changes in the wafer W.

[0081] Next, in the processing unit 16, a drying process is performed (step S104). In this drying process, the wafer W is rotated at a predetermined rotational speed (e.g., 1000 rpm) for a predetermined time. Thereby, the DIW remaining on the wafer W is thrown off, and the wafer W is dried. After that, the rotation of the wafer W is stopped.

[0082] Then, in the processing unit 16, a delivery process is performed (step S105). In the delivery process, the wafer W held by the holding unit 31 is transferred to the substrate transfer device 17. When this delivery process is completed, the substrate processing for one wafer W is completed.

[0083] <Steps of SPM process>

[0084] Next, referring to Figures 6-9 , the specific steps of the SPM process in step S102 will be described. Figure 6 is a flowchart showing the steps of the SPM process of the first embodiment. In addition, Figures 7 to 9 is a diagram showing an operation example of the processing unit 16 in the SPM process.

[0085] As Figure 6 shown, in the SPM process, first, a preheating process is performed (step S201). In the preheating process, by opening the valves 304 and 307 for a predetermined time (e.g., 30 seconds), SPM is supplied from the back surface supply unit 90 to the central portion of the back surface of the wafer W. The SPM supplied to the wafer W diffuses on the front surface of the wafer W due to the centrifugal force accompanying the rotation of the wafer W (refer to Figure 7 ). Thereby, the temperature of the wafer W rises.

[0086] Next, the control unit 18 acquires the temperature of the central portion of the wafer W from the temperature sensor 80 (step S202). Moreover, the control unit 18 determines whether the difference between the temperature of the central portion of the wafer W acquired in step S202 and the peripheral portion assumed temperature (peripheral portion assumed temperature - temperature of the central portion) is 40°C or less (step S203). Here, the peripheral portion assumed temperature is the temperature of the peripheral portion of the wafer W assumed when SPM is released to the front surface peripheral portion of the wafer W. The peripheral portion assumed temperature is obtained through prior experiments and stored in the storage unit 19.

[0087] In the case where the difference from the peripheral portion assumed temperature is not 40°C or less (step S203, NO), the control unit 18 returns the process to step S202. On the other hand, in the case where the difference from the peripheral portion assumed temperature is 40°C or less (step S203, YES), the control unit 18 controls the switching unit 309 to cause the SPM to flow out to the front surface supply unit 40. Thereby, the control unit 18 causes the SPM to start being released from the front surface supply unit 40 to the front surface peripheral portion of the wafer W (steps S204, Figure 8 ).

[0088] Next, the control unit 18 controls the moving mechanism 43 of the front supply unit 40 to move the nozzle 41 from the peripheral portion to the center portion of the wafer W (scan) (step S205). As a result, the SPM is diffused over the entire front surface of the wafer W (see FIG. Figure 9 ). Alternatively, in step S205, when the nozzle 41 reaches the center of the wafer W, the control unit 18 stops supplying SPM from the front supply unit 40 and the back supply unit 90. Alternatively, after the nozzle 41 reaches the center of the wafer W, the control unit 18 moves the nozzle 41 toward the peripheral portion of the wafer W again, and stops supplying SPM when the nozzle 41 reaches the peripheral portion of the wafer W. Alternatively, after the nozzle 41 moves from a peripheral portion of the wafer W (for example, a peripheral portion on the negative side of the X-axis) via the center to another peripheral portion (for example, a peripheral portion on the positive side of the X-axis), the control unit 18 stops supplying SPM.

[0089] As described above, the processing unit 16 of the first embodiment releases SPM onto the front edge of the wafer W while maintaining a temperature difference of 40°C or less from the assumed peripheral temperature, thereby suppressing vibration of the wafer W. This, for example, can prevent damage to the wafer W at the contact point between the wafer W and the gripper 31a. Furthermore, since a sweeping operation is possible, the in-plane uniformity of the SPM processing can be improved.

[0090] Furthermore, using the processing unit 16 of the first embodiment, during the preheating process, SPM is supplied to the back side of the wafer W to heat the center portion of the wafer W. This allows, for example, heating of the center portion of the wafer W without providing a separate heating mechanism. Furthermore, the same drainage system can be used for the SPM discharged from the front supply unit 40. Furthermore, since the temperature conditions are the same as for the SPM discharged from the front supply unit 40, temperature control is facilitated.

[0091] (Second embodiment)

[0092] Figure 10 : is a diagram showing the structure of the SPM supply mechanism of the second embodiment. Figure 10 As shown, the processing unit 16A of the second embodiment includes a first SPM supply mechanism 70A that supplies SPM to the front supply unit 40 and a second SPM supply mechanism 70B that supplies SPM to the back supply unit 90 .

[0093] The first SPM supply mechanism 70A includes a sulfuric acid supply source 301A, a sulfuric acid supply path 302A, a temperature control unit 303A, and a valve 304A as a sulfuric acid supply system. Furthermore, the first SPM supply mechanism 70A includes a hydrogen peroxide supply source 305A, a hydrogen peroxide supply path 306A, and a valve 307A as a hydrogen peroxide supply system. Furthermore, the first SPM supply mechanism 70A includes a mixing unit 308A.

[0094] The second SPM supply mechanism 70B includes a sulfuric acid supply system comprising a sulfuric acid supply source 301B, a sulfuric acid supply path 302B, a temperature control unit 303B, and a valve 304B. Furthermore, the second SPM supply mechanism 70B includes a hydrogen peroxide supply source 305B, a hydrogen peroxide supply path 306B, and a valve 307B as a hydrogen peroxide supply system. Furthermore, the second SPM supply mechanism 70B includes a mixing unit 308B.

[0095] This processing unit 16A can supply SPM mixed at different mixing ratios to the front and back sides of the wafer W. Therefore, the control unit 18 can control the mixing units 308A and 308B to supply SPM mixed at a higher reaction temperature than the SPM released onto the front side of the wafer W to the back side of the wafer W. This allows the temperature difference to be kept below 40°C, even when SPM of the same temperature is supplied, even if the temperature difference does not reach 40°C.

[0096] Alternatively, the control unit 18 may change the mixing ratio of the SPM supplied to the back surface of the wafer W according to the release position of the SPM to the front surface of the wafer W. Figure 11 An example illustrating this situation will be given. Figure 11 FIG. 1 is a diagram showing an example of the relationship between the release position of SPM on the front surface of the wafer W and the mixing ratio of SPM released on the back surface of the wafer W. FIG.

[0097] like Figure 11 As shown in the figure, the closer the SPM release position from the front surface of the wafer W is to the center due to the sweeping operation, the lower the temperature of the peripheral portion of the wafer W becomes. For example, as the SPM release position from the front surface of the wafer W moves from 140 mm (the peripheral portion) to 0 mm (the center), the peripheral temperature of the wafer W gradually decreases to 130°C, 128°C, and 126°C. This is because the farther the SPM release position is from the peripheral portion of the wafer W, the greater the temperature drop in the SPM until it reaches the peripheral portion.

[0098] Therefore, the control unit 18 may also reduce the target temperature of the SPM released to the back side of the chip W as the release position of the SPM on the front side of the chip W is closer to the center, thereby making the target temperature of the SPM released to the back side of the chip W consistent with the temperature of the peripheral portion of the chip W.

[0099] The control unit 18 can change the temperature of the SPM released onto the back surface of the wafer W by changing the mixing ratio of the SPM released onto the back surface of the wafer W.

[0100] For example, the storage unit 19 may pre-store mixing ratio information indicating the relationship between the release position of the SPM on the front surface of the wafer W and the mixing ratio of the SPM released on the back surface of the wafer W. In this case, the control unit 18 can control the mixing unit 308B based on the release position of the SPM on the front surface of the wafer W and the mixing ratio information to appropriately change the mixing ratio of the SPM released on the back surface of the wafer W. Furthermore, the release position of the SPM on the front surface of the wafer W can be calculated based on, for example, the elapsed time from the start of the scanning operation and the movement speed of the nozzle 41, or can be acquired by a sensor provided on the moving mechanism 43 of the front supply unit 40.

[0101] In addition, without being limited to the above example, the control unit 18 may obtain the temperature of the peripheral portion of the chip W from the temperature sensor 80, for example, and control the mixing unit 308B according to the obtained peripheral portion temperature, thereby changing the mixing ratio of the SPM released to the back side of the chip W.

[0102] Alternatively, the control unit 18 may obtain the peripheral and central temperatures of the wafer W from the temperature sensor 80 and change the mixing ratio of the SPM released to the back surface of the wafer W so that the central temperature approaches the peripheral temperature.

[0103] (Third embodiment)

[0104] Figure 12 : is a diagram showing the structure of the processing unit of the third embodiment. Figure 12 As shown, the processing unit 16B of the third embodiment includes a first back surface supply unit 90B1 and a second back surface supply unit 90B2.

[0105] The first backside supply unit 90B1 releases SPM onto the center portion of the backside of the wafer W. The second backside supply unit 90B2 releases SPM onto a portion of the backside of the wafer W that is radially outward of the center portion of the backside of the wafer W, that is, closer to the peripheral edge of the wafer W. For example, the first backside supply unit 90B1 releases SPM onto a portion of the backside of the wafer W that is between the center portion and the peripheral edge.

[0106] As described above, by providing the second backside supply unit 90B2, for example, when the first backside supply unit 90B1 alone cannot keep the temperature difference between the periphery and the center of the wafer W below 40°C, the temperature difference can be kept below 40°C. Furthermore, since the wafer W can be heated more uniformly, the in-plane uniformity of the SPM process can be improved.

[0107] In addition, in the processing unit 16B, a common SPM supply mechanism may be provided in the first back surface supply unit 90B1 and the second back surface supply unit 90B2, or an SPM supply mechanism may be provided in each of the first back surface supply unit 90B1 and the second back surface supply unit 90B2.

[0108] (Other embodiments)

[0109] In each of the above-described embodiments, during the preliminary heating process, the wafer W is heated by supplying SPM to the back surface of the wafer W. The present invention is not limited thereto, and during the preliminary heating process, a heating fluid other than SPM may be released to the back surface of the wafer W to heat the wafer W. As the heating fluid other than SPM, for example, in addition to heated DIW, a heated gas (for example, an inert gas such as N2 gas or air) may be used.

[0110] In addition, in the above-described embodiments, examples are described in which the front surface of the wafer W is the processed surface. However, the present invention is not limited thereto, and the processed surface may also be the back surface of the wafer W. In this case, the front center portion of the wafer W is heated in the preliminary heat treatment, and then the SPM is released to the peripheral portion of the back surface of the wafer W.

[0111] As described above, the substrate processing apparatus of the embodiment (for example, the processing units 16, 16A, and 16B) includes a holding portion (for example, the holding portion 31), an opposite surface releasing portion (for example, the back surface supply portion 90, the first back surface supply portion 90B1, and the second back surface supply portion 90B2), a processed surface releasing portion (for example, the front surface supply portion 40), and a moving mechanism (for example, the moving mechanism 43). The holding portion holds a substrate (for example, a wafer W). The opposite surface releasing portion releases SPM, which is a mixture of sulfuric acid and hydrogen peroxide, from the central portion of the opposite surface (for example, the back surface of the wafer W) of the substrate that is opposite to the processed surface (for example, the front surface of the wafer W). The processed surface releasing portion releases SPM, which is a mixture of sulfuric acid and hydrogen peroxide, from the peripheral portion of the processed surface. The moving mechanism moves the processed surface releasing portion from the peripheral portion to the central portion of the processed surface.

[0112] Thus, the center of the substrate can be preheated by the SPM released from the opposite-surface release portion. Therefore, when the SPM is released from the processed-surface release portion toward the peripheral portion of the processed surface of the substrate, a temperature difference between the center and peripheral portions of the substrate can be minimized. Therefore, during substrate processing using the SPM, particularly when the SPM release position is shifted from the peripheral portion to the center of the substrate while processing the substrate, vibration of the substrate can be suppressed.

[0113] In addition, a substrate processing apparatus (for example, processing unit 16A) according to an embodiment includes a first SPM supply mechanism (for example, first SPM supply mechanism 70A) and a second SPM supply mechanism (for example, second SPM supply mechanism 70B). The first SPM supply mechanism includes a first mixing section (for example, mixing section 308A) capable of varying the mixing ratio of sulfuric acid and hydrogen peroxide, and supplies the SPM mixed in the first mixing section to the processed surface release section. The second SPM supply mechanism includes a second mixing section (for example, mixing section 308B) capable of varying the mixing ratio of sulfuric acid and hydrogen peroxide, and supplies the SPM mixed in the second mixing section to the opposite surface release section.

[0114] This allows SPM mixed at different ratios to be supplied to the processed surface and the opposite surface of the substrate. Thus, for example, SPM mixed at a ratio that results in a higher reaction temperature than the SPM released onto the processed surface can be supplied to the opposite surface of the substrate. This significantly reduces the temperature difference between the center and periphery of the substrate, even when supplying SPM at the same temperature fails to do so.

[0115] The opposite surface release portion may also include: a first release portion (as an example, a first back surface supply portion 90B1) that releases the first SPM to the central portion of the opposite surface; and a second release portion (as an example, a second back surface supply portion 90B2) that releases the second SPM to a position radially outward of the substrate on the opposite surface than the central portion.

[0116] The provision of the second relief portion can significantly reduce the temperature difference between the periphery and the center of the substrate, for example, when the first relief portion alone cannot sufficiently reduce the temperature difference. Furthermore, since the substrate can be heated more uniformly, the in-plane uniformity of substrate processing using SPM can be improved.

[0117] The embodiments disclosed herein are illustrative in all respects and should not be considered restrictive. In fact, the above embodiments can be implemented in a variety of ways. In addition, the above embodiments can be omitted, replaced, or modified in a variety of ways without departing from the scope and spirit of the appended claims.

Claims

1. A substrate processing method, characterized in that: include: a holding step of holding and rotating the substrate; a preheating step of releasing a heating fluid to a central portion of the opposite surface of the substrate, wherein the heating fluid supplied to the substrate diffuses on the opposite surface of the substrate due to a centrifugal force caused by the rotation of the substrate, thereby increasing the temperature of the substrate, wherein the opposite surface is a surface of the substrate opposite to the surface to be processed; a releasing step of releasing SPM as a mixed solution of sulfuric acid and hydrogen peroxide onto the peripheral portion of the processed surface after the preheating step, in a state where the difference between an assumed peripheral portion temperature and the temperature of the central portion of the processed surface obtained by a temperature sensor is 40° C. or less, wherein the assumed peripheral portion temperature is a temperature previously obtained through experiments as the peripheral portion of the substrate and stored in a storage unit, and the peripheral portion temperature of the substrate is a temperature assumed when the SPM is released onto the peripheral portion of the processed surface; as well as a moving step of moving the release position of the SPM from the peripheral portion to the central portion of the processed surface after the releasing step.

2. The substrate processing method according to claim 1, wherein: The preheating step heats the central portion of the opposing surface by releasing SPM, which is a mixed solution of sulfuric acid and hydrogen peroxide, toward the central portion of the opposing surface.

3. The substrate processing method according to claim 1, wherein: The SPM released onto the opposite surface is formed by mixing sulfuric acid and hydrogen peroxide at a mixing ratio that causes a higher reaction temperature than the SPM released onto the treated surface.

4. The substrate processing method according to claim 1, wherein: The method further includes a mixing ratio changing step of changing the mixing ratio of the SPM released to the opposite surface according to a change in a release position of the SPM to the processed surface during the moving step.

5. The substrate processing method according to any one of claims 2 to 4, wherein: The preheating step releases a first SPM to a central portion of the opposing surface, and releases a second SPM to a position of the opposing surface that is radially outward of the central portion of the substrate.

6. A substrate processing device, characterized in that: include: a holding portion for holding and rotating the substrate; an opposite surface releasing portion for releasing the heating fluid to a central portion of an opposite surface of the substrate, the opposite surface being a surface opposite to a processed surface of the substrate; a treated surface releasing portion that releases SPM as a mixed solution of sulfuric acid and hydrogen peroxide toward a peripheral portion of the treated surface; a moving mechanism for moving the processed surface releasing portion from a peripheral portion to a central portion of the processed surface; and control unit, storage unit and temperature sensor, The control unit can perform the following steps: a holding step of holding and rotating the substrate using the holding portion; a preheating step of releasing a heating fluid toward a central portion of the opposite surface by a processing surface releasing portion, so that the heating fluid supplied to the substrate diffuses on the opposite surface of the substrate due to a centrifugal force caused by the rotation of the substrate, thereby increasing the temperature of the substrate; a releasing step of releasing the SPM from the peripheral portion of the processed surface using the processed surface releasing portion after the preheating step, in a state where the difference between the assumed peripheral portion temperature and the temperature of the central portion of the processed surface acquired by the temperature sensor is 40° C. or less, wherein the assumed peripheral portion temperature is a temperature obtained in advance as the peripheral portion temperature of the substrate through experiments and stored in the storage portion, and the peripheral portion temperature of the substrate is a temperature assumed when the SPM is released from the peripheral portion of the processed surface; as well as A moving step of moving the SPM release position from the peripheral portion to the central portion of the processed surface using the moving mechanism after the releasing step.

7. The substrate processing device according to claim 6, wherein: Also includes: a first SPM supply mechanism having a first mixing portion capable of changing a mixing ratio of sulfuric acid and hydrogen peroxide, for supplying the SPM mixed in the first mixing portion to the treated surface release portion; and The second SPM supply mechanism includes a second mixing portion capable of changing a mixing ratio of sulfuric acid and hydrogen peroxide, and supplies the SPM mixed in the second mixing portion to the opposite-surface release portion.

8. The substrate processing device according to claim 6 or 7, wherein: The opposite surface release portion includes: a first releasing portion for releasing the first SPM from the central portion of the opposite surface; and A second releasing portion releases the second SPM at a position radially outward of the substrate relative to the central portion of the opposite surface.

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