SUBSTRATE PROCESSING METHOD AND SUBSTRATE PROCESSING SYSTEM

Abstract

A substrate processing method includes an etching step and a polishing step. In the etching step, a film on a substrate is etched, the film being formed on a rear surface of the substrate on the reverse side of a main surface. In the polishing step, the rear surface of the substrate is polished after the etching step.

Description

[Technical field]

[0001] The present disclosure relates to a substrate processing method and a substrate processing system. [Background technology]

[0002] Various processes for substrates such as semiconductor wafers and glass substrates are performed while the substrate is held on a substrate holding table. During this process, the back surface of the substrate, which is the opposite side to the main surface, may come into contact with the substrate holding table, causing particles to adhere to the back surface of the substrate or burrs to form.

[0003] In response to this, a technique is known in which foreign matter such as particles and burrs is removed from the rear surface of the substrate by subjecting the rear surface of the substrate to a cleaning process or polishing process using a brush. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-21026 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure provides a technique capable of appropriately removing foreign matter from the rear surface of a substrate on which a film has been formed. [Means for solving the problem]

[0006] A substrate processing method according to an embodiment of the present disclosure includes an etching step, a polishing step, and a method for etching a film on a substrate having a back surface opposite to a main surface, and a polishing step, which polishes the back surface of the substrate after the etching step. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide an effect of appropriately removing foreign matter from the rear surface of a substrate on which a film is formed. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic plan view of a substrate processing system according to an embodiment. [Diagram 2] FIG. 2 is a schematic side view of the substrate processing system according to the embodiment. [Diagram 3] FIG. 3 is a diagram showing a configuration of a wafer according to the embodiment. [Figure 4] FIG. 4 is a schematic diagram of the first processing unit according to the embodiment. [Diagram 5] FIG. 5 is a schematic plan view of the second processing unit according to the embodiment. [Figure 6] FIG. 6 is a schematic side view of the second processing unit according to the embodiment. [Figure 7] FIG. 7 is a flowchart showing a procedure of substrate processing executed by the substrate processing system according to the embodiment. [Figure 8A] FIG. 8A is a diagram illustrating an example of the operation of the first processing unit. [Figure 8B] FIG. 8B is a diagram illustrating an example of the operation of the first processing unit. [Figure 9A] FIG. 9A is a diagram illustrating an example of the operation of the second processing unit. [Figure 9B] FIG. 9B is a diagram illustrating an example of the operation of the second processing unit. [Figure 9C] FIG. 9C is a diagram illustrating an example of the operation of the second processing unit. [Figure 9D] FIG. 9D is a diagram illustrating an example of the operation of the second processing unit. [Figure 10] FIG. 10 is a diagram for explaining an improvement in the foreign matter removal rate by the substrate processing method according to the embodiment. [Figure 11] FIG. 11 is a schematic plan view of a substrate processing system according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, with reference to the drawings, an embodiment of the substrate processing method and the substrate processing system disclosed in the present application will be described in detail. Note that the disclosed technology is not limited to the following embodiment. It should be noted that the drawings are schematic, and the dimensional relationship of each element, the ratio of each element, and the like may differ from reality. Furthermore, there may be parts in which the dimensional relationship and ratio differ between the drawings.

[0010] Incidentally, a film may be formed on the back surface of a substrate for various purposes. In the above-mentioned conventional technology, removal of foreign matter from the back surface of the substrate on which the film is formed is not taken into consideration. For example, when a cleaning process using a brush is performed on the back surface of the substrate as in the conventional technology, it is difficult to remove particles embedded in the film on the back surface of the substrate. In addition, when a polishing process is performed on the back surface of the substrate, the back surface of the substrate may be scratched by particles embedded in the film on the back surface of the substrate or particles attached to the back surface of the substrate, which may cause new burrs. Therefore, a technology capable of appropriately removing foreign matter from the back surface of the substrate on which the film is formed is expected.

[0011] <Configuration of the substrate processing system> First, the configuration of a substrate processing system 1 according to an embodiment will be described with reference to Figures 1 and 2. Figure 1 is a schematic plan view of the substrate processing system 1 according to an embodiment. Figure 2 is a schematic side view of the substrate processing system 1 according to an embodiment. In the following, to clarify the positional relationship, an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other are defined, and the positive direction of the Z-axis is defined as the vertical upward direction.

[0012] 1, a substrate processing system 1 according to the embodiment includes a loading / unloading station 2, a transfer station 3, and a processing station 4. These are arranged in the order of the loading / unloading station 2, the transfer station 3, and the processing station 4.

[0013] The substrate processing system 1 transports a substrate, which in this embodiment is a semiconductor wafer (hereinafter, wafer W), carried in from the carry-in / out station 2 to a processing station 4 via a delivery station 3, and processes the substrate in the processing station 4. The substrate processing system 1 also returns the processed wafer W from the processing station 4 to the carry-in / out station 2 via the delivery station 3, and unloads the wafer W from the carry-in / out station 2 to the outside.

[0014] The loading / unloading station 2 includes a cassette mounting section 11 and a transfer section 12. On the cassette mounting section 11, a plurality of cassettes C are mounted, each of which accommodates a plurality of wafers W in a horizontal state.

[0015] The transfer section 12 is disposed between the cassette placement section 11 and the delivery station 3, and has therein a first transfer device 13. The first transfer device 13 includes a plurality of (for example, five) wafer holders each holding one wafer W.

[0016] The first transport device 13 is capable of moving horizontally and vertically as well as rotating around a vertical axis, and can use multiple wafer holding parts to simultaneously transport multiple wafers W between the cassette C and the delivery station 3.

[0017] Next, the transfer station 3 will be described. As shown in Fig. 2, a plurality of substrate placement units (SBU) 14 and a plurality of reversing mechanisms (RVS) 15 are disposed inside the transfer station 3. Specifically, the substrate placement units 14 are disposed at positions corresponding to a first processing station 4U and a second processing station 4L of the processing station 4 described next. Also, the reversing mechanisms 15 are disposed at positions corresponding to the first processing station 4U and a second processing station 4L of the processing station 4.

[0018] The processing station 4 includes a first processing station 4U and a second processing station 4L. The first processing station 4U and the second processing station 4L are spatially separated by a partition wall, a shutter, or the like, and are arranged side by side in the height direction.

[0019] The first processing station 4U and the second processing station 4L have a similar configuration and, as shown in FIG. 1, include a transport section 16, a second transport device 17, a plurality of first processing units (CH1) 18, and a plurality of second processing units (CH2) 19.

[0020] The second transfer device 17 is disposed inside the transfer section 16 and transfers the wafer W between the delivery station 3, the first processing unit 18, and the second processing unit 19.

[0021] The second transfer device 17 includes one wafer holding part that holds one wafer W. The second transfer device 17 is capable of moving in the horizontal and vertical directions and rotating about a vertical axis, and transfers one wafer W using the wafer holding part.

[0022] The multiple first processing units 18 and the multiple second processing units 19 are disposed adjacent to the transport section 16. As an example, the multiple first processing units 18 are disposed side by side along the X-axis direction on the positive Y-axis side of the transport section 16, and the multiple second processing units 19 are disposed side by side along the X-axis direction on the negative Y-axis side of the transport section 16.

[0023] The first processing unit 18 performs a predetermined process on the wafer W with its main surface Wa (see FIG. 3) facing upward. In the embodiment, the first processing unit 18 performs a process of etching a film F (see FIG. 3) formed on the back surface Wb (see FIG. 3) of the wafer W.

[0024] Here, the main surface Wa of the wafer W is the surface on which a pattern (circuit formed in a convex shape) is formed, and the back surface Wb is the surface opposite to the main surface Wa. The first processing unit 18 will be described in detail later.

[0025] The film F formed on the back surface Wb of the wafer W is, for example, a silicon nitride film, a silicon oxide film, or a multilayer film including a silicon nitride film and a silicon oxide film. In this embodiment, the film F is a multilayer film in which a silicon oxide film F1 (see FIG. 3) and a silicon nitride film F2 (see FIG. 3) are laminated in this order from the back surface Wb side of the wafer W.

[0026] The second processing unit 19 performs a predetermined process on the wafer W with its back surface Wb (see FIG. 3) facing upward. In the embodiment, the second processing unit 19 mainly performs a process of polishing the back surface Wb (see FIG. 3) of the wafer W and a process of cleaning the back surface Wb (see FIG. 3) of the wafer W with a brush. The second processing unit 19 will be described in detail later.

[0027] 1, the substrate processing system 1 includes a control device 5. The control device 5 is, for example, a computer, and includes a control unit 6 and a storage unit 7. The storage unit 7 stores programs for controlling various processes executed in the substrate processing system 1. The control unit 6 controls the operation of the substrate processing system 1 by reading and executing the programs stored in the storage unit 7.

[0028] Such a program may be recorded in a computer-readable storage medium and installed from the storage medium into the storage unit 7 of the control device 5. Examples of computer-readable storage media include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical disk (MO), and a memory card.

[0029] In the substrate processing system 1 configured as described above, first, the first transfer device 13 of the loading / unloading station 2 takes out the wafer W from the cassette C and places the taken out wafer W on the substrate placement part 14 of the delivery station 3. The wafer W placed on the substrate placement part 14 is taken out of the substrate placement part 14 by the second transfer device 17 of the processing station 4 and carried into the first processing unit 18, where the first processing unit 18 performs an etching process. When the etching process is completed, the second transfer device 17 takes out the processed wafer W from the first processing unit 18 and carries it to the reversing mechanism 15, where the reversing mechanism 15 reverses the front and back of the wafer W. The reversed wafer W is taken out of the reversing mechanism 15 by the second transfer device 17 and carried into the second processing unit 19, where the second processing unit 19 performs a polishing process and a cleaning process. When the polishing process and the cleaning process are completed, the second transfer device 17 takes out the processed wafer W from the second processing unit 19 and transfers it to the inversion mechanism 15, which again inverts the front and back of the wafer W. The wafer W that has been inverted again is taken out of the inversion mechanism 15 by the first transfer device 13 and returned to the cassette C.

[0030] <Substrate processing> Fig. 3 is a diagram showing the configuration of a wafer W according to an embodiment. The wafer W shown in Fig. 3 is, for example, a silicon wafer, and has a pattern formed on its main surface Wa, and a film F, which is a multilayer film formed by stacking a silicon oxide film F1 and a silicon nitride film F2, on its back surface Wb opposite to the main surface Wa. For convenience of explanation, the pattern formed on the main surface Wa of the wafer W is omitted in Fig. 2.

[0031] Foreign matter is present on the back surface Wb of the wafer W due to contact between the back surface Wb and the substrate holding table. The foreign matter is, for example, a particle P1 attached to the back surface Wb of the wafer W, a burr B1 formed on the back surface Wb of the wafer W, and a particle P2 embedded in the film F. The substrate processing system removes the foreign matter from the back surface Wb of the wafer W by, for example, a cleaning process using a brush or a polishing process (hereinafter, appropriately referred to as a "polishing process, etc.").

[0032] However, when the back surface Wb of the wafer W is polished, the back surface Wb of the wafer W may be scratched by particles P1 attached to the back surface Wb of the wafer W or particles P2 embedded in the film F, which may result in the generation of new burrs B1. In addition, when the back surface Wb of the wafer W is cleaned, it is difficult to remove particles P2 embedded in the film F.

[0033] Therefore, in the substrate processing system 1 according to the embodiment, prior to a polishing process or the like in the second processing unit 19, the film F formed on the back surface Wb is etched in the first processing unit 18 to remove the particles P1, P2, and the burrs B1 remaining on the back surface Wb are removed by a polishing process or the like. This makes it possible to appropriately remove foreign matter from the back surface Wb of the wafer W on which the film F is formed.

[0034] <Configuration of the first processing unit> Next, the configuration of the first processing unit 18 according to the embodiment will be described with reference to Fig. 4. Fig. 4 is a schematic diagram of the first processing unit 18 according to the embodiment. As shown in Fig. 4, the first processing unit 18 includes a chamber 21, a substrate holder 22, a processing liquid supply unit 23, and a collection cup 24.

[0035] The chamber 21 accommodates a substrate holder 22, a processing liquid supplier 23, and a collection cup 24. An FFU 21a that forms a downflow within the chamber 21 is provided on the ceiling of the chamber 21.

[0036] The substrate holding unit 22 includes a holding unit 22a that holds the wafer W horizontally, a support member 22b that extends vertically and supports the holding unit 22a, and a drive unit 22c that rotates the support member 22b around a vertical axis.

[0037] A plurality of gripping portions 22a1 for gripping the peripheral edge of the wafer W are provided on the upper surface of the holder 22a, and the wafer W is held horizontally by the gripping portions 22a1 at a slight distance from the upper surface of the holder 22a.

[0038] The processing liquid supply part 23 is inserted into a hollow part that passes through the holder 22a and the support member 22b along the rotation axis. Inside the processing liquid supply part 23, a flow path is formed that extends along the rotation axis.

[0039] A first chemical liquid supply unit 25, a second chemical liquid supply unit 26, and a rinsing liquid supply unit 27 are connected in parallel to a flow path formed inside processing liquid supply unit 23.

[0040] First chemical liquid supply unit 25 has, in order from the upstream side, first chemical liquid supply source 25a, valve 25b, and flow rate regulator 25c. First chemical liquid supply source 25a is, for example, a tank that stores the first chemical liquid. Flow rate regulator 25c adjusts the flow rate of the first chemical liquid supplied from first chemical liquid supply source 25a to processing liquid supply unit 23 via valve 25b. In this embodiment, the first chemical liquid is hydrofluoric acid.

[0041] The second chemical liquid supply unit 26 has, in order from the upstream side, a second chemical liquid supply source 26a, a valve 26b, and a flow rate regulator 26c. The second chemical liquid supply source 26a is, for example, a tank that stores the second chemical liquid. The flow rate regulator 26c adjusts the flow rate of the second chemical liquid supplied from the second chemical liquid supply source 26a to the processing liquid supply unit 23 via the valve 26b. In this embodiment, the second chemical liquid is SC-1 (a mixture of ammonia, hydrogen peroxide, and water).

[0042] The rinsing liquid supply unit 27 includes, in order from the upstream side, a rinsing liquid supply source 27a, a valve 27b, and a flow rate regulator 27c. The rinsing liquid supply source 27a is a tank that stores a rinsing liquid such as DIW. The flow rate regulator 27c regulates the flow rate of the rinsing liquid supplied from the rinsing liquid supply source 27a to the processing liquid supply unit 23 via the valve 27b.

[0043] The processing liquid supply unit 23 supplies the chemical liquid supplied from at least one of the first chemical liquid supply unit 25, the second chemical liquid supply unit 26, and the rinsing liquid supply unit 27 to the back surface Wb (see FIG. 3) of the wafer W held by the substrate holding unit 22.

[0044] In addition, the first processing unit 18 can heat the chemical liquid discharged from the processing liquid supply part 23 to a predetermined temperature by a heater (not shown).

[0045] Recovery cup 24 is disposed so as to surround substrate holding unit 22. At the bottom of recovery cup 24, drain port 24a for discharging the chemical solution supplied from processing liquid supply unit 23 to the outside of chamber 21, and exhaust port 24b for exhausting the atmosphere within chamber 31 are formed.

[0046] The first processing unit 18 is configured as described above, and after the peripheral portion of the wafer W, whose main surface Wa faces upward, is held by the multiple gripping portions 22a1 of the holding portion 22a, the wafer W is rotated using the driving portion 22c.

[0047] Next, the first processing unit 18 sequentially supplies a plurality of chemical liquids from the processing liquid supply unit 23 toward the center of the back surface Wb of the rotating wafer W. In this embodiment, the first processing unit 18 supplies hydrofluoric acid, DIW, SC-1, and DIW from the processing liquid supply unit 23 toward the center of the back surface Wb of the rotating wafer W in this order.

[0048] This etches the film F formed on the back surface Wb of the wafer W. At this time, particles P1 attached to the back surface Wb of the wafer W and particles P2 embedded in the film F on the back surface Wb of the wafer W are removed.

[0049] The first processing unit 18 performs a rinsing process to wash away SC-1 remaining on the wafer W with DIW, which is a rinsing liquid, and then performs a drying process to dry the wafer W by rotating the wafer W.

[0050] <Configuration of the second processing unit> Next, the configuration of the second processing unit 19 according to the embodiment will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is a schematic plan view of the second processing unit 19 according to the embodiment. Fig. 6 is a schematic side view of the second processing unit 19 according to the embodiment.

[0051] As shown in FIGS. 5 and 6, the second processing unit 19 includes a chamber 201, a substrate holder 202, a collection cup 203, a polishing mechanism 204, a cleaning mechanism 205, a first supply part 206, and a second supply part 207.

[0052] The chamber 201 accommodates a substrate holder 202, a collection cup 203, a polishing mechanism 204, a cleaning mechanism 205, a first supply unit 206, and a second supply unit 207. An FFU (Fun Filter Unit) 211 that forms a downflow in the chamber 201 is provided on the ceiling of the chamber 201.

[0053] The substrate holding part 202 includes a main body part 221 having a diameter larger than the wafer W, a plurality of gripping parts 222 provided on the upper surface of the main body part 221, a support member 223 that supports the main body part 221, and a drive part 224 that rotates the support member 223.

[0054] The substrate holding part 202 holds the wafer W by gripping the peripheral edge of the wafer W using the multiple gripping parts 222. In this way, the wafer W is held horizontally while being slightly spaced apart from the upper surface of the main body part 221.

[0055] Recovery cup 203 is disposed so as to surround substrate holding part 202. At the bottom of recovery cup 203, a drain port 231 for discharging the chemical liquid discharged from first supply part 206 and second supply part 207 to the outside of chamber 201, and an exhaust port 232 for exhausting the atmosphere inside chamber 201 are formed.

[0056] The polishing mechanism 204 includes a polishing brush 241 and an arm 243 that extends in a horizontal direction (here, the Y-axis direction) and supports the polishing brush 241 from above via a shaft 242. The polishing mechanism 204 also includes a moving mechanism 245 that moves the arm 243 in the horizontal direction (here, the X-axis direction) along a rail 244. The moving mechanism 245 can also move the arm 243 in the vertical direction (the Z-axis direction). The polishing mechanism 204 also includes a rotating mechanism (not shown) that can rotate the polishing brush 241 around the shaft 242.

[0057] The cleaning mechanism 205 includes a brush 251 and an arm 253 that extends in a horizontal direction (here, the Y-axis direction) and supports the brush 251 from above via a shaft 252. The cleaning mechanism 205 also includes a moving mechanism 255 that moves the arm 253 in the horizontal direction (here, the X-axis direction) along a rail 254. The moving mechanism 255 can also move the arm 253 in the vertical direction (the Z-axis direction). The cleaning mechanism 205 also includes a rotation mechanism (not shown) that can rotate the brush 251 around the shaft 252.

[0058] The first supply unit 206 is disposed outside the collection cup 203. The first supply unit 206 includes a nozzle 261, an arm 262 that extends in the horizontal direction and supports the nozzle 261, and a rotating and lifting mechanism 263 that rotates and raises and lowers the arm 262.

[0059] The nozzle 261 is connected to a first cleaning liquid supply source 265 via a valve 264, a flow rate regulator (not shown), etc. The nozzle 261 is connected to a rinsing liquid supply source 267 via a valve 266, a flow rate regulator (not shown), etc. The first supply unit 206 ejects the first cleaning liquid supplied from the first cleaning liquid supply source 265 toward the wafer W. The first supply unit 206 ejects the rinsing liquid supplied from the rinsing liquid supply source 267 toward the wafer W. The first cleaning liquid supplied from the first cleaning liquid supply source 265 is, for example, SC-1. The rinsing liquid supplied from the rinsing liquid supply source 267 is, for example, DIW.

[0060] The second supply unit 207 is disposed outside the collection cup 203. The second supply unit 207 includes a nozzle 271, an arm 272 that extends in the horizontal direction and supports the nozzle 271, and a rotating and lifting mechanism 273 that rotates and raises and lowers the arm 272.

[0061] Nozzle 271 is, for example, a two-fluid nozzle, and is connected to a second cleaning liquid supply source 275 via a valve 274 and a flow regulator (not shown), and is connected to a gas supply source 277 via a valve 276 and a flow regulator (not shown), etc.

[0062] The second supply unit 207 supplies the cleaning liquid, which is obtained by mixing the cleaning liquid supplied from the second cleaning liquid supply source 275 and the gas supplied from the gas supply source 277 in the nozzle 271, to the wafer W from the nozzle 271. The cleaning liquid supplied from the second cleaning liquid supply source 275 is, for example, DIW, and the gas supplied from the gas supply source 277 is, for example, an inert gas such as nitrogen.

[0063] The second processing unit 19 is configured as described above, and holds and rotates the peripheral portion of the wafer W with the back surface Wb facing upward by the substrate holding part 202. Next, the second processing unit 19 brings the polishing brush 241 of the polishing mechanism 204 arranged above the rotating wafer W into contact with the back surface Wb of the wafer W. Then, the second processing unit 19 polishes the back surface Wb of the wafer W by, for example, moving the polishing brush 241 from the center to the outer periphery of the wafer W while rotating the polishing brush 241. This removes the burr B1 remaining on the back surface Wb of the wafer W after the etching process in the first processing unit 18. At this stage, scraps of the burr B1 remain on the back surface Wb of the wafer W.

[0064] Following the polishing process of the back surface Wb of the wafer W, the second processing unit 19 brings the brush 251 of the cleaning mechanism 205 into contact with the wafer W while supplying the first cleaning liquid from the first supply unit 206 toward the back surface Wb of the rotating wafer W. Then, the second processing unit 19 moves the brush 251, for example, from the center to the outer periphery of the wafer W while rotating it. This cleans the back surface Wb of the wafer W, and makes it possible to remove shavings of the burrs B1 remaining on the back surface Wb of the wafer W.

[0065] Next, the second processing unit 19 places the nozzle 271 of the second supply part 207 above the rotating wafer W, and supplies the second cleaning liquid in the form of a mist from the nozzle 271 toward the back surface Wb of the wafer W. This cleans the back surface Wb of the wafer W, and makes it possible to remove foreign matter from the back surface Wb that has not been removed by the etching process in the first processing unit 18, the polishing process in the second processing unit 19, the cleaning process using the brush 251, or the like.

[0066] Next, the second processing unit 19 performs a rinsing process to wash away the chemical liquid remaining on the wafer W by supplying a rinsing liquid from the first supply unit 206. Then, the second processing unit 19 performs a drying process to dry the wafer W by rotating the wafer W.

[0067] <Specific Operation of the Substrate Processing System> Next, a specific operation of the substrate processing system 1 according to the embodiment will be described. FIG. 7 is a flow chart showing a procedure of substrate processing performed by the substrate processing system 1 according to the embodiment. Also, FIG. 8A and FIG. 8B are diagrams for explaining an example of the operation of the first processing unit 18, and FIG. 9A to FIG. 9D are diagrams for explaining an example of the operation of the second processing unit 19. More specifically, FIG. 8A and FIG. 8B show an example of the operation of the etching process (step S102) in FIG. 7. FIG. 9A and FIG. 9B show an example of the operation of the polishing process (step S103) in FIG. 7. FIG. 9C shows an example of the operation of the first cleaning process (step S104) in FIG. 7, and FIG. 9D shows an example of the operation of the second cleaning process (step S105) in FIG. 7. Each process procedure shown in FIG. 7 is performed under the control of the control device 5.

[0068] In the substrate processing system 1 according to the embodiment, the etching process (step S102) shown in Fig. 7 is performed in the first processing unit 18. In the substrate processing system 1, the processes from the polishing process (step S103) to the drying process (step S107) shown in Fig. 7 are performed in the second processing unit 19.

[0069] 7, a loading process is first performed in the substrate processing system 1 (step S101). In the loading process, the wafer W is loaded into the chamber 21 of the first processing unit 18 by the second transfer device 17. At this time, the wafer W is loaded with the main surface Wa of the wafer W facing upward.

[0070] Next, in the first processing unit 18, an etching process is performed (step S102). In the etching process, the control unit 6 first operates the substrate holding part 22 to hold the wafer W with the multiple gripping parts 22a1 of the holding part 22a. At this stage, particles P1, P2 and burrs B1 are present as foreign matter on the back surface Wb of the wafer W on which the film F is formed, as shown in FIG. 8A.

[0071] Next, the control unit 6 operates the driving unit 22c to rotate the wafer W as shown in FIG. 8B.

[0072] Next, the control unit 6 operates the processing liquid supply unit 23 to supply hydrofluoric acid toward the back surface Wb of the rotating wafer W. For example, the control unit 6 supplies hydrofluoric acid having a concentration of 49% and a temperature of 20° C. to 50° C. for 10 seconds to 180 seconds.

[0073] Next, the control unit 6 operates the processing liquid supply unit 23 to supply the DIW toward the back surface Wb of the rotating wafer W.

[0074] Next, the control unit 6 operates the processing liquid supply unit 23 to supply SC-1 toward the back surface Wb of the rotating wafer W. For example, the control unit 6 supplies SC-1 having a mixture ratio of ammonia:hydrogen peroxide:water=1:1:5 to 1:10:100 and a temperature of 20° C. to 70° C. for 10 to 30 seconds.

[0075] Next, the control unit 6 operates the processing liquid supply unit 23 to supply the DIW toward the back surface Wb of the rotating wafer W.

[0076] Next, the control unit 6 increases the rotation speed of the wafer W, for example, to shake off the chemical solution remaining on the rear surface Wb of the wafer W and dry the wafer W.

[0077] 8B, the film F is etched by the multiple chemical solutions (here, hydrofluoric acid and SC-1) supplied in sequence so that the film F remains on the back surface Wb of the wafer W. At this time, the particles P1 attached to the back surface Wb of the wafer W and the particles P2 embedded in the film F on the back surface Wb of the wafer W are removed together with the film F.

[0078] In this manner, in the etching process, the first processing unit 18 etches the film F so that the film F remains on the back surface Wb of the wafer W. This makes it possible to prevent the back surface Wb of the wafer W from being damaged in the polishing process performed after the etching process.

[0079] In the etching process, the first processing unit 18 etches the film F by sequentially supplying a plurality of chemical solutions to the back surface Wb of the wafer W. This makes it possible to selectively etch the silicon nitride film F2, which is the surface layer of the film F.

[0080] Next, a substrate reversal process is performed in the substrate processing system 1. In the substrate reversal process, the wafer W is carried out of the chamber 21 by the second transfer device 17, and after the wafer W is inverted by the reversal mechanism 15, the wafer W is carried into the chamber 201 of the second processing unit 19 by the second transfer device 17. At this time, the wafer W is carried into the chamber 201 with the back surface Wb facing upward, in other words, with the main surface Wa facing downward.

[0081] Next, in the second processing unit 19, a polishing process is performed (step S103). In the polishing process, the control unit 6 first operates the substrate holding part 202 to hold the wafer W with the multiple gripping parts 222 of the substrate holding part 202. At this stage, burrs B1 remain as foreign matter on the back surface Wb of the wafer W, as shown in FIG. 9A.

[0082] Next, the control unit 6 operates the driving unit 22c to rotate the wafer W as shown in FIG. 9B.

[0083] Next, the control unit 6 operates the polishing mechanism 204 to bring the polishing brush 241 arranged above the rotating wafer W into contact with the back surface Wb of the wafer W. Then, the control unit 6 polishes the back surface Wb of the wafer W by moving the polishing brush 241, for example, from the center to the outer periphery of the wafer W while rotating the polishing brush 241.

[0084] 9C, the burrs B1 remaining on the back surface Wb of the wafer W are removed. At this stage, shavings of the burrs B1 remain on the back surface Wb of the wafer W.

[0085] Next, in the second processing unit 19, a first cleaning process is performed (step S104). In the first cleaning process, the control unit 6 operates the cleaning mechanism 205 to bring the brush 251 arranged above the rotating wafer W into contact with the back surface Wb of the wafer W. The control unit 6 also operates the first supply unit 206 to supply the first cleaning liquid SC-1 from the nozzle 261 arranged above the rotating wafer W toward the back surface Wb of the wafer W. For example, the control unit 6 supplies SC-1 having a mixture ratio of ammonia:hydrogen peroxide:water=1:1:5 to 1:10:100 and a temperature of 20° C. to 70° C. Then, the control unit 6 cleans the back surface Wb of the wafer W by moving the brush 251, for example, from the center to the outer periphery of the wafer W while rotating the brush 251.

[0086] As a result, as shown in FIG. 9C, shavings of the burrs B1 remaining on the rear surface Wb of the wafer W are removed.

[0087] Next, in the second processing unit 19, a second cleaning process is performed (step S105). In the second cleaning process, the control unit 6 operates the second supply unit 207 to supply the second cleaning liquid in the form of mist from a nozzle 271 disposed above the rotating wafer W toward the back surface Wb of the wafer W, as shown in Fig. 9D. This cleans the back surface Wb of the wafer W, and removes foreign matter from the back surface Wb that has not been removed by the etching process (step S102), the polishing process (step S103), and the first cleaning process (step S104).

[0088] Next, in the second processing unit 19, a rinsing process is performed (step S106). In the rinsing process, the control unit 6 operates the first supply unit 206 to supply a rinsing liquid from the nozzle 261 disposed above the rotating wafer W toward the back surface Wb of the wafer W. As a result, the chemical liquid on the back surface Wb of the wafer W is washed away.

[0089] Next, a drying process is performed in the second processing unit 19 (step S107). In the drying process, the control unit 6 increases the rotation speed of the wafer W, for example, to shake off the rinsing liquid remaining on the back surface Wb of the wafer W, thereby drying the wafer W.

[0090] Next, in the substrate processing system 1, an unloading process is performed (step S108). In the unloading process, first, the wafer W is unloaded from the chamber 201 by the second transfer device 17, and the wafer W is inverted again by the inversion mechanism 15. After the wafer W is inverted again by the inversion mechanism 15, the wafer W is taken out of the inversion mechanism 15 by the first transfer device 13 and accommodated in the cassette C. At this time, the wafer W is accommodated in the cassette C with its main surface Wa facing upward. When the unloading process is completed, the substrate processing is completed.

[0091] In the above embodiment, the first cleaning process is performed after the polishing process, but the first cleaning process may be performed after the etching process and before the polishing process. Also, the first cleaning process and the second cleaning process may be performed after the etching process and before the polishing process. Also, the first cleaning process and the second cleaning process may be omitted.

[0092] <Improvement of foreign matter removal rate by substrate processing method according to embodiment> 10 is a diagram for explaining an improvement in the foreign matter removal rate by the substrate processing method according to the embodiment. The present inventors processed a wafer W by the substrate processing method according to the embodiment, and investigated the foreign matter removal rate on the back surface Wb of the wafer W.

[0093] "SCR" in FIG. 10 shows the results of performing the first cleaning process and the second cleaning process in order without performing the etching process and the polishing process (Comparative Example 1). "Polish+SCR" in FIG. 10 shows the results of performing the polishing process, the first cleaning process, and the second cleaning process in order without performing the etching process (Comparative Example 2). "BSS+Polish+SCR" in FIG. 10 shows the results of performing the etching process, the polishing process, the first cleaning process, and the second cleaning process in order as in the substrate processing method according to the embodiment (Example 1). "BSS+SCR+Polish" in FIG. 10 shows the results of performing the polishing process, the first cleaning process, and the second cleaning process in the order of Example 1 (Example 2).

[0094] In Comparative Example 1 and Comparative Example 2, in which no etching process was performed, the foreign matter removal rates were both less than 80%, and did not satisfy the predetermined allowable specifications. In contrast, in Example 1 and Example 2, in which an etching process was performed prior to the polishing process, the first cleaning process, and the second cleaning process, the foreign matter removal rates were both 80% or more, and satisfied the predetermined allowable specifications. This comparison result shows that the substrate processing method according to the embodiment appropriately removed foreign matter from the back surface Wb of the wafer W.

[0095] Thus, according to the substrate processing method of the embodiment, foreign matter can be appropriately removed from the back surface Wb of the wafer W on which the film F is formed, compared to a method that does not involve an etching process.

[0096] <Modification> The configuration of the substrate processing system is not limited to the configuration shown in the embodiment. Therefore, the configuration of a substrate processing system according to a modification of the embodiment will be described below with reference to Fig. 11. Fig. 11 is a schematic plan view of a substrate processing system 1A according to a modification of the embodiment.

[0097] A substrate processing system 1A of the modified example shown in FIG. 11 includes a first substrate processing system 1A1 for performing an etching process, and a second substrate processing system 1A2 for performing a polishing process, a first cleaning process, and a second cleaning process.

[0098] The first substrate processing system 1A1 includes a loading / unloading station 2, a transfer station 3A1, and a processing station 4A1. The loading / unloading station 2 is similar to the loading / unloading station 2 included in the substrate processing system 1 according to the embodiment, and therefore a description thereof will be omitted here.

[0099] The transfer station 3A1 has a plurality of substrate mounting parts 14 disposed therein. Unlike the transfer station 3 of the substrate processing system 1 according to the embodiment, the transfer station 3A1 has no reversing mechanism 15 disposed therein.

[0100] The processing station 4A1 includes a first processing station 4U and a second processing station 4L, similar to the processing station 4 included in the substrate processing system 1 according to the embodiment. The first processing station 4U and the second processing station 4L have the same configuration, and include a transfer section 16, a second transfer device 17, and a plurality of first processing units (CH1) 18. Unlike the first processing station 4U and the second processing station 4L of the substrate processing system 1 according to the embodiment, the first processing station 4U and the second processing station 4L do not include a plurality of second processing units (CH2) 19.

[0101] The second substrate processing system 1A2 includes a loading / unloading station 2, a transfer station 3, and a processing station 4A2. The loading / unloading station 2 and the transfer station 3 are similar to the loading / unloading station 2 and the transfer station 3 included in the substrate processing system 1 according to the embodiment, respectively, and therefore will not be described here.

[0102] The processing station 4A2 includes a first processing station 4U and a second processing station 4L, similar to the processing station 4 included in the substrate processing system 1 according to the embodiment. The first processing station 4U and the second processing station 4L have the same configuration, and include a transfer section 16, a second transfer device 17, and a plurality of second processing units (CH2) 19. Unlike the first processing station 4U and the second processing station 4L of the substrate processing system 1 according to the embodiment, the first processing station 4U and the second processing station 4L do not include a plurality of first processing units (CH1) 18.

[0103] 11, the first substrate processing system 1A1 includes a control device 5A1. The control device 5A1 is, for example, a computer, and includes a control unit 6A1 and a storage unit 7A1. The storage unit 7A1 stores programs for controlling various processes executed in the first substrate processing system 1A1. The control unit 6A1 reads out and executes the programs stored in the storage unit 7A1 to control the operation of the first substrate processing system 1A1.

[0104] 11, the second substrate processing system 1A2 includes a control device 5A2. The control device 5A2 is, for example, a computer, and includes a control unit 6A2 and a storage unit 7A2. The storage unit 7A2 stores programs for controlling various processes executed in the second substrate processing system 1A2. The control unit 6A2 reads out and executes the programs stored in the storage unit 7A2 to control the operation of the second substrate processing system 1A2.

[0105] These programs may be recorded in a computer-readable storage medium and installed from the storage medium into the storage unit 7A1 of the control device 5A1 or the storage unit 7A2 of the control device 5A2. Examples of computer-readable storage media include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical disk (MO), and a memory card.

[0106] In the substrate processing system 1A configured as described above, first, the first transfer device 13 of the first substrate processing system 1A1 takes out the wafer W from the cassette C and places the taken out wafer W on the substrate placement part 14 of the delivery station 3A1. The wafer W placed on the substrate placement part 14 is taken out of the substrate placement part 14 by the second transfer device 17 of the processing station 4A1 and carried into the first processing unit 18, where the first processing unit 18 performs an etching process on the wafer W. When the etching process is completed, the second transfer device 17 takes out the processed wafer W from the first processing unit 18 and places it on the substrate placement part 14 of the delivery station 3A1. The wafer W placed on the substrate placement part 14 is taken out of the substrate placement part 14 by the first transfer device 13 and returned to the cassette C. The wafer W returned to the cassette C is transferred from the first substrate processing system 1A1 to the cassette placement part 11 of the second substrate processing system 1A2.

[0107] Thereafter, the wafer W is taken out of the cassette C by the first transfer device 13 of the second substrate processing system 1A2 and transferred to the inversion mechanism 15 of the delivery station 3. Then, the inversion mechanism 15 inverts the wafer W. The inverted wafer W is taken out of the inversion mechanism 15 by the second transfer device 17 and carried into the second processing unit 19, where it is subjected to polishing and cleaning. When the polishing and cleaning are completed, the second transfer device 17 takes out the processed wafer W from the second processing unit 19 and transfers it to the inversion mechanism 15, where the inversion mechanism 15 inverts the wafer W again. The inverted wafer W is taken out of the inversion mechanism 15 by the first transfer device 13 and returned to the cassette C.

[0108] <Effects> The substrate processing method according to the embodiment includes an etching process (e.g., step S102) and a polishing process (e.g., step S103). The etching process etches a film on a substrate (e.g., wafer W) having a film (e.g., film F) formed on a back surface (e.g., back surface Wb) opposite to a main surface (e.g., main surface Wa). The polishing process polishes the back surface of the substrate after the etching process. This allows foreign matter to be appropriately removed from the back surface of the substrate on which the film is formed.

[0109] Furthermore, the substrate processing method according to the embodiment may further include a first cleaning step (e.g., step S104) of cleaning the back surface of the substrate with a brush (e.g., brush 251) after the polishing step or after the etching step and before the polishing step. This makes it possible to remove shavings of burrs (e.g., burrs B1) remaining on the back surface of the substrate and particles (e.g., particles P1) attached to the back surface of the substrate.

[0110] In the substrate processing method according to the embodiment, the first cleaning step may clean the back surface of the substrate with a brush while supplying a cleaning liquid (e.g., the first cleaning liquid) to the back surface of the substrate. This makes it possible to more appropriately remove shavings of burrs remaining on the back surface of the substrate and particles adhering to the back surface of the substrate.

[0111] Furthermore, the substrate processing method according to the embodiment may further include a second cleaning step (e.g., step S105) of cleaning the rear surface of the substrate by supplying a mist of cleaning liquid (e.g., second cleaning liquid) to the rear surface of the substrate after the first cleaning step. This makes it possible to remove foreign matter that has not been removed by the first cleaning step from the rear surface of the substrate.

[0112] In the substrate processing method according to the embodiment, the etching step may etch the film so that the film remains on the back surface of the substrate, thereby preventing the back surface of the substrate from being damaged in a polishing step performed after the etching step.

[0113] In the substrate processing method according to the embodiment, the etching step may etch the film by sequentially supplying a plurality of chemical solutions (e.g., hydrofluoric acid and SC-1) to the rear surface of the substrate, thereby selectively etching the surface layer (e.g., silicon nitride film) of the film (e.g., multilayer film including silicon nitride film and silicon oxide film) formed on the rear surface of the substrate.

[0114] In the substrate processing method according to the embodiment, the film may be a silicon nitride film, a silicon oxide film, or a multilayer film including a silicon nitride film and a silicon oxide film, so that foreign matter can be appropriately removed from the rear surface of the substrate on which the silicon nitride film, the silicon oxide film, or the multilayer film including a silicon nitride film and a silicon oxide film is formed.

[0115] Moreover, the substrate processing system according to the embodiment (e.g., substrate processing system 1, 1A) includes an etching apparatus (e.g., first processing unit 18) and a back surface processing apparatus (e.g., second processing unit 19). The etching apparatus etches a film on a substrate having a film formed on the back surface opposite to the main surface. The back surface processing apparatus has a polishing mechanism (e.g., polishing mechanism 204) that polishes the back surface of the substrate after the film is etched. This makes it possible to properly remove foreign matter from the back surface of the substrate on which the film is formed.

[0116] Furthermore, the substrate processing system according to the embodiment may further include an inversion mechanism (e.g., inversion mechanism 15) that inverts the substrate. The etching apparatus may etch the film with the main surface of the substrate facing upward. The polishing mechanism may polish the back surface of the substrate inverted by the inversion mechanism after the film is etched. The inversion mechanism may invert the substrate again after the back surface of the substrate is polished by the polishing mechanism. This allows the substrate processing to be completed with the main surface of the substrate facing upward.

[0117] In the substrate processing system according to the embodiment, the back surface processing device may further include a cleaning mechanism (e.g., cleaning mechanism 205) that cleans, with a brush, the back surface of the substrate after it has been polished by the polishing mechanism, or the back surface of the substrate after the film has been etched by the etching device and before it has been polished by the polishing mechanism. This makes it possible to more appropriately remove shavings of burrs remaining on the back surface of the substrate and particles adhering to the back surface of the substrate.

[0118] Furthermore, the substrate processing system according to the embodiment may further include an inversion mechanism (e.g., inversion mechanism 15) that inverts the substrate. The etching apparatus may etch the film with the main surface of the substrate facing upward. The polishing mechanism may polish the back surface of the substrate inverted by the inversion mechanism after the film is etched. The cleaning mechanism may clean the back surface of the substrate after it has been polished by the polishing mechanism. The inversion mechanism may invert the substrate again after the back surface of the substrate has been cleaned by the cleaning mechanism. This allows the substrate processing to be completed with the main surface of the substrate facing upward.

[0119] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The above embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0120] 1. 1A PCB Processing System 15 Reversal mechanism 18 First Processing Unit 19 Second Processing Unit 23 Processing liquid supply section 204 Polishing mechanism 205 Cleaning mechanism 206 1st supply section 207 2nd supply section 241 Abrasive Brush 251 Brush F membrane W wafer Wa Main surface Inside Wb

Claims

1. an etching step of etching a film formed on a back surface of a substrate opposite to a main surface; a polishing step of polishing the back surface of the substrate after the etching step; Including, The etching step includes: The substrate processing method includes etching the film so that the film remains on the back surface of the substrate.

2. 2. The substrate processing method according to claim 1, further comprising a first cleaning step of cleaning the back surface of the substrate with a brush after the polishing step, or after the etching step and before the polishing step.

3. 3. The substrate processing method according to claim 2, wherein the first cleaning step cleans the rear surface of the substrate with a brush while supplying a cleaning liquid to the rear surface of the substrate.

4. 4. The substrate processing method according to claim 2, further comprising, after the first cleaning step, a second cleaning step of cleaning the rear surface of the substrate by supplying a mist of the cleaning liquid to the rear surface of the substrate.

5. The etching step includes:

5. The substrate processing method according to claim 1, wherein the film is etched by sequentially supplying a plurality of chemical solutions to the rear surface of the substrate.

6. 6. The substrate processing method according to claim 1, wherein the film is a silicon nitride film, a silicon oxide film, or a multi-layer film including a silicon nitride film and a silicon oxide film.

7. an etching apparatus for etching a film on a substrate having a back surface opposite to a main surface thereof; a back surface treatment device having a polishing mechanism for polishing the back surface of the substrate after the film is etched; Equipped with The etching apparatus includes: A substrate processing system that etches the film such that the film remains on the backside of the substrate.

8. Further comprising an inversion mechanism for inverting the substrate, The etching apparatus includes: Etching the film while the main surface of the substrate is facing upward; The polishing mechanism includes: After the film is etched, polishing the back surface of the substrate inverted by the inversion mechanism; The inversion mechanism includes: The substrate processing system of claim 7 , wherein the substrate is inverted again after the back surface of the substrate is polished by the polishing mechanism.

9. The rear surface processing device includes: The substrate processing system of claim 7, further comprising a cleaning mechanism that uses a brush to clean the back surface of the substrate after it has been polished by the polishing mechanism, or the back surface of the substrate after the film has been etched by the etching device and before it has been polished by the polishing mechanism.

10. Further comprising an inversion mechanism for inverting the substrate, The etching apparatus includes: Etching the film while the main surface of the substrate is facing upward; The polishing mechanism includes: After the film is etched, polishing the back surface of the substrate inverted by the inversion mechanism; The cleaning mechanism includes: cleaning the back surface of the substrate after it has been polished by the polishing mechanism; The inversion mechanism includes: The substrate processing system of claim 9 , wherein the substrate is inverted again after the back surface of the substrate is cleaned by the cleaning mechanism.

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