Substrate processing method, program, and substrate processing apparatus

Abstract

To smooth a process of sticking a substrate to another substrate.SOLUTION: According to an aspect of the present disclosure, there is provided a substrate processing method including a film forming step of forming, on a back surface of a substrate having a front surface on which a pattern or a device structure is formed and the back surface opposite to the front surface, a back surface film in which stress is generated by exposure, and an exposure step of exposing at least a part of the back surface film so as to reduce warpage of the substrate after forming the back surface film.SELECTED DRAWING: Figure 13

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a substrate processing apparatus equipped with a correction member that corrects warpage of a substrate by partially contacting the upper surface of the substrate supported by a support. Patent Document 2 discloses a warpage correction method that roughens the back surface of a substrate, forms grooves on the back surface, and corrects warpage of the substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-103022 [Patent Document 2] International Publication No. 2019 / 176522 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a substrate processing method, a program, and a substrate processing apparatus that are useful for facilitating the process of bonding a substrate to another substrate. [Means for solving the problem]

[0005] A substrate processing method according to one aspect of the present disclosure includes a film formation step of forming a back surface film, which generates stress by exposure, on the back surface of a substrate having a front surface on which a pattern or a device structure is formed and a back surface facing opposite to the front surface, and an exposure step of exposing at least a portion of the back surface film to light so as to reduce warpage of the substrate after the back surface film is formed. [Effects of the Invention]

[0006] According to the present disclosure, a substrate processing method, a program, and a substrate processing apparatus are provided that are useful for facilitating the process of bonding a substrate to another substrate. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a plan view schematically illustrating an example of a wafer processing system. [Figure 2] FIG. 2 is a side view schematically showing an example of the substrate processing apparatus. [Figure 3] FIG. 3 is a side view schematically illustrating an example of the measurement unit. [Figure 4] FIG. 4 is a schematic diagram showing an example of the liquid processing unit. [Figure 5] 5(a) and 5(b) are schematic diagrams showing an example of a heat treatment unit. [Figure 6] FIG. 6 is a schematic diagram showing an example of the reversing unit. [Figure 7] FIG. 7 is a diagram illustrating an example of stress generated by exposure. [Figure 8] FIG. 8 shows an example of the measurement result of the height distribution when exposure is performed on the entire surface of the film formed on the back surface. [Figure 9] FIG. 9 shows an example of the measurement result of the height distribution when exposure is performed on a part of the film formed on the back surface. [Figure 10] FIG. 10 is a side view schematically showing an example of an exposure unit. [Figure 11] FIG. 11 is a plan view schematically showing an example of an exposure unit. [Figure 12] FIG. 12 is a flowchart showing an example of a substrate processing method. [Figure 13] FIG. 13 is a schematic diagram showing an example of a substrate processing method. [Figure 14] Fig. 14(a) is a schematic diagram illustrating the manner in which spin exposure is performed, and Fig. 14(b), Fig. 14(c), and Fig. 14(d) are schematic diagrams illustrating the shapes of the exposed regions. [Figure 15]Fig. 15(a) is a schematic diagram illustrating the manner in which scanning exposure is performed, and Fig. 15(b) and Fig. 15(c) are schematic diagrams illustrating the shape of the exposed area. [Figure 16] Fig. 16(a) is a schematic diagram illustrating the manner in which exposure is performed by combining spin exposure and scanning exposure, and Fig. 16(b), Fig. 16(c), and Fig. 16(d) are schematic diagrams illustrating the shapes of the exposed regions. [Figure 17] Fig. 17(a) is a graph showing an example of the relationship between the exposed area and the height distribution, and Fig. 17(b) and Fig. 17(c) are schematic diagrams showing the exposed region. [Figure 18] Fig. 18(a) is a schematic diagram illustrating an example of a method for adjusting the exposed area, and Fig. 18(b), Fig. 18(c), and Fig. 18(d) are schematic diagrams illustrating examples of the degree of density of the exposed area. [Figure 19] FIG. 19 is a graph illustrating the relationship between the thickness of the film formed on the rear surface and the amount of warpage. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment will be described below with reference to the drawings. In the description, identical elements or elements having identical functions are given the same reference numerals, and redundant description will be omitted. Some drawings show a Cartesian coordinate system defined by an X-axis, a Y-axis, and a Z-axis. In the following embodiment, the X-axis and the Y-axis correspond to the horizontal direction, and the Z-axis corresponds to the up-down direction. The direction of the arrow representing the Z-axis indicates vertically upward.

[0009] [Wafer processing system] First, the configuration of a wafer processing system according to one embodiment will be described. FIG. 1 schematically shows a wafer processing system in a plan view. The wafer processing system 1 (substrate processing apparatus) shown in FIG. 1 is a system that performs processing to reduce warpage of wafers W (substrates) to be processed, and then performs processing to bond two wafers W together. The wafers W may be circular semiconductor wafers. The wafers W have a pair of main surfaces facing opposite directions, and a pattern or device structure may already be formed on one of the main surfaces of the wafers W before processing by the wafer processing system 1. The pattern refers to a concave-convex pattern. The device structure refers to layers that constitute a semiconductor device.

[0010] In the present disclosure, of the pair of main surfaces of the wafer W, one main surface on which a pattern or device structure is formed is referred to as the "front surface Wa," and the other main surface is referred to as the "back surface Wb" (see FIG. 3, etc.). The wafer W to be processed by the wafer processing system 1 has a front surface Wa on which a pattern or device structure is formed, and a back surface Wb facing in the opposite direction to the front surface Wa. The following description will be given using as an example a case where a device structure is formed on the front surface Wa.

[0011] The wafer processing system 1 includes, for example, a substrate processing apparatus 10, a transfer apparatus 112, and a substrate processing apparatus 110. The substrate processing apparatus 10 is an apparatus that receives a wafer W having a device structure formed on its surface Wa and performs processing to reduce warpage of the wafer W. Details of the substrate processing apparatus 10 will be described later. The transfer apparatus 112 is an apparatus that transfers the wafer W, which has been processed by the substrate processing apparatus 10, to the substrate processing apparatus 110.

[0012] The substrate processing apparatus 110 is an apparatus that performs a process of bonding a wafer W that has been processed by the substrate processing apparatus 10 to another wafer W. The substrate processing apparatus 110 performs bonding to the other wafer W while holding the back surface Wb side of the wafer W that has been processed by the substrate processing apparatus 10. The other wafer W may also be a wafer W that has been processed by the substrate processing apparatus 10. The substrate processing apparatus 110 may bond a device structure formed on a front surface Wa of one wafer W to a device structure formed on a front surface Wa of the other wafer W.

[0013] (Substrate processing equipment) 2 is a schematic side (front) view of the substrate processing apparatus 10. As shown in FIGS. 1 and 2, the substrate processing apparatus 10 includes a load / unload block 20, a processing block 30, and a control device 100.

[0014] The carry-in / out block 20 is a block that carries wafers W into and out of the substrate processing apparatus 10. The carry-in / out block 20 has, for example, a plurality of mounting tables 22. Each of the plurality of mounting tables 22 supports a cassette C. The cassette C stores a plurality of wafers W. The wafers W may be stored in the cassette C with their surfaces Wa facing upward. The carry-in / out block 20 has, for example, a plurality of transport units 24, a shelf unit 26, a measurement unit 40, and two or more reversing units 50.

[0015] A plurality of transfer units 24 transfer wafers W between the cassette C and a position where they can be handed over to the processing block 30. Any of the transfer units 24 transfers a wafer W between the cassette C and the measurement unit 40, and any of the transfer units 24 transfers a wafer W between the measurement unit 40 and the shelf unit 26 (inversion unit 50). Each transfer unit 24 is provided with a drive mechanism for each of the X direction, Y direction, up / down direction, and θ direction around the vertical axis as necessary, and may be provided with a drive mechanism for all directions.

[0016] The shelf unit 26 is divided into a plurality of cells arranged in the vertical direction. The shelf unit 26 is provided at a position accessible to a transfer unit 34 (described later) of the processing block 30. The measurement unit 40 is a unit that acquires information for measuring the amount of warpage of the wafer W. A specific example of the measurement unit 40 will be described later.

[0017] Each of the two or more inversion units 50 is a unit that inverts the wafer W upside down. Some of the two or more inversion units 50 invert the wafer W so that the back surface Wb faces upward. Other of the two or more inversion units 50 invert the wafer W so that the front surface Wa faces upward. The two or more inversion units 50 may be provided on the shelf unit 26. Specific examples of the inversion units 50 will be described later.

[0018] The processing block 30 is connected to the carry-in / out block 20. The processing block 30 may receive a wafer W with its backside Wb facing upward from the carry-in / out block 20 before processing in the processing block 30. The processing block 30 may unload a wafer W with its backside Wb facing upward after processing in the processing block 30 to the carry-in / out block 20. The processing block 30 includes one or more transfer units 34, one or more liquid processing units 60, one or more heat processing units 70, and one or more exposure units 80.

[0019] 2, the processing block 30 may be partitioned into multiple layers 31 arranged in the vertical direction. Each of the multiple layers 31 may be provided with one or more processing units selected from the liquid processing units 60, the thermal processing units 70, and the exposure units 80. Each of the multiple layers 31 is divided into a first area in which one or more processing units are arranged, a transfer area 32 in which the transfer unit 34 transfers the wafer W, and a second area in which one or more processing units are arranged. In the X-axis direction, the first area, the transfer area 32, and the second area are arranged in this order.

[0020] The transfer unit 34 has a transfer arm that is movable in, for example, the X direction, Y direction, up-down direction, and θ direction. The transfer unit 34 moves within the transfer area 32 and can transfer the wafer W to one or more processing units selected from the liquid processing unit 60, the heat processing unit 70, and the exposure unit 80. The processing block 30 has, for example, multiple transfer units 34 arranged at different heights. Each of the multiple transfer units 34 can transfer the wafer W to a corresponding area among the multiple transfer areas 32 that are located at different heights. In the processing block 30, one transfer unit 34 may be provided for two or more layers 31, or one transfer unit 34 may be provided for one layer 31.

[0021] The liquid processing unit 60 is a unit that forms a film of processing liquid on the back surface Wb. The heat processing unit 70 is a unit that performs heat processing on the film of processing liquid. A film is formed on the back surface Wb by performing heat processing on the film of processing liquid. Hereinafter, the film formed on the back surface Wb by the liquid processing unit 60 and the heat processing unit 70 will be referred to as the "back surface film." The exposure unit 80 is a unit that exposes at least a portion of the back surface film formed on the back surface Wb. The heat processing unit 70 performs heat processing on the back surface film after exposure by the exposure unit 80. Specific examples of the liquid processing unit 60, the heat processing unit 70, and the exposure unit 80 will be described later.

[0022] The control device 100 (controller) is, for example, a computer, and has a program storage unit (not shown). The program storage unit stores a program for controlling the processing of wafers W in the substrate processing apparatus 10. The program storage unit also stores a program for controlling the operations of the various processing units and transfer unit described above to cause the apparatus to perform wafer processing in the substrate processing apparatus 10 (for example, a substrate processing method described below). The program may be recorded on a computer-readable storage medium H and installed into the control device 10 from the storage medium H.

[0023] The above-described configuration of the substrate processing apparatus 10 is an example. The arrangement and number of various processing units or transfer units may be changed as appropriate. Processing units other than the measurement unit 40, the liquid processing unit 60, the heat treatment unit 70, and the exposure unit 80 may be arranged in either the carry-in / out block 20 or the processing block 30. For example, the substrate processing apparatus 10 may be provided with one or more processing units selected from a unit that performs hydrophobic processing, a unit that performs cleaning processing, a unit that performs cooling, a unit that acts as an intermediary between two transfer units, and a unit that aligns the wafer W.

[0024] (measurement unit) 3 shows a schematic side view of the measurement unit 40. The measurement unit 40 generates image information for measuring the amount of warpage of the wafer W. The measurement unit 40 performs measurement processing for generating the image information while supporting the wafer W with its front surface Wa facing upward and its back surface Wb facing downward. The measurement unit 40 includes, for example, a housing 41, a rotation holder 42, a drive mechanism 45, and an imaging unit 46.

[0025] The housing 41 houses the rotary holder 42, the drive mechanism 45, and the imaging unit 46. One side wall of the housing 41 is formed with a loading / unloading opening 41a for loading the wafer W into the housing 41 and unloading the wafer W from the housing 41.

[0026] The rotary holder 42 holds and rotates the wafer W. The rotary holder 42 includes a holder 43 and a rotary driver 44. The holder 43 is, for example, a suction chuck that holds the wafer W approximately horizontally by suction. The holder 43 supports the back side of the wafer W. Supporting the back side of the wafer W means supporting the wafer W in a state of contact with the back side Wb or in a state of contact with a layer such as a film formed on the back side Wb.

[0027] The rotation drive unit 44 includes a power source such as an electric motor, and rotates the holder 43. The rotation of the holder 43 causes the wafer W supported on the holder 43 to rotate. The holder 43 may support the wafer W such that the central axis of rotation by the rotation drive unit 44 substantially coincides with the center of the wafer W. The rotation drive unit 44 may include an encoder for detecting the rotational position (rotation angle) of the holder 43 about the central axis.

[0028] The driving mechanism 45 is, for example, a linear actuator, and moves the rotation holding unit 42 in one horizontal direction. The driving mechanism 45 may reciprocate the rotation holding unit 42 between a first position close to the loading / unloading opening 41a and a second position away from the loading / unloading opening 41a and close to the imaging unit 46.

[0029] The imaging unit 46 is capable of capturing an image of the edge surface of the wafer W. The imaging unit 46 includes an illumination module 46a and a camera 46b. The illumination module 46a emits light at the timing when the camera 46b captures an image. The camera 46b captures an image of the edge surface of the wafer W via an optical system included in the illumination module 46a. From the captured image of the edge surface of the wafer W, information indicating the state of warpage at the peripheral portion of the wafer W can be detected.

[0030] (liquid processing unit) 4 schematically shows the liquid processing unit 60. The liquid processing unit 60 performs liquid processing using a processing liquid (hereinafter referred to as "processing liquid L") for forming the back surface film. The liquid processing unit 60 performs liquid processing using the processing liquid L while supporting the wafer W with the back surface Wb facing upward and the front surface Wa facing downward. The liquid processing unit 60 includes a rotation holder 62 and a liquid supply unit 64.

[0031] The rotary holder 62 supports the wafer W so that the backside Wb faces upward, and rotates the wafer W. The rotary holder 62 includes a rotary drive unit 622, a shaft 624, and a holder 626. The rotary drive unit 622 includes a power source such as an electric motor, and rotates the shaft 624 around a vertical rotation axis.

[0032] The holding portion 626 (support member) is provided at the upper end of the shaft 624. The holding portion 626 holds (supports) the wafer W so as not to come into contact with the device structure formed on the surface Wa. The holding portion 626 includes a first portion 626a and a second portion 626b. The first portion 626a is formed in a disk shape and connects the shaft 624 and the second portion 626b. The second portion 626b is provided on the outer periphery of the upper surface of the first portion 626a and holds a portion of the circumference of the outer edge of the wafer W. As shown in the enlarged view of FIG. 4, a recess is formed in the second portion 626b into which the outer edge of the wafer W is fitted. At least a portion of the second portion 626b is provided to be movable horizontally relative to the first portion 626a so as to switch between a state in which the wafer W is held and a state in which the wafer W is released from its holding state.

[0033] The liquid supply unit 64 supplies the processing liquid L to the back surface Wb of the wafer W by discharging the processing liquid L toward the back surface Wb. The processing liquid L is a solution that generates stress when exposure is performed on a back surface film formed with the processing liquid L. The generation of stress due to exposure of the back surface film will be described later. The liquid supply unit 64 includes a liquid source 641, a pump 642, a valve 643, a nozzle 644, a pipe 645, and a drive mechanism 646.

[0034] The liquid source 641 functions as a supply source of the processing liquid L. The pump 642 sucks the processing liquid L from the liquid source 641 and delivers it to the nozzle 644 via a pipe 645 and a valve 643. The valve 643 opens and closes the flow path in the pipe 645. The nozzle 644 is disposed above the wafer W supported by the holder 626 so that its discharge port faces the back surface Wb of the wafer W. The nozzle 644 is configured to discharge the processing liquid L delivered by the pump 642 onto the back surface Wb of the wafer W.

[0035] The pipe 645 connects, in order from the upstream side, a liquid source 641, a pump 642, a valve 643, and a nozzle 644. The drive mechanism 646 includes a drive source such as an electric motor, and is configured to move the nozzle 644 in the horizontal and vertical directions.

[0036] (Heat treatment unit) FIG. 5(a) schematically shows a heat treatment unit 70. The heat treatment unit 70 shown in FIG. 5(a) uses a heating plate to heat a coating formed on the back surface Wb. The coating formed on the back surface Wb collectively refers to a film of the processing liquid L before it is formed, and a film formed by heating the film of the processing liquid L. Hereinafter, for ease of explanation, the coating of the processing liquid L formed on the back surface Wb will be referred to as a "back surface film F." The heat treatment unit 70 performs heat treatment on the back surface film F formed on the wafer W while supporting the wafer W with the back surface Wb facing up and the front surface Wa facing down.

[0037] As shown in FIG. 5(a), the heat treatment unit 70 includes a housing 71, a support 72, and a heating plate 74. The housing 71 houses the support 72 and the heating plate 74 and forms a space for performing heat treatment on the back surface film F. The support 72 (support member) supports the wafer W so as not to come into contact with the device structure formed on the front surface Wa. The support 72 is formed, for example, in an annular shape, and supports from below the outer periphery of the front surface Wa where no device structure is formed. The support 72 may be connected to the inner wall of the housing 71 via a fixing member.

[0038] The hot plate 74 is disposed at a position where it does not come into contact with the wafer W supported by the support part 72. The hot plate 74 is disposed, for example, below the support part 72 with a gap between it and the support part 72. A heater such as a resistance heating element is built into the hot plate 74. As the temperature of the hot plate 74 rises, heat is transferred to the back surface film F formed on the back surface Wb.

[0039] FIG. 5(b) schematically illustrates a heat treatment unit 70 that applies heat to the back surface film F by a method different from that of the heat treatment unit 70 illustrated in FIG. 5(a). The heat treatment unit 70 illustrated in FIG. 5(b) includes a housing 71, a support 72, and one or more irradiation units 76. The one or more irradiation units 76 are provided within the housing 71 so as to be able to irradiate light onto the back surface film F formed on the back surface Wb of the wafer W supported by the support 72. The irradiation of light heats the back surface film F. Note that, unlike the light for exposure by the exposure unit 80, the emitted light from the one or more irradiation units 76 may be selected so that substantially no reaction occurs in the back surface film F even when the light is irradiated.

[0040] A back surface film F is formed on the back surface Wb through processing in the liquid processing unit 60 and the heat processing unit 70. The liquid processing unit 60 and the heat processing unit 70 constitute a film forming section that forms a back surface film that generates stress due to exposure. In the present disclosure, stress generated by exposure also includes stress generated by performing heat processing after irradiation with exposure light.

[0041] (reversal unit) 6 schematically shows the reversing unit 50 as viewed from the side. The reversing unit 50 includes, for example, a holder 56 and a drive mechanism 58. The holder 56 is a portion that holds the wafer W. The holder 56 holds the wafer W with either the front surface Wa or the back surface Wb facing upward. The holder 56 may have a configuration similar to that of the holder 626 of the liquid processing unit 60 shown in FIG. 4. The holder 56 may include a portion 56a corresponding to the first portion 626a of the holder 626 and a portion 56b corresponding to the second portion 626b of the holder 626.

[0042] The drive mechanism 58 is connected to the holder 56 and rotates the holder 56 around a horizontal axis. The drive mechanism 58 is, for example, an actuator including a drive source such as an electric motor. The drive mechanism 58 may rotate the holder 56 by 180° around the horizontal axis so that the holder 56 is upside down. As the holder 56 rotates around the horizontal axis (180° rotation), the wafer W is turned upside down.

[0043] <Properties of the backside film> Here, the relationship between the stress generated by exposure to the back surface film F and the reduction in warpage will be described with reference to FIGS. 7 to 9. FIG. 7 uses a table to schematically show the relationship between the type of back surface film F and the stress and deformation generated by exposure. The back surface film F is an expanding film whose volume increases due to a chemical reaction or the like, or a contracting film whose volume decreases due to a chemical reaction or the like. In the schematic diagram in the table of FIG. 7, the back surface Wb faces downward, and the back surface film F is located below the wafer W (bare wafer). The back surface film F is, for example, a film containing a resin that crosslinks upon exposure (a resin-containing film that crosslinks upon exposure).

[0044] As shown in Figure 7, if the back surface film F formed on the back surface Wb is an expanding film, it will expand due to a chemical change associated with exposure, generating inward stress. In this case, assuming that the wafer W before exposure is not warped, the peripheral portion of the wafer W will bend downward. If the back surface film F formed on the back surface Wb is a shrinking film, it will shrink due to a chemical change associated with exposure, generating outward stress. In this case, assuming that the wafer W before exposure is not warped, the peripheral portion of the wafer W will bend upward.

[0045] The treatment liquid L for forming the expansion film may be, for example, a solvent containing a component that crosslinks upon exposure (more specifically, irradiation with light for exposure and heat treatment). In one example, the treatment liquid L is a negative resist containing a photosensitive epoxy resin, and its viscosity may be 800 cP to 1200 cP. In the following, an example will be described in which the back surface film F is an expansion film.

[0046] 8 and 9 show examples of measurement results of the in-plane height distribution of a wafer W after a back surface film F is formed on the back surface Wb and the back surface film F is exposed to light. Assuming that the wafer W is flat, the in-plane position of the wafer W is specified by coordinates of the x-axis and y-axis, which are orthogonal to each other. The z-axis, which is orthogonal to the x-axis and y-axis, represents the height position of the upper surface of the back surface film F at each position in the plane, and the height position is measured with the back surface Wb facing upward.

[0047] The measurement results shown in Figure 8 calculate the distribution of height positions when exposure light is irradiated onto the entire surface of the backside film F. It can be seen that the peripheral portion of the wafer W is deformed so as to warp upward relative to the central portion of the wafer W. The measurement results shown in Figure 9 calculate the distribution of height positions when exposure light is irradiated onto both ends of the backside film F in the x-axis direction, and exposure light is not irradiated onto the central portion (within a 150 mm range) in the x-axis direction. In this case, when focusing on each region at both ends in the x-axis direction, stress is generated toward the central portion along the y-axis direction. As a result, it can be seen that both ends in the y-axis direction are deformed so as to warp upward.

[0048] From the above considerations, it can be seen that if warpage exists before the back surface film F is formed, the warpage can be reduced by forming the back surface film F on the back surface Wb and exposing at least a portion of the back surface Wb. Which region of the back surface film F should be irradiated with exposure light in order to reduce warpage is determined, for example, by trials or simulations before the wafer processing system 1 is produced.

[0049] (Exposure unit) Fig. 10 schematically shows an example of the exposure unit 80 when viewed from the side, and Fig. 11 schematically shows an example of the exposure unit 80 when viewed from the top. The exposure unit 80 (exposure section) is configured to expose at least a portion of the back surface film F to light so as to reduce warpage of the wafer W after the back surface film F is formed on the back surface Wb. The exposure unit 80 is configured to be able to adjust the range of exposure of the back surface film F in response to, for example, an operation instruction from the control device 100.

[0050] The exposure unit 80 may perform a process of irradiating the back surface film F with exposure light while supporting the wafer W with the back surface Wb facing up and the front surface Wa facing down. As shown in FIGS. 10 and 11 , the exposure unit 80 has a housing 81, a rotary holder 82, a drive mechanism 85 (drive unit), and an irradiation unit 88.

[0051] The housing 81 houses the rotary holder 82, the drive mechanism 85, and the irradiation unit 88. One side wall of the housing 81 is formed with a loading / unloading opening 81a for loading the wafer W into the housing 81 and unloading the wafer W from the housing 81.

[0052] The rotary holder 82 is a part that holds the wafer W so that the back surface Wb faces upward and rotates the wafer W. The rotary holder 82 includes a rotation drive unit 822, a shaft 824, and a holder 826. The rotation drive unit 822 includes a power source such as an electric motor, and rotates the shaft 824 around a vertical rotation axis. The holder 826 (support member) is provided at the upper end of the shaft 824. The holder 826 holds (supports) the wafer W so as not to come into contact with the device structure formed on the front surface Wa.

[0053] Holder 826 may have a configuration similar to that of holder 626 of rotary holder 62 included in liquid processing unit 60. Holder 826 includes a first portion 826a and a second portion 826b. First portion 826a is formed in a disk shape and connects shaft 824 and second portion 826b. Second portion 826b is provided on the outer periphery of the upper surface of first portion 826a and holds a portion of the circumference of the outer edge of wafer W. Second portion 826b may have a configuration similar to that of second portion 626b of liquid processing unit 60. At least a portion of second portion 826b is provided to be horizontally movable relative to first portion 826a so as to switch between a state in which wafer W is held and a state in which the wafer W is released from its holding state.

[0054] The drive mechanism 85 is, for example, a linear actuator, and moves the rotational holding unit 82 in one horizontal direction. The direction in which the drive mechanism 85 moves the rotational holding unit 82 is defined as "direction D1," and the horizontal direction perpendicular to direction D1 is defined as "direction D2." The drive mechanism 85 moves the rotational holding unit 82 back and forth in direction D1 (second direction) between a first position close to the loading / unloading opening 81a and a second position away from the loading / unloading opening 81a.

[0055] The irradiation unit 88 can irradiate exposure light onto at least a portion of the back surface film F formed on the wafer W held by the rotary holder 82 (rotation drive unit 822). The irradiation unit 88 is disposed midway between the first position and the second position in the direction D1. This allows the irradiation unit 88 to irradiate exposure light onto the back surface film F while the wafer W moves in the direction D1. The irradiation unit 88 includes a case 881, a support substrate 883, and a plurality of LEDs 884.

[0056] The case 881 is attached to, for example, the upper wall of the housing 81, and houses a support substrate 883 and a plurality of LEDs 884. An opening 881a for emitting light for exposure is formed in the bottom of the case 881. A shutter for opening and closing the opening 881a may be provided in the case 881. The support substrate 883 is provided vertically above the opening 881a. The support substrate 883 is formed so as to extend in a direction intersecting the direction D1 (for example, the direction D2). The support substrate 883 may be a circuit board. The support substrate 883 is fixed to, for example, any location on the case 881.

[0057] Each of the plurality of LEDs 884 is a light source that emits light for exposure. The plurality of LEDs 884 is provided on the lower surface of the support substrate 883 and is supported by the support substrate 883. The plurality of LEDs 884 (plurality of light sources) are arranged side by side along direction D2 (first direction). The plurality of LEDs 884 may be arranged at equal intervals in direction D2. As the plurality of LEDs 884, 50 to 150 LEDs 884 may be provided. In the example shown in FIG. 11, the plurality of LEDs 884 are arranged in a single row, but the plurality of LEDs 884 may be arranged in a matrix of two or more rows.

[0058] Each LED 884 emits light as exposure light in a frequency band at which a chemical reaction (crosslinking) occurs in the back surface film F. Each LED 884 emits, for example, ultraviolet light as exposure light. Each LED 884 can emit exposure light vertically downward. The multiple LEDs 884 may be individually controllable to be turned on (lit) and off (exited). The driving mechanism 85 moves the rotation holder 82 along direction D1 so that the wafer W crosses the multiple LEDs 884 in a planar view. While the driving mechanism 85 moves the wafer W in direction D1, exposure light is irradiated onto the back surface film F from at least some of the multiple LEDs 884.

[0059] [Substrate processing method] Next, an example of a substrate processing method performed using the substrate processing apparatus 10 will be described. This substrate processing method includes at least a film formation process and an exposure process. The film formation process is a process of forming a back surface film F that generates stress by exposure. The exposure process is a process of exposing at least a portion of the back surface film F to light after the back surface film F is formed so as to reduce warpage of the wafer W. The film formation process and the exposure process may be performed within the substrate processing apparatus 10.

[0060] The film forming step may include a liquid treatment step and a first heating step. The liquid treatment step is a step of supplying a treatment liquid L to the rear surface Wb to form a film of the treatment liquid L. The first heating step is a step of forming a film by subjecting the film of the treatment liquid L to a heat treatment. In the substrate processing method, a second heating step (heating step) may be performed after the exposure step. The second heating step is a step of subjecting the rear surface film F after exposure to a heat treatment.

[0061] The substrate processing method may include a loading step, an unloading step, a first inversion step, and a second inversion step. The loading step is a step of loading the wafer W into the substrate processing apparatus 10 before the back surface film F is formed thereon. The unloading step is a step of unloading the wafer W from the substrate processing apparatus 10 after at least a portion of the back surface film F has been exposed. The first inversion step is a step of inverting the wafer W before the back surface film F is formed thereon so that the back surface Wb faces upward. The second inversion step is a step of inverting the wafer W after at least a portion of the back surface film F has been exposed thereon so that the front surface Wa faces upward.

[0062] The carry-in process, the carry-out process, the first inversion process, and the second inversion process may be performed in the carry-in / out block 20. The film formation process, the exposure process, and the second heating process may be performed in the processing block 30. In each of the film formation process, the exposure process, and the second heating process, the wafer W may be supported with the back surface Wb facing upward so as not to come into contact with the region of the front surface Wa in which the pattern or device structure is formed.

[0063] The substrate processing method may include a first measurement step (measurement step), a condition adjustment step, and a second measurement step. The first measurement step is a step of measuring the amount of warpage of the wafer W before the film formation step. The amount of warpage measured in the measurement step means the difference between the measurement value at the uppermost position and the measurement value at the lowermost position among the measurement data of the edge face height of the wafer W (the difference between the height at the uppermost position and the height at the lowermost position in the measurement data). The condition adjustment step is a step of changing the processing conditions in at least one of the film formation step and the exposure step according to the measurement result of the amount of warpage. In the condition adjustment step, for example, the processing conditions in the exposure step are changed for each individual wafer W. The second measurement step is a step of measuring the amount of warpage of the wafer W after exposure of at least a portion of the backside film F and post-exposure heat treatment are performed.

[0064] 12 illustrates a processing flow executed in a substrate processing method. In this processing flow, an exposure target range in the exposure process is predetermined. The exposure target range represents the maximum range to be exposed on the back surface film F. Depending on the processing conditions in the exposure process, the exposure light may be irradiated onto the entire exposure target range. Depending on the processing conditions in the exposure process, the exposure light may be irradiated onto a portion of the exposure target range. In other words, the exposure light may not necessarily be irradiated onto the entire exposure target range.

[0065] In the substrate processing apparatus 10, for example, a plurality of wafers W are processed in units of a lot. Each of the plurality of wafers W processed in one lot is the same type of wafer W. Therefore, before being introduced into the substrate processing apparatus 10, the warpage tendencies of the wafers W in the same lot are similar. On the other hand, the degree of warpage may differ even between wafers W in the same lot. In the processing flow, processing conditions in the exposure process are set for each wafer W in order to reduce the difference in the degree of warpage between wafers W.

[0066] The process flow shown in FIG. 12 describes a series of steps executed when focusing on one wafer W. FIG. 13 also schematically shows the state of the wafer W at each step of the process flow. In this process flow, step S01 is executed with the wafer W to be processed housed in a cassette C on the mounting table 22. In step S01, for example, the control device 100 controls the transfer unit 24 to transfer the wafer W from the cassette C to the measuring unit 40. Then, the control device 100 acquires image information obtained by capturing an image of the end face of the wafer W from the measuring unit 40.

[0067] Thereafter, the control device 100 calculates the amount of warpage, which indicates the degree of warpage of the edge surface of the wafer W, from the image information obtained by the measurement unit 40. In one example, the control device 100 calculates the height position of the upper end of the edge surface of the wafer W for each position (angle) in the circumferential direction around the center of the wafer W by comparing the image obtained from the measurement unit 40 with a reference image of the edge surface of a reference wafer that is not warped. Then, the control device 100 calculates the difference between the maximum value of the height position and the minimum value of the height position as the amount of warpage. Some of the processes in step S01 correspond to the measurement process. In FIG. 13, the device structure formed on the front surface Wa is marked with "D." Step S01 is performed with the front surface Wa on which the device structure D is formed facing upward.

[0068] Next, step S02 is executed. In step S02, for example, the control device 100 controls the transport unit 24 to transport the wafer W from the measurement unit 40 to the reversing unit 50 (first reversing section) provided on the shelf unit 26. Then, the control device 100 causes the reversing unit 50 to reverse the wafer W upside down so that the front surface Wa faces downward and the back surface Wb faces upward. A part of step S02 corresponds to a first reversing step. By executing step S02, the wafer W transitions to a state in which the back surface Wb faces upward (see also FIG. 13).

[0069] Next, step S03 is executed. In step S03, for example, controller 100 controls transfer unit 34 to transfer wafer W from inversion unit 50 to liquid processing unit 60. Then, controller 100 controls liquid processing unit 60 to form a film of a processing liquid (rear surface film F) on rear surface Wb. By executing step S03, rear surface film F is formed on rear surface Wb facing upward (see also FIG. 13).

[0070] Next, step S04 is executed. In step S04, for example, the control device 100 controls the transfer unit 34 to transfer the wafer W from the liquid processing unit 60 to the heat processing unit 70. Then, the control device 100 causes the heat processing unit 70 to perform heat processing on the wafer W so that a back surface film F is formed. A part of step S07 corresponds to the first heating step.

[0071] Next, step S05 is executed. In step S05, for example, the control device 100 controls the transport unit 34 to transport the wafer W from the heat treatment unit 70 to the exposure unit 80. Then, the control device 100 controls the exposure unit 80 to irradiate the exposure light onto at least a portion of the exposure target range of the back surface film F. In FIG. 13, "Fr" is attached to the portion of the back surface film F irradiated with the exposure light, and a pattern different from that of the other portion irradiated with the exposure light is attached. Part of step S05 corresponds to an exposure process.

[0072] Here, an example of a method for irradiating exposure light in accordance with the exposure target range will be described with reference to FIGS. 14 to 16. In the exposure process included in step S05, exposure light may be irradiated from at least some of the multiple LEDs 884 arranged in direction D2 while the wafer W is moved along direction D1, thereby exposing at least a portion of the backside film F. Irradiating exposure light while the wafer W is moved along direction D1 is not limited to irradiating exposure light while the wafer W continues to move in direction D1. Irradiating exposure light while the wafer W is moved along direction D1 also includes irradiating exposure light while the movement in direction D1 is temporarily stopped and the wafer W is moved (including rotated) in a direction different from direction D1.

[0073] 14, the control device 100 moves the rotary holder 82 (wafer W) in direction D1 using the drive mechanism 85 until the center of the wafer W reaches the positions of the plurality of LEDs 884. Then, the control device 100 controls the irradiation unit 88 to emit exposure light from at least some of the plurality of LEDs 884 while rotating the wafer W using the rotation drive unit 822 of the rotary holder 82. Thereafter, the control device 100 moves the rotary holder 82 (wafer W) using the drive mechanism 85 to return the wafer W to its initial position, with the irradiation unit 88 stopping the emission of all exposure light.

[0074] As described above, irradiating the wafer W with exposure light from at least some of the LEDs 884 includes irradiating the wafer W with exposure light for at least a portion of the period during which the wafer W is rotated while its movement in the direction D1 is stopped. In the present disclosure, irradiating the wafer W with exposure light for at least a portion of the period during which the wafer W is rotated while its movement in the direction D1 is stopped is referred to as "spin exposure." Figures 14(b), 14(c), and 14(d) illustrate examples of the shapes of areas exposed by spin exposure. The areas indicated by multiple diagonal lines represent exposed areas, and this also applies to the subsequent figures. Unlike the example shown in Figure 14(b) and other figures, the shapes of areas exposed by spin exposure do not need to be point-symmetric with respect to the center of the wafer W or line-symmetric with respect to an imaginary line passing through the center of the wafer W.

[0075] 15, the control device 100 causes the drive mechanism 85 to move the rotary holder 82 (wafer W) in direction D1 to a position where the entire wafer W has passed the irradiation unit 88. While moving the wafer W along direction D1 using the drive mechanism 85, the control device 100 controls the irradiation unit 88 to emit exposure light from at least some of the multiple LEDs 884. Then, with the irradiation unit 88 stopping the emission of all exposure light, the control device 100 causes the drive mechanism 85 to move the rotary holder 82 (wafer W) so as to return the wafer W to its initial position.

[0076] As described above, irradiating the wafer W with exposure light from at least some of the LEDs 884 includes irradiating the wafer W with exposure light for at least a portion of the time period while the wafer W is being moved along the direction D1. In the present disclosure, irradiating the wafer W with exposure light for at least a portion of the time period while the wafer W is being moved along the direction D1 is referred to as "scanning exposure." Exemplary shapes of areas exposed by scanning exposure are shown in FIGS. 15(b) and 15(c). Unlike the example shown in FIG. 15(b) and other figures, the shape of the area exposed by scanning exposure does not have to be line-symmetric with respect to an imaginary line passing through the center of the wafer W.

[0077] Exposure may be performed by combining spin exposure and scan exposure, as shown in Fig. 16. For example, the control device 100 executes the following controls in order. (a) The wafer W is moved by the drive mechanism 85 from the initial position until the center of the wafer W reaches a position corresponding to the LED 884, and exposure light is irradiated from the irradiation unit 88 so that the exposure light irradiates half of the area to be exposed by scanning exposure. (b) The wafer W is rotated by the rotary drive unit 822 while the irradiation unit 88 irradiates the wafer W with exposure light so that the exposure light irradiates the entire area of ​​the region to be exposed by spin exposure. (c) The driving mechanism 85 moves the wafer W to a position where the entire wafer W passes through the irradiation unit 88, and the irradiation unit 88 irradiates the exposure light onto the remaining half of the area to be exposed by the scanning exposure.

[0078] The control device 100 may control the driving mechanism 85 to return the wafer W to the initial position after sequentially executing the above controls (a), (b), and (c). The control device 100 may execute the following control (c1) instead of the above control (c). (c1) The wafer W is moved to the initial position by the drive mechanism 85, and exposure light is irradiated from the irradiation unit 88 so that the exposure light irradiates the remaining half of the area to be exposed by scanning exposure.

[0079] When executing the control (c1) above, the control device 100 may rotate the wafer W by 180° after executing the control (b) above. Note that the control device 100 may execute the control (a) above, the half rotation of the wafer W, and the control (c1) above even when performing scanning exposure without performing spin exposure. By performing scanning exposure during reciprocating movement rather than during unidirectional movement, the exposure unit 80 can be made smaller.

[0080] 16(b), 16(c), and 16(d) show examples of the shapes of areas exposed by a combination of scanning exposure and spin exposure. The control device 100 may control the exposure unit 80 to perform all of either scanning exposure or spin exposure, and then perform all of the other of scanning exposure and spin exposure. In the exposure unit 80, by selecting scanning exposure or spin exposure, adjusting the positions and number of the multiple LEDs 884 to be lit, and the timing at which the LEDs 884 are lit, it is possible to irradiate exposure light in accordance with the exposure target range.

[0081] Next, with reference to Figures 17 and 18, an example of a method for changing conditions to reduce variations in the degree of warpage within the same lot will be described. Figure 17(a) shows measurement results of the distribution of height positions on the diameter of a wafer W when a backside film F is formed on a wafer W in an unwarped state and the backside film F is irradiated with exposure light under different conditions. The horizontal axis represents the distance on the y-axis from the center of the wafer W, and the vertical axis represents the measurement value of the height position. "Full exposure" is the measurement result when the entire backside film F is irradiated with exposure light, as shown in Figure 17(b).

[0082] "w:10mm" and "w:5mm" are measurement results when exposure light is applied to a partial area having an area of ​​50% of the entire area of ​​the backside film F. As shown in Figure 17(c), multiple strip-shaped areas, each extending in one direction (the vertical direction of the paper) and arranged at equal intervals in a direction perpendicular to the one direction (the horizontal direction of the paper), are exposed, thereby adjusting the exposed area (hereinafter referred to as the "exposed area"). The width of the strip-shaped areas is represented by "w", and the spacing between adjacent strip-shaped areas is represented by "p". In "w:10mm", the width w is set to 10mm and the spacing p is set to 20mm. In "w:5mm", the width w is set to 5mm and the spacing p is set to 5mm. The radius of the wafer W is 150mm.

[0083] 17(a) shows that when the exposure area of ​​the exposure target region is different, the height position at the end face of the wafer W is different, and as a result, the amount of warpage is different. When the amount of warpage of the wafer W before exposure is relatively large within the same lot, the control device 100 changes the processing conditions in the exposure process so that the exposure area of ​​the exposure target region is increased. When the amount of warpage of the wafer W before exposure is relatively small within the same lot, the control device 100 changes the processing conditions in the exposure process so that the exposure area of ​​the exposure target region is decreased.

[0084] 18(a) shows an enlarged view of two or more LEDs 884 that can irradiate the exposure target area with exposure light among the plurality of LEDs 884. In the enlarged view of FIG. 18(a), the LEDs 884 with patterns indicate that they are lit, and the LEDs 884 with patterns indicate that they are not lit. The ratio of the number of LEDs 884 that are lit to the number of LEDs 884 that are not lit varies between exposure areas of 100%, 80%, and 50%.

[0085] FIG. 18(b) schematically shows the area exposed when the exposure area is 100%. FIG. 18(c) schematically shows the area exposed when the exposure area is 80%, and FIG. 18(d) schematically shows the area exposed when the exposure area is 50%. Note that the arrangement and number of the LEDs 884 lit in FIG. 18(a) do not match the arrangement and number of the strip-shaped areas in FIGS. 18(c) and 18(d) because they are schematic diagrams. As exemplified in FIGS. 18(a) and 18(b), the exposure area may be adjusted by adjusting the density of the exposed and unexposed portions in the exposure target area. Note that instead of adjusting the density, the exposure area may be adjusted by dividing the exposure target area into two parts, an exposed part and an unexposed part, and adjusting the size of the exposed part. However, by adjusting the density, the exposed portions in the exposure target area are dispersed even if the exposure area is reduced, so the density may be adjusted from the perspective of correcting the warp more accurately depending on the state of the warp.

[0086] As described above, in the condition adjustment process, the area of ​​the exposure target range to be irradiated with exposure light (exposure area) may be changed according to the measurement result of the amount of warpage. In the condition adjustment process, the ratio of the number of LEDs 884 (two or more target light sources) that are irradiated with exposure light to the number of LEDs that are not irradiated with exposure light may be changed according to the measurement result of the amount of warpage. The control device 100 may acquire the amount of warpage of the wafer W before forming the backside film F, and change the processing conditions in the exposure process according to the acquired result of the amount of warpage. The control device 100 may previously store information correlating the relationship between the amount of warpage and the arrangement of the LEDs 884 that are turned on among the multiple LEDs 884. The information correlating the relationship between the amount of warpage and the arrangement of the LEDs 884 that are to be turned on may be preset by a worker such as an operator.

[0087] Returning to FIG. 12, after step S05 is performed, step S06 is performed. In step S06, for example, the control device 100 controls the transport unit 34 to transport the wafer W from the exposure unit 80 to the heat treatment unit 70 (heat processing unit). Then, the control device 100 controls the heat treatment unit 70 to perform a heat treatment on the back surface film F after it has been irradiated with the exposure light. This promotes crosslinking in the portion of the back surface film F irradiated with the exposure light. The heat treatment unit 70 that performs the heat treatment in step S04 and the heat treatment unit 70 that performs the heat treatment in step S06 may be the same heat treatment unit 70 or different heat treatment units 70. Part of step S06 corresponds to the second heating step. While steps S03 to S06 are performed, the back surface Wb continues to face upward (see FIG. 13).

[0088] Next, step S07 is executed. In step S07, for example, the control device 100 controls the transport unit 34 to transport the wafer W from the heat treatment unit 70 to the reversing unit 50 (second reversing section) provided in the shelf unit 26. Then, the control device 100 causes the reversing unit 50 to invert the wafer W upside down so that the front surface Wa faces upward and the back surface Wb faces downward. A part of step S07 corresponds to a second inversion step. The inversion unit 50 that inverts the wafer W in step S02 and the inversion unit 50 that inverts the wafer W in step S07 may be the same inversion unit 50 or may be different inversion units 50. Execution of step S07 causes the wafer W to transition to a state in which the front surface Wa faces upward.

[0089] Next, step S08 is executed. In step S08, for example, the control device 100 controls the transfer unit 24 to transfer the wafer W from the inversion unit 50 to the measurement unit 40. Then, similar to step S01, the control device 100 acquires image information obtained by capturing an image of the end face of the wafer W from the measurement unit 40. Thereafter, similar to step S01, the control device 100 measures the amount of warpage from the image information acquired by the measurement unit 40.

[0090] The control device 100 may compare the difference between the amount of warpage measured in step S01 and the amount of warpage measured in step S08 to evaluate whether the series of processes in the substrate processing apparatus 10 are being performed as intended. A part of step S08 corresponds to a second measurement step. The measurement unit 40 that images the end face of the wafer W in step S01 and the measurement unit 40 that images the end face of the wafer W in step S08 may be the same measurement unit 40 or may be different measurement units 40.

[0091] After step S08 is performed, the control device 100 controls the transfer unit 24 to transfer the wafer W from the measuring unit 40 to the cassette C. This completes the series of processes for one wafer W. The control device 100 may also perform the series of processes of steps S01 to S08 for each of the other wafers W. The period during which the series of processes for one wafer W is performed and the period during which the series of processes for another wafer W are performed may at least partially overlap.

[0092] [Variations] The series of processes shown in Fig. 12 is an example and can be modified as appropriate. In the series of processes described above, the control device 100 may execute one step and the next step in parallel, or may execute each step in an order different from that of the example described above. The control device 100 may execute steps with content different from that of the example described above.

[0093] In the condition adjustment step, the process conditions in the film formation step may be changed instead of the process conditions in the exposure step. Figure 19 shows the measurement results of the amount of warpage when a back surface film F is formed on the back surface Wb of a wafer W in an unwarped state while changing the process conditions so that the film thicknesses differ, and the back surface film F is exposed to light. In the graph of Figure 19, the horizontal axis represents the measured film thickness, and the vertical axis represents the measured amount of warpage. The four plots in the graph represent combinations of the measured film thickness and warpage, and the dashed line is a linear approximation line (calculated by the least squares method) obtained from the combination of the four measurement values.

[0094] 19, it can be seen that the amount of warpage varies depending on the film thickness, and that there is a correlation between film thickness and the amount of warpage. When the amount of warpage of a wafer W before exposure is relatively large within the same lot, the control device 100 changes the processing conditions in the film formation process so that the film thickness becomes larger. When the amount of warpage of a wafer W before exposure is relatively small within the same lot, the control device 100 changes the processing conditions in the film formation process so that the film thickness becomes smaller.

[0095] For example, the control device 100 changes the supply amount of the processing liquid L in the liquid processing step or the time for which the wafer W is rotated and dried after the supply of the processing liquid L in the liquid processing step, as a processing condition in the film formation step, in accordance with the measurement result of the amount of warpage. Alternatively, the control device 100 may change the heating time or heating temperature in the heat treatment step in accordance with the measurement result of the amount of warpage. The control device 100 may pre-store information correlating the amount of warpage with setting values ​​such as the supply amount of the processing liquid L that affect the film thickness. Information correlating the relationship between the amount of warpage and the supply amount of the processing liquid L that affect the film thickness may be set in advance by a worker such as an operator.

[0096] The control device 100 may not execute the first measurement step and the condition adjustment step. The control device 100 may execute the first measurement step and the condition adjustment step, but not execute the second measurement step. In at least some of the liquid processing step, the first heating step, the exposure step, and the second heating step, the processing may be performed with the wafer W supported with the back surface Wb facing downward. At least one of the first measurement step and the second measurement step may be performed using a measurement device provided separately from the substrate processing apparatus 10. In one example of the various examples described above, at least some of the matters described in the other examples may be combined.

[0097] Summary of this disclosure The present disclosure includes the following methods or configurations [1] to

[20] .

[0098] [1] A substrate processing method including: a film formation step of forming a back surface film (F) that generates stress by exposure on a back surface (Wb) of a substrate having a front surface (Wa) on which a pattern or device structure (F) is formed and a back surface facing opposite to the front surface (Wa); and an exposure step of exposing at least a portion of the back surface film (F) to light so as to reduce warpage of the substrate (W) after the back surface film (F) is formed. In this substrate processing method, exposure of the back surface film (F) generates stress within the back surface film (F) without applying external force to the substrate (W), thereby reducing warpage of the substrate (W). For example, warpage of the substrate (W) is corrected without creating irregularities in the back surface film F itself as a result of the correction of warpage. Therefore, in the subsequent bonding process, it is easy for the device used to perform that process to hold the back surface (Wb). This is useful for facilitating the process of bonding to another substrate.

[0099] [2] The substrate processing method according to [1] above, further comprising a carrying-in step of carrying the substrate (W) into the substrate processing apparatus (10) before the back surface film (F) is formed thereon, and a carrying-out step of carrying the substrate (W) out of the substrate processing apparatus (10) after at least a portion of the back surface film (F) has been exposed, wherein the film forming step and the exposure step are performed in the substrate processing apparatus (10). In this case, the process for correcting the warpage is performed by one substrate processing apparatus, which is useful for simplifying the entire apparatus.

[0100] [3] The substrate processing method according to [2] above, further comprising a first inversion step of inverting the substrate (W) before the back surface film (F) is formed so that the back surface (Wb) faces upward, and a second inversion step of inverting the substrate (W) after at least a portion of the back surface film (F) has been exposed so that the front surface (Wa) faces upward. In this case, the back surface film (F) can be formed and exposed to light with the back surface (Wb) facing upward, which makes it easy to supply a treatment liquid or the like to the back surface film (F) in the film formation step and the exposure step.

[0101] [4] The substrate processing method according to [3] above, further comprising a heating step of heating the substrate (W) after the backside film (F) has been formed, wherein the substrate processing apparatus (10) comprises a load / unload block (20) and a processing block (30) connected to the load / unload block (20), the load step, the unload step, the first reversal step, and the second reversal step are performed in the load / unload block (20), and the film formation step, the exposure step, and the heating step are performed in the processing block (30). In this case, various processes and transportation of the wafer W are performed in the processing block 30 with the back surface (Wb) facing upward, which allows the number of types of members for supporting the substrate (W) arranged in the processing block 30 to be reduced.

[0102] [5] The substrate processing method according to [4] above, wherein in each of the film formation process, the exposure process, and the heating process, the substrate (W) is supported with the back surface (Wb) facing upward so as not to come into contact with the area of ​​the front surface (Wa) on which the pattern or device structure (D) is formed. In this case, various processes can be performed with the back surface (Wb) facing upward, while reducing the influence on the pattern or device structure (D).

[0103] [6] The substrate processing method according to any one of [1] to [5] above, further comprising: a measurement step of measuring the amount of warpage of the substrate (W) before the film formation step; and a condition adjustment step of changing the processing conditions in at least one of the film formation step and the exposure step according to the measurement result of the amount of warpage. In this case, the difference in the degree of warping between the substrates (W) can be reduced.

[0104] [7] The substrate processing method according to [6] above, further comprising a second measurement step of measuring the amount of warpage of the substrate (W) after exposure of at least a portion of the back surface film (F) and heat treatment after exposure are performed. In this case, even while changing the processing conditions in accordance with the individual substrate (W), it is possible to grasp whether or not the desired warpage correction is being performed in the film forming step and the exposure step.

[0105] [8] A substrate processing method according to [6] or [7] above, wherein an exposure target range in the exposure process is predetermined, and in the condition adjustment process, processing conditions in the exposure process are changed so that the area of ​​the exposure target range that is irradiated with exposure light changes depending on the measurement results of the amount of warpage. It was discovered that by changing the exposure area within the exposure target range, it is possible to adjust the degree of warpage correction based on the formation of a film on the back surface (Wb) and the exposure of that film. With the above method, warpage correction can be performed in accordance with the warpage state of each substrate (W) before the processing for warpage correction is performed.

[0106] [9] The substrate processing method according to [8] above, wherein in the exposure process, exposure light is irradiated from at least some of the plurality of light sources (884) arranged in the first direction (D2) to expose at least a portion of the backside film (F), and in the condition adjustment process, the ratio of the number of two or more target light sources that irradiate exposure light and the number that do not irradiate exposure light is changed according to the measurement result of the amount of warpage, and the two or more target light sources are two or more light sources among the plurality of light sources (884) that are arranged in positions that allow exposure light to be irradiated onto the exposure target range. In this case, the exposure area can be easily adjusted by adjusting the light source that emits the exposure light among the plurality of light sources (884).

[0107]

[10] The substrate processing method according to [6] or [7] above, wherein in the condition adjustment step, the processing conditions in the film formation step are changed so that the thickness of the back surface film (F) changes depending on the measurement results of the amount of warpage. It was discovered that by changing the thickness of the film, it is possible to adjust the degree of warpage correction based on the formation of a film on the back surface (Wb) and the exposure of that film. With the above method, warpage correction can be performed according to the warpage state of each substrate (W) before the treatment for warpage correction is performed.

[0108]

[11] The substrate processing method according to any one of [1] to

[10] above, wherein in the exposure step, exposure light is irradiated from at least some of the plurality of light sources (884) arranged in the first direction (D2) to expose at least a portion of the backside film (F), and irradiating exposure light from at least some of the plurality of light sources (884) includes irradiating exposure light during at least a portion of the period while the substrate (W) is being rotated. In this case, exposure light can be irradiated onto a specific area of ​​the back surface film (F) formed on the back surface (Wb) that is set to extend circumferentially around the center of the substrate (W).

[0109]

[12] The substrate processing method according to any one of [1] to

[11] above, wherein in the exposure step, exposure light is applied to at least a portion of the backside film (F) by irradiating the exposure light from at least a portion of the plurality of light sources (884) arranged in a first direction (D2), and irradiating the exposure light from at least a portion of the plurality of light sources (884) includes irradiating the exposure light during at least a portion of the period during which the substrate (W) is moved along a second direction (D1) intersecting the first direction (D2). In this case, exposure light can be emitted to a specific region of the back surface film (F) formed on the back surface (Wb) that is set to extend in one direction along the back surface (Wb).

[0110]

[13] A program for causing an apparatus to execute the substrate processing method according to any one of [1] to

[12] above. This program executes the substrate processing method described in [1] above, and is therefore useful for facilitating the process of bonding a substrate to another substrate.

[0111]

[14] A substrate processing apparatus (10) comprising: a film forming unit (60, 70) that forms a back surface film (F) that generates stress by exposure on a back surface (Wb) of a substrate having a front surface (Wa) on which a pattern or device structure (D) is formed and a back surface (Wb) facing opposite to the front surface (Wa); and an exposure unit (80) that exposes at least a portion of the back surface film (F) to light so as to reduce warpage of the substrate (W) after the back surface film (F) is formed. This substrate processing apparatus (10) is useful for facilitating the process of bonding a substrate to another substrate, similar to the substrate processing method described in [1] above.

[0112]

[15] The substrate processing apparatus (10) according to the above item

[14] , comprising a loading / unloading block (20) for loading a substrate (W) into the substrate processing apparatus (10) before a back surface film (F) is formed thereon, and for unloading the substrate (W) from the substrate processing apparatus (10) after processing by the film forming section (60, 70) and the exposure section (80). In this case, as with the substrate processing method described in [2] above, this is useful for simplifying the entire apparatus.

[0113]

[16] The substrate processing apparatus (10) described in

[15] above, further comprising: a first inversion unit (50) that inverts the substrate (W) before the back surface film (F) is formed so that the back surface (Wb) faces upward; and a second inversion unit (50) that inverts the substrate (W) after at least a portion of the back surface film (F) has been exposed so that the front surface (Wa) faces upward. In this case, similarly to the substrate processing method described in [3] above, it is easy to supply the processing liquid and the like to the back surface film (F).

[0114]

[17] The substrate processing apparatus (10) according to the above item

[16] , wherein the first reversing unit (50) and the second reversing unit (50) are arranged in a load / unload block (20), and the substrate processing apparatus (10) includes a processing block connected to the load / unload block (20) and including a film forming unit (60, 70), a heat processing unit (70) that heats the back surface film (F), and an exposure unit (80). In this case, similarly to the substrate processing method described in [4] above, it is possible to reduce the number of types of members for supporting the substrate (W) placed in the processing block (30).

[0115]

[18] The substrate processing apparatus (10) according to

[17] above, wherein the film forming unit (60, 70), the thermal processing unit (70), and the exposure unit (80) each have a support member (626, 72, 826) that supports the substrate (W) with the back surface (Wb) facing upward so as not to contact a region of the front surface (Wa) on which a pattern or device structure (D) is formed. In this case, similar to the substrate processing method described in [5] above, various processes can be performed with the back surface (Wb) facing upward, while reducing the impact on the pattern or device structure (D).

[0116]

[19] The substrate processing apparatus (10) according to any one of the above items

[14] to

[18] , further comprising a control unit (100) that acquires the amount of warpage of the substrate (W) before the film forming unit (60, 70) forms the back surface film (F), and changes processing conditions in at least one of the film forming unit (60, 70) and the exposure unit (80) according to the acquired result of the amount of warpage. In this case, similarly to the substrate processing method described in [6] above, it is possible to reduce the difference in the degree of warpage between the substrates (W).

[0117]

[20] The substrate processing apparatus (10) according to any one of

[14] to

[19] above, wherein the exposure unit (80) comprises a rotary holder (82) that holds and rotates the substrate (W), a plurality of light sources (884) that are arranged in a line in a first direction (D2) and emit light for exposure, and a drive unit (85) that moves the rotary holder (82) along a second direction (D1) that intersects with the first direction (D2) so that the substrate (W) crosses the plurality of light sources (884) in a planar view. In this case, exposure light can be irradiated onto at least one of a specific region in the back surface film (F) formed on the back surface (Wb) that is set to extend circumferentially around the center of the substrate (W) and a specific region that is set to extend in one direction along the back surface (Wb). [Explanation of symbols]

[0118] 1...wafer processing system, 10...substrate processing apparatus, 20...loading / unloading block, 30...processing block, 40...measurement unit, 50...inversion unit, 60...liquid processing unit, 70...heat processing unit, 80...exposure unit, 100...control device.

Claims

1. a film forming step of forming a back surface film that generates stress by exposure on the back surface of a substrate having a front surface on which a pattern or device structure is formed and a back surface facing opposite to the front surface; an exposure step of exposing at least a portion of the rear surface film to light after forming the rear surface film so as to reduce warpage of the substrate; A substrate processing method comprising:

2. a carrying-in step of carrying the substrate before the rear surface film is formed into a substrate processing apparatus; and unloading the substrate from the substrate processing apparatus after at least a portion of the rear surface film has been exposed. the film forming step and the exposure step are performed in the substrate processing apparatus. The substrate processing method according to claim 1 .

3. a first inversion step of inverting the substrate before the back surface film is formed so that the back surface faces upward; a second inversion step of inverting the substrate after at least a portion of the back surface film has been exposed so that the front surface faces upward; The substrate processing method according to claim 2 .

4. The method further includes a heating step of heating the substrate after the rear surface film is formed, the substrate processing apparatus includes a load / unload block and a processing block connected to the load / unload block; the carrying-in step, the carrying-out step, the first reversing step, and the second reversing step are performed in the carrying-in / out block; the film forming step, the exposure step, and the heating step are performed in the processing block; The substrate processing method according to claim 3 .

5. In each of the film forming step, the exposure step, and the heating step, the substrate is supported with the back surface facing upward so as not to come into contact with a region of the front surface in which the pattern or the device structure is formed. The substrate processing method according to claim 4 .

6. a measuring step of measuring the amount of warpage of the substrate before the film forming step; and a condition adjusting step of changing processing conditions in at least one of the film forming step and the exposure step according to the measurement result of the amount of warpage. The substrate processing method according to any one of claims 1 to 5.

7. a second measurement step of measuring the amount of warpage of the substrate after the exposure of at least a portion of the rear surface film and the post-exposure heat treatment are performed; The substrate processing method according to claim 6 .

8. an exposure target range in the exposure step is determined in advance, In the condition adjusting step, processing conditions in the exposure step are changed in accordance with the measurement result of the amount of warpage so that an area of ​​the exposure target range to be irradiated with exposure light is changed. The substrate processing method according to claim 6 .

9. In the exposure step, exposure light is emitted from at least some of a plurality of light sources arranged in a first direction, thereby exposing at least a portion of the back surface film; In the condition adjustment step, a ratio of the number of target light sources that emit light for exposure to the number of target light sources that do not emit light for exposure is changed according to the measurement result of the amount of warpage; the two or more target light sources are two or more light sources among the plurality of light sources that are arranged at positions where they can irradiate the exposure target range with light for exposure; The substrate processing method according to claim 8 .

10. In the condition adjusting step, processing conditions in the film forming step are changed in accordance with the measurement result of the amount of warpage so that the thickness of the rear surface film is changed. The substrate processing method according to claim 6 .

11. In the exposure step, exposure light is emitted from at least some of a plurality of light sources arranged in a first direction, thereby exposing at least a portion of the back surface film; irradiating the substrate with exposure light from at least some of the plurality of light sources includes irradiating the substrate with exposure light during at least a portion of a period while the substrate is being rotated; The substrate processing method according to any one of claims 1 to 5.

12. In the exposure step, exposure light is emitted from at least some of a plurality of light sources arranged in a first direction, thereby exposing at least a portion of the back surface film; irradiating the exposure light from at least some of the plurality of light sources includes irradiating the exposure light during at least a portion of a period during which the substrate is moved along a second direction intersecting the first direction; The substrate processing method according to any one of claims 1 to 5.

13. A program for causing an apparatus to execute the substrate processing method according to any one of claims 1 to 5.

14. a film forming unit that forms a back surface film that generates stress by exposure on the back surface of a substrate having a front surface on which a pattern or device structure is formed and a back surface facing opposite to the front surface; an exposure unit that exposes at least a portion of the rear surface film to light after the rear surface film is formed so as to reduce warpage of the substrate; A substrate processing apparatus comprising:

15. a carry-in / out block that carries the substrate into the substrate processing apparatus before the rear surface film is formed, and carries the substrate out of the substrate processing apparatus after the processing by the film forming unit and the exposure unit. The substrate processing apparatus according to claim 14 .

16. a first inversion unit that inverts the substrate before the back surface film is formed so that the back surface faces upward; a second inversion unit that inverts the substrate after at least a portion of the back surface film has been exposed so that the front surface faces upward; The substrate processing apparatus according to claim 15 .

17. the first reversing unit and the second reversing unit are disposed in the carry-in / out block, a processing block connected to the carry-in / out block, in which the film forming unit, a heat processing unit that heats the rear surface film, and the exposure unit are arranged; The substrate processing apparatus of claim 16 .

18. each of the film forming unit, the heat processing unit, and the exposure unit has a support member that supports the substrate with the back surface facing upward so as not to come into contact with a region of the front surface on which the pattern or the device structure is formed; The substrate processing apparatus of claim 17 .

19. a control unit that acquires a warpage amount of the substrate before the formation of the rear surface film by the film formation unit, and changes processing conditions in at least one of the film formation unit and the exposure unit according to the acquired result of the warpage amount; The substrate processing apparatus according to any one of claims 14 to 18.

20. The exposure section a rotation holder that holds and rotates the substrate; a plurality of light sources arranged side by side in a first direction and emitting light for exposure; a drive unit that moves the rotary holder along a second direction that intersects with the first direction so that the substrate crosses the plurality of light sources in a plan view, The substrate processing apparatus according to any one of claims 14 to 18.

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