Substrate processing method and substrate processing system
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Filing Date
- 2024-08-05
- Publication Date
- 2026-05-11
Smart Images
Figure 2025041580000001
Abstract
Description
Substrate processing method and substrate processing system
[0001] The present disclosure relates to a substrate processing method and a substrate processing system.
[0002] Patent Document 1 discloses a substrate processing method including a grinding step of grinding the surface of a substrate, a measurement step of measuring the thickness of the ground substrate, a condition determination step of determining processing conditions for a wet etching process to be performed on the substrate based on the measured thickness of the substrate, and a damaged layer removal step of supplying a processing liquid to the ground substrate based on the determined processing conditions to perform a wet etching process and remove a damaged layer formed on the surface of the substrate.
[0003] International Publication No. 2017 / 018219
[0004] The technology according to the present disclosure appropriately controls the surface shape of a substrate after the surface of the substrate has been ground and etched.
[0005] One aspect of the present disclosure is a substrate processing method for processing a substrate, comprising grinding a surface of a substrate and etching the surface of the substrate after grinding, wherein grinding and etching are performed on the surfaces of a plurality of substrates, and when it is expected that the surface shape of a first substrate after grinding will be different from the surface shape of a second substrate subsequent to the first substrate after grinding, the plurality of substrates are divided into a plurality of groups, with the boundary between the first substrate and the second substrate, and in the group starting with the second substrate, the target thickness after grinding of the first n-th substrate (n is a natural number greater than or equal to 1) is made larger than the target thickness after grinding of the n+1th substrate and thereafter.
[0006] According to the present disclosure, it is possible to appropriately control the surface shape of a substrate after the surface of the substrate has been ground and etched.
[0007] FIG. 1 is a plan view showing an outline of the configuration of a wafer processing system; FIG. 2 is a side view showing an outline of the configuration of an etching apparatus; FIG. 3 is an explanatory diagram showing how a nozzle moves in a radial direction; FIG. 4 is a side view showing an example of the configuration of a grinding unit and a chuck; FIG. 5 is a flow chart showing main steps of wafer processing; FIG. 6 is a flow chart showing main steps of a method for determining optimal etching conditions; FIG. 7 is an explanatory diagram showing how grinding of a first surface of a wafer is controlled; FIG. 8 is an explanatory diagram showing how grinding and etching are performed on both sides of a wafer in one group; and FIG. 9 is an explanatory diagram showing how grinding and etching are performed on one side of a wafer in one group.
[0008] In the manufacturing process of semiconductor devices, the cut surface of a disk-shaped silicon wafer (hereinafter referred to as "wafer") obtained by cutting a single crystal silicon ingot using a wire saw or the like is flattened and further smoothed to make the wafer thickness uniform. The flattening of the cut surface is performed, for example, by surface grinding or lapping. The smoothing is performed, for example, by spin etching, in which an etching solution is supplied from above the cut surface of the wafer while the wafer is rotating.
[0009] The above-mentioned Patent Document 1 discloses that a wet etching process is performed on a ground wafer to remove a damaged layer formed on the surface of the wafer by the grinding process. In the condition determination process described in Patent Document 1, the operation of a nozzle supplying a processing liquid, the rotation speed of the wafer, the supply amount of the processing liquid, the supply time of the processing liquid, the type of the processing liquid, etc. are determined based on the wafer thickness obtained in the measurement process.
[0010] Here, the thickness of the wafer after grinding may not be uniform across the wafer surface. For example, if the center of the wafer after grinding is recessed relative to the outer periphery and the recession is large, when wet etching the wafer surface to make the thickness across the wafer uniform after grinding, the amount of etching at the center will be smaller than the amount of etching at the outer periphery. As described above, one of the purposes of wet etching is to remove a damaged layer on the wafer surface, but in such cases, there is a risk that the damaged layer formed at the center of the wafer surface will not be sufficiently removed.
[0011] The technology disclosed herein appropriately controls the surface shape of a substrate after the surface of the substrate has been ground and etched. Hereinafter, a wafer processing system as a substrate processing system and a wafer processing method as a substrate processing method according to the present embodiment will be described with reference to the drawings. Note that in this specification and the drawings, elements having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.
[0012] In the wafer processing system 1 according to this embodiment, a wafer W serving as a substrate obtained by slicing an ingot is subjected to processing to improve the in-plane thickness uniformity. Hereinafter, the slicing surfaces of the wafer W will be referred to as a first surface Wa and a second surface Wb. The first surface Wa is the surface opposite the second surface Wb. The first surface Wa and the second surface Wb may also be collectively referred to as the surfaces of the wafer W.
[0013] 1, the wafer processing system 1 has a configuration in which a loading / unloading station 2 and a processing station 3 are integrally connected. In the loading / unloading station 2, for example, a cassette C capable of accommodating a plurality of wafers W is loaded and unloaded between the loading / unloading station 2 and the outside. The processing station 3 is equipped with various processing devices that perform desired processing on the wafers W.
[0014] The loading / unloading station 2 is provided with a cassette mounting table 10 on which a plurality of cassettes C, e.g., three cassettes C, can be mounted. A wafer transfer device 20 is provided adjacent to the cassette mounting table 10 on the negative side of the X-axis. The wafer transfer device 20 is configured to be movable on a transfer path 21 extending in the Y-axis direction. The wafer transfer device 20 also has, for example, two transfer arms 22, 22 that hold and transfer wafers W. Each transfer arm 22 is configured to be movable horizontally, vertically, around a horizontal axis, and around a vertical axis. The configuration of the transfer arms 22 is not limited to this embodiment and may have any configuration. The wafer transfer device 20 is configured to be able to transfer wafers W to the cassettes C on the cassette mounting table 10 and to a transition device 30, which will be described later.
[0015] In the loading / unloading station 2 , a transition device 30 for transferring the wafer W to and from the processing station 3 is provided adjacent to the wafer transfer device 20 on the negative side of the X axis of the wafer transfer device 20 .
[0016] For example, three processing blocks G1 to G3 are provided in the processing station 3. The first processing block G1, the second processing block G2, and the third processing block G3 are arranged in this order from the positive side of the X axis (the side of the loading / unloading station 2) to the negative side.
[0017] The first processing block G1 is provided with an etching device 40, a thickness measurement device 50, a reversing device 51, and a wafer transfer device 60. The etching device 40, the thickness measurement device 50, and the reversing device 51 are arranged in a stacked configuration. Note that the number and arrangement of the etching device 40, the thickness measurement device 50, and the reversing device 51 are not limited to this.
[0018] The etching device 40 etches silicon (Si) on the first surface Wa or the second surface Wb after grinding by the grinding device 90 described below. In order to improve the throughput of wafer processing, a plurality of etching devices 40 may be provided.
[0019] As shown in FIG. 2, the etching device 40 includes a wafer holder 41 , a rotating mechanism 42 , a nozzle 43 , and a moving mechanism 44 .
[0020] The wafer holding unit 41 holds the outer edge of the wafer W at multiple points, three points in this embodiment. The configuration of the wafer holding unit 41 is not limited to the example shown in the figure, and for example, the wafer holding unit 41 may include a chuck (not shown) that suction-holds the wafer W from below. The wafer holding unit 41 is configured to be rotatable about a vertical rotation center line 41a by a rotation mechanism 42, thereby allowing the wafer W held on the wafer holding unit 41 to rotate.
[0021] The nozzle 43 supplies the etching liquid E to the first surface Wa or the second surface Wb of the wafer W held by the wafer holder 41. The nozzle 43 is connected to an etching liquid supply source (not shown) that supplies the etching liquid E to the nozzle 43. The nozzle 43 is provided above the wafer holder 41 and configured to be movable in the horizontal and vertical directions by a movement mechanism 44. In one example, the nozzle 43 is configured to be capable of reciprocating movement (scan movement) or swiveling along a rotation center line 41 a of the wafer holder 41, i.e., above the center of the wafer W as shown in FIG. 3 .
[0022] The etching solution E contains hydrofluoric acid (HF), nitric acid (HNO ３ ) and phosphoric acid (H ３ P.O. ４ In one example, the etching solution E is a mixed solution containing hydrofluoric acid, nitric acid, phosphoric acid, and water. The etching target may be, for example, amorphous silicon.
[0023] The thickness measurement device 50 shown in FIG. 1 includes, in one example, a measurement unit (not shown) and a calculation unit (not shown). The measurement unit includes a sensor that measures the thickness of the wafer W after etching at multiple points. The calculation unit acquires the thickness distribution of the wafer W from the measurement results (thickness of the wafer W) obtained by the measurement unit, and further calculates the thickness deviation (TTV: Total Thickness Variation) of the wafer W. The thickness deviation of the wafer W is the difference between the thickness of the target shape and the measured thickness. Note that the calculation of the thickness distribution and thickness deviation of the wafer W may be performed by the control device 120 described below instead of the calculation unit. In other words, a calculation unit (not shown) may be provided within the control device 120 described below. Note that the configuration of the thickness measurement device 50 is not limited to this and may be configured as desired.
[0024] The reversing device 51 vertically reverses the first surface Wa and the second surface Wb of the wafer W. The reversing device 51 may have any configuration.
[0025] The wafer transfer device 60 is disposed on the negative side of the transition device 30 in the X-axis direction. The wafer transfer device 60 has, for example, two transfer arms 61, 61 that hold and transfer a wafer W. Each transfer arm 61 is configured to be movable horizontally, vertically, around a horizontal axis, and around a vertical axis. The wafer transfer device 60 is configured to be able to transfer the wafer W to the transition device 30, the etching device 40, the thickness measurement device 50, the inversion device 51, the cleaning device 70 described below, the thickness measurement device 71 described below, the buffer device 72 described below, and the inversion device 73 described below.
[0026] The second processing block G2 is provided with a cleaning device 70, a thickness measuring device 71, a buffer device 72, an inverting device 73, and a wafer transfer device 80. The cleaning device 70, the thickness measuring device 71, the buffer device 72, and the inverting device 73 are arranged in a stacked configuration. Note that the number and arrangement of the cleaning devices 70, the thickness measuring devices 71, the buffer device 72, and the inverting device 73 are not limited to this.
[0027] The cleaning device 70 cleans at least the first surface Wa or the second surface Wb after grinding by the grinding device 90 described below.
[0028] In one example, the thickness measuring device 71 has the same configuration as the above-described thickness measuring device 50. However, the configuration of the thickness measuring device 71 is not limited to this, and can be configured arbitrarily.
[0029] The buffer device 72 temporarily holds unprocessed wafers W that are transferred from the first processing block G1 to the second processing block G2. The configuration of the buffer device 72 is arbitrary. The buffer device 72 may also include an alignment mechanism (not shown) that adjusts the center position of the wafer W relative to chucks 93 a, 93 b (described later) and / or the horizontal orientation of the wafer W.
[0030] The reversing device 73 vertically reverses the first surface Wa and the second surface Wb of the wafer W. The reversing device 73 may have any configuration.
[0031] The wafer transfer device 80 is disposed, for example, on the Y-axis positive side of the cleaning device 70, the thickness measurement device 71, the buffer device 72, and the inverting device 73. The wafer transfer device 80 has, for example, two transfer arms 81, 81 that suction-hold and transport the wafer W using a suction-holding surface (not shown). Each transfer arm 81 is supported by an articulated arm member 82 and is configured to be movable horizontally, vertically, around a horizontal axis, and around a vertical axis. The wafer transfer device 80 is configured to be able to transport the wafer W to the etching device 40, the thickness measurement device 50, the inverting device 51, the cleaning device 70, the thickness measurement device 71, the buffer device 72, the inverting device 73, and a grinding device 90, which will be described later.
[0032] The third processing block G3 is provided with a grinding device 90. The grinding device 90 grinds and flattens the first surface Wa or the second surface Wb of the wafer W.
[0033] The grinding apparatus 90 has a rotary table 91. The rotary table 91 is configured to be rotatable about a vertical rotation center line 92 by a rotation mechanism (not shown). Four chucks 93a, 93b are provided on the rotary table 91 as substrate holders that suction-hold the wafer W. Porous chucks, for example, are used for the chucks 93a, 93b. The surfaces of the chucks 93a, 93b, i.e., the holding surfaces for the wafer W, have a convex shape in which the central portion protrudes compared to the outer periphery in a side view. Note that although this protrusion in the central portion is minute, in the following description, the protrusion in the central portion of the chucks 93a, 93b may be illustrated exaggerated for clarity.
[0034] Of the four chucks 93a, 93b, two first chucks 93a are chucks used for grinding at a first processing position B1, which will be described later. These two first chucks 93a are arranged in positions that are point-symmetrical with respect to the rotation center line 92. The remaining two second chucks 93b are chucks used for grinding at a second processing position B2, which will be described later. These two second chucks 93b are also arranged in positions that are point-symmetrical with respect to the rotation center line 92. In other words, the first chucks 93a and the second chucks 93b are arranged alternately in the circumferential direction.
[0035] As shown in FIG. 4 , the four chucks 93a, 93b are respectively held by four chuck bases 94. The chuck base 94 is provided with a tilt adjustment mechanism 95 that adjusts the relative tilt between the grinding units 101, 111 (described later) and the chucks 93a, 93b. The tilt adjustment mechanism 95 has a fixed shaft 96 provided on the underside of the chuck base 94 and multiple, for example, two, lift shafts 97. Each lift shaft 97 is configured to be extendable and retractable, and raises and lowers the chuck base 94. The tilt adjustment mechanism 95 tilts the chucks 93a, 93b and the chuck base 94 by vertically raising and lowering the other end of the chuck base 94 using one end of the outer periphery of the chuck base 94 (a position corresponding to the fixed shaft 96) as a base point. This allows the relative tilt between the grinding surfaces of the grinding units 101, 111 at processing positions B1 to B2 (described later) and the upper surfaces of the chucks 93a, 93b to be adjusted. The configuration of the tilt adjustment mechanism 95 is not limited to this, and it is sufficient if it can adjust the relative angle (parallelism) of the surfaces (holding surfaces) of the chucks 93a and 93b with respect to the grinding surfaces of the grinding portions 101 and 111.
[0036] 1, the four chucks 93a, 93b can be moved to delivery positions A1-A2 and processing positions B1-B2 by rotating the rotary table 91. Furthermore, each of the four chucks 93a, 93b is configured to be rotatable about a vertical axis by a rotation mechanism (not shown).
[0037] The first transfer position A1 is located on the positive X-axis side and the positive Y-axis side of the rotation center line 92 of the turntable 91, where the wafer W is transferred to the first chuck 93a when the first surface Wa is ground. The second transfer position A2 is located on the positive X-axis side and the negative Y-axis side of the rotation center line 92 of the turntable 91, where the wafer W is transferred to the second chuck 93b when the second surface Wb is ground.
[0038] First processing position B1 is a position on the negative X-axis side and the negative Y-axis side with respect to rotation center line 92 of turntable 91, and first grinding unit 100 is disposed thereat. First grinding unit 100 grinds, for example, first surface Wa or second surface Wb of wafer W held by first chuck 93 a.
[0039] As shown in FIG. 4 , the first grinding unit 100 has a grinding section 101. The grinding section 101 has a grinding stone 102, a grinding wheel 103, a mount 104, a spindle 105, and a drive section 106. The grinding wheel 103 has an annular shape and supports the grinding stone 102 on its underside. The mount 104 supports the grinding wheel 103. The spindle 105 rotates the grinding wheel 103 and the grinding stone 102 via the mount 104. The drive section 106 is attached to the spindle 105 and incorporates, for example, a motor (not shown), which rotates the spindle 105. As shown in FIG. 1 , the grinding section 101 is configured to be movable vertically along a support 107 by a drive section (not shown).
[0040] The second processing position B2 is a position on the negative X-axis side and the positive Y-axis side with respect to the rotation center line 92 of the rotary table 91, and the second grinding unit 110 is disposed thereat. The second grinding unit 110 grinds, for example, the second surface Wb or the first surface Wa of the wafer W held by the second chuck 93b. The second grinding unit 110 has the same configuration as the first grinding unit 100.
[0041] As described above, the holding surfaces of the chucks 93 a, 93 b have a convex shape. Therefore, when the wafer W is ground using the grinding units 100, 110, the annularly arranged grinding wheels 102, 112 contact the wafer W in an arc-shaped line from the center to the outer periphery. In this state, the entire surface of the wafer W is ground by rotating the chucks 93 a, 93 b and the grinding wheels 103, 113, respectively.
[0042] In addition, in the grinding units 100, 110, the tilt adjustment mechanism 95 described above adjusts the relative angle (tilt) between the holding surfaces of the chucks 93a, 93b and the grinding surfaces of the grinding wheels 102, 112, thereby controlling the shape of the wafer W after grinding to any one of flat, convex, concave, W-shaped, M-shaped, or a combination of any two of these. The flat shape is a shape in which the entire surface of the wafer W is adjusted to a desired thickness deviation (TTV) or less, preferably a shape in which the thickness is controlled to be uniform over the entire surface. The convex shape is a shape in which the thickness at the center of the wafer W is greater than the thickness at the outer periphery. The concave shape is a shape in which the thickness at the central concave portion of the wafer W is smaller than the thickness at the outer periphery. The W shape is a shape in which the thickness at the radial center point of the wafer W is smaller than the thickness at the center and outer periphery. The M shape is a shape in which the thickness at the radial center point of the wafer W is greater than the thickness at the center and outer periphery.
[0043] A thickness measuring device (not shown) for measuring the thickness of the wafer W after grinding may be provided at the transfer positions A1, A2 or the processing positions B1, B2.
[0044] The wafer processing system 1 described above is provided with at least one controller 120. The controller 120 processes computer-executable instructions that cause the wafer processing system 1 to perform the various steps described in this disclosure. The controller 120 may be configured to control each element of the wafer processing system 1 to perform the various steps described herein. In one embodiment, some or all of the controller 120 may be included in the wafer processing system 1. The controller 120 may include a processing unit, a storage unit, and a communication interface. The controller 120 may be implemented, for example, by a computer. The processing unit may be configured to read from the storage unit a program that provides logic or routines that enable various control operations to be performed, and to execute the read program to perform various control operations. This program may be stored in the storage unit in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit and read from the storage unit by the processing unit for execution. The medium may be various computer-readable storage media or a communication line connected to the communication interface. The storage medium may be temporary or non-temporary. The processing unit may be a CPU (Central Processing Unit) or one or more circuits. The storage unit may include a RAM (Random Access Memory), a ROM (Read Only Memory), a HDD (Hard Disk Drive), an SSD (Solid State Drive), or a combination thereof. The communication interface may communicate with the wafer processing system 1 via a communication line such as a LAN (Local Area Network).
[0045] Next, wafer processing performed using the wafer processing system 1 configured as described above will be described. In this embodiment, processing is performed on a wafer W cut from an ingot using a wire saw or the like, or a lapped wafer W, to improve the in-plane thickness uniformity. Furthermore, in this embodiment, a case will be described in which the target shape of the wafer W after a series of processing is a flat type. This flat type refers to a shape in which the thickness is uniform within the wafer surface, and includes, for example, a case in which both surfaces of the wafer W are horizontal, as well as a case in which the both surfaces are not horizontal.
[0046] First, a cassette C containing a plurality of wafers W is placed on the cassette mounting table 10 of the carry-in / out station 2. In the cassette C, the wafers W are stored with their first surfaces Wa facing upward and their second surfaces Wb facing downward. Next, the wafer transfer device 20 removes the wafers W from the cassette C and transfers them to the transition device 30. The wafers W transferred to the transition device 30 are then transferred to the buffer device 72 by the wafer transfer device 60.
[0047] Next, the wafer W is transferred to the grinding device 90 by the wafer transfer device 80 and transferred to the first chuck 93a at the first transfer position A1. The second surface Wb of the wafer W is held by suction on the first chuck 93a.
[0048] Next, the rotary table 91 is rotated to move the wafer W to the first processing position B1, and the first surface Wa of the wafer W is then ground by the first grinding unit 100 (S1 in FIG. 5).
[0049] Next, the rotary table 91 is rotated to move the wafer W to the first delivery position A1.
[0050] Next, the wafer W is transferred to the cleaning device 70 by the wafer transfer device 80. In the cleaning device 70, the first surface Wa of the wafer W is cleaned (S2 in FIG. 5). In S2, the second surface Wb of the wafer W may also be cleaned.
[0051] Next, the wafer W is transferred to the thickness measuring device 71 by the wafer transfer device 80 or the wafer transfer device 60. The thickness measuring device 71 measures the thickness of the wafer W at multiple points after grinding the first surface Wa, thereby obtaining the thickness distribution of the wafer W, and further calculates the thickness deviation of the wafer W (S3 in FIG. 5). The calculated thickness distribution and thickness deviation of the wafer W are output to, for example, the control device 120. Note that if the grinding device 90 is provided with a thickness measuring device, the thickness of the wafer W after grinding may be measured by the thickness measuring device of the grinding device 90.
[0052] Here, the grinding of the first surface Wa in S1 is performed, for example, so that the thickness of the wafer W after grinding is uniform across the wafer surface and the shape of the wafer W is flat. However, the shape of the wafer W after grinding may not be flat due to, for example, wear of the grinding wheel 102, the parallelism between the first chuck 93a and the grinding wheel 102, or other device characteristics.
[0053] Therefore, the control device 120 determines the relative tilt (parallelism) between the first chuck 93a and the grinding wheel 102 based on the thickness distribution and thickness deviation of the wafer W acquired in S3 so as to offset the worsening tendency of the thickness deviation of the wafer W. Then, the tilt adjustment mechanism 95 adjusts the relative tilt between the first chuck 93a and the grinding wheel 102 (S4 in FIG. 5). Hereinafter, adjusting the tilt of the first chuck 93a in this manner will be referred to as tilt axis correction of the first chuck 93a. In this case, the first surface Wa of the wafer W to be ground next in the first grinding unit 100 can be flattened, and the thickness deviation of the wafer W can be kept small.
[0054] Next, the wafer W is transferred to the reversing device 73 by the wafer transfer device 80. In the reversing device 73, the first surface Wa and the second surface Wb of the wafer W are reversed upside down (S5 in FIG. 5). That is, the wafer W is reversed so that the first surface Wa faces downward and the second surface Wb faces upward.
[0055] Next, the wafer W is transferred to the grinding device 90 by the wafer transfer device 80 and transferred to the second chuck 93b at the second transfer position A2. The first surface Wa of the wafer W is held by suction on the second chuck 93b.
[0056] Next, the rotary table 91 is rotated to move the wafer W to the second processing position B2, and the second surface Wb of the wafer W is then ground by the second grinding unit 110 (S6 in FIG. 5).
[0057] Next, the rotary table 91 is rotated to move the wafer W to the second delivery position A2.
[0058] Next, the wafer W is transferred to the cleaning device 70 by the wafer transfer device 80. In the cleaning device 70, the second surface Wb of the wafer W is cleaned (S7 in FIG. 5). In S7, the first surface Wa of the wafer W may also be cleaned.
[0059] Next, the wafer W is transferred to the thickness measuring device 71 by the wafer transfer device 80 or the wafer transfer device 60. The thickness measuring device 71 measures the thickness of the wafer W at multiple points after grinding the second surface Wb to obtain the thickness distribution of the wafer W, and further calculates the thickness deviation of the wafer W (S8 in FIG. 5). The calculated thickness distribution and thickness deviation of the wafer W are output to, for example, the control device 120. Note that if the grinding device 90 is provided with a thickness measuring device, the thickness of the wafer W after grinding may be measured by the thickness measuring device of the grinding device 90.
[0060] The control device 120 determines the relative tilt (parallelism) between the second chuck 93b and the grinding wheel 112 based on the thickness distribution and thickness deviation of the wafer W acquired in S8, and the tilt adjustment mechanism 95 corrects the tilt axis of the second chuck 93b (S9 in FIG. 5). Note that S9 is the same as S4 described above. In this case, the second surface Wb of the wafer W to be ground next in the second grinding unit 110 can be flattened, and the thickness deviation of the wafer W can be kept small.
[0061] Next, the wafer W is transferred by the wafer transfer device 60 to the etching device 40. In the etching device 40, the second surface Wb of the wafer W is etched with the etching solution E under predetermined etching conditions (S10 in FIG. 5). In S10, the second surface Wb is etched under the predetermined etching conditions, thereby processing the second surface Wb into a target shape.
[0062] Next, the wafer W is transferred to the reversing device 51 by the wafer transfer device 60. In the reversing device 51, the first surface Wa and the second surface Wb of the wafer W are reversed upside down (S11 in FIG. 5). That is, the wafer W is reversed so that the first surface Wa faces upward and the second surface Wb faces downward.
[0063] Next, the wafer W is transferred by the wafer transfer device 60 to the thickness measurement device 50. The thickness measurement device 50 measures the thickness of the wafer W at multiple points after etching the second surface Wb to obtain the thickness distribution of the wafer W, and further calculates the thickness deviation of the wafer W (S12 in FIG. 5). The calculated thickness distribution and thickness deviation of the wafer W are output to, for example, the control device 120.
[0064] The control device 120 determines optimal etching conditions for the first surface Wa, which optimize the etching amount distribution in the etching process on the first surface Wa, from the output thickness distribution and thickness deviation of the wafer W (S13 in FIG. 5). In S13, the following S130 to S133 are performed to determine the optimal etching conditions.
[0065] First, a plurality of learning data to be used in the optimization process described below is acquired (S130 in FIG. 6) before processing is performed on the wafer W in the wafer processing system 1. The learning data is an etching amount distribution of the wafer W under certain etching conditions.
[0066] In S130, the dummy wafer is etched under, for example, a plurality of different etching conditions. Specifically, the dummy wafer is etched by changing, for example, the rotation speed (also referred to as the number of rotations) of the dummy wafer during etching, the scanning speed (also referred to as the swing speed) of the nozzle 43, the scanning width (see the scanning width L in FIG. 3 , also referred to as the swing radius) of the nozzle 43, or the number of loops of the nozzle 43. In this case, the etching time for each dummy wafer is the same. The dummy wafer is etched by rotating the dummy wafer and supplying etching solution E from the nozzle 43 to the dummy wafer while the nozzle 43 is reciprocating, similar to the etching in S14 described below. In the following description, the reciprocating movement of the nozzle 43 between both ends of the dummy wafer is considered to be one loop.
[0067] Etching of the dummy wafer under each etching condition is carried out for a predetermined desired time (desired number of loops). Then, the etching amount distribution of the dummy wafer is acquired and output to the control device 120. Furthermore, the control device 120 compresses the output etching amount distribution under each etching condition into an etching amount distribution per unit time (unit number of loops), and stores each compressed etching amount distribution as the learning data.
[0068] Next, a target etching amount distribution for the etching process in S14, which will be described later, is obtained based on the thickness distribution in the target shape of the wafer W after etching and the thickness distribution in the surface shape of the wafer W after etching (hereinafter referred to as the "measured shape") obtained in S12 (S131 in FIG. 6). The target etching amount distribution for the etching process can be obtained, for example, by calculating the difference between the thickness distribution in the target shape of the wafer W and the thickness distribution in the measured shape.
[0069] Next, the learning data to be used for superimposition and the number of times the learning data is superimposed are optimized using an optimization method so that the multiple learning data are superimposed to achieve the target etching amount distribution obtained in S131 (S132 in FIG. 6).
[0070] In S132, for example, the control of the etching amount distribution is applied to a knapsack problem, and the number of times that the learning data is overlapped with the learning data is optimized. For example, the etching amount distribution is the knapsack in the knapsack problem, and the learning data is the item in the knapsack problem. Then, the number of times that the learning data is overlapped with the learning data is optimized so that the difference between the overlapped etching amount distribution and the target etching amount distribution is minimized.
[0071] Next, the etching conditions corresponding to the learning data optimized in S132 are integrated to determine the optimal etching conditions (S133 in FIG. 6). Specifically, the optimal etching conditions are determined by integrating the selected etching conditions so that the optimal number of overlaps is used. In other words, the optimal etching conditions that optimize the etching amount distribution are determined.
[0072] Next, the wafer W is transferred by the wafer transfer device 60 to the etching device 40. In the etching device 40, the first surface Wa of the wafer W is etched with the etching solution E under the optimal etching conditions determined in S13 (S14 in FIG. 5). In S14, by etching the first surface Wa under the optimal etching conditions, the etching amount distribution is optimized and the first surface Wa is processed into a target shape.
[0073] Next, the wafer W is transferred by the wafer transfer device 60 to the thickness measurement device 50. The thickness measurement device 50 measures the thickness of the wafer W at multiple points on both the first surface Wa and the second surface Wb after etching to obtain the thickness distribution of the wafer W (S15 in FIG. 5). Furthermore, the thickness deviation of the wafer W may be calculated. The calculated thickness distribution of the wafer W is output to, for example, the control device 120, and is used, for example, in processing another wafer W to be processed next in the wafer processing system 1.
[0074] Thereafter, the wafer W that has been subjected to all the processes is transferred to the cassette C on the cassette mounting table 10 via the transition device 30. In this way, a series of wafer processes in the wafer processing system 1 is completed.
[0075] According to this embodiment, among the plurality of wafers W to be continuously processed, the mth wafer W (m is a natural number of 1 or more) ｍ On the other hand, the wafer W obtained in S3 ｍ Based on the thickness distribution and thickness deviation of the wafer W, the tilt axis of the first chuck 93a is corrected in step S4. ｍ＋１ On the other hand, when the first surface Wa is ground in S1, the first surface Wa is flattened, and the wafer W ｍ＋１ Similarly, the thickness deviation of the m-th wafer W can be suppressed to a small value. ｍ On the other hand, the wafer W obtained in S8 ｍ Based on the thickness distribution and thickness deviation of the wafer W, the tilt axis of the second chuck 93b is corrected in step S9. ｍ＋１ On the other hand, in S1, the wafer W after the first surface Wa is ground is ｍ＋１ The thickness deviation can be kept small.
[0076] Furthermore, according to this embodiment, the m-th wafer W ｍ On the other hand, the wafer W obtained in S12 ｍ In S13, the optimum etching conditions for the first surface Wa are determined based on the thickness distribution and thickness deviation of the wafer W. ｍ By etching the first surface Wa under the optimum etching conditions, the distribution of the amount of etching can be optimized, and the first surface Wa can be processed into a target shape.
[0077] In the above embodiment, the second surface Wb is etched in S10, and then the first surface Wa is etched in S14. However, the order of etching these surfaces may be reversed. For example, between S7 and S8 or between S8 and S10, the first surface Wa and the second surface Wb of the wafer W are inverted upside down. That is, the wafer W is inverted so that the second surface Wb faces downward and the first surface Wa faces upward. Thereafter, the first surface Wa is etched, and then the second surface Wb is etched.
[0078] In the above embodiment, the etching amount distribution is used as the etching index distribution (learning data) for controlling the etching process of the wafer W. However, an etching amount deviation distribution may also be used. The etching amount deviation distribution is a distribution of values obtained by subtracting the average value of the etching amount from the etching amount within the wafer surface. In such a case, when determining the optimal etching conditions in S13, the etching amount deviation distribution is used instead of the etching amount distribution.
[0079] In the above embodiment, the acquisition of the plurality of learning data in S130 is performed in the wafer processing system 1, but it may be performed outside the wafer processing system 1. In such a case, the control device 120 determines the optimal etching conditions based on the plurality of learning data acquired outside the wafer processing system 1.
[0080] Here, when performing the processes S1 to S15 on a plurality of wafers W, there is a case where, after the continuous processing of a first group of wafers W has been performed, a predetermined interval is then passed and the continuous processing of a second group of wafers W is performed. The number of wafers W in the first group and the second group is not particularly limited, but an example is 25 wafers in one lot. Furthermore, in this embodiment, the last wafer W in the first group corresponds to the first substrate in this disclosure, and the first wafer W in the second group corresponds to the second substrate in this disclosure.
[0081] In the first group, tilt axis correction of the first chuck 93a is performed in S4 for each wafer W. Then, for at least the second and subsequent wafers W, by grinding the first surface Wa using the first chuck 93a after the tilt axis correction, the first surface Wa of the wafer W after grinding can be flattened, and the thickness deviation of the wafer W (hereinafter referred to as "thickness deviation after grinding") can be suppressed to a small value.
[0082] In this regard, in the second group, which is an interval from the first group, when the first surface Wa of the first wafer W is ground in S1, the first surface Wa of the wafer W after grinding is not flat, and the thickness deviation after grinding of the wafer W (=De １ -Dc １In the illustrated example, the shape of the wafer W (first surface Wa) after grinding is such that the thickness Dc at the center １ is the thickness at the outer periphery De １ It is a small concave shape compared to the
[0083] Here, the main factor that causes the thickness deviation after grinding of the first wafer W in the second group to worsen when an interval is long is heat accumulation at the processing point when the first surface Wa is ground. When the first surface Wa of the wafer W held by the first chuck 93 a is ground by the grinding unit 101, heat accumulation due to processing load occurs in each axis, such as the lifting shaft 97 of the tilt adjustment mechanism 95, the axis that rotates the first chuck 93 a, and the spindle 105 of the grinding unit 101.
[0084] In this regard, in the first group, since multiple wafers W are processed consecutively, each axis becomes fully extended due to heat accumulation, and grinding of the first surface Wa is stabilized for at least the second and subsequent wafers W.
[0085] Furthermore, the tilt axis of the first chuck 93a is corrected in S4 for the last wafer W in the first group. That is, the tilt axis of the first chuck 93a is corrected in a state in which each axis is fully extended due to heat accumulation. However, if an interval elapses after the first group, when the first surface Wa of the first wafer W in the second group is ground, each axis, such as the lift shaft 97, the rotation axis of the first chuck 93a, and the spindle 105, cools and contracts. As a result, the relative tilt between the first chuck 93a and the grinding wheel 102 may not be properly adjusted, and the first surface Wa of the first wafer W may not be properly ground. As a result, the thickness deviation of the wafer W after grinding worsens, as described above, and the wafer W may have a concave shape.
[0086] The interval time is, more specifically, the time from the end of grinding the last wafer W of the first group to the start of grinding the first wafer W of the second group, and is equal to or longer than a predetermined time. The predetermined time that worsens the post-grinding thickness deviation of the first wafer W of the second group mainly depends on the amount of heat accumulated at the processing point. The amount of heat accumulated varies depending on various factors. For example, the longer the time it takes to grind multiple wafers W, the greater the amount of heat accumulated. Also, for example, the greater the load when grinding multiple wafers W, the greater the amount of heat accumulated.
[0087] In addition to the heat accumulation described above, another factor that may cause the thickness deviation after grinding of the first wafer W in the second group to worsen is a change in the cutting edge condition of the grinding wheel 102. If the cutting edge condition of the grinding wheel 102 changes and deteriorates, the thickness deviation after grinding of the wafer W will worsen.
[0088] As described above, the first wafer W of the second group has a concave shape in which the center is more polished than the target shape (flat type), and then in S14, the first surface Wa of the wafer W is etched. In this case, the target thickness of the wafer W after etching is set to D ２ Then, the etching amount of the outer periphery (= De １ -D ２ ) compared to the etching amount in the center (= Dc １ -D ２ In particular, when the thickness deviation (depression amount) after grinding is large, the etching amount at the center of the wafer W becomes small, and there is a risk that the damaged layer formed at the center cannot be sufficiently removed.
[0089] Therefore, as shown in FIG. 7B, the target thickness of the first wafer W in the second group when grinding the first surface Wa is increased. In this example, since the shape of the first wafer W after grinding is a concave shape, the target thickness Ec of the central portion of the first wafer W is set to 1 / 2. １ is set to be larger than the target thickness of the second and subsequent wafers W. In this way, the target thickness Ee of the outer periphery of the first wafer W is １ The target thickness of the second and subsequent wafers W will also be larger than the target thickness of the second and subsequent wafers W. The target thickness of the second and subsequent wafers W is the same as the target thickness when the first surface Wa is ground normally.
[0090] Target thickness Ec of the center of the first wafer W １ is, for example, the target thickness E of the wafer W after subsequent etching. ２ In this case, when etching the first surface Wa of the first wafer W, the etching amount (=Ec １ -E ２ ) can be ensured, and the damaged layer formed in the central portion can be sufficiently removed. At this time, the etching amount of the first wafer W is greater than the etching amount of the second and subsequent wafers W.
[0091] In this embodiment, a plurality of wafers W are processed based on the above findings obtained by the inventors through extensive research. Specifically, first, a plurality of wafers W to be processed are divided into a plurality of groups, each divided into groups spaced apart by an interval of, for example, a predetermined time or more. That is, in each group, the thickness deviation after grinding the first surface Wa or the second surface Wb of at least the first wafer W is poor. Below, a case where a plurality of wafers W in one group are continuously processed will be described. Also, the nth (n is a natural number equal to or greater than 1) wafer W to be processed in one group is called a wafer W. ｎ It is written as follows.
[0092] As shown in FIG. １ On the other hand, when the first surface Wa is ground in S1, the shape of the first surface Wa after grinding becomes a concave shape. Subsequently, in S4, the tilt axis of the first chuck 93a is corrected based on the thickness distribution and thickness deviation of the wafer W after grinding. Then, the tilt axis of the second wafer W is corrected. ２ On the other hand, since the first surface Wa is ground in S1 using the first chuck 93a after the tilt axis correction, the shape of the first surface Wa after grinding becomes flat.
[0093] In addition, the wafer W １ On the other hand, when the second surface Wb is ground in S6, the shape of the second surface Wb after grinding becomes a concave shape. Subsequently, in S9, the tilt axis of the second chuck 93b is corrected based on the thickness distribution and thickness deviation of the wafer W after grinding. ２On the other hand, since the second surface Wb is ground in S6 using the second chuck 93b after the tilt axis correction, the shape of the second surface Wb after grinding becomes flat.
[0094] Here, the wafer W １ The thickness before grinding is T １０ The target thickness of the center of the first surface Wa after grinding is Tc １１ , the target thickness of the outer periphery is Te １１ The target thickness of the center of the second surface Wb after grinding is Tc １２ , the target thickness of the outer periphery is Te １２ In addition, the wafer W ２ The thickness before grinding is T ２０ The target thickness after grinding the first surface Wa is T ２１ The target thickness after grinding the second surface Wb is T ２２ Let's say.
[0095] In this embodiment, the wafer W １ Target thickness Tc of the center after double-sided grinding １２ , wafer W ２ Target thickness T after double-sided grinding ２２ Same as or target thickness T ２２ Then, the wafer W １ The target thickness Te of the outer periphery after double-side grinding １２ Wafer W ２ Target thickness T after double-sided grinding ２２ In such a case, for example, the wafer W １ The amount of grinding on both sides of the wafer W ２ The amount of grinding on both sides of the wafer W may be less than that of the wafer W. １ The amount of grinding on one side of the wafer W ２ The amount of grinding on one side may be less than that of the other side.
[0096] For example, a wafer W １ When reducing the amount of grinding on both sides of the wafer W １ The grinding amount (=T １０ -Tc １１ ) to the wafer W ２ The grinding amount of the first surface Wa (=T ２０ -Tc ２１ ) and the wafer W １The grinding amount of the center of the second surface Wb (= Tc １１ -Tc １２ ) also wafer W ２ The grinding amount of the first surface Wa (=T ２１ -Tc ２２ In this case, the wafer W １ The grinding times for both surfaces are balanced, making it easy to control the grinding of both surfaces.
[0097] Also, for example, a wafer W １ When the amount of grinding on one side of the wafer W is reduced, １ The grinding amount (=T １０ -Tc １１ ) to the wafer W ２ The grinding amount of the first surface Wa (=T ２０ -Tc ２１ ) and the wafer W １ The grinding amount of the center of the second surface Wb (= Tc １１ -Tc １２ ) to the wafer W ２ The grinding amount of the first surface Wa (=T ２１ -Tc ２２ In this case, the wafer W １ Therefore, the amount of wear of the grinding wheel 102 that grinds the first surface Wa can be reduced.
[0098] In addition, the wafer W １ The amount of grinding at the center of the first surface Wa of the wafer W ２ The amount of grinding of the first surface Wa of the wafer W １ The amount of grinding at the center of the second surface Wb of the wafer W ２ In this case, the amount of grinding of the wafer W may be less than the amount of grinding of the first surface Wa. １ This reduces the amount of wear of the grinding wheel 112 that grinds the second surface Wb.
[0099] Next, the wafer W １ On the other hand, when the second surface Wb is etched in S10, the shape of the second surface Wb after etching becomes flat. １ The target thickness of the center of １３ , the target thickness of the outer periphery is Te １３The wafer W after grinding the second surface Wb is １ Target thickness Tc of the center １２ is the target thickness Tc of the central portion after etching １３ The thickness of the wafer W is larger than the thickness of the damaged layer. １ When etching the second surface Wb of the wafer W, a sufficient etching amount (=Tc １２ -Tc １３ ) can be secured, and the damaged layer formed in the central portion can be sufficiently removed. １ The etching amount of the second surface Wb (=Tc １２ -Tc １３ ) is the wafer W ２ The etching amount of the second surface Wb (=T ２２ -T ２３ ) will be more.
[0100] In addition, the wafer W １ On the other hand, when the first surface Wa is etched in S14, the shape of the first surface Wa after etching becomes flat. １ The target thickness is T １４ The second surface Wb is the surface of the wafer W after etching. １ Target thickness Tc of the center １３ is the target thickness after etching T １４ The thickness of the wafer W is larger than the thickness of the damaged layer. １ When etching the second surface Wb of the wafer W, a sufficient etching amount (=Tc １３ -T １４ ) can be secured, and the damaged layer formed in the central portion can be sufficiently removed. １ The etching amount of the first surface Wa (=Tc １３ -T １４ ) is the wafer W ２ The etching amount of the first surface Wa (=T ２３ -T ２４ ) will be more.
[0101] As described above, the first wafer W １ When both sides of the wafer W are ground and etched,１ The shape of the is flat and its thickness is T １４ This wafer W １ Thickness T １４ is the second wafer W ２ Thickness T ２４ In addition, the second and subsequent wafers W ２ In the processes of S1 to S15, after grinding each surface (S1, S6) and after etching each surface (S10, S14), the wafer W ２ The surface shape of the
[0102] According to the above embodiment, the wafer W １ The target thickness Tc of the center after grinding both sides of １２ , wafer W ２ Target thickness T after double-sided grinding ２２ Since the wafer W １ As a result, the etching amount can be sufficiently secured when etching both sides of the wafer W. １ Therefore, the damaged layers formed on both surfaces of the substrate can be appropriately removed.
[0103] In this embodiment, the wafer W after the series of processes S1 to S15 is １ The target shape of the wafer is a flat type. This flat type has a uniform thickness within the wafer surface. For example, the wafer W １ 8 shows an example in which the central portion of the first surface Wa is slightly recessed compared to the outer periphery, and the central portion of the second surface Wb is slightly bulged compared to the outer periphery.
[0104] In this regard, in the above embodiment, the second surface Wb is etched under predetermined etching conditions in S10, but these etching conditions may be optimized. The method for determining the optimum etching conditions for the second surface Wb is the same as the method for determining the optimum etching conditions for the first surface Wa in S13. In such a case, the wafer W after the series of processes in S1 to S15 is １ The shape can be made flat with both sides horizontal.
[0105] In the above embodiment, the first wafer W １ On the other hand, the shapes of the first surface Wa and the second surface Wb after grinding are each concave in the middle, but they may also be convex in the middle. １ The target thickness Te of the outer periphery after grinding both sides of １２ , wafer W ２ Target thickness T after double-sided grinding ２２ Then, the wafer W １ As a result, the etching amount can be sufficiently secured when etching both sides of the wafer W. １ Therefore, the damaged layers formed on both surfaces of the substrate can be appropriately removed.
[0106] In the above embodiment, the first wafer W １ The target thickness Tc of the center after grinding both sides of １２ The second wafer W ２ Target thickness T after double-sided grinding ２２ Although it was made larger, this wafer W １ The target thickness control for double-sided grinding is １ For example, the second wafer W ２ When the shape of the first surface Wa after grinding is also a concave shape, or when the shape of the wafer W ２ When the shape of the second surface Wb after grinding becomes a concave shape, ２ The target thickness Tc of the center after grinding both sides of １２ The third wafer W ３ Target thickness T after double-sided grinding ３２ Then, the wafer W ２ As a result, the etching amount can be sufficiently secured when etching both sides of the wafer W. ２ In this case, the damaged layers formed on both sides of the third and subsequent wafers W can be appropriately removed. ３ In the processes of S1 to S15, after grinding each surface (S1, S6) and after etching each surface (S10, S14), the wafer W ３ The surface shape of the
[0107] As described above, in each group, up to the nth wafer Wｎ The target thickness after grinding on both sides of the wafer W after n+1 is ｎ＋１ In this case, the thickness of the wafer W is set to be larger than the target thickness after grinding on both sides of the wafer W. ｎ As a result, the etching amount can be sufficiently secured when etching both sides of the wafer W. ｎ In this case, the damaged layers formed on both surfaces of the wafers W up to the nth wafer in each group can be appropriately removed. ｎ The etching amount of the n+1th and subsequent wafers W ｎ＋１ The etching amount is larger than that of the
[0108] In the above embodiment, the plurality of wafers W to be processed are divided into a plurality of groups based on the interval time, but the basis for grouping is not limited to this. When the surface shape of a first wafer W after grinding is expected to be different from the surface shape of a second wafer W after grinding, the grouping is performed based on the boundary between the first wafer W and the second wafer W. In this example, the first wafer W is the last wafer to be processed in the first group, and the second wafer W is the first wafer to be processed in the second group.
[0109] The above-described cases in which the surface shape of a first wafer W after grinding differs from the surface shape of a second wafer W subsequent to the first wafer W include cases in which the target surface shapes of the first wafer W and the second wafer W are intentionally changed. Also included are cases in which the surface shapes differ between the first wafer W and the second wafer W due to changes in the types and thicknesses of films formed on the first surface Wa and the second surface Wb of the first wafer W.
[0110] In the above embodiment, a case has been described in which various processes are performed on both the first surface Wa and the second surface Wb of the wafer W, but the technology of the present disclosure can also be applied to a case in which various processes are performed on one surface of the wafer W. For example, when processing the first surface Wa of the wafer W, grinding of the first surface Wa (S1), cleaning of the first surface Wa (S2), thickness measurement of the wafer W (S3), tilt axis correction of the first chuck 93a (S4), determination of optimal etching conditions for the first surface Wa (S13), etching of the first surface Wa (S14), and thickness measurement of the wafer W (S15) are performed in this order. In processing the first surface Wa of the wafer W, tilt axis correction of the first chuck 93a is performed in S4 based on the thickness distribution and thickness deviation of the wafer W acquired in S3, and optimal etching conditions for the first surface Wa are also determined in S13 based on the thickness distribution and thickness deviation of the wafer W.
[0111] As shown in FIG. １ On the other hand, when the first surface Wa is ground, the shape of the first surface Wa after grinding becomes a concave shape. Subsequently, the tilt axis of the first chuck 93a is corrected based on the thickness distribution and thickness deviation of the wafer W after grinding. Then, the tilt axis of the second wafer W is corrected. ２ On the other hand, since the first surface Wa is ground using the first chuck 93a after the tilt axis correction, the shape of the first surface Wa after grinding becomes flat.
[0112] Here, the target thickness of the center portion after grinding the first surface Wa is Tc １１ , the target thickness of the outer periphery is Te １１ The target thickness after grinding the first surface Wa is T ２１ In this embodiment, the wafer W １ The target thickness Tc of the center after grinding １１ , wafer W ２ Target thickness after grinding T ２１ Then, the wafer W １ The target thickness Te of the outer periphery after grinding １１ Wafer W ２ Target thickness after grinding T ２１ It becomes bigger.
[0113] Next, the wafer W １On the other hand, when the first surface Wa is etched, the shape of the first surface Wa after etching becomes flat. １ The target thickness is T １４ The wafer W after grinding as described above １ Target thickness Tc of the center １１ is the target thickness after etching T １４ The thickness of the wafer W is larger than the thickness of the damaged layer. １ When etching the first surface Wa of the wafer W, a sufficient etching amount (=Tc １１ -T １４ ) can be secured, and the damaged layer formed in the central portion can be sufficiently removed. １ The etching amount of the first surface Wa (=Tc １１ -T １４ ) is the wafer W ２ The etching amount of the first surface Wa (=T ２１ -T ２４ ) will be more.
[0114] As described above, the first wafer W １ When the first surface Wa of the wafer W is ground and etched, １ The shape of the is flat and its thickness is T １４ This wafer W １ Thickness T １４ is the second wafer W ２ Thickness T ２４ In addition, the second and subsequent wafers W ２ In the process of (1), in both the process after grinding the first surface Wa and the process after etching the first surface Wa, ２ The surface shape of the
[0115] In the above embodiment, the same effects as those of the above embodiment can be obtained. １ The target thickness Tc of the center after grinding １１ , wafer W ２ Target thickness after grinding T ２１ Since it is larger, the wafer W １ The first surface Wa can be etched to properly remove the damaged layer.
[0116] In the above embodiment, the target shape of the wafer W after etching is flat (a flat type), but this is not limited thereto. For example, the technology of the present disclosure can be applied to any of the target shapes of the wafer W after etching, such as a convex shape, a concave shape, a W-shape, and an M-shape.
[0117] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. For example, the components of the above-described embodiments may be arbitrarily combined. Such an arbitrary combination naturally provides the functions and effects of each of the components involved in the combination, and also provides other functions and effects that are apparent to those skilled in the art from the description of this specification.
[0118] Furthermore, the effects described herein are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that are apparent to those skilled in the art from the description of this specification, in addition to or in place of the above-described effects.
[0119] 1 wafer processing system 40 etching device 90 grinding device 120 control device W wafer Wa first surface Wb second surface
Claims
1. A substrate processing method for processing a substrate, comprising: grinding a surface of a substrate; and etching the surface of the substrate after grinding, wherein grinding and etching are performed on the surfaces of a plurality of substrates; and, when it is expected that the surface shape after grinding of a first substrate will be different from the surface shape after grinding of a second substrate subsequent to the first substrate, the plurality of substrates are divided into a plurality of groups with the boundary between the first substrate and the second substrate; and, in the group starting with the second substrate, the target thickness after grinding of the first n-th substrate (n is a natural number equal to or greater than 1) substrates is set to be greater than the target thickness after grinding of the n+1th substrate and thereafter.
2. The substrate processing method according to claim 1, wherein the time from the end of grinding of said first substrate to the start of grinding of said second substrate is set to be equal to or longer than a predetermined time.
3. The substrate processing method according to claim 1, wherein the etching amount of the first n-th substrate in the group is made greater than the etching amount of the n+1th substrate and thereafter.
4. A substrate processing method as described in claim 1, comprising: measuring a thickness after grinding of the mth substrate (m is a natural number equal to or greater than 1) and obtaining a thickness distribution of the mth substrate; and determining a relative inclination between a substrate holding part that holds the m+1th substrate and a grinding part that grinds the surface of the m+1th substrate based on the thickness distribution of the mth substrate when grinding the surface of the m+1th substrate.
5. A substrate processing method as described in claim 1, comprising: measuring the thickness after grinding of the mth substrate (m is a natural number equal to or greater than 1) and obtaining a thickness distribution of the mth substrate; and determining optimal etching conditions for the surface of the mth substrate based on the thickness distribution of the mth substrate.
6. A substrate processing method as described in claim 1, comprising: grinding a first surface and a second surface of a substrate; and etching the first surface and the second surface of the substrate after grinding, wherein a target thickness after grinding of the first and second surfaces of the first n-th substrate in the group is made larger than a target thickness after grinding of the first and second surfaces of the n+1th substrate and the n+1th and subsequent substrates, and wherein the amount of grinding of the first surface and the amount of grinding of the second surface of the first n-th substrate in the group is made smaller than the amount of grinding of the first surface and the second surface of the n+1th substrate and subsequent substrates, respectively.
7. A substrate processing method as claimed in claim 1, comprising: grinding a first surface and a second surface of a substrate; and etching the first surface and the second surface of the substrate after grinding; wherein a target thickness after grinding of the first and second surfaces of the first n-th substrate in the group is made larger than a target thickness after grinding of the first and second surfaces of the n+1th substrate and thereafter; wherein either the amount of grinding of the first surface or the amount of grinding of the second surface of the first n-th substrate in the group is made smaller than the amount of grinding of the first surface or the amount of grinding of the second surface of the n+1th substrate and thereafter; and wherein the other of the amount of grinding of the first surface or the amount of grinding of the second surface of the first n-th substrate in the group is made the same as the amount of grinding of the first surface or the amount of grinding of the second surface of the n+1th substrate and thereafter.
8. A substrate processing system for processing substrates, comprising: a grinding device that grinds surfaces of substrates; an etching device that etches the surfaces of the substrates after grinding; and a control device, wherein the control device performs the following controls: control for grinding the surfaces of a plurality of substrates in the grinding device and etching the surfaces of the plurality of substrates in the etching device; control for dividing the plurality of substrates into a plurality of groups with the boundary between the first substrate and the second substrate when it is expected that the surface shape after grinding of a first substrate will be different from the surface shape after grinding of a second substrate subsequent to the first substrate; and control for setting the target thickness after grinding of the first n-th substrate (n is a natural number greater than or equal to 1) in the group starting with the second substrate to be larger than the target thickness after grinding of the n+1th substrate and thereafter.
9. The substrate processing system according to claim 8, wherein the control device executes control so that the time from the end of grinding of the first substrate to the start of grinding of the second substrate is equal to or longer than a predetermined time.
10. The substrate processing system according to claim 8, wherein the control device executes control so that the etching amount of the first n-th substrate in the group is greater than the etching amount of the n+1th substrate and thereafter.
11. A substrate processing system as described in claim 8, further comprising a thickness measuring device that measures the thickness of a substrate after grinding, the grinding device having a substrate holding section that holds a substrate, and a grinding section that grinds the surface of the substrate held by the substrate holding section, and the control device performs the following controls: measuring the thickness after grinding of an m-th substrate (m is a natural number equal to or greater than 1) in the thickness measuring device and acquiring a thickness distribution of the m-th substrate; and determining a relative inclination between the substrate holding section that holds the (m+1)th substrate and the grinding section that grinds the surface of the (m+1)th substrate based on the thickness distribution of the m-th substrate.
12. A substrate processing system as described in claim 8, further comprising a thickness measuring device that measures the thickness of the substrate after grinding, wherein the control device performs the following controls: measuring the thickness of the mth substrate after grinding (m is a natural number equal to or greater than 1) in the thickness measuring device, and acquiring a thickness distribution of the mth substrate; and determining optimal etching conditions for the surface of the mth substrate based on the thickness distribution of the mth substrate.
13. The substrate processing system of claim 8, wherein the control device performs the following controls: controlling grinding of the first and second surfaces of a substrate in the grinding device; controlling etching of the first and second surfaces of the substrate after grinding in the etching device; controlling target thicknesses after grinding of the first and second surfaces of the first n-th substrate in the group to be greater than target thicknesses after grinding of the first and second surfaces of the n+1th substrate and thereafter; and controlling the amount of grinding of the first surface and the second surface of the first n-th substrate in the group to be less than the amount of grinding of the first surface and the second surface of the n+1th substrate and thereafter, respectively.
14. The substrate processing system of claim 8, wherein the control device performs the following controls: controlling grinding of the first and second surfaces of a substrate in the grinding device; controlling etching of the first and second surfaces of the substrate after grinding in the etching device; controlling a target thickness after grinding of the first and second surfaces of the first n-th substrate in the group to be larger than a target thickness after grinding of the first and second surfaces of the n+1th substrate and thereafter; controlling either the amount of grinding of the first surface or the amount of grinding of the second surface of the first n-th substrate in the group to be smaller than the amount of grinding of the first surface or the amount of grinding of the second surface of the n+1th substrate and thereafter; and controlling the other of the amount of grinding of the first surface or the amount of grinding of the second surface of the first n-th substrate in the group to be equal to the amount of grinding of the first surface or the amount of grinding of the second surface of the n+1th substrate and thereafter.