Substrate Processing Method and Substrate Processing System

Abstract

Provided is a substrate processing method for processing a substrate, comprising grinding a first surface of the substrate, and, after the first surface has been ground, grinding a second surface of the substrate opposite the first surface. During the grinding of the first surface, a first grinding mark is formed that curves and extends from a central portion of the first surface toward an outer periphery. During the grinding of the second surface, a second grinding mark is formed curving and extending from a central portion of the second surface toward the outer periphery. The curving direction of the first grinding mark and the curving direction of the second grinding mark are opposite from each other in a transparent view from one surface.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a substrate processing system for grinding both surfaces of a substrate. The substrate processing system includes a first main surface grinding device that holds the substrate from below with the first main surface of the substrate facing upward and grinds the first main surface of the substrate, and a second main surface grinding device that holds the ground first main surface of the substrate from below with the second main surface of the substrate facing upward and grinds the second main surface of the substrate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technology according to the present disclosure suppresses grinding damage to the substrate after grinding both surfaces of the substrate.

Means for Solving the Problems

[0005] One aspect of the present disclosure is a substrate processing method for processing a substrate, including grinding a first surface of the substrate, and after grinding the first surface, grinding a second surface on the opposite side of the first surface of the substrate, wherein when grinding the first surface, a first grinding mark that curves and extends from the central portion to the outer peripheral portion of the first surface is formed, when grinding the second surface, a second grinding mark that curves and extends from the central portion to the outer peripheral portion of the second surface is formed, and the bending direction of the first grinding mark and the bending direction of the second grinding mark are opposite when viewed through one surface. Further, the grinding of the first surface and the grinding of the second surface are performed by a grinding apparatus including a first grinding unit that grinds one side of the substrate such that the bending direction of the grinding marks is in a first direction, a second grinding unit that grinds one side of the substrate such that the bending direction of the grinding marks is in a second direction opposite to the first direction, and a transport unit that positions the substrate with respect to the first grinding unit and the second grinding unit. The grinding of the first surface of one substrate and the grinding of the second surface of the one substrate are performed by positioning the one substrate by the transport unit at the same grinding unit, either the first grinding unit or the second grinding unit.

Effects of the Invention

[0006] According to the present disclosure, it is possible to suppress grinding damage to the substrate after grinding both surfaces of the substrate.

Brief Description of the Drawings

[0007]

Figure 1

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Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0008] In the manufacturing process of semiconductor devices, for example, as disclosed in Patent Document 1 described above, both the front and back surfaces of a disk-shaped silicon wafer cut from a single-crystal silicon ingot by a wire saw or the like are ground and flattened. Then, a silicon wafer (hereinafter sometimes referred to as a "wafer") is manufactured.

[0009] Here, in order to improve the productivity of wafer manufacturing and reduce man-hours, it is necessary to suppress the grinding damage in the grinding process as much as possible. However, conventionally, suppressing this grinding damage has not been considered.

[0010] The technology according to the present disclosure suppresses the grinding damage of a substrate during double-sided grinding of the substrate. Hereinafter, a wafer processing system as a substrate processing system according to the present embodiment and a wafer processing method as a substrate processing method will be described with reference to the drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

[0011] In the wafer processing system 1 according to the present embodiment, a process for improving the in-plane uniformity of the thickness is performed on a wafer W as a substrate obtained by cutting from an ingot. Hereinafter, the cut surface of the wafer W is referred to as a first surface Wa and a second surface Wb. The first surface Wa is the surface on the opposite side of the second surface Wb. Also, the first surface Wa and the second surface Wb may be collectively referred to as one side of the wafer W.

[0012] As shown in FIG. 1, the wafer processing system 1 has a configuration in which a loading / unloading station 10 and a processing station 11 are integrally connected. The loading / unloading station 10 is, for example, for loading and unloading a cassette C capable of accommodating a plurality of wafers W between the outside. The processing station 11 is provided with various processing apparatuses for performing desired processing on the wafer W. In the following description, a plurality of wafers W accommodated in the cassette C are referred to as one lot.

[0013] The loading / unloading station 10 is provided with a cassette mounting table 20. In the illustrated example, a plurality of, for example, two cassettes C can be mounted on the cassette mounting table 20 in a row in the Y-axis direction. Note that the number of cassettes C mounted on the cassette mounting table 20 is not limited to the present embodiment and can be arbitrarily determined.

[0014] The processing station 11 is provided with, for example, three processing blocks G1 to G3. The first processing block G1, the second processing block G2, and the third processing block G3 are arranged in this order from the X-axis negative direction side (the loading / unloading station 10 side) to the positive direction side.

[0015] The first processing block G1 is provided with an etching device 30, a cleaning device 40, and a wafer transfer device 50. The etching device 30 is provided, for example, in three stages in the vertical direction on the loading / unloading station 10 side of the first processing block G1. The cleaning device 40 is provided, for example, in three stages in the vertical direction on the X-axis positive direction side of the etching device 30. The wafer transfer device 50 is arranged on the Y-axis positive direction side of the etching device 30 and the cleaning device 40. Note that the number and arrangement of the etching device 30, the cleaning device 40, and the wafer transfer device 50 are not limited to this.

[0016] The etching device 30 etches the first surface Wa after grinding or the second surface Wb after grinding. For example, an etching solution (chemical solution) is supplied to the first surface Wa or the second surface Wb after grinding, and the first surface Wa or the second surface Wb after grinding is wet-etched. Examples of the etching solution include HF, HNO 3 、H 3 PO 4 、TMAH, Choline, KOH, etc. are used.

[0017] The cleaning device 40 cleans the first surface Wa after grinding or the second surface Wb after grinding. For example, a brush is brought into contact with the first surface Wa or the second surface Wb to scrub and clean the first surface Wa or the second surface Wb. Note that for cleaning the first surface Wa or the second surface Wb, a pressurized cleaning liquid may be used. Also, the cleaning device 40 may be configured to be able to clean the first surface Wa and the second surface Wb simultaneously when cleaning the wafer W.

[0018] The wafer transfer device 50 holds and transfers the wafer W and, for example, has two transfer arms 51. Each transfer arm 51 is configured to be movable in the horizontal direction, the vertical direction, around the horizontal axis, and around the vertical axis. And the wafer transfer device 50 is configured to be able to transfer the wafer W to the cassette C on the cassette mounting table 20, the etching device 30, Cleaning device 40 , the transition device 60 described later, and the inversion device 61 described later.

[0019] In the second processing block G2, a transition device 60, an inversion device 61, and a wafer transfer device 70 are provided. The transition device 60 and the inversion device 61 are provided, for example, stacked in this order from the lower stage in the vertical direction. The wafer transfer device 70 is disposed on the negative Y-axis side of the transition device 60 and the inversion device 61. Note that the number and arrangement of the transition device 60, the inversion device 61, and the wafer transfer device 70 are not limited to this.

[0020] The transition device 60 temporarily places the wafer W in order to transfer the wafer W. The inversion device 61 inverts the first surface Wa and the second surface Wb of the wafer W in the vertical direction.

[0021] The wafer transfer device 70 holds and transfers the wafer W and, for example, has two transfer arms 71. Each transfer arm 71 is configured to be movable in the horizontal direction, the vertical direction, around the horizontal axis, and around the vertical axis. And the wafer transfer device 70 is configured to be able to transfer the wafer W to the cleaning device 40, the transition device 60, the inversion device 61, and the grinding device 80 described later.

[0022] The third processing block G3 is provided with a grinding device 80. Note that the number and arrangement of the grinding devices 80 are not limited to this.

[0023] The grinding device 80 has a rotating table 81. The rotating table 81 is configured to be rotatable about a vertical rotation center line 82 by a rotation mechanism (not shown). On the rotating table 81, four chucks 83 as holding parts for sucking and holding the wafer W are provided. Among the four chucks 83, two first chucks 83a are chucks used for grinding the first surface Wa and suck and hold the second surface Wb. These two first chucks 83a are arranged at positions that are point-symmetrical with respect to the rotation center line 82. The remaining two second chucks 83b are chucks used for grinding the second surface Wb and suck and hold the first surface Wa. These two second chucks 83b are also arranged at positions that are point-symmetrical with respect to the rotation center line 82. That is, the first chucks 83a and the second chucks 83b are arranged alternately in the circumferential direction.

[0024] For example, a porous chuck is used for the chuck 83. The surface of the chuck 83, that is, the holding surface of the wafer W, has a convex shape in which the central part protrudes more than the end part in a side view. Note that although the protrusion of the central part is minute, in FIG. 2, the protrusion of the central part of the chuck 83 is shown enlarged for clarity of explanation.

[0025] As shown in FIG. 2, the chuck 83 is held by the chuck base 84. The chuck base 84 is provided with an inclination adjustment unit 85 for adjusting the relative inclination between the grinding wheels 101 and 111 provided in the respective grinding units 100 and 110 described later and the chuck 83. The inclination adjustment unit 85 has a fixed shaft 86 provided on the lower surface of the chuck base 84 and a plurality of, for example, two elevating shafts 87. Each elevating shaft 87 is configured to be telescopically extendable and raises and lowers the chuck base 84. By this inclination adjustment unit 85, with one end portion (the position corresponding to the fixed shaft 86) of the outer peripheral portion of the chuck base 84 as a base point, the other end portion is raised and lowered in the vertical direction by the elevating shafts 87, so that the chuck 83 and the chuck base 84 can be inclined. And thereby, the relative inclination between the surfaces of the grinding wheels 101 and 111 provided in the respective grinding units 100 and 110 at the machining positions B1 to B2 described later and the surface of the chuck 83 can be adjusted.

[0026] Note that the configuration of the inclination adjustment unit 85 is not limited to this, and any configuration can be selected as long as the relative angle (parallelism) between the surface of the chuck 83 and the surfaces of the grinding wheels 101 and 111 can be adjusted.

[0027] As shown in FIG. 1, the four chucks 83 can be moved to the delivery positions A1 to A2 and the machining positions B1 to B2 by the rotation of the rotary table 81. Further, each of the four chucks 83 is configured to be rotatable about a vertical axis by a rotation mechanism (not shown).

[0028] The first delivery position A1 is a position on the negative X-axis side and the positive Y-axis side of the rotary table 81, and the wafer W is delivered between the first chuck 83a when grinding the wafer W. The second delivery position A2 is a position on the negative X-axis side and the negative Y-axis side of the rotary table 81, and the wafer W is delivered between the second chuck 83b when grinding the wafer W. At the delivery positions A1 and A2, a thickness measurement unit 90 for measuring the thickness of the ground wafer W is provided. The thickness measurement unit 90 measures the thickness of the wafer W at a plurality of points and measures the in-plane distribution of the thickness. The configuration of the thickness measurement unit 90 is arbitrary, and for example, it includes a non-contact sensor (not shown).

[0029] The first machining position B1 is a position on the positive X-axis side and the negative Y-axis side of the rotary table 81, and the first grinding unit 100 as the first grinding part is arranged. The first grinding unit 100 grinds either one side of the first surface Wa or the second surface Wb of the wafer W held by the first chuck 83a. The second machining position B2 is a position on the positive X-axis side and the positive Y-axis side of the rotary table 81, and the second grinding unit 110 as the second grinding part is arranged. The second grinding unit 110 grinds either one side of the first surface Wa or the second surface Wb held by the second chuck 83b.

[0030] In this embodiment, the rotary table 81 functions as a transfer unit that transfers and positions the wafer W held by the first chuck 83a to the first grinding unit 100, or transfers and positions the wafer W held by the second chuck 83b to the second grinding unit 110.

[0031] As shown in FIG. 2, the first grinding unit 100 includes a grinding wheel 102 having an annular grinding wheel 101 on the lower surface, a mount 103 that supports the grinding wheel 102, a spindle 104 that rotates the grinding wheel 102 via the mount 103, and a drive unit 105 that incorporates, for example, a motor (not shown). The first grinding unit 100 is configured to be movable in the vertical direction along the support column 106 shown in FIG. 1.

[0032] The second grinding unit 110 has the same configuration as the first grinding unit 100. That is, the second grinding unit 110 includes a grinding wheel 112 having an annular grinding wheel 111, a mount 113, a spindle 114, a drive unit 115, and a support column 116.

[0033] As shown in FIG. 1, the above-described wafer processing system 1 is provided with a control device 120. The control device 120 is a computer including, for example, a CPU, a memory, etc., and has a program storage unit (not shown). A program for controlling the processing of the wafer W in the wafer processing system 1 is stored in the program storage unit. Note that the above program may be recorded on a computer-readable storage medium H and installed from the storage medium H into the control device 120. Further, the storage medium H may be temporary or non-temporary.

[0034] Next, grinding of the wafer W by the first grinding unit 100 and grinding of the wafer W by the second grinding unit 110 will be described.

[0035] As shown in FIG. 3, the chucks 83a and 83b have a convex shape at the central portion of the holding surface of the wafer W. Therefore, when grinding the first surface Wa of the wafer W using the first grinding unit 100, the first chuck 83a is tilted so that the first surface Wa of the wafer W held by the first chuck 83a and the surface of the grinding wheel 101 are parallel. Further, as shown by the thick lines in FIGS. 4 and 5, a part of the annular grinding wheel 101 contacts the wafer W as the first processing point R1. More specifically, the annular grinding wheel 101 and the wafer W are in arc-shaped contact from the central portion to the outer peripheral end portion, and in such a state, the first chuck 83a and the grinding wheel 102 are rotated respectively, so that the entire surface of the first surface Wa is ground. The same applies when grinding the second surface Wb of the wafer W using the first grinding unit 100.

[0036] When the first grinding unit 100 is used to grind the first surface Wa, a first grinding mark Ga, which is a so-called Sommer mark that curves and extends from the central portion toward the outer peripheral portion, is formed on the first surface Wa. Also, when the first grinding unit 100 is used to grind the second surface Wb, a second grinding mark Gb that curves and extends from the central portion toward the outer peripheral portion is formed on the second surface Wb. Each of these first grinding mark Ga and second grinding mark Gb has curved convex portions that are continuous in the clockwise direction. In the following description, the bending direction may be referred to as "clockwise".

[0037] As shown in FIG. 3, when the first surface Wa of the wafer W is ground using the second grinding unit 110, the second chuck 83b is tilted so that the first surface Wa of the wafer W held by the second chuck 83b is parallel to the surface of the grinding wheel 111. Also, as shown by the thick line portion in FIG. 6, a part of the annular grinding wheel 111 contacts the wafer W as the second machining point R2. More specifically, the annular grinding wheel 111 and the wafer W are in arc-shaped contact from the central portion to the outer peripheral end portion, and in this state, by rotating the second chuck 83b and the grinding wheel 112 respectively, the entire surface of the first surface Wa is ground. The same applies when the second surface Wb of the wafer W is ground using the second grinding unit 110.

[0038] When the first surface Wa is ground using the second grinding unit 110, a first grinding mark Ga that curves and extends from the central portion toward the outer peripheral portion is formed on the first surface Wa. Also, when the second surface Wb is ground using the second grinding unit 110, a second grinding mark Gb that curves and extends from the central portion toward the outer peripheral portion is formed on the second surface Wb. Each of these first grinding mark Ga and second grinding mark Gb has curved convex portions that are continuous in the counterclockwise direction. In the following description, the bending direction may be referred to as "counterclockwise".

[0039] As shown in FIG. 7, when the relative positional relationship between the first chuck 83a and the grinding wheel 101 is different from the relative positional relationship between the second chuck 83b and the grinding wheel 111, the position of the first machining point R1 when the first grinding unit 100 is used is different from the position of the second machining point R2 when the second grinding unit 110 is used. For this reason, the bending directions of the grinding marks Ga and Gb when the first grinding unit 100 is used and the bending directions of the grinding marks Ga and Gb when the second grinding unit 110 is used are opposite on the same surface of the wafer W.

[0040] Here, when the surfaces Wa and Wb of a single wafer W are ground with different grinding units 100 and 110 respectively, the grinding marks Ga and Gb overlap. For example, as shown in FIG. 8(a), the first surface Wa is ground with the first grinding unit 100 to form a first clockwise grinding mark Ga. Then, as shown in FIG. 8(b), the second surface Wb is ground with the second grinding unit 110 to form a second counterclockwise grinding mark Gb. Then, as shown in FIG. 8(c), on the wafer W, the grinding marks Ga and Gb overlap when viewed through from one surface. In such a case, there is a possibility that the grinding damage becomes large.

[0041] On the contrary, in the present embodiment, the surfaces Wa and Wb of a single wafer W are ground with the same grinding units 100 and 110 respectively. For example, as shown in FIG. 9(a), the first surface Wa is ground with the first grinding unit 100 to form a first clockwise grinding mark Ga. Then, as shown in FIG. 9(b), the second surface Wb is ground with the first grinding unit 100 to form a second clockwise grinding mark Gb. When the bending directions of the grinding marks Ga and Gb are made the same in this way, the grinding marks Ga and Gb on the wafer W do not cross and overlap as shown in FIG. 9(c). In such a case, the grinding damage can be suppressed as compared with the case where the grinding marks Ga and Gb overlap. Note that when the surfaces Wa and Wb of a single wafer W are ground with the second grinding unit 110 respectively, the grinding marks Ga and Gb do not overlap when viewed through from one surface, and the same effect can be obtained.

[0042] As described above, the inventors have found that the bending directions of the grinding marks Ga and Gb are correlated with the grinding damage, and have found that the grinding damage can be suppressed by appropriately controlling the directions of the grinding marks Ga and Gb.

[0043] Next, the wafer processing performed using the wafer processing system 1 configured as described above will be explained. In the present embodiment, a desired process is performed on a wafer W that is cut out from an ingot by a wire saw or the like and lapped.

[0044] First, a cassette C containing a plurality of wafers W is placed on the cassette mounting table 20 of the loading / unloading station 10. In the cassette C, the wafers W are stored with the first surface Wa facing upward and the second surface Wb facing downward.

[0045] Next, the wafer W in the cassette C is taken out by the wafer transfer device 50 and transferred to the transition device 60.

[0046] Next, the wafer W is transferred to the grinding device 80 by the wafer transfer device 70 and delivered to the first chuck 83a at the first delivery position A1. At the first chuck 83a, the second surface Wb of the wafer W is sucked and held.

[0047] Next, the rotary table 81 is rotated to move the wafer W to the first processing position B1. Then, the first surface Wa of the wafer W is ground by the first grinding unit 100 (step S1 in FIG. 10). At this time, as shown in FIG. 9(a), a first grinding mark Ga in the clockwise direction is formed on the first surface Wa.

[0048] Next, the rotary table 81 is rotated to move the wafer W to the first delivery position A1.

[0049] Next, the wafer W is transferred to the cleaning device 40 by the wafer transfer device 70. In the cleaning device 40, the first surface Wa of the wafer W is cleaned (step S2 in FIG. 10).

[0050] Next, the wafer W is transported by the wafer transfer device 70 to the inversion device 61. In the inversion device 61, the first surface Wa and the second surface Wb of the wafer W are inverted in the vertical direction (step S3 in FIG. 10). That is, the wafer W is inverted such that the second surface Wb faces upward and the first surface Wa faces downward.

[0051] Next, the wafer W is transported by the wafer transfer device 70 to the grinding device 80 and delivered to the first chuck 83a at the first delivery position A1. In the first chuck 83a, the first surface Wa of the wafer W is adsorbed and held.

[0052] Next, the rotary table 81 is rotated to move the wafer W to the first processing position B1. Then, the second surface Wb of the wafer W is ground by the first grinding unit 100 (step S4 in FIG. 10). At this time, as shown in FIG. 9(b), a second grinding mark Gb in the clockwise direction is formed on the second surface Wb. Then, since the bending directions of the grinding marks Ga and Gb are the same, the grinding marks Ga and Gb do not overlap when viewed through from one surface as shown in FIG. 9(c).

[0053] Next, the rotary table 81 is rotated to move the wafer W to the second delivery position A2.

[0054] Next, the wafer W is transported by the wafer transfer device 70 to the cleaning device 40. In the cleaning device 40, the second surface Wb of the wafer W is cleaned (step S5 in FIG. 10).

[0055] Next, the wafer W is transported by the wafer transfer device 50 to the inversion device 61. In the inversion device 61, the first surface Wa and the second surface Wb of the wafer W are inverted in the vertical direction (step S6 in FIG. 10). That is, the wafer W is inverted such that the first surface Wa faces upward and the second surface Wb faces downward.

[0056] Next, the wafer W is transported to the etching apparatus 30 by the wafer transfer apparatus 50. In the etching apparatus 30, the first surface Wa of the wafer W is etched with an etching solution (step S7 in FIG. 10). Thereby, grinding debris, grinding damage, etc. remaining on the first surface Wa are removed.

[0057] Next, the wafer W is transported to the reversing device 61 by the wafer transfer apparatus 50. In the reversing device 61, the first surface Wa and the second surface Wb of the wafer W are reversed in the vertical direction (step S8 in FIG. 10). That is, the wafer W is reversed such that the second surface Wb faces upward and the first surface Wa faces downward.

[0058] Next, the wafer W is transported to the etching apparatus 30 by the wafer transfer apparatus 50. In the etching apparatus 30, the second surface Wb of the wafer W is etched with an etching solution (step S9 in FIG. 10). Thereby, grinding debris, grinding damage, etc. remaining on the second surface Wb are removed.

[0059] Thereafter, the wafer W on which all processes have been performed is transported to the cassette C on the cassette mounting table 20 by the wafer transfer apparatus 50. Thus, a series of wafer processes in the wafer processing system 1 is completed. Note that the wafer W on which a desired process has been performed in the wafer processing system 1 may be polished outside the wafer processing system 1.

[0060] According to the above embodiment, since the surfaces Wa and Wb of one wafer W are ground by the same first grinding unit 100, the grinding marks Ga and Gb on the wafer W can be formed so as not to overlap. For this reason, grinding damage can be suppressed. As a result, a flattening and smoothing process for removing grinding damage as in the prior art becomes unnecessary or can be reduced, so that it is possible to improve the productivity of wafer manufacturing and reduce man-hours.

[0061] In the above embodiment, a plurality of wafers W accommodated in the same cassette C may be alternately transported one by one to the first grinding unit 100 and the second grinding unit 110.

[0062] For example, if all of the plurality of wafers W accommodated in the same cassette C are conveyed to the first grinding unit 100 and the first surface Wa and the second surface Wb are ground using the first grinding unit 100, the second grinding unit 110 is not used until grinding a plurality of wafers W in the next lot. That is, the first grinding unit 100 and the second grinding unit 110 cannot be used in parallel, and the efficiency of wafer processing is poor.

[0063] On the other hand, for example, with respect to a plurality of wafers W accommodated in the same cassette C, one wafer W is conveyed to the first grinding unit 100, and the next wafer W is conveyed to the second grinding unit 110. That is, the control device 120 performs conveyance control of the wafer W in the grinding device 80, and distributes and conveys the wafers W in the same cassette C to the first grinding unit 100 and the second grinding unit 110 alternately. In such a case, the first grinding unit 100 and the second grinding unit 110 can be used in parallel, and the processing of the wafer W can be performed efficiently, and the throughput of the processing of the wafer W can be improved.

[0064] Next, the grinding device 80 according to another embodiment will be described. As shown in FIG. 11, in the grinding device 80, the first grinding unit 100 (grinding wheel 102) and the second grinding unit 110 (grinding wheel 112) are arranged so that the same grinding marks are formed by the first processing point R1 and the second processing point R2 with respect to the chuck 83. As a result, the bending directions of the grinding marks Ga and Gb when the first grinding unit 100 is used and the bending directions of the grinding marks Ga and Gb when the second grinding unit 110 is used are the same. That is, when grinding the first surface Wa or the second surface Wb of the wafer W using the first grinding unit 100, the first grinding mark Ga or the second grinding mark Gb that rotates clockwise is formed respectively. Also, when grinding the first surface Wa or the second surface Wb of the wafer W using the second grinding unit 110, the first grinding mark Ga or the second grinding mark Gb that rotates clockwise is formed respectively.

[0065] In such a case, for one wafer W, in step S1, the wafer W is moved to the first processing position B1, and the first grinding unit 100 grinds the first surface Wa of the wafer W. Then, a first grinding mark Ga that rotates clockwise is formed on the first surface Wa.

[0066] Thereafter, for the same one wafer W, in step S3, the wafer W is moved to the second processing position B2, and the second grinding unit 110 grinds the second surface Wb of the wafer W. Then, a second grinding mark Gb that rotates clockwise is formed on the second surface Wb. In this way, the control device 120 controls the rotary table 81 which is a transfer unit, the first grinding unit 100, and the second grinding unit 110.

[0067] According to the present embodiment, when viewed through one surface of the wafer W, the grinding marks Ga and Gb do not cross and overlap. As a result, grinding damage can be suppressed.

[0068] Note that the grinding marks Ga and Gb when the first grinding unit 100 is used and the grinding marks Ga and Gb when the second grinding unit 110 is used may each be counterclockwise. That is, in the grinding device 80 in which the first grinding unit 100 (grinding wheel 102) and the second grinding unit 110 (grinding wheel 112) are arranged with respect to the chuck 83 so that the bending directions of the grinding marks Ga and Gb are in one direction, the same effect as described above can be obtained. Since a continuous process of continuously conveying a plurality of wafers W accommodated in the same cassette C to the first grinding unit 100 first and then to the second grinding unit 110 becomes possible, the throughput of the processing of the wafers W can be improved.

[0069] Next, the wafer processing system 1 according to another embodiment will be described. As shown in FIG. 12, the wafer processing system 1 has a plurality of, for example, two grinding devices 200 and 210 instead of the grinding device 80 of the above embodiment. The grinding devices 200 and 210 are arranged side by side in this order from the negative X-axis side to the positive X-axis side. The wafer transfer device 70 is configured to move along a rail 72 extending in the X-axis direction and transfer the wafer W to the grinding devices 200 and 210.

[0070] The first grinding device 200 has a chuck 201 for sucking and holding the wafer W and a grinding unit 202. The chuck 201 is configured to be movable between a delivery position and a processing position by a moving mechanism (not shown). At the delivery position, the wafer W is delivered between the chuck 201 when the wafer W is ground. The grinding unit 202 is arranged at the processing position.

[0071] The grinding unit 202 has the same configuration as the grinding unit 100 of the above embodiment, 110 and grinds the first surface Wa of the wafer W held by the chuck 201. The grinding unit 202 is arranged with respect to the chuck 201 such that a first grinding mark Ga in the clockwise direction is formed on the first surface Wa of the wafer W.

[0072] The second grinding device 210 has the same configuration as the first grinding device 200 and has a chuck 211 and a grinding unit 212. The grinding unit 212 grinds the second surface Wb of the wafer W held by the chuck 211. The grinding unit 212 is arranged with respect to the chuck 211 such that a second grinding mark Gb in the clockwise direction is formed on the second surface Wb of the wafer W.

[0073] In such a case, for one wafer W, in step S1, the first surface Wa is ground in the first grinding device 200, and a first grinding mark Ga in the clockwise direction is formed on the first surface Wa. Also, thereafter, for the same one wafer W, in step S3, the second surface Wb is ground in the second grinding device 210. And a second grinding mark Gb in the clockwise direction is formed on the second surface Wb.

[0074] According to this embodiment, when viewed through one surface of the wafer W, the grinding marks Ga and Gb do not cross and overlap. As a result, grinding damage can be suppressed.

[0075] Note that before being carried into the wafer processing system 1, it is conceivable that grinding marks have been formed on the wafer W in advance by the previous processing. In such a case, if the bending direction of the grinding marks is known in advance, the transfer control may be performed so that opposite grinding marks are formed on the same surface. Alternatively, an imaging unit (not shown) for imaging one side of the wafer W may be provided inside the second grinding device 210, and the grinding unit 212 may be set according to the imaged first grinding mark Ga.

[0076] In the above embodiment, the control is performed so that the first grinding mark Ga formed on the first surface Wa of the wafer W and the second grinding mark Gb formed on the second surface Wb do not overlap. However, the method of the present disclosure can also be applied when one side of the wafer W is ground in multiple steps. For example, in one-sided grinding consisting of two steps, in the first step of grinding the first surface Wa, the first grinding mark Ga facing right is formed, and in the second step of grinding the first surface Wa, the control is performed so that the first grinding mark Ga facing left is formed. Then, on the first surface Wa, the grinding marks Ga of the first step and the second step do not overlap, and grinding damage can be suppressed.

[0077] Note that when the bending direction of the first grinding mark Ga formed using the first grinding device 200 is known in advance, the transfer control may be performed on the grinding unit 212 of the second grinding device 210 so that the first grinding mark Ga in the direction opposite to the bending direction is formed.

[0078] Also, for example, in two-sided grinding consisting of two steps, according to the bending directions of the grinding marks Ga and Gb formed in the first-step two-sided grinding in the first-step grinding device, the bending directions of the grinding marks Ga and Gb formed in the second-step two-sided grinding in the second-step grinding device are set so that the grinding damage is minimized.

[0079] For example, when the grinding marks Ga and Gb formed by the first-stage double-sided grinding do not overlap, they cross with respect to the grinding marks Ga and Gb of the first stage, and the grinding marks Ga and Gb formed by the second-stage double-sided grinding are made not to cross and overlap.

[0080] Also, for example, when the grinding marks Ga and Gb formed by the first-stage double-sided grinding overlap, they cross with respect to the grinding mark Ga or the grinding mark Gb on one side, and the grinding marks Ga and Gb formed by the second-stage double-sided grinding overlap.

[0081] Also, for example, when the grinding marks Ga and Gb formed by the first-stage double-sided grinding overlap, the contribution rates to the grinding damage may be different on the first surface Wa and the second surface Wb. For example, when the surface with a smaller contribution to the grinding damage is the first surface Wa, on the first surface Wa, the first grinding mark Ga formed by the first-stage grinding and the first grinding mark Ga formed by the second-stage grinding are made to overlap. On the other hand, when the surface with a larger contribution to the grinding damage is the second surface Wb, on the First second surface Wb, the second grinding mark Gb formed by the first-stage grinding and the second grinding mark Gb formed by the second-stage grinding are made not to cross and overlap.

[0082] The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The above embodiments may be omitted, substituted, or changed in various forms without departing from the scope and gist of the appended claims.

Description of Reference Numerals

[0083] 1 Wafer processing system 80 Grinding device 120 Control device Ga First grinding mark Gb Second grinding mark W Wafer Wa First surface Wb Second surface

Claims

1. A substrate processing method for processing a substrate, comprising: grinding a first surface of the substrate; after grinding the first surface, grinding a second surface of the substrate opposite to the first surface of the substrate; when grinding the first surface, a first grinding mark is formed that curves and extends from a central portion of the first surface toward an outer peripheral portion; when grinding the second surface, a second grinding mark is formed that curves and extends from a central portion of the second surface toward an outer peripheral portion; the bending direction of the first grinding mark and the bending direction of the second grinding mark are opposite when viewed through one surface; the grinding of the first surface and the grinding of the second surface are a first grinding unit that grinds one side of the substrate so that the bending direction of the grinding mark is in a first direction; a second grinding unit that grinds one side of the substrate so that the bending direction of the grinding mark is in a second direction opposite to the first direction; performed by a grinding apparatus including a transfer unit that positions the substrate in the first grinding unit and the second grinding unit; The grinding of the first surface of one substrate and the grinding of the second surface of the one substrate are performed by positioning the one substrate in the same grinding unit, either the first grinding unit or the second grinding unit, by the transfer unit. A substrate processing method.

2. The substrate processing method according to claim 1, wherein a plurality of substrates in the same cassette are alternately transferred one by one to the first grinding unit and the second grinding unit.

3. A substrate processing method for processing a substrate, comprising: grinding a first surface of the substrate; after grinding the first surface, grinding a second surface of the substrate opposite to the first surface of the substrate; when grinding the first surface, a first grinding mark is formed that curves and extends from a central portion of the first surface toward an outer peripheral portion; when grinding the second surface, a second grinding mark is formed that curves and extends from a central portion of the second surface toward an outer peripheral portion; the bending direction of the first grinding mark and the bending direction of the second grinding mark are opposite when viewed through one surface; the double-sided grinding of the first surface and the second surface is performed in two steps; the bending direction of the grinding mark formed in the second-step double-sided grinding is set according to the bending direction of the grinding mark formed in the first-step double-sided grinding; when the grinding marks formed in the first-step double-sided grinding overlap when viewed through one surface, on the surface with a small contribution rate to grinding damage, the grinding marks formed in the first-step grinding and the grinding marks formed in the second-step grinding overlap. A substrate processing method in which, on a surface where the contribution rate to grinding damage is large, the grinding marks formed by the first-stage grinding and the grinding marks formed by the second-stage grinding do not overlap.

4. A substrate processing system for processing a substrate, comprising: a grinding device for grinding one side of the substrate; a transfer device for transferring the substrate to the grinding device; a control device, and the grinding device grinds a first surface of the substrate, the grinding device grinds a second surface of the substrate on the side opposite to the first surface, when grinding the first surface, a first grinding mark that curves and extends from the central portion to the outer peripheral portion of the first surface is formed, when grinding the second surface, a second grinding mark that curves and extends from the central portion to the outer peripheral portion of the second surface is formed, the control device controls the grinding device and the transfer device so that the bending directions of the first grinding mark and the second grinding mark are opposite when viewed through one surface, the grinding device a holding portion for holding the substrate, a first grinding portion for grinding one side of the substrate held by the holding portion so that the bending direction of the grinding mark is in a first direction, a second grinding portion for grinding one side of the substrate held by the holding portion so that the bending direction of the grinding mark is in a second direction opposite to the first direction, a transfer portion for transferring the substrate held by the holding portion to the first grinding portion and the second grinding portion, and the control device performs control to transfer one substrate to the same grinding portion of either the first grinding portion or the second grinding portion when grinding the first surface and the second surface of the one substrate, a substrate processing system.

5. The substrate processing system according to claim 4, wherein the control device performs control on the transfer device and the transfer portion to alternately transfer a plurality of substrates in the same cassette, one by one, to the first grinding portion and the second grinding portion.

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