Processing method and processing device

Abstract

To properly control the thickness and flatness of a ground substrate.SOLUTION: A processing method of a substrate is provided, including: grinding a substrate; obtaining the thickness and thickness distribution of the one ground substrate; and grinding another substrate on the basis of the obtained thickness and thickness distribution, and when the other substrate is ground, the amount of grinding of the other substrate is adjusted on the basis of difference between the target thickness of the one substrate and the thickness of the one ground substrate, and a relative tilt between a holding mechanism that holds the substrate and a grinding mechanism that grinds the substrate is adjusted on the basis of the thickness distribution of the one ground substrate.SELECTED DRAWING: Figure 8

Description

[Technical field]

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

[0002] Patent Document 1 discloses a grinding apparatus having a plurality of substrate holding parts for holding substrates, a plurality of annular grinding parts for grinding the substrates, and a load measuring part for measuring the load acting on at least the substrate holding parts or the grinding parts. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 013037 Summary of the Invention [Problem to be solved by the invention]

[0004] The technique disclosed herein appropriately controls the thickness and flatness of the substrate after grinding. [Means for solving the problem]

[0005] One aspect of the present disclosure is a method for processing a substrate, comprising: A grinding mechanism having a grinding wheel is lowered, and the grinding wheel is grinding one substrate, acquiring a thickness and a thickness distribution of the one substrate after grinding, and grinding another substrate based on the acquired thickness and thickness distribution, wherein, when grinding the other substrate, a difference between a target thickness of the one substrate and a thickness of the one substrate after grinding is acquired, The lowering amount of the grinding mechanism is adjusted. The other substrate Thickness and adjusting a relative inclination between a holding mechanism for holding the substrate and the grinding mechanism for grinding the substrate based on a thickness distribution of the substrate after grinding. and adjust the flatness of the other substrate. do. Effect of the Invention

[0006] According to the present disclosure, the thickness and flatness of the substrate after grinding can be appropriately controlled. [Brief description of the drawings]

[0007] [Figure 1] 1 is a plan view showing a schematic outline of a configuration of a processing device according to an embodiment of the present invention; [Diagram 2] FIG. 4 is a side view showing an example of the configuration of various grinding mechanisms and chucks. [Diagram 3] FIG. 2 is a plan view showing the arrangement of a chuck base and a chuck. [Figure 4] FIG. 2 is an explanatory diagram showing a state of a wafer grinding process. [Diagram 5] FIG. 4 is an explanatory diagram showing measurement points of the thickness of a wafer. [Figure 6] FIG. 4 is a flow diagram showing an example of a grinding process. [Figure 7] FIG. 4 is an explanatory diagram showing the state of rough grinding in a rough grinding section. [Figure 8] FIG. 4 is a flow diagram showing an example of a grinding process. [Figure 9] FIG. 11 is a plan view showing a schematic outline of another configuration example of the processing device; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] In the manufacturing process of semiconductor devices, a semiconductor substrate (hereinafter referred to as a "wafer") having a plurality of devices such as electronic circuits formed on its surface is ground to thin the wafer. The wafer is ground, for example, by holding the surface of the wafer opposite to the surface to be ground with a holding mechanism, and bringing a grinding wheel of the grinding mechanism into contact with the surface to be ground while rotating the holding mechanism.

[0009] The grinding device described in the above-mentioned Patent Document 1 is a grinding device for performing the grinding process of such wafers. In the grinding device described in Patent Document 1, after the thickness of the wafer to be ground reaches a target thickness, the points at which the load acting on at least the substrate holding part (holding mechanism) or the grinding part (grinding mechanism) becomes zero are measured in a state where the grinding wheel is stopped from descending for a certain period of time while rotating (a so-called spark-out state) and in a state where the grinding wheel starts to rise while rotating (a so-called escape cut state).

[0010] However, when grinding wafers using the method described in Patent Document 1, grinding of the wafer may continue even in the above-mentioned spark-out state or escape cut state due to the characteristics of the grinding mechanism (e.g., the rigidity (elasticity) and thermal expansion of the device components such as the holding mechanism and grinding mechanism). In other words, grinding may continue unintentionally even after the wafer thickness reaches the target thickness, and the finished thickness and flatness of the wafer after grinding may not be appropriately controlled. Therefore, there is room for improvement in the conventional wafer grinding method.

[0011] Therefore, the technology disclosed herein appropriately controls the thickness and flatness of the substrate after grinding. Hereinafter, the processing apparatus as a processing apparatus and the processing method as a processing method according to the present embodiment will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configurations are denoted by the same reference numerals, and duplicated descriptions will be omitted.

[0012] In the processing apparatus 1 according to the present embodiment, a wafer W as a substrate is ground to thin it. The wafer W is a semiconductor wafer such as a silicon wafer or a compound semiconductor wafer. In the following description, the surface held by a chuck as a holding mechanism may be referred to as a "holding surface," and the surface opposite to the holding surface where processing such as grinding is performed may be referred to as a "grinding surface."

[0013] 1, the processing apparatus 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 stage 10. A wafer transport area 20 is provided adjacent to the cassette mounting stage 10 on the Y-axis positive side of the cassette mounting stage 10. The wafer transport area 20 is provided with a wafer transport device 22 that is movable on a transport path 21 extending in the X-axis direction.

[0015] The wafer transfer device 22 has a transfer fork 23 that holds and transfers the wafer W. The transfer fork 23 is configured to be movable horizontally, vertically, around a horizontal axis, and around a vertical axis. The wafer transfer device 22 is configured to be able to transfer the wafer W to the cassette C on the cassette mounting table 10, the alignment unit 50, and the first cleaning unit 60.

[0016] In the processing station 3, processing such as grinding and cleaning is performed on the wafer W. The processing station 3 includes a transfer unit 30 that transfers the wafer W, a grinding unit 40 that performs a grinding process on the wafer W, an alignment unit 50 that adjusts the horizontal orientation of the wafer W before the grinding process, a first cleaning unit 60 that cleans the wafer W before or after the grinding process, and a second cleaning unit 70.

[0017] The transfer unit 30 is an articulated robot equipped with a plurality of, for example, three, arms 31. Each of the three arms 31 is configured to be freely rotatable. A transfer pad 32 that suctions and holds the wafer W is attached to the arm 31 at the tip end. The arm 31 at the base end is attached to a lifting mechanism 33 that raises and lowers the arm 31 in the vertical direction. The transfer unit 30 is configured to be able to transport the wafer W to the delivery position A0 of the grinding unit 40, the alignment unit 50, the first cleaning unit 60, and the second cleaning unit 70.

[0018] The grinding section 40 is provided with a rotary table 41. On the rotary table 41, four chucks 42 are provided as a holding mechanism for suction-holding the wafer W. For example, a porous chuck is used as the chuck 42, and it suction-holds the holding surface of the wafer W. The surface of the chuck 42 has a convex shape in which the center protrudes compared to the ends in a side view. Note that this protrusion of the center is very small, but in FIG. 2, the protrusion of the center of the chuck 42 is illustrated large for clarity of explanation.

[0019] 2 and 3, the four chucks 42 are respectively held by four chuck bases 43. In the following description, the four chuck bases may be referred to as first to fourth chuck bases 43a to 43d, respectively, as shown in Fig. 3. The chuck bases 43a to 43d hold the first to fourth chucks 42a to 42d, respectively.

[0020] The chuck base 43 is provided with an inclination adjustment mechanism 44 that adjusts the relative inclination between the various grinding mechanisms (rough grinding mechanism 80, medium grinding mechanism 90, and finish grinding mechanism 100) and the chuck 42. The inclination adjustment mechanism 44 has a fixed shaft 45 provided on the lower surface of the chuck base 43 and a plurality of, for example, two, lifting shafts 46. Each lifting shaft 46 is configured to be freely expandable and contractible, and lifts and lowers the chuck base 43. The inclination adjustment mechanism 44 can tilt the chuck 42 and the chuck base 43 by vertically lifting and lowering one end of the outer periphery of the chuck base 43 (the position corresponding to the fixed shaft 45) using the lifting shaft 46 as a base point and the other end. This allows the relative inclination between the various grinding mechanisms at the processing positions A1 to A3 and the upper surface of the chuck 42 to be adjusted. The configuration of the tilt adjustment mechanism 44 is not limited to this, and can be selected arbitrarily as long as it can adjust the relative angle (parallelism) of the chuck 42 with respect to the grinding wheel.

[0021] The four chucks 42 are movable to the delivery position A0 and the processing positions A1 to A3 by rotation of the rotary table 41. In addition, each of the four chucks 42 is configured to be rotatable about a vertical axis by a rotation mechanism (not shown).

[0022] At the delivery position A0, the transfer unit 30 delivers and receives the wafer W. At the processing position A1, a rough grinding mechanism 80 is disposed and performs rough grinding of the wafer W. At the processing position A2, a medium grinding mechanism 90 is disposed and performs medium grinding of the wafer W. At the processing position A3, a finish grinding mechanism 100 is disposed and performs finish grinding of the wafer W.

[0023] The rough grinding mechanism 80 has a rough grinding wheel 81 with an annular rough grinding stone 81a on its underside, a mount 82 that supports the rough grinding wheel 81, a spindle 83 that rotates the rough grinding wheel 81 via the mount 82, and a drive unit 84 that incorporates, for example, a motor (not shown). The rough grinding mechanism 80 is configured to be movable in the vertical direction along a support column 85 shown in FIG.

[0024] Here, as described above, the chuck 42 has a convex shape at the center of the holding surface. Therefore, when the wafer W is ground using the rough grinding mechanism 80, a part of the annular rough grinding wheel 81a comes into contact with the wafer W as a processing point R, as shown by the bold line in Fig. 4. More specifically, the annular rough grinding wheel 81a comes into contact with the wafer W from the center to the outer peripheral edge in an arc shape, and the entire surface of the wafer W is ground by rotating the chuck 42 and the rough grinding wheel 81 in this state.

[0025] 1, the processing position A1 is provided with a thickness measuring mechanism 110 as an end point detection mechanism for measuring the thickness of the wafer W during at least rough grinding. The thickness measuring mechanism 110 may have any configuration, but may have, for example, a contact sensor and a calculation unit. The thickness measuring mechanism 110 detects that the wafer W has been ground to a target thickness in the rough grinding mechanism 80 (end point detection).

[0026] The medium grinding mechanism 90 has a similar configuration to the rough grinding mechanism 80. That is, the medium grinding mechanism 90 has a medium grinding wheel 91 equipped with an annular medium grinding stone 91a, a mount 92, a spindle 93, a drive unit 94, and a support column 95. The grain size of the abrasive grains of the medium grinding stone is smaller than the grain size of the abrasive grains of the rough grinding stone.

[0027] The finish grinding mechanism 100 has a similar configuration to the rough grinding mechanism 80. That is, the finish grinding mechanism 100 has a finish grinding wheel 101 equipped with an annular finish grinding stone 101a, a mount 102, a spindle 103, a drive unit 104, and a support column 105. The grain size of the abrasive grains of the finish grinding stone is smaller than the grain size of the abrasive grains of the medium grinding stone.

[0028] Similarly to the processing position A1, the processing positions A2 and A3 are each provided with a thickness measuring mechanism 110 as an end point detection mechanism for measuring at least the thickness of the wafer W during the grinding process. The configuration of the thickness measuring mechanism 110 can be selected arbitrarily, but for example, it has at least one of a contact sensor or a non-contact sensor and a calculation unit. The thickness measuring mechanism 110 detects (end point detection) that the wafer W has been ground to the target thickness in the intermediate grinding mechanism 90 and the finish grinding mechanism 100.

[0029] 1, the delivery position A0 is further provided with a thickness measuring mechanism 120 for measuring the thickness of the wafer W after the grinding process. The thickness measuring mechanism 120 has a sensor 121 and a calculation unit 122. Note that it is preferable to use a non-contact sensor as the sensor 121 in order to prevent the wafer W after the finish grinding at the processing position A3 from being scratched.

[0030] 5, the sensor 121 measures the thickness of the wafer W after the grinding process at, for example, three points in the radial direction. The measurement point M1 is the center of the wafer W. The measurement point M2 is the middle of the wafer W, which is located at a distance r / 2 from the center, where r is the radius of the wafer W. The measurement point M3 is the outer periphery of the wafer W.

[0031] At the measurement point M1, with the rotation of the chuck 42 (wafer W) stopped, the thickness of the wafer W is measured by the thickness measurement mechanism 120. Note that at this time, the thickness of the wafer W may be measured while the chuck 42 is being rotated.

[0032] At measurement point M2 and measurement point M3, the thickness of the wafer W is measured at multiple points in the circumferential direction by the thickness measurement mechanism 120 while rotating the chuck 42 (wafer W). Then, a moving average or moving median is calculated from the measurement results of the multiple points, and this is set as the thickness of the wafer W at each of measurement points M2 and M3. Note that at this time, the thickness of the wafer W may be measured at only one point in the circumferential direction while the rotation of the chuck 42 (wafer W) is stopped, and the measurement result of this one point may be used as a representative value to be set as the thickness of the wafer W at each of measurement points M2 and M3.

[0033] The measurement results of the sensor 121 are output to the calculation unit 122. The calculation unit 122 acquires the thickness distribution of the wafer W from the measurement results (thickness of the wafer W) at multiple points (measurement points M1 to M3) by the sensor 121, and further calculates the flatness (TTV: Total Thickness Variation) of the wafer W. The acquired thickness and thickness distribution of the wafer W are output to the control unit 130 described later, and are used to adjust the thickness and flatness of the wafer W after the grinding process, as described later.

[0034] The thickness measurement points of the wafer W by the thickness measurement mechanism 120 are not limited to the three points in the radial direction shown in Fig. 5. That is, for example, the thickness measurement may be performed using only one point in the radial direction (preferably, a middle part in the radial direction where the end point of the thickness of the wafer W is detected in the grinding process as described later) as a representative point, or the thickness measurement may be performed at any two or more points.

[0035] The processing apparatus 1 described above is provided with a control unit 130 as shown in FIG. The control unit 130 is, for example, a computer equipped with a CPU, a memory, and the like, and has a program storage unit (not shown). The program storage unit stores a program for controlling the processing of the wafer W in the processing apparatus 1. The program storage unit also stores a program for controlling the operation of the drive system of the above-mentioned various processing units and the transport device, and for realizing the processing process described below in the processing apparatus 1. The above program may be recorded in a computer-readable storage medium and installed in the control unit 130 from the storage medium. The storage medium may be temporary or non-temporary.

[0036] Next, a processing method performed using the processing apparatus 1 configured as above will be described. In the processing apparatus 1, a plurality of wafers W accommodated in a cassette C are successively processed. In the following description, the n-th wafer W to be processed among the wafers W to be successively processed will be referred to as the "wafer W". n " shall be referred to as "

[0037] First, a cassette C storing a plurality of wafers W is placed on the cassette placement stage 10 of the carry-in / out station 2. Next, the first wafer W1 in the cassette C is taken out by the wafer transfer device 22 and transferred to the alignment section 50 of the processing station 3 (Step S1 in FIG. 6: Loading of wafer W). In the alignment section 50, the horizontal orientation of the wafer W1 is adjusted by adjusting the position of a notch portion (not shown) formed in the wafer W1 (Step S2 in FIG. 6: Alignment).

[0038] The wafer W1, whose horizontal orientation has been adjusted, is then transferred from the alignment unit 50 by the transfer unit 30 and delivered to the first chuck 42a at the delivery position A0. Next, the turntable 41 is rotated to move the wafer W1 held by the first chuck 42a sequentially to the processing positions A1 to A3.

[0039] At the processing position A1, the grinding surface of the wafer W1 is roughly ground by the rough grinding mechanism 80 (step S3: rough grinding in FIG. 6). A detailed method of rough grinding of the wafer W1 at the processing position A1 will be described below with reference to FIG. 7. The left diagram in FIG. 7 is an explanatory diagram showing the positional relationship between the rough grinding wheel 81 and the wafer W during rough grinding. The right diagram in FIG. 7 is a graph showing the time-series change in the height position of the rough grinding wheel 81, with the vertical axis representing the height position of the lower surface (rough grinding stone 81a) of the rough grinding wheel 81 and the horizontal axis representing time.

[0040] First, the rough grinding wheel 81 is lowered at high speed from the standby position H1 to the grinding start position H2 (time T0 to T1). After that, the rough grinding wheel 81 is decelerated and lowered at a low speed to the contact position H3 with the wafer W1 (time T1 to T2: air cut).

[0041] When the rough grinding wheel 81 is lowered to bring the rough grinding stone 81a into contact with the wafer W, the rough grinding wheel 81 is further lowered to grind the wafer W1 to a grinding end position H4 (target thickness of the wafer W in the rough grinding mechanism 80) in the rough grinding mechanism 80 (time T2 to T5: grinding step). In this grinding step, the height of the grinding surface of the wafer W is measured using, for example, the above-mentioned thickness measuring mechanism 110, and the lowering of the rough grinding wheel 81 is stopped (end point detection) when the height of the grinding surface reaches a desired height (the thickness of the wafer W1 reaches a desired target thickness) (time T5). The end point detection of the thickness of the wafer W1 is performed, for example, at the measurement point M2 shown in FIG. 5, that is, at the middle part in the radial direction of the wafer W. In this grinding step, the lowering speed of the rough grinding wheel 81 may be changed stepwise (for example, at times T3 and T4) between times T2 and T5, or the lowering speed may be controlled to be constant.

[0042] When the rough grinding wheel 81 reaches the grinding end position H4 and stops descending, the height position of the rough grinding wheel 81 is made to wait at the grinding end position H4 for a certain period of time (time T5 to T6: spark out). In the spark out state, the rough grinding wheel 81 continues to rotate, and for example, when the thickness measurement mechanism 110 at the above-mentioned processing position A1 has a contact type sensor, the sensor removes scratches on the grinding surface and improves the surface condition of the wafer W1. Also, in the spark out state, when the thickness measurement mechanism 110 has such a contact type sensor, the sensor is retracted from the grinding surface to prevent new scratches from being made on the grinding surface of the wafer W1 due to contact with the sensor, and the rough grinding wheel 81 continues to rotate.

[0043] After the spark-out is completed, the rough grinding wheel 81 starts to rise while continuing to rotate (time T6 to T7: escape cut). In the escape cut state, the rough grinding wheel 81 is raised at a low speed to prevent wheel marks from remaining on the grinding surface of the wafer W1 when the wafer W1 and the rough grinding wheel 81a are separated from each other. Note that, even in this escape cut, the contact sensor is kept retracted from the grinding surface, as in the spark-out.

[0044] When the wafer W and the rough grinding wheel 81a are separated from each other, the rough grinding wheel 81 is then accelerated to move the rough grinding wheel 81 to the standby position H1 (after time T7), and the rough grinding of the wafer W in the rough grinding mechanism 80 is completed.

[0045] At the processing position A2, the grinding surface of the wafer W1 is medium-grinded by the medium grinding mechanism 90 (step S4: medium grinding in FIG. 6). The medium grinding by the medium grinding mechanism 90 is performed, for example, in the same manner as the rough grinding by the rough grinding mechanism 80 shown in FIG. 7. That is, by controlling the height position of the medium grinding wheel 91, air cut, grinding step, spark out, and escape cut are performed in this order.

[0046] At the processing position A3, the grinding surface of the wafer W1 is finish-ground by the finish grinding mechanism 100 (step S5 in FIG. 6: finish grinding). The finish grinding by the finish grinding mechanism 100 is performed, for example, in the same manner as the rough grinding by the rough grinding mechanism 80 shown in FIG. 7. That is, by controlling the height position of the finish grinding wheel 101, air cut, grinding step, spark out, and escape cut are performed in this order.

[0047] When the finish grinding process of the wafer W1 is completed, the rotary table 41 is then rotated to move the wafer W1 held by the chuck 42 to the transfer position A0. At the transfer position A0, for example, while rotating the wafer W1, the thickness measuring mechanism 120 measures the thickness of the wafer W1 after the finish grinding at multiple points including the center and the peripheral edge (see FIG. 5) (Step S6 in FIG. 6: Measurement of the finished thickness). Then, based on the measured thicknesses of the wafer W1 at the multiple points, the thickness distribution of the wafer W1 after the finish grinding is acquired, and further, the flatness (TTV) is calculated (Step S7 in FIG. 6: Acquisition of thickness distribution flatness). The acquired thickness distribution and flatness are output to, for example, the control unit 130.

[0048] In addition, while the wafer W1 is being ground at the processing positions A1 to A3 and the thickness (thickness distribution) after finish grinding at the transfer position A0 is being acquired, the next wafers W2 to W4 held by the second to fourth chucks 42b to 42d are processed in sequence. That is, the turntable 41 is rotated to move the wafers W2 to W4 held by the second to fourth chucks 42b to 42d together with the wafer W1 held by the first chuck 42a to the processing positions A1 to A3 and the transfer position A0 in sequence.

[0049] The wafer W1, whose thickness, thickness distribution, and flatness after finish grinding have been obtained, is then transported by the transport unit 30 from the transfer position A0 to the second cleaning unit 70, where it is cleaned and dried while held on the transport pad 32 (step S8 in FIG. 6: first cleaning).

[0050] Next, the wafer W1 is transferred by the transfer unit 30 from the second cleaning unit 70 to the first cleaning unit 60, and is further cleaned using a cleaning liquid nozzle (not shown) (Step S9 in FIG. 6: second cleaning).

[0051] Thereafter, the wafer W1 which has been subjected to all the processes is transferred by the transfer fork 23 of the wafer transfer device 22 to the cassette C on the cassette mounting table 10 (Step S10 in FIG. 6: Transferring the wafer W). In this manner, a series of processing steps for the first wafer W1 accommodated in the cassette C is completed. Further, a series of processing steps for the wafers W2 to W4 held in the second to fourth chucks 42b to 42d is completed by the same processing steps.

[0052] Here, in the above grinding process operation, as described above, even in the state of spark out or escape cut after the grinding step, grinding of the wafer W may proceed due to, for example, the device characteristics of the processing device 1 (rigidity (elasticity) of the chuck 42 and the rough grinding mechanism 80, thermal expansion, etc.). More specifically, for example, in the grinding step, the grinding wheel is lowered (pressed) in a state where the grinding stone is in contact with the wafer W, and elastic force is accumulated, and such elastic force is released (restored) in the state of spark out or escape cut, so that grinding of the wafer W may proceed unintentionally. In addition, for example, frictional heat generated by grinding the wafer W may cause thermal expansion of the chuck 42 and various grinding mechanisms, and such thermal expansion may cause grinding of the wafer W to proceed unintentionally.

[0053] Therefore, when grinding the wafer W in the processing apparatus 1, it is necessary to control the thickness and flatness (finished shape) of the wafer W after finish grinding, taking into account the grinding of the wafer W that proceeds in such a spark-out or escape cut state. In addition, the device characteristics of the above-mentioned processing apparatus 1 may change over time due to environmental factors (e.g., the processing atmosphere temperature, etc.), and in the processing apparatus 1, it is necessary to further take such environmental factors into consideration in controlling the thickness and flatness (finished shape) of the wafer W after finish grinding.

[0054] Therefore, in the processing apparatus 1 according to the present embodiment, the thickness and thickness distribution of the first wafer W1 after finish grinding acquired in steps S6 and S7 of FIG. 6 are used to determine the thickness of the wafers W1 to be subsequently processed. n The grinding conditions are corrected.

[0055] As described above, the four chucks 42a to 42d are provided on the rotary table 41, and it is considered that the four chucks 42a to 42d have different device characteristics. In other words, even if the wafer W is ground under the same conditions in each of the four chucks 42a to 42d, there is a risk that the results of the grinding process on the wafer W will vary due to the differences in the device characteristics of the four chucks 42a to 42d. Therefore, in the processing apparatus 1 according to the present embodiment, such a wafer W n The grinding conditions are independently corrected for each of the four chucks 42. More specifically, the grinding conditions for the wafers W1 to W4 held on the chucks 42a to 42d are corrected based on the thicknesses and thickness distributions of the wafers W1 to W4 after the finish grinding. n The grinding conditions are corrected.

[0056] The wafers W to be processed subsequently are n Regarding the detailed grinding method of the wafer W n The following description will be given taking as an example a case where a wafer W is held by the first chuck 42a, but the wafer W held by the second to fourth chucks 42b to 42d will be described in detail below. n The same correction is made as below.

[0057] First, the wafer W is taken out of the cassette C by the wafer transfer device 22. n After the horizontal orientation of the wafer W is adjusted in the alignment unit 50, the wafer W is transferred to the first chuck 42a at the transfer position A0 by the transfer unit 30 (steps P1 and P2 in FIG. 8). Then, the rotary table 41 is rotated to transfer the wafer W held by the chuck 42a to the first chuck 42a. n is moved sequentially to the processing positions A1 to A3.

[0058] At the processing position A1, the wafer W is processed by the method shown in FIG. n The grinding surface is roughly ground (Step P3 in FIG. 8). That is, by controlling the height position of the rough grinding wheel 81, air cut, grinding step, spark out, and escape cut are performed in this order.

[0059] At the processing position A2, the wafer W is processed by the method shown in FIG. n The grinding surface is semi-ground (step P4 in FIG. 8). That is, by controlling the height position of the semi-grinding wheel 91, air cut, grinding step, spark out, and escape cut are carried out in this order.

[0060] At the processing position A3, the wafer W is processed by the method shown in FIG. n The ground surface is finish ground (step P5 in FIG. 8). That is, by controlling the height position of the finish grinding wheel 101, air cut, grinding step, spark out, and escape cut are performed in this order.

[0061] Here, the wafer W n In the finish grinding, the wafer W is chucked on the first chuck 42a prior to the finish grinding. n The wafer W that was processed immediately before n-4 (Continuously processed wafers W n-1 ~W n-3 are held by second to fourth chucks 42b to 42d, respectively. The grinding conditions are corrected based on the thickness and thickness distribution after finish grinding as the grinding process result of (a). Specifically, the wafer W after finish grinding n-4 Based on the thickness distribution of the wafer W n-4 The amount of grinding is increased at the positions where the thickness of the wafer is large, and decreased at the positions where the thickness is small. n The relative inclination of the chuck 42 and the finish grinding wheel 101a is adjusted so that the in-plane thickness of the wafer W becomes uniform (so that the TTV becomes small). nThe grinding amount is adjusted (Step Q1 in FIG. 8). In addition, the wafer W after finish grinding n-4 Based on the thickness of the wafer W n-4 The amount of descent of the finish grinding wheel 101 (grinding end position H4 at time T5 in FIG. 7) is adjusted so as to increase the amount of grinding when the thickness is greater than the desired target thickness, and decrease the amount of grinding when the thickness is smaller than the desired target thickness (step Q2 in FIG. 8).

[0062] In this embodiment, the wafer W used to adjust the lowering amount of the finish grinding wheel 101 is n-4 The thickness after the finish grinding is the thickness of the wafer W after the finish grinding in step S7 of FIG. n-4 The thickness measured to obtain the thickness distribution of the wafer W after finish grinding, i.e., the thickness measured in step S6 of FIG. 6, is used. As the thickness after finish grinding, the average value of thicknesses measured at multiple points (see FIG. 5) to obtain the thickness distribution may be used, or any one point selected from these multiple points may be used as a representative value. However, n From the viewpoint of precisely controlling the thickness of the wafer, n-4 It is preferable to use the thickness at the measurement position where the end point detection is performed, that is, the measurement point M2 shown in FIG.

[0063] Then, the wafer W is placed at the adjusted tilt. n While holding the grinding wheel 101 in this state, the height position of the finish grinding wheel 101 is controlled so as to achieve the adjusted lowering amount, and rough grinding is performed.

[0064] Wafer W n After the finish grinding process is completed, the rotary table 41 is rotated to grind the wafer W held by the chuck 42a. n At the delivery position A0, the wafer W is moved to the delivery position A0 by the thickness measuring mechanism 120. n The thickness of the wafer W is measured at multiple points. n The thickness of the wafer W after grinding is determined based on the thickness of the wafer W after grinding. nThe thickness distribution and flatness (TTV) of the next wafer W held by the first chuck 42a are acquired (steps P6 and P7 in FIG. 8). The acquired thickness, thickness distribution and flatness are output to the control unit 130, and the thickness, thickness distribution and flatness are then output to the control unit 130. n+4 It is used to adjust the relative inclination between the chuck 42a and the finish grinding wheel 101a and the amount of descent of the finish grinding wheel 101 in the grinding process.

[0065] Then, the wafer W on which the thickness distribution and TTV were obtained was n After being cleaned in the second cleaning section 70 and the first cleaning section 60, the wafers W are transferred to the cassette C on the cassette mounting table 10 (steps P8 to P10 in FIG. 8). When the processing of all the wafers W accommodated in the cassette C is completed in this manner, a series of processing steps in the processing apparatus 1 is completed. In this embodiment, the wafer W held by the first chuck 42a n The above description is given by taking as an example the case where the grinding processing conditions are corrected during the finish grinding of the wafer W held by the second to fourth chucks 42b to 42d. n In the finish grinding, the grinding conditions are corrected in a similar manner.

[0066] According to the above embodiment, the wafer W in the processing device 1 n During the grinding process, the W processed immediately before in each chuck 42 is n-4 Based on the thickness and thickness distribution after the finish grinding, the relative inclination between the chuck 42 and the finish grinding wheel 101a and the amount of lowering of the finish grinding wheel 101 are adjusted. n The thickness can be appropriately improved and the flatness can be improved.

[0067] In this manner, the wafer W that was previously processed on each chuck 42 n-4 By referring to the thickness and thickness distribution after the finish grinding, even if the device characteristics (e.g., the rigidity of the device) of the processing device 1 change over time due to changes in environmental factors (e.g., an increase in the atmospheric temperature due to processing), the wafer W can be appropriately adjusted to follow such changes in the device characteristics.n The finished thickness and flatness can be adjusted.

[0068] Furthermore, according to this embodiment, the wafer W n The amount of grinding (the amount of lowering of the finish grinding wheel 101) of the wafer W is adjusted. n-4 The thickness of the wafer W after finish grinding is n The wafer W is used to adjust the flatness (relative inclination between the chuck 42 and the finish grinding wheel 101a). n-4 That is, the thickness distribution of the wafer W was measured. n The thickness and flatness of the wafer W are adjusted independently after the finish grinding. n-4 It is not necessary to measure the thickness of the wafer W after the finish grinding, and both the thickness and flatness after the finish grinding can be efficiently adjusted based on only one thickness measurement result. n This makes it possible to appropriately improve the throughput in adjusting the thickness and flatness of the substrate.

[0069] Furthermore, according to the present embodiment, a series of adjustment operations according to the technology of the present disclosure, specifically, the wafer W n-4 Acquisition of the thickness and thickness distribution of the wafer W based on the acquired information n The relative inclination between the chuck and the grinding wheel and the amount of lowering of the grinding wheel during grinding are automatically controlled, for example, by the control unit 130. In other words, since the series of adjustment operations does not require manual work by an operator or the like, the wafer W can be easily adjusted. n Therefore, the improvement of thickness and flatness after finish grinding can be more easily and appropriately performed.

[0070] In the above embodiment, the thickness of the wafer W after finish grinding is measured by the thickness measuring mechanism 120 disposed at the transfer position A0, but the measurement position of the thickness of the wafer W is not limited to the transfer position A0.

[0071] Specifically, instead of the thickness measurement at the delivery position A0 by the thickness measurement mechanism 120, the thickness of the wafer W after finish grinding may be measured by a thickness measurement mechanism 110 for end point detection arranged at the processing position A3. Also, for example, as shown in Fig. 9, in addition to or instead of the thickness measurement mechanism 120, a thickness measurement unit 140 independent of the grinding unit 40 may be arranged by being stacked with, for example, the alignment unit 50 and the first cleaning unit 60, and the thickness of the wafer W after finish grinding may be measured in the thickness measurement unit 140.

[0072] In the above embodiment, the relative inclination between the chuck 42 and the grinding wheel and the amount of descent of the grinding wheel are adjusted in the finish grinding mechanism 100, but these adjustments may be performed in the rough grinding mechanism 80 and the medium grinding mechanism 90 in addition to the finish grinding mechanism 100. That is, the thickness and thickness distribution of the wafer W may be obtained sequentially after each grinding process, and the adjustment may be performed for each grinding mechanism based on the obtained thickness and thickness distribution. In this case, the thickness and flatness of the wafer W after finish grinding can be controlled more precisely.

[0073] In the processing apparatus 1 according to the above embodiment, four chucks 42a to 42d are provided on the rotary table 41, and the grinding conditions are corrected for each chuck 42, taking into consideration the difference in the device characteristics of each chuck 42. However, the method of correcting the grinding conditions is not limited to this, and for example, when the difference in the device characteristics of each chuck 42 is small, the grinding conditions may be corrected for the wafers W held by the other chucks 42. In other words, when the wafer W is n The wafer W whose processing results are referred to in order to adjust the thickness and flatness of the wafer W is the wafer W processed on the same chuck 42. n-4 However, the present invention is not limited to the above, and may be applied to any wafer W that has been processed on another chuck 42. m The processing results for (n-4≦m≦n-1) can be referenced.

[0074] In the above embodiment, the wafer W after finish grinding nThe thickness and flatness are adjusted for each chuck 42 based on the wafer W n immediately before the wafer W n-4 processed. However, the wafer W that refers to the processing result is not limited to the wafer W n-4 . That is, at least the wafer W n processed before the wafer W m (1 ≦ m < n), if the relative inclination of the chuck and the grinding wheel and the lowering amount of the grinding wheel can be adjusted based on the processing results, at least the wafer W n final thickness and flatness can be improved.

[0075] In the above embodiment, based on the thickness and thickness distribution after finish grinding of the first wafer W1 accommodated in the cassette C (more specifically, the wafers W1 to W4 first processed by the respective chucks 42a to 42d), the wafers W n thickness and flatness after finish grinding were adjusted. However, when performing the above adjustment operation, the final thickness and flatness of the wafer W first processed by each chuck 42 cannot be adjusted. Therefore, the first wafers W1 to W4 for which the thickness and thickness distribution after finish grinding have been obtained may be re-ground so that the wafers W1 to W4 have a desired target thickness flatness based on the obtained thickness and thickness distribution after finish grinding.

[0076] Also, for example, instead of adjusting the thickness and flatness after finish grinding of the wafer W n based on the processing results of the wafers W1 to W4 first processed by the chucks 42a to 42d, for example, the grinding process of the dummy wafer W0 is performed in advance for each chuck 42, and based on the processing results of the dummy wafer W0, the wafer W n (n ≧ 1) final thickness and flatness may be adjusted. By performing the adjustment operation based on the processing results of the dummy wafer W0 in this way, it is not necessary to perform the above re-grinding on the wafers W1 to W4 first processed by the chucks 42a to 42d. That is, the throughput related to the grinding of the wafers W1 to W4 can be improved.

[0077] In the above embodiment, a single wafer W is processed in the processing apparatus 1. n In the above description, the wafer is ground to be thinned, but the configuration of the wafer processed by the processing apparatus 1 is not limited to this. For example, this embodiment can be applied to a case where a first wafer is ground to be thinned in a laminated wafer formed by bonding a first wafer and a second wafer. In such a case, the second wafer is held on the opposite side of the first wafer to be ground by the chuck 42, and in this state, a grinding wheel is brought into contact with the first wafer.

[0078] Furthermore, when processing overlapped wafers in the processing apparatus 1 in this manner, the thickness distribution of the second wafer held by the chuck 42 may be acquired in advance, and the thickness distribution of the second wafer may be compared with the thickness distribution of at least another second wafer constituting another overlapped wafer previously processed, thereby further adjusting the relative inclination between the chuck and the grinding wheel, and the amount of lowering of the grinding wheel. In other words, the thickness and flatness after finish grinding of the first wafer caused by the difference in thickness distribution of the second wafer may be further adjusted. In such a case, the thickness distribution of the second wafer can be calculated, for example, by measuring the total thickness (thickness distribution) of the overlapped wafer before grinding processing in thickness measuring unit 140 shown in FIG. 9, and then measuring the thickness (thickness distribution) of the first wafer after finish grinding in thickness measuring mechanism 120, and further subtracting the thickness (thickness distribution) of the first wafer from the total thickness (thickness distribution) of the overlapped wafer.

[0079] The embodiments disclosed herein should be considered as illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0080] 1 Processing equipment 42 Chuck 44 Tilt adjustment mechanism 80 Rough grinding mechanism 90 Medium grinding mechanism 100 Finish grinding mechanism 120 Thickness measurement mechanism 130 Control section W wafer

Claims

1. A method for processing a substrate, comprising the steps of: lowering a grinding mechanism having a grinding wheel and grinding one substrate with the grinding wheel; Obtaining a thickness and a thickness distribution of the one substrate after grinding; grinding another substrate based on the obtained thickness and thickness distribution; When grinding the other substrate, Based on a difference between a target thickness of the first substrate and a thickness of the first substrate after grinding, The lowering amount of the grinding mechanism is adjusted to adjust the thickness of the other substrate; a processing method for adjusting flatness of the other substrate by adjusting a relative inclination between a holding mechanism that holds the substrate and the grinding mechanism that grinds the substrate based on a thickness distribution after grinding of the one substrate.

2. the thickness distribution of the one substrate after grinding is obtained by measuring the thickness of the one substrate at multiple points; 2 . The processing method according to claim 1 , wherein the post-grinding thickness of the one substrate used for adjusting the grinding amount of the other substrate is at least one of the thicknesses measured when obtaining a thickness distribution of the one substrate.

3. In the grinding of the first substrate, an end point of the grinding process is detected by measuring a thickness of the first substrate during the grinding process; 3. The processing method according to claim 1, wherein the post-grinding thickness of the one substrate used for adjusting the grinding amount is obtained at the same measurement position as a thickness measurement position of the one substrate at the time of detecting the end point.

4. Continuous processing of multiple substrates 4. The processing method according to claim 1, wherein the one substrate is one of a plurality of substrates processed successively, the one substrate being processed immediately before the other substrate.

5. a processing apparatus for processing a substrate is provided with a plurality of the holding mechanisms; Continuous processing of multiple substrates The processing method according to any one of claims 1 to 4, wherein the one substrate is at least one of a plurality of substrates to be processed successively that is held in the same holding mechanism before the other substrates.

6. The grinding mechanism includes: a rough grinding mechanism for rough grinding the substrate; a finish grinding mechanism for finish grinding the substrate after rough grinding, The thickness and thickness distribution of the first substrate after grinding are acquired at least after finish grinding of the first substrate; 6. The processing method according to claim 1, wherein adjustment of the grinding amount of the other substrate and adjustment of the relative inclination are performed at least in the finish grinding mechanism.

7. The processing method according to any one of claims 1 to 6, further comprising re-grinding the one substrate based on the acquired thickness and thickness distribution after grinding of the one substrate.

8. A processing apparatus for continuously processing a plurality of substrates, A holding mechanism for holding the substrate; a grinding mechanism for grinding the substrate held by the holding mechanism; a thickness measuring mechanism for measuring the thickness of the substrate; a tilt adjustment mechanism that adjusts a relative tilt between the holding mechanism and the grinding mechanism; A control unit that controls the grinding process of the substrate, The control unit is by lowering the grinding mechanism, the substrate held by the holding mechanism is ground by a grindstone provided in the grinding mechanism; grinding one substrate, acquiring a thickness and a thickness distribution of the one substrate after grinding, and grinding another substrate based on the acquired thickness and thickness distribution of the one substrate; When grinding the other substrate, a processing apparatus that adjusts a lowering amount of the grinding mechanism based on a difference between a target thickness of the one substrate and a thickness of the one substrate after grinding, thereby adjusting a thickness of the other substrate to be ground, and adjusts a relative inclination between the holding mechanism and the grinding mechanism based on a thickness distribution of the one substrate after grinding, thereby adjusting a flatness of the other substrate.

9. The control unit is acquiring the thickness distribution based on thicknesses at a plurality of points of the one substrate after grinding measured by the thickness measuring mechanism; The processing apparatus according to claim 8 , wherein at least one of the thicknesses measured when the thickness distribution is obtained is used as a post-grinding thickness of the one substrate used for adjusting the grinding amount of the other substrate.

10. an end point detection mechanism for measuring a thickness of the substrate during the grinding process of the substrate by the grinding mechanism; The control unit is 10. The processing apparatus according to claim 8 or 9, which controls the operation of the thickness measurement mechanism so that the post-grinding thickness of the one substrate used to adjust the grinding amount of the other substrate is obtained at the same measurement position as the thickness measurement position of the substrate by the end point detection mechanism.

11. A plurality of the holding mechanisms are provided, The control unit is The processing apparatus according to any one of claims 8 to 10, wherein the adjustment of the amount of grinding of the other substrate and the adjustment of the relative inclination are performed based at least on the thickness and thickness distribution after grinding of the one substrate that was held before the other substrate in the same holding mechanism.

12. The grinding mechanism includes: a rough grinding mechanism for rough grinding the substrate; a finish grinding mechanism for finish grinding the substrate after rough grinding, The control unit is acquiring the thickness and thickness distribution after at least grinding of the one substrate by the finish grinding mechanism; 12. The processing apparatus according to claim 8, wherein the grinding process is controlled so as to adjust at least the amount of grinding of the other substrate in the finish grinding mechanism and the relative inclination.

13. The control unit is The processing apparatus according to any one of claims 8 to 12, wherein the grinding process is controlled so as to re-grind the one substrate based on the acquired thickness and thickness distribution of the one substrate after grinding.

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