Substrate processing system and substrate processing method

Abstract

A substrate processing system that processes a bonded substrate formed by joining a first substrate and a second substrate, the substrate processing system including: a processing device that grinds the first substrate; a first thickness measuring device that measures a thickness of the first substrate before grinding by the processing device and a total thickness of the bonded substrate including the first substrate; and a second thickness measuring device that measures a thickness of the first substrate after grinding by the processing device.

Description

TECHNICAL FIELD

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

[0002] In Patent Literature 1, there is disclosed a grinding processing apparatus that adjusts a tilt angle of a holding table to adjust a wafer thickness. In the grinding processing apparatus, a final thickness measuring device that measures a thickness of a wafer after secondary grinding at a plurality of points in a radial direction is provided in the vicinity of a secondary grinding position, and a thickness distribution in the radial direction of the wafer is grasped based on the thickness of the wafer measured by the device. Further, based on the grasped thickness distribution in the radial direction, the angle of the wafer with respect to a grindstone is adjusted by tilting the holding table by a tilt angle adjustment mechanism, and the thickness of the wafer after secondary grinding is adjusted.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2008-264913 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] The technology related to the present disclosure improves the throughput of substrate processing including grinding of a substrate.

[0008] SOLUTION TO PROBLEM

[0009] A substrate processing system that processes a stacked substrate in which a first substrate is joined to a second substrate, the substrate processing system including: a processing device that grinds the first substrate; a first thickness measuring device that measures a thickness of the first substrate before grinding by the processing device and a total thickness of the stacked substrate including the first substrate; and a second thickness measuring device that measures a thickness of the first substrate after grinding by the processing device.

[0010] EFFECT OF THE INVENTION

[0011] According to the present disclosure, the throughput of substrate processing including grinding of a substrate can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 FIG. 1 is a side view showing an example of a structure of a stacked wafer processed by a wafer processing system.

[0013] Figure 2 FIG. 2 is a plan view showing an example of a structure of the wafer processing system.

[0014] Figure 3 FIG. 3 is a side view showing an example of an internal structure of the wafer processing system.

[0015] Figure 4 is an explanatory diagram showing the thickness of the upper wafer, the thickness of the lower wafer, and the overall thickness of the overlapped wafer.

[0016] Figure 5 is a side view showing a structure example of each grinding unit.

[0017] Figure 6 is a plan view showing a structure example of the first thickness measuring device.

[0018] Figure 7 is a side view showing a structure example of the first thickness measuring device.

[0019] Figure 8 is a perspective view showing a structure example of the first thickness measuring device.

[0020] Figure 9 is an explanatory diagram showing an example of a measurement position of the thickness when viewed from above.

[0021] Figure 10 is a plan view showing an example of a case where the thickness measurement by the overall thickness measuring section is performed.

[0022] Figure 11 is a plan view showing an example of a case where the thickness measurement by the partial thickness measuring section is performed.

[0023] Figure 12 is an explanatory diagram showing an air flow generated inside the first thickness measuring device.

[0024] Figure 13 is a plan view showing a structure example of the second thickness measuring device.

[0025] Figure 14 is a side view showing a structure example of the second thickness measuring device.

[0026] Figure 15 is a flowchart showing an example of main processes of wafer processing.

[0027] Figure 16 is an explanatory diagram showing an example of main processes in the first thickness measuring device.

[0028] Figure 17 is an explanatory diagram showing an example of main processes in the second thickness measuring device.

[0029] Figure 18 is a plan view showing a structure example of a wafer processing system according to another embodiment. DETAILED DESCRIPTION

[0030] In recent years, in a manufacturing process of a semiconductor device, a stacked wafer in which a semiconductor substrate (hereinafter, referred to as "upper wafer") on which a plurality of electronic circuits or the like are formed on a surface is bonded to a lower wafer is thinned by grinding a back surface of the upper wafer.

[0031] The thinning of the upper wafer is performed by bringing a grinding tool into contact with the back surface of the upper wafer while the back surface of the lower wafer is held by a holding chuck, and then performing grinding. However, in the case where the grinding of the upper wafer is performed like this, it is possible that the flatness (TTV: Total Thickness Variation) of the upper wafer after the grinding is deteriorated due to the relative inclination between the grinding tool brought into contact with the back surface of the upper wafer and the holding chuck holding the lower wafer.

[0032] In the grinding processing apparatus disclosed in the above-described Patent Document 1, the thickness of the wafer is adjusted by adjusting the inclination angle of the holding chuck table, thereby achieving, for example, a uniform thickness. Specifically, after the secondary grinding (fine grinding) is completed, the thickness of the wafer is measured at a plurality of points in the radial direction to grasp the thickness distribution in the radial direction of the wafer, and the holding chuck table is inclined based on the thickness distribution to adjust the angle of the wafer with respect to the grinding tool. In addition, in the grinding processing apparatus, a final thickness measuring device is provided in the vicinity of the secondary grinding position, and the thickness of the wafer is measured while the wafer is held by the holding chuck. Moreover, the operation time for grasping the thickness distribution in the radial direction is shortened, and as a result, improvement of the production efficiency is achieved.

[0033] However, in the grinding processing apparatus disclosed in the Patent Document 1, the secondary grinding of the wafer and the thickness measurement of the wafer are performed at the secondary grinding position. In the case where the inclination of the holding chuck table after the secondary grinding is utilized for adjustment of the inclination of the holding chuck table at the time of grinding of the next wafer, the operation time at the secondary grinding position of the grinding processing apparatus is lengthened, and as a result, the throughput of the entire wafer processing is decreased. Thus, the conventional wafer processing has room for improvement.

[0034] The technology related to the present disclosure improves the throughput of the substrate processing including grinding of a substrate. Hereinafter, a wafer processing system as a substrate processing system related to the present embodiment, and a wafer processing method as a substrate processing method will be described with reference to the drawings. Furthermore, in the present specification and the drawings, the same reference numerals are attached to elements having substantially the same functional structure, and thus repeated description is omitted.

[0035] In the wafer processing system 1 related to the present embodiment described later, as shown in Figure 1As shown, a superimposed wafer T, which is formed by bonding an upper wafer W (serving as a first substrate) and a lower wafer S (serving as a second substrate), is processed. Furthermore, in the wafer processing system 1, the upper wafer W is thinned. Hereinafter, in the upper wafer W, the side that is bonded to the lower wafer S is called surface Wa, and the side opposite to surface Wa is called back surface Wb. Similarly, in the lower wafer S, the side that is bonded to the upper wafer W is called surface Sa, and the side opposite to surface Sa is called back surface Sb.

[0036] The upper wafer W is, for example, a semiconductor wafer such as a silicon substrate, on which a device layer Dw, including multiple devices, is formed. Additionally, a surface film Fw is formed on the device layer Dw, and the upper wafer S is bonded to the lower wafer S through this surface film Fw. Examples of surface films Fw include oxide films (SiO2 films, TEOS films), SiC films, SiCN films, or adhesives.

[0037] The lower wafer S has, for example, the same structure as the upper wafer W, with a device layer Ds and a surface film Fs formed on its surface Sa. Furthermore, the lower wafer S need not be a device wafer with the device layer Ds formed; for example, it could be a support wafer supporting the upper wafer W. In this case, the lower wafer S functions as a protective element protecting the device layer Dw of the upper wafer W.

[0038] Furthermore, in the accompanying drawings used in the following description, to avoid the clutter of the illustrations, the illustrations of device layers Dw and Ds and surface films Fw and Fs are sometimes omitted.

[0039] like Figure 2 and Figure 3 As shown, the wafer processing system 1 has a structure in which a loading / unloading station 2 and a processing station 3 are connected as one unit. The loading / unloading station 2 is, for example, a box C capable of accommodating multiple overlapping wafers T that is loaded and unloaded between the system and the outside. The processing station 3 is equipped with various processing devices for performing desired processing on the overlapping wafers T.

[0040] A box-loading platform 10 is provided in the loading / unloading station 2, which serves as the loading / unloading area. In the illustrated example, multiple boxes, such as two boxes C, are freely arranged in a row along the Y-axis on the box-loading platform 10. Furthermore, the number of boxes C placed on the box-loading platform 10 is not limited to this embodiment and can be arbitrarily determined.

[0041] The processing station 3 is provided with, for example, three processing blocks Gl to G3. The first processing block Gl, the second processing block G2, and the third processing block G3 are arranged in this order from the negative direction side of the X axis (the side of the carrying-in and carrying-out station 2) to the positive direction side. The respective processing blocks Gl to G3 are spatially partitioned by partition walls, and the coincident wafer T is carried between the respective processing blocks Gl to G3 via the carrying-in and carrying-out ports formed in the respective processing devices. Further, a gate (not shown) for opening and closing the carrying-in and carrying-out ports formed in the respective processing devices is provided.

[0042] The first processing block Gl is provided with an etching processing device 30 and a wafer carrying device 40. The etching processing device 30 is provided, for example, in two layers stacked in the vertical direction. The wafer carrying device 40 is arranged on the positive direction side of the Y axis of the etching processing device 30. Further, the number and arrangement of the etching processing device 30 and the wafer carrying device 40 are not limited to this.

[0043] The etching processing device 30 etches the back surface Wb of the upper wafer W and the back surface Sb of the lower wafer S after grinding. At this time, cleaning processing such as removal of fine particles and removal of metal components is also performed. For example, an etching liquid is supplied to the back surfaces Wb and Sb to perform wet etching on the back surfaces Wb. The etching liquid uses, for example, FPM, HF, HNO3, H3PO4, TMAH, Choline, KOH, or the like.

[0044] The wafer carrying device 40 as the first substrate carrying device has, for example, two carrying arms 41 that hold and carry the coincident wafer T. Each carrying arm 41 is configured to be movable in the horizontal direction and the vertical direction and to be rotatable around the horizontal axis and the vertical axis. Further, the wafer carrying device 40 is configured to be able to carry the coincident wafer T to the cassette placement table 10, the etching processing device 30, a first cleaning device 50 to be described later, a second cleaning device 51 to be described later, a first thickness measuring device 52 to be described later, and a second thickness measuring device 53 to be described later.

[0045] In addition, a fan filter unit (FFU) not shown is provided in the first processing block Gl. Thereby, the cleanliness of the inside of the first processing block Gl is maintained to be high, and the pressure of the inside is maintained to be higher than that of the inside of the second processing block G2.

[0046] The first cleaning device 50, the second cleaning device 51, the first thickness measuring device 52, the second thickness measuring device 53, and the wafer conveyance device 60 are provided in the second processing block G2 as the processing region. The first cleaning device 50, the second cleaning device 51, the first thickness measuring device 52, and the second thickness measuring device 53 are provided in this order from the upper side. The wafer conveyance device 60 is disposed on the Y-axis negative direction side of the first cleaning device 50, the second cleaning device 51, the first thickness measuring device 52, and the second thickness measuring device 53. Note that the number and disposition of the first cleaning device 50, the second cleaning device 51, the first thickness measuring device 52, the second thickness measuring device 53, and the wafer conveyance device 60 are not limited to this.

[0047] The first cleaning device 50 cleans the back surface Wb of the upper wafer W and the back surface Sb of the lower wafer S before grinding in the processing device 70 described later. For example, the back surface Wb is spin cleaned by supplying a cleaning liquid to the back surface Wb, and the back surface Sb is brush cleaned by bringing a brush into contact with the back surface Sb.

[0048] The second cleaning device 51 cleans the back surface Wb of the upper wafer W and the back surface Sb of the lower wafer S after grinding in the processing device 70 described later. The second cleaning device 51 also spin cleans the back surface Wb by supplying a cleaning liquid to the back surface Wb, and brush cleans the back surface Sb by bringing a brush into contact with the back surface Sb, like the first cleaning device 50.

[0049] The first thickness measuring device 52 measures the thickness Hw (refer to Figure 4 ) of the upper wafer W before grinding in the processing device 70 described later, and the entire thickness Ht (refer to Figure 4 ) of the stacked wafer T including the upper wafer W. In addition, the first thickness measuring device 52 adjusts the direction and position of the stacked wafer T in the horizontal direction before grinding. Note that the detailed structure of the first thickness measuring device 52 and the detailed method of thickness measurement are described later.

[0050] The second thickness measuring device 53 measures the thickness Hw (refer to Figure 4 ) of the upper wafer W after grinding in the processing device 70 described later. In addition, the second thickness measuring device 53 adjusts the direction and position of the stacked wafer T in the horizontal direction after grinding. Note that the detailed structure of the second thickness measuring device 53 and the detailed method of thickness measurement are described later.

[0051] The wafer transport apparatus 60, serving as a second substrate transport apparatus, includes, for example, two transport arms 61 that adsorb and hold overlapping wafers T using an adsorption and holding surface (not shown) for transport. Each transport arm 61 is configured to be freely movable in the horizontal and vertical directions, and freely movable about the horizontal and vertical axes. Furthermore, the wafer transport apparatus 60 is configured to transport overlapping wafers T to the second cleaning apparatus 51, the first thickness measuring apparatus 52, and the processing apparatus 70 described later.

[0052] Furthermore, in this embodiment, the case in which the wafer transfer device 60 does not transfer the overlapping wafer T to the first cleaning device 50 and the second thickness measuring device 53 based on the wafer processing process described later is used as an example. However, it is also possible to configure the wafer processing process in a way that allows the overlapping wafer T to be transferred to the first cleaning device 50 and the second thickness measuring device 53.

[0053] A processing device 70 is provided in the third processing block G3, which serves as the processing area. Furthermore, the number and configuration of the processing devices 70 are not limited thereto.

[0054] The processing apparatus 70 includes a rotary table 71. Four holding disks 72 are provided on the rotary table 71 as a third substrate holding portion for holding and holding the superimposed wafer T. The holding disks 72, for example, are porous holding disks, which hold and hold the back surface Sb of the lower wafer S in the superimposed wafer T. The surface of the holding disk 72, i.e., the holding surface of the superimposed wafer T, has a convex shape in which the central portion protrudes more than the ends when viewed from the side. Furthermore, this central protrusion is slight; therefore, the convex shape of the holding disk 72 is omitted in the illustrations described below.

[0055] like Figure 5 As shown, the retaining disc 72 is held in the retaining disc base 73. The retaining disc base 73 is provided with a tilt adjustment section 74 for adjusting the relative tilt between the grinding wheels of each grinding unit (rough grinding unit 80, intermediate grinding unit 90, and fine grinding unit 100, described later) and the retaining disc 72. The tilt adjustment section 74 has a fixed shaft 75 provided on the lower surface of the retaining disc base 73, and multiple, for example, two lifting shafts 76. Each lifting shaft 76 is configured to extend and retract freely for raising and lowering the retaining disc base 73. Through this tilt adjustment section 74, with one end of the outer periphery of the retaining disc base 73 (the position corresponding to the fixed shaft 75) as a base point, the other end can be raised and lowered vertically via the lifting shafts 76, thereby tilting the retaining disc 72 and the retaining disc base 73. Furthermore, this allows adjustment of the relative tilt between the surfaces of the grinding wheels of each grinding unit 80, 90, and 100 in machining positions A1 to A3 and the surface of the retaining disc 72.

[0056] Furthermore, the structure of the tilt adjustment part 74 is not limited to this; it can be selected arbitrarily as long as it can adjust the relative angle (parallelism) between the surface of the holding disc 72 and the surface of the grinding wheel.

[0057] like Figure 2 As shown, the four holding discs 72 can be moved to the transfer position A0 and the processing positions A1 to A3 by rotating the rotary table 71. In addition, the four holding discs 72 are each configured to be rotatable about a vertical axis by a rotating mechanism (not shown).

[0058] At the handover position A0, the overlapping wafer T is handed over by the wafer transport device 60. A rough grinding unit 80 is configured at processing position A1 to perform rough grinding on the upper wafer W. A medium grinding unit 90 is configured at processing position A2 to perform medium grinding on the upper wafer W. A fine grinding unit 100 is configured at processing position A3 to perform fine grinding on the upper wafer W.

[0059] like Figure 5 As shown, the rough grinding unit 80 includes a rough grinding wheel 81 with an annular rough grinding tool on its lower surface, a mounting member 82 supporting the rough grinding wheel 81, a spindle 83 that rotates the rough grinding wheel 81 via the mounting member 82, and a drive unit 84, for example, incorporating a motor (not shown). Furthermore, the rough grinding unit 80 is capable of moving along... Figure 2 The support column 85 shown is configured to move in the vertical direction.

[0060] The intermediate grinding unit 90 has the same structure as the rough grinding unit 80. That is, the intermediate grinding unit 90 has an intermediate grinding wheel 91 with an annular intermediate grinding tool, a mounting member 92, a spindle 93, a drive unit 94, and a support 95. The abrasive grains of the intermediate grinding tool are smaller than those of the rough grinding tool.

[0061] The fine grinding unit 100 has the same structure as the rough grinding unit 80 and the medium grinding unit 90. That is, the fine grinding unit 100 has a fine grinding wheel 101 with an annular fine grinding tool, a mounting member 102, a spindle 103, a drive unit 104, and a support 105. The abrasive grains of the fine grinding tool are smaller than those of the medium grinding tool.

[0062] Furthermore, an exhaust unit (not shown) is provided in the third processing block G3. This allows for the removal of particles and the like generated during the grinding process in the processing apparatus 70, and maintains the internal pressure of the third processing block G3 at a lower level than that of the second processing block G2. In other words, in the wafer processing system 1, the internal pressures of the first processing block G1, the second processing block G2, and the third processing block G3 are controlled to increase sequentially.

[0063] like Figure 2As shown in the above wafer processing system 1, a control device 110 is provided. The control device 110 is, for example, a computer provided with a CPU, a memory, and the like, and has a program storage section (not shown). A program for controlling wafer processing in the wafer processing system 1 is stored in the program storage section. Further, the above program can be recorded in a storage medium H which is readable by the computer, and installed in the control device 11 from the storage medium H.

[0064] Next, the detailed structure of the above first thickness measuring device 52 will be described.

[0065] As shown in Figure 6 and Figure 7 The first thickness measuring device 52 has a holding disk 300 as a first substrate holding section which holds the stacked wafer T. The holding disk 300 adsorbs and holds the central portion of the back surface Sb of the lower wafer S in the stacked wafer T. Further, the diameter of the holding disk 300 is, for example, less than half of the diameter of the stacked wafer T.

[0066] The holding disk 300 is formed with a cutout section 301 which extends from the central portion of the holding disk 300 to the outer end portion in the radial direction (Y-axis direction). The cutout section 301 is formed in a manner that the lower sensor 332 of the overall thickness measuring section 330 to be described later can advance and retreat.

[0067] The holding disk 300 is configured to be rotatable about a vertical axis and movable in the horizontal direction. A rotation mechanism 310 for rotating the holding disk 300 is provided below the holding disk 300. A driving section (not shown) such as a motor is built in the rotation mechanism 310. The rotation mechanism 310 is supported by a support member 311. The support member 311 is attached to a guide rail 312 which extends in the horizontal direction (Y-axis direction). The support member 311 is configured to be movable along the guide rail 312 by a movement mechanism 313 provided to the guide rail 312. A driving section (not shown) such as a motor is built in the movement mechanism 313. Further, in the present embodiment, the rotation mechanism 310 and the movement mechanism 313 which drive the holding disk 300 constitute the "first driving section" according to the present disclosure.

[0068] A position detection unit 320, serving as a first position detection unit, is provided on the side (positive X-axis direction side) of the holding disk 300. The position detection unit 320 detects the horizontal position of the overlapping wafer T before grinding. The position detection unit 320 has a sensor that irradiates light onto the outer periphery of the lower wafer S held on the holding disk 300 and receives the light. Alternatively, the position detection unit 320 may also have a sensor that captures images of the outer periphery of the lower wafer S. Furthermore, while rotating the overlapping wafer T held on the holding disk 300, the position of the groove portion of the lower wafer S is detected by the position detection unit 320, and the position (eccentricity) of the center portion of the overlapping wafer T (upper wafer W) is also detected. The detection result of the position detection unit 320 is output to the control device 110. Furthermore, based on the detection result, the orientation (θ alignment) of the overlapping wafer T in the horizontal direction is adjusted, and the position (XY alignment) in the horizontal direction is adjusted. In addition, in this embodiment, the position of the groove portion of the lower wafer S is detected, but it is not limited to this. For example, the position of the orientation plane of the lower wafer S can be detected to adjust the orientation and position of the overlapping wafer T in the horizontal direction.

[0069] Overall thickness measuring units 330 are provided above and below the holding plate 300. Overall thickness measuring units 330 measure... Figure 4 The overall thickness Ht of the overlapping wafer T shown is also output to the control device 110, as measured by the overall thickness measuring unit 330.

[0070] like Figures 6-8 As shown, the overall thickness measurement unit 330 includes an upper sensor 331, a lower sensor 332, and a calculation unit (not shown). The upper sensor 331 is positioned above the overlapping wafer T held on the holding disk 300 and measures the distance from the upper sensor 331 to the back surface Wb of the upper wafer W. The lower sensor 332 is positioned below the overlapping wafer T held on the holding disk 300 and measures the distance from the lower sensor 332 to the back surface Sb of the lower wafer S. Furthermore, the upper sensor 331 and the lower sensor 332 are arranged facing each other on the same coordinate axis, so that the measurement point of the upper sensor 331 and the measurement point of the lower sensor 332 are at the same position when viewed from above. Moreover, in the overall thickness measurement unit 330, the overall thickness Ht of the overlapping wafer T is derived by the calculation unit based on the distance between the upper sensor 331 and the back surface Wb of the upper wafer W, and the distance between the lower sensor 332 and the back surface Sb of the lower wafer S. Furthermore, the upper sensor 331 and the lower sensor 332 can be distance-measuring sensors, and known sensors, such as confocal sensors, can be used. Additionally, the calculation unit (not shown) can be located either inside or outside the first thickness measuring device 52.

[0071] The upper sensor 331 and the lower sensor 332 move relative to the holding disk 300 by moving it horizontally. Furthermore, the lower sensor 332 is configured to move freely forward and backward relative to the notch 301. That is, by moving the holding disk 300 horizontally, the lower sensor 332 enters or retracts relative to the notch 301. Moreover, the overall thickness measuring unit 330 can measure the overall thickness Ht of the overlapping wafer T at multiple points.

[0072] Furthermore, the upper sensor 331 and the lower sensor 332 are positioned such that when the overlapping wafer T is rotated during the horizontal position detection performed by the aforementioned position detection unit 320, the lower sensor 332 will not interfere with the notch portion 301, that is, a position closer to the positive Y-axis direction than the position detection unit 320.

[0073] Above the holding plate 300, a partial thickness measuring unit 340, serving as the first measuring unit, is also provided. The partial thickness measuring unit 340 measures... Figure 4 The thickness Hw of the upper wafer W is shown. The partial thickness measurement unit 340 measures the thickness of the upper wafer W without contacting it. Furthermore, the thickness Hw of the upper wafer W measured by the partial thickness measurement unit 340 is output to the control device 110. In the control device 110, the thickness Hs other than that of the upper wafer W is calculated by subtracting the thickness Hw of the upper wafer W from the overall thickness Ht of the overlapping wafer T measured by the overall thickness measurement unit 330. This thickness Hs includes the thickness of the lower wafer S, the thicknesses of device layers Dw and Ds, and the thicknesses of surface films Fw and Fs, but in the following description, it is sometimes simply referred to as the thickness Hs of the lower wafer S.

[0074] The calculated thickness Hs of the lower wafer S is output to the control device 110. Furthermore, based on the thickness Hs of the lower wafer S, the relative angle (parallelism) between the surface of the holding disk 72 in the processing device 70 and the surface of the grinding wheel is adjusted.

[0075] like Figures 6-8 As shown, the partial thickness measurement unit 340 includes a sensor 341 and a calculation unit (not shown). The sensor 341 illuminates the upper wafer W and receives reflected light from the surface Wa of the upper wafer W and reflected light from the back surface Wb. Furthermore, in the partial thickness measurement unit 340, the calculation unit measures the thickness Hw of the upper wafer W based on the two reflected lights. Additionally, the sensor 341 is positioned in the Y-axis direction at the same position as the aforementioned position detection unit 320. Moreover, the sensor 341 can be any thickness-measuring sensor, and a known sensor, such as a spectroscopic interferometer sensor, can be used. Furthermore, the calculation unit (not shown) can be located either inside or outside the first thickness measurement device 52.

[0076] The sensor 341 moves relatively to the holding disk 300 by moving the holding disk 300 in the horizontal direction. Also, the partial thickness measuring section 340 can measure the thickness Hw of the upper wafer W at a plurality of points.

[0077] The entire thickness measuring section 330 and the partial thickness measuring section 340 measure the entire thickness Ht of the stacked wafer T and the thickness Hw of the upper wafer W, respectively, at the same measurement point when viewed in plan view. That is, as shown in Figure 9 , the entire thickness measuring section 330 and the partial thickness measuring section 340 measure the entire thickness Ht of the stacked wafer T and the thickness Hw of the upper wafer W, respectively, at three points, for example, in the radial direction. The measurement point P1 is the center portion of the upper wafer W. The measurement point P2 is the intermediate portion of the upper wafer W, which is the position of R / 2 from the center portion in the case where the radius of the upper wafer W is R. The measurement point P3 is the outer peripheral portion of the upper wafer W.

[0078] As shown in Figure 10 (a), in the measurement of the entire thickness Ht at the measurement point P1 by the entire thickness measuring section 330, the entire thickness Ht of the stacked wafer T is measured in a state where the rotation of the holding disk 300 (the stacked wafer T) is stopped. At this time, the lower sensor 332 enters the cutout portion 301. Thus, in order to avoid interference between the lower sensor 332 and the holding disk 300, the holding disk 300 is not rotated.

[0079] On the other hand, as shown in Figure 11 (a), in the measurement of the thickness Hw of the upper wafer W at the measurement point P1 by the partial thickness measuring section 340, interference between the sensor 341 and the holding disk 300 does not occur, and thus the holding disk 300 (the stacked wafer T) can be rotated or the rotation can be stopped.

[0080] As shown in Figure 10 (b), in the measurement of the entire thickness Ht at the measurement point P2 by the entire thickness measuring section 330, the entire thickness Ht of the stacked wafer T is measured at a plurality of points in the circumferential direction while the holding disk 300 is rotated. At this time, since the diameter of the holding disk 300 is less than half the diameter of the stacked wafer T, the lower sensor 332 retreats from the cutout portion 301, and thus the lower sensor 332 does not interfere with the holding disk 300 even if the holding disk 300 is rotated.

[0081] In addition, as shown in Figure 11 (b), in the measurement of the thickness Hw of the upper wafer W at the measurement point P2 by the partial thickness measuring section 340, the thickness Hw of the upper wafer W is also measured at a plurality of points in the circumferential direction while the holding disk 300 is rotated.

[0082] Furthermore, the average value of the movement of multiple points along the circumference measured at measurement point P2 is calculated as the overall thickness Ht of the overlapping wafer T or the thickness Hw of the upper wafer W at measurement point P2. Alternatively, the measured thickness at measurement point P2 can be set as the center value of the movement of multiple points along the circumference.

[0083] like Figure 10 (c) and Figure 11 As shown in (c), at measurement point P3, the overall thickness Ht of the overlapping wafer T and the thickness Hw of the upper wafer W are measured in the same way as at measurement point P2.

[0084] Furthermore, in this embodiment, the average value or the central value of multiple points along the circumference is set as the measured thickness at measurement points P2 and P3. However, the thickness measurement can also be performed at a designated coordinate point. For example, at measurement points P2 and P3, the overall thickness Ht of the overlapping wafer T or the thickness Hw of the upper wafer W is measured while the rotation of the overlapping wafer T is stopped. Thus, at measurement points P2 and P3, the overall thickness Ht or the thickness Hw of the upper wafer W is measured at a single point along the circumference. Moreover, the thickness measured at this designated coordinate point can be used as a representative point for the thickness at measurement points P2 and P3.

[0085] Furthermore, in this embodiment, the measurement result of the thickness Hw of the upper wafer W is used to adjust the parallelism between the surface of the holding disk 72 and the surface of the fine grinding wheel 101, as described later, but its application is not limited thereto. For example, the thickness Hw of the upper wafer W may also be measured at a designated measurement point in order to grasp the tendency of the thickness Hw of the upper wafer W.

[0086] Furthermore, in the first thickness measuring device 52 of this embodiment, the holding disk 300 moves in the horizontal direction (Y-axis direction), while the upper sensor 331 and lower sensor 332 of the overall thickness measuring unit 330 and the sensor 341 of the partial thickness measuring unit 340 are fixed. However, the holding disk 300 can move horizontally relative to either the overall thickness measuring unit 330 or the partial thickness measuring unit 340. For example, the holding disk 300 may be fixed, while the upper sensor 331 and lower sensor 332, or sensor 341, move horizontally. Alternatively, the holding disk 300 may move horizontally, and the upper sensor 331 and lower sensor 332, or sensor 341, may also move horizontally.

[0087] like Figure 6As shown, a first gate 350 is provided on the side wall surface on the negative direction side of the X-axis of the first thickness measuring device 52. The first gate 350 is configured so as to open and close the first transfer port by a driving mechanism 351. Further, by opening the first gate 350, the first thickness measuring device 52 is communicated with the inside of the first processing block Gl, and the in-and-out transfer of the superimposed wafer T is performed by the wafer transfer device 40.

[0088] In addition, a second gate 360 is provided on the side wall surface on the negative direction side of the Y-axis of the first thickness measuring device 52. The second gate 360 is configured so as to open and close the second transfer port by a driving mechanism 361. Further, by opening the second gate 360, the first thickness measuring device 52 is communicated with the inside of the second processing block G2, and the in-and-out transfer of the superimposed wafer T is performed by the wafer transfer device 60.

[0089] An exhaust portion 370 is connected to the lower portion of the first thickness measuring device 52. The exhaust portion 370 has an exhaust path 371 provided below the driving portion such as the guide rail 312, and an exhaust mechanism 372 such as a vacuum pump connected to the exhaust path 371. The exhaust portion 370 exhausts, to the outside of the first thickness measuring device 52, the fine particles and the like generated due to the driving such as the rotation and movement of the holding disc 300, by the operation of the exhaust mechanism 372.

[0090] In addition, the exhaust portion 370 is configured so as to be able to exhaust (depressurize) the processing space of the first thickness measuring device 52. The internal pressure of the first thickness measuring device 52 is controlled to be maintained at a pressure lower than the internal pressure of the first processing block Gl and higher than the internal pressure of the second processing block G2. In other words, in the first thickness measuring device 52, the air flow from the first processing block Gl flows in when the first gate 350 is opened, and the air flow to the second processing block G2 flows out when the second gate 360 is opened. Thus, as shown in (a) of FIG. 10, the inflow of the fine particles and the like due to the grinding processing in the processing device 70 to the inside of the first thickness measuring device 52 is suppressed, and the outflow of the fine particles and the like to the side of the first processing block Gl (the cassette C) as the clean space is also suppressed. Figure 12 As shown, the inflow of the fine particles and the like due to the grinding processing in the processing device 70 to the inside of the first thickness measuring device 52 is suppressed, and the outflow of the fine particles and the like to the side of the first processing block Gl (the cassette C) as the clean space is also suppressed.

[0091] Specifically, for example, as shown in (a) of FIG. 10, when the first gate 350 and the second gate 360 are closed, the outflow of the air flow from the first thickness measuring device 52 does not occur, and only the air flow is exhausted from the exhaust portion 370. In addition, even in the case where the first gate 350 is closed like this, as shown in (a) of FIG. 10, a slight amount of air flow from the first processing block Gl as the clean space flows in from the slight gap formed on the side of the first gate 350. Figure 12 Figure 12

[0092] In addition, as shown in (b) of FIG. 10, when the first gate 350 is opened, the air flow from the first processing block Gl as the clean space flows in from the slight gap formed on the side of the first gate 350. Figure 12 ​​As shown in (b), in a case where the first gate 350 is opened, only the gas flow is discharged from the exhaust portion 370.

[0093] Further, as shown in (c), in a case where the second gate 360 is opened, the inflow of the gas flow from the second gate 360 side to the first thickness measuring device 52 is not generated, and in addition, the outflow of the gas flow from the first gate 350 side to the outside of the first thickness measuring device 52 is not generated. Figure 12

[0094] As such, in the first thickness measuring device 52, the gas flow is only flown in from the first gate 350 (the first processing block G1) side, and the gas flow is not flown in from the second gate 360 (the processing device 70) side. That is, the inflow of the particles and the like from the processing device 70 is suppressed.

[0095] In addition, in the first thickness measuring device 52, the gas flow is only flown out from the second gate 360 (the processing device 70) side and the exhaust portion 370, and the gas flow is not flown out to the first gate 350 (the first processing block G1) side. That is, the outflow of the particles and the like to the first processing block G1 which is the clean space is suppressed.

[0096] Further, as shown in (c), in a case where the second gate 360 is opened, the inflow of the gas flow from the second gate 360 side to the first thickness measuring device 52 is not generated, and in addition, the outflow of the gas flow from the first gate 350 side to the outside of the first thickness measuring device 52 is not generated. Figure 12

[0097] Next, the detailed structure of the second thickness measuring device 53 will be described. Further, in the second thickness measuring device 53, elements having substantially the same functional structure as the first thickness measuring device 52 are labeled with the same reference numerals, and thus the repeated description is omitted.

[0098] As shown in (a) and (b), the second thickness measuring device 53 has a holding disk 400 which is a second substrate holding portion that holds the stacked wafer T. The holding disk 400 adsorbs a central portion of the back surface Sb of the lower wafer S in the stacked wafer T. Further, the diameter of the holding disk 400 is, for example, larger than the diameter of the holding disk 300 provided in the first thickness measuring device 52, and can be more than half of the diameter of the stacked wafer T. Figure 13 Figure 14 In the second thickness measuring device 53, the thickness Hw of the ground upper wafer W is measured, in other words, the thickness Hw which is smaller than the thickness Hw of the upper wafer W before grinding in the first thickness measuring device 52. Therefore, by adsorbing the stacked wafer T with the holding disk 400 having a larger diameter than the holding disk 300 as such, the warping of the stacked wafer T after being thinned by grinding is suppressed.

[0099] In the second thickness measuring device 53, the thickness Hw of the ground upper wafer W is measured, in other words, the thickness Hw which is smaller than the thickness Hw of the upper wafer W before grinding in the first thickness measuring device 52. Therefore, by adsorbing the stacked wafer T with the holding disk 400 having a larger diameter than the holding disk 300 as such, the warping of the stacked wafer T after being thinned by grinding is suppressed.

[0100] ​​​The holding disk 400 is configured so as to be rotatable about the vertical axis by the rotation mechanism 310 and movable in the horizontal direction along the guide rail 312. In addition, a position detection section 320 as a second position detection section is provided on the side of the holding disk 400 (on the positive direction side of the X axis), and the direction and position of the ground wafer T in the horizontal direction are adjusted, and the position (eccentricity) of the center portion of the upper wafer W is detected. Further, in the present embodiment, the rotation mechanism 310 and the moving mechanism 313 that drive the holding disk 400 constitute a "second driving section" according to the present disclosure.

[0101] A partial thickness measurement section 440 as a second measurement section that measures the thickness Hw of the ground upper wafer W is provided above the holding disk 400. The partial thickness measurement section 440 measures the thickness of the upper wafer W in a manner so as not to come into contact with the upper wafer W. Further, as described above, the measurement of the thickness Hw of the ground upper wafer W is performed in the second thickness measurement device 53, in other words, the measurement of the thickness Hw that is smaller than the thickness Hw of the upper wafer W before grinding in the first thickness measurement device 52. Therefore, a sensor 441 capable of measuring a small thickness is provided in the partial thickness measurement section 440 as compared with the partial thickness measurement section 340 provided in the first thickness measurement device 52.

[0102] Further, the thickness Hw of the upper wafer W measured by the partial thickness measurement section 440 is output to the control device 110. Also, based on the thickness Hw of the upper wafer W, the relative angle (parallelism) of the surface of the holding disk 72 with respect to the surface of the grinding wheel at the time of the grinding process on the wafer to be processed next in the wafer processing system 1 is adjusted.

[0103] When viewed from above, the partial thickness measurement section 440 measures the thickness Hw of the upper wafer W at the same measurement points as the entire thickness measurement section 330 and the partial thickness measurement section 340 in the first thickness measurement device 52. That is, the partial thickness measurement section 440 measures the thickness Hw of the upper wafer W at three points in the radial direction, for example, as shown in FIG. 6. Figure 9 Further, the measurement method of the thickness Hw of the upper wafer W performed by the partial thickness measurement section 440 is the same as the measurement method of the thickness Hw of the upper wafer W performed by the partial thickness measurement section 340 shown in FIG. 5. Figure 11

[0104] Further, in the second thickness measurement device 53, as in the first thickness measurement device 52, instead of the moving average or the moving central value of a plurality of points in the circumferential direction, the thickness measured at a specified coordinate can be used as the representative point for the thickness of the measurement points P2, P3 at the time of the thickness measurement at the measurement points P2, P3.

[0105] ​Furthermore, in this embodiment, the measurement result of the thickness Hw of the upper wafer W is used to adjust the relative angle between the surface of the holding disk 72 and the surface of the grinding wheel when grinding the overlapping wafer T to be processed next, but its application is not limited to this. For example, the thickness Hw of the upper wafer W may also be measured at a designated measurement point in order to grasp the tendency of the thickness Hw of the upper wafer W.

[0106] Furthermore, as described above, the overall thickness Ht of the overlapping wafer T is not measured in the second thickness measuring device 53. Therefore, the overall thickness measuring unit 330 is not provided in the second thickness measuring device 53 as in the first thickness measuring device 52. In addition, since the overall thickness measuring unit 330 (lower sensor 332) is not provided in the second thickness measuring device 53, a cutout for the lower sensor 332 to enter is not formed in the holding plate 400.

[0107] like Figure 13 As shown, a first gate 350 is provided on the side wall of the second thickness measuring device 53 in the negative X-axis direction. The first gate 350 is configured such that the first conveying port can be opened and closed freely by a drive mechanism 351. Moreover, by opening the first gate 350, the second thickness measuring device 53 is connected to the interior of the first processing block G1, and the wafer conveying device 40 can move the overlapping wafer T in and out.

[0108] Furthermore, as described above, in the second thickness measuring device 53, the wafer transfer device 60 of the second processing block G2 does not handle the loading and unloading of the overlapping wafer T; only the wafer transfer device 40 of the first processing block G1 handles the loading and unloading of the overlapping wafer T. Therefore, the second thickness measuring device 53 does not have a second transfer port on the side of the second processing block G2, i.e., it does not have a second gate 360. Although the thickness Hw of the ground overlapping wafer T (upper wafer W) is measured in the second thickness measuring device 53 as described above, by omitting the second gate 360 ​​on the side of the second processing block G2 and handling the loading and unloading of the overlapping wafer T only by the wafer transfer device 40, particles generated during the grinding process in the processing unit 70 are prevented from flowing into the interior of the second thickness measuring device 53.

[0109] Furthermore, an exhaust vent 370 is provided at the lower part of the second thickness measuring device 53. This configuration allows for the discharge of particles generated, such as those produced by the rotation of the holding disc 400 or its horizontal movement, to the outside of the second thickness measuring device 53, and also allows for the reduction of internal pressure within the second thickness measuring device 53. The internal pressure of the second thickness measuring device 53 is controlled to be maintained, for example, at a pressure lower than the internal pressure of the first processing block G1.

[0110] The first thickness measuring device 52 and the second thickness measuring device 53 involved in this embodiment are configured as described above. Next, the wafer processing performed using the wafer processing system 1 configured as described above will be described. In this embodiment, the upper wafer W and the lower wafer S are bonded in a bonding device (not shown) provided outside the wafer processing system 1, and an overlapping wafer T is pre-formed.

[0111] First, a cassette C containing multiple overlapping wafers T is placed on the cassette mounting stage 10 of the loading / unloading station 2. Next, the overlapping wafers T are removed from the cassette C by the wafer transport device 40 and transported to the first cleaning device 50. In the first cleaning device 50, cleaning fluid is supplied to the back surface Wb of the upward-facing wafer W while the overlapping wafers T are rotated, thereby performing rotational cleaning on the back surface Wb. Additionally, cleaning fluid is supplied while a cleaning brush (not shown) is in contact with the back surface Sb of the lower wafer S, thereby brushing and cleaning the back surface Sb. Figure 15 Step E1).

[0112] Next, the first gate 350 of the first thickness measuring device 52 is opened, and the overlapping wafer T is transported to the first thickness measuring device 52 by the wafer transport device 40. At this time, the internal pressure of the first thickness measuring device 52 is controlled to be lower than the internal pressure of the first processing block G1, thus preventing the first processing block G1, which serves as a clean space, from being contaminated due to the opening of the first gate 350. In the first thickness measuring device 52, the overlapping wafer T is first held by the holding disk 300 at the transport-in / transport-out position (in situ).

[0113] Next, keep the plate at 300 degrees. Figure 16 Move to the alignment position as shown in (a). Then, as... Figure 16 As shown in (b), while rotating the overlapping wafer T, the position detection unit 320 detects the horizontal position of the overlapping wafer T and the position (eccentricity) of the center of the upper wafer W. Based on the detection result, the horizontal orientation (θ alignment) of the overlapping wafer T is adjusted, and the horizontal position (XY alignment) is also adjusted. Figure 15 Step E2).

[0114] Additionally, at the alignment point, through Figure 11 The method shown involves measuring the thickness Hw of the upper wafer W before grinding using a partial thickness measuring unit 340. Figure 15Step E3). That is, firstly, the thickness Hw at the center of the upper wafer W (measurement point P1) is measured. When measuring the thickness Hw of the upper wafer W at measurement point P1, the holding disk 300 (overlapping wafer T) can be rotated or stopped. In addition, the measurement of the thickness Hw of the upper wafer W at measurement point P1 can also be performed simultaneously with the detection of the horizontal position of the overlapping wafer T (step E2). The thickness Hw (thickness Hw distribution) of the upper wafer W measured in this way is output to the control device 110.

[0115] Next, as Figure 16 As shown in (c), the holding disk 300 is moved and rotated sequentially in the negative Y-axis direction to measure the thickness Hw at multiple points (measurement points P2, P3) on the radial direction of the upper wafer W. When measuring the thickness Hw of the upper wafer W at measurement points P2 and P3, the holding disk 300 is rotated while the thickness Hw of the upper wafer W is measured at multiple points along the circumference, and the average value or center value of the measured circumferential points is calculated.

[0116] Next, as Figure 16 As shown in (d), the holding plate 300 is moved to the side of the overall thickness measuring section 330, and by... Figure 10 The method shown determines the overall thickness Ht of the overlapping wafer T. Figure 15 Step E4). That is, firstly, the overall thickness Ht at the center of the overlapping wafer T (measurement point P1) is measured. At measurement point P1, the lower sensor 332 enters the notch 301, so the overall thickness Ht of the overlapping wafer T at measurement point P1 is measured by the overall thickness measuring unit 330 while the rotation of the overlapping wafer T is stopped.

[0117] Next, as Figure 16 As shown in (e), the holding disk 300 is moved and rotated sequentially in the negative Y-axis direction to measure the overall thickness Ht at multiple points (measurement points P2, P3) in the radial direction of the overlapping wafer T. When measuring the overall thickness Ht of the overlapping wafer T at measurement points P2, P3, the holding disk 300 is rotated while the overall thickness Ht of the overlapping wafer T is measured at multiple points along the circumference, and the average value or center value of the measured circumferential points is calculated. The overall thickness Ht (distribution of overall thickness Ht) of the overlapping wafer T measured in this way is output to the control device 110.

[0118] When the alignment in step E2 and the thickness measurement in steps E3 and E4 are completed as described above, as Figure 16 As shown in (f), the holding disk 300 is moved to the loading / unloading position. At this time, by rotating the holding disk 300, the horizontal position of the upper wafer W, which was measured in step E2, is aligned with the desired position.

[0119] In the control device 110, the thickness Hs of the lower wafer S is calculated by subtracting the thickness Hw of the upper wafer W, measured in step E3, from the thickness Ht of the overlapping wafer T measured in step E4. Figure 15 (Step E5). Furthermore, the thickness Hs, as described above, includes the thickness of the lower wafer S, the thicknesses of the device layers Dw and Ds, and the thicknesses of the surface films Fw and Fs. Regarding the thickness Hs of the lower wafer S, the thickness Hs at each measurement point P1, P2, and P3 is calculated, thereby obtaining the distribution of the thickness Hs of the lower wafer S.

[0120] Furthermore, in the control device 110, the tilt adjustment section 74 at the processing position A3 of the processing device 70 is controlled based on the distribution of the thickness Hs of the lower wafer S calculated in step E5. Specifically, based on the distribution of the thickness Hs of the lower wafer S, the parallelism between the surface of the holding disk 72 and the surface of the fine grinding wheel 101 is adjusted to ensure that the in-plane thickness of the upper wafer W, which is coupled to the lower wafer S, is uniform after fine grinding. Figure 15 Step E6). In the following description, the adjustment of the parallelism between the surface of the holding disc 72 and the surface of the fine grinding wheel 101 is sometimes referred to as tilt correction.

[0121] Next, the second gate 360 ​​of the first thickness measuring device 52 is opened, and the overlapping wafer T is transported by the wafer transport device 60 to the processing device 70 and handed over to the holding disk 72 at the handover position A0. At this time, since the internal pressure of the first thickness measuring device 52 is controlled to be higher than the internal pressure of the second processing block G2, the entry of particles and the like from the processing device 70 into the first thickness measuring device 52 is suppressed.

[0122] Next, the rotary table 71 is rotated to move the overlapping wafer T to the processing position A1. Then, the rough grinding unit 80 performs rough grinding on the back surface Wb of the upper wafer W. Figure 15 Step E7). At this time, while measuring the overall thickness Ht of the overlapping wafer T using a contact thickness gauge (not shown), the upper wafer W is ground to the desired thickness.

[0123] Next, the rotary table 71 is rotated to move the overlapping wafer T to the processing position A2. Then, the intermediate grinding unit 90 performs intermediate grinding on the back surface Wb of the upper wafer W. Figure 15 Step E8). At this time, while measuring the overall thickness Ht of the overlapping wafer T using a contact thickness gauge (not shown), the upper wafer W is ground. Then, while measuring the thickness Hw of the upper wafer W using a non-contact thickness gauge (not shown), the upper wafer W is ground.

[0124] Next, the rotary table 71 is rotated to move the overlapping wafer T to the processing position A3. Then, the back surface Wb of the upper wafer W is precision ground by the precision grinding unit 100. Figure 15 (Step E9). In this fine grinding, the holding disk 72 and the fine grinding wheel 101, which have been pitch-corrected in step E6, are used. At this time, the upper wafer W is ground to the desired thickness while measuring the thickness Hw of the upper wafer W using a non-contact thickness gauge (not shown).

[0125] Next, the rotary table 71 is rotated to move the overlapping wafer T to the junction position A0. At the junction position A0, the back surface Wb of the ground upper wafer W can also be cleaned by the cleaning unit (not shown).

[0126] After processing in the processing unit 70, the overlapped wafer T is then transported by the wafer transport unit 60 to the second cleaning unit 51. In the second cleaning unit 51, the same cleaning process as in step E1 is performed. That is, while rotating the overlapped wafer T, cleaning fluid is supplied to the back surface Wb of the upper wafer W to perform rotational cleaning of the back surface Wb, and cleaning fluid is supplied while the cleaning brush (not shown) is in contact with the back surface Sb of the lower wafer S to perform brush cleaning of the back surface Sb. Figure 15 Step E10).

[0127] Next, the first gate 350 of the second thickness measuring device 53 is opened, and the overlapping wafer T is transported to the second thickness measuring device 53 by the wafer transport device 40. At this time, the internal pressure of the second thickness measuring device 53 is controlled to be lower than the internal pressure of the first processing block G1, thus preventing the first processing block G1, which serves as a clean space, from being contaminated due to the opening of the first gate 350. In the second thickness measuring device 53, the overlapping wafer T is first held in place by the holding disk 400 at the loading / unloading position (in situ).

[0128] Next, keep the plate at 400 degrees. Figure 17 Move to the alignment position as shown in (a). Then, as... Figure 17 As shown in (b), while rotating the overlapping wafer T, the position detection unit 320 detects the horizontal position of the overlapping wafer T and the position (eccentricity) of the center of the upper wafer W. Based on the detection result, the horizontal orientation (θ alignment) of the overlapping wafer T is adjusted, and the horizontal position (XY alignment) is also adjusted. Figure 15 Step E11).

[0129] Additionally, at the alignment position, through Figure 11 The method shown involves measuring the thickness Hw of the upper wafer W after grinding using a partial thickness measuring unit 440. Figure 15of Step E12). That is, first, the thickness Hw at the center portion (measurement point Pl) of the upper wafer W is measured. At the time of measurement of the thickness Hw of the upper wafer W at the measurement point Pl, either the holding disk 400 (the aligned wafer T) can be rotated or the rotation can be stopped. Further, the measurement of the thickness Hw of the upper wafer W at the measurement point Pl can be performed simultaneously with the detection of the horizontal position of the aligned wafer T (Step El l).

[0130] Next, as shown in (c) of FIG. 8, the movement of the holding disk 400 to the negative side of the Y-axis and the rotation are sequentially performed, and the thickness Hw at a plurality of points (measurement points P2, P3) in the radial direction of the upper wafer W is measured. At the time of measurement of the thickness Hw of the upper wafer W at the measurement points P2, P3, the thickness Hw of the upper wafer W is measured at a plurality of points in the circumferential direction while the holding disk 400 is rotated, and a moving average or a moving median of a plurality of points in the circumferential direction measured is calculated. The thickness Hw of the upper wafer W thus measured (distribution of the thickness Hw) is output to the control device 110. Figure 17 When the alignment in Step El l and the measurement of the thickness Hw of the upper wafer W in Step E12 are completed as above, as shown in (d) of FIG. 8, the holding disk 400 is moved to the in-out position. At this time, by rotating the holding disk 400, the horizontal position of the aligned wafer T measured in Step El l is aligned to the desired position.

[0131] Figure 17 When the alignment in Step El l and the measurement of the thickness Hw of the upper wafer W in Step E12 are completed as above, as shown in (d) of FIG. 8, the holding disk 400 is moved to the in-out position. At this time, by rotating the holding disk 400, the horizontal position of the aligned wafer T measured in Step El l is aligned to the desired position.

[0132] In the control device 110, the tilt adjustment section 74 at the processing position A3 of the processing device 70 is controlled on the basis of the distribution of the thickness Hw of the upper wafer W measured by Step E12. Specifically, on the basis of the distribution of the thickness Hw of the upper wafer W after grinding, the parallelism between the surface of the holding disk 72 and the surface of the fine grinding wheel 101 is adjusted so that the in-plane thickness of the upper wafer W to be processed after fine grinding is uniform (Step E13). Figure 15 of Step E12). That is, first, the thickness Hw at the center portion (measurement point Pl) of the upper wafer W is measured. At the time of measurement of the thickness Hw of the upper wafer W at the measurement point Pl, either the holding disk 400 (the aligned wafer T) can be rotated or the rotation can be stopped. Further, the measurement of the thickness Hw of the upper wafer W at the measurement point Pl can be performed simultaneously with the detection of the horizontal position of the aligned wafer T (Step El l).

[0133] Next, the first gate 350 of the second thickness measurement device 53 is opened, and the aligned wafer T is carried to the etching processing device 30 by the wafer carrying device 40. In the etching processing device 30, the back surface Wb of the upper wafer W and the back surface Sb of the lower wafer S are subjected to wet etching processing (cleaning processing) (Step E14). Figure 15 of Step E12). That is, first, the thickness Hw at the center portion (measurement point Pl) of the upper wafer W is measured. At the time of measurement of the thickness Hw of the upper wafer W at the measurement point Pl, either the holding disk 400 (the aligned wafer T) can be rotated or the rotation can be stopped. Further, the measurement of the thickness Hw of the upper wafer W at the measurement point Pl can be performed simultaneously with the detection of the horizontal position of the aligned wafer T (Step El l).

[0134] ​After that, the bonded wafer T on which all the processes have been performed is carried to the cassette C of the cassette placement table 10 by the wafer carrying device 40. In this way, the series of wafer processes in the wafer processing system 1 ends.

[0135] Further, in the wafer processing system 1, sometimes the process for the nth bonded wafer T and the process for the (n+1)th bonded wafer T are performed in parallel. In this case, the steps El to E12 are performed for the nth bonded wafer T, and the tilt correction for the grinding of the (n+1)th upper wafer W is performed in step E13. On the other hand, the steps El to E5 are performed for the (n+1)th bonded wafer T, and the tilt correction for the grinding of the (n+1)th upper wafer W is performed in step E6. As such, in step E13 of the nth and step E6 of the (n+1)th, the same tilt correction for the grinding of the (n+1)th upper wafer W is performed. Therefore, in this case, the parallelism between the surface of the holding chuck 72 at the processing position A3 and the surface of the fine grinding wheel 101 is adjusted based on the thickness Hw of the nth upper wafer W measured by step E12 and the thickness Hs of the (n+1)th lower wafer S calculated by step E5.

[0136] According to the above embodiment, the measurement of the thickness Hw of the upper wafer W before and after the grinding in the processing device 70 is performed by the first thickness measuring device 52 and the second thickness measuring device 53 which are independently provided outside the processing device 70, respectively. Thus, in the present embodiment, the wafer processing time in the processing device 70 can be shortened compared to the case where the thickness measurement is performed in the processing device 70 as in the past. As a result, the throughput of the wafer processing can be improved.

[0137] Further, as such, the first thickness measuring device 52 and the second thickness measuring device 53 are independently provided from other processing devices in the wafer processing system 1, and thus do not affect the wafer processing time in other processing devices (for example, the first cleaning device 50 and the second cleaning device 51) in the wafer processing system 1. As a result, the throughput of the wafer processing can be further improved.

[0138] Further, in the present embodiment, the parallelism between the surface of the holding chuck 72 and the surface of the fine grinding wheel 101 is adjusted in step E13 based on the thickness Hw of the upper wafer W measured by step E12, and thus the in-plane thickness uniformity after the fine grinding of the upper wafer W to be processed next can be improved.

[0139] Further, in the present embodiment, the measurement of the thickness Hw of the upper wafer W before polishing in step E3 and the measurement of the overall thickness Ht of the lapped wafer T before polishing in step E4 are performed by the first thickness measurement device 52. As such, the two thickness measurements before polishing are each performed in the same device, so the wafer processing time in the wafer processing system 1 can be further shortened, thereby further increasing throughput.

[0140] Further, in the present embodiment, the parallelism between the surface of the holding disk 72 and the surface of the fine polishing wheel 101 is adjusted in step E6 based on the thickness Hs of the lower wafer S calculated in step E5, so the in-plane thickness of the upper wafer W after fine polishing can be made uniform.

[0141] Further, in the present embodiment, the measurement of the thickness Hw in step E3, the measurement of the overall thickness Ht in step E4, and the measurement of the thickness Hw in step E12 are each performed at the same measurement point P1, P2, P3. Therefore, the parallelism between the surface of the holding disk 72 and the surface of the fine polishing wheel 101 can be appropriately performed.

[0142] Further, in the present embodiment, in each of the first thickness measurement device 52 and the second thickness measurement device 53, the sensor 341, 441 of the position detection section 320 and the partial thickness measurement section 340, 440 is disposed at the same position in the Y-axis direction (the driving direction of the holding disk 300, 400). Thus, the detection of the horizontal position by the position detection section 320 and the measurement of the thickness Hw at the center portion of the upper wafer W by the partial thickness measurement section 340, 440 can be performed at the same position, so the wafer processing time in the first thickness measurement device 52 and the second thickness measurement device 53 can be shortened.

[0143] Further, in the present embodiment, in the wafer processing system 1, the internal pressure of the first to third processing blocks G1 to G3 is controlled to be sequentially higher, and the internal pressure of the first thickness measurement device 52 is controlled to be lower than the internal pressure of the first processing block G1 and higher than the internal pressure of the third processing block G3. In other words, in the wafer processing system 1, an air flow is formed that flows from the first processing block G1 to the second and third processing blocks G2, G3 via the first thickness measurement device 52. Thus, particles and the like generated in the processing device 70 of the third processing block G3 are suppressed from flowing into the interior of the first processing block G1 and the first thickness measurement device 52, which are clean spaces, that is, the lapped wafer T subjected to the series of processes in the wafer processing system 1 can be suppressed from being contaminated.

[0144] In addition, in the present embodiment, a timing at which the first gate 350 and the second gate 360 of the first thickness measuring device 52 are simultaneously opened is not created in a series of wafer processes. In other words, when alignment of the bonded wafer T is performed, the first processing block Gl and the second processing block G2 are not directly communicated, and thus inflow of particles and the like into the first processing block Gl can be further suppressed.

[0145] In addition, in the present embodiment, the second thickness measuring device 53 that measures the thickness of the ground upper wafer W in the processing device 70 is not subjected to the transfer of the bonded wafer T by the wafer transfer device 60, and the second gate 360 is not provided. Thus, the second processing block G2 that is communicated with the processing device 70 is not communicated with the second thickness measuring device 53, and thus the bonded wafer T that has been subjected to a series of processes can be further prevented from being contaminated.

[0146] Further, in the above embodiment, as shown in steps El and E2, E10 and El 1 of Figure 15 the bonded wafer T is cleaned before alignment of the bonded wafer T is performed, but the cleaning of the bonded wafer T can be appropriately omitted.

[0147] In addition, in the above embodiment, as shown in step El 1 of Figure 15 the bonded wafer T is aligned in the second thickness measuring device 53 after the bonded wafer T is subjected to the grinding process. However, in a case where a horizontal position of the bonded wafer T does not shift when the bonded wafer T is transferred, for example, in the grinding process (steps E7 to E9), the alignment of the bonded wafer T can be omitted.

[0148] Further, in the above embodiment, as shown in steps El and E2, E10 and El 1 of Figure 2 the bonded wafer T is cleaned before alignment of the bonded wafer T is performed, but the cleaning of the bonded wafer T can be appropriately omitted.

[0149] In addition, in a case where the order of the cleaning (steps El, E10) and the alignment (steps E2, El 1) of the bonded wafer T is changed as described above, the first cleaning device 50 and the second thickness measuring device 53 can be configured in a manner that the bonded wafer T can be transferred by the wafer transfer device 60. In other words, the second gate 360 for transferring the bonded wafer T between the wafer transfer device 60 and the second thickness measuring device 53 can be provided in the second thickness measuring device 53.

[0150] Further, in the above embodiment, in the first thickness measuring device 52 and the second thickness measuring device 53, the partial thickness measuring sections 340, 440 are provided, respectively, and in the first thickness measuring device 52, the entire thickness measuring section 330 is provided to collect information (thickness) required for the pitch correction at the processing position A3, but information (thickness) used other than the pitch correction can also be collected.

[0151] Further, in the above embodiment, in the steps E3, E4, and E12, the thickness measurement is performed at three points (measurement points Pl, P2, and P3) in the radial direction of the lapped wafer T (upper wafer W), but the measurement points P can also be four or more points. The more the number of measurement points, the more the distribution of the thickness Hw of the upper wafer W and the thickness Hs of the lower wafer S can be appropriately grasped, and as a result, in the step E6, the parallelism between the surface of the holding disc 72 and the surface of the fine grinding wheel 101 can be appropriately adjusted.

[0152] Further, the position of the measurement point of the thickness Hw of the upper wafer W is not limited to the present embodiment. For example, in the case where the position at which the thickness Hw of the ground upper wafer W generates unevenness, i.e., a singular point, is known in advance, the singular point can also be set as the measurement point of the thickness Hw. Further, for example, after the thickness measurement at the measurement points Pl to P3 in the step E12, the thickness Hw of the upper wafer W at the singular point can also be measured.

[0153] Specifically, for example, in the case where the thickness Hw of the upper wafer W at the singular point is measured in the second thickness measuring device 53, the holding disc 400 (lapped wafer T) is rotated in a state where the lapped wafer T is held to the holding disc 400, and the holding disc 400 is moved in the horizontal direction to move the singular point directly below the sensor 441 of the partial thickness measuring section 440. Thereby, the thickness Hw of the upper wafer W is measured by the partial thickness measuring section 440. Further, in the case where a plurality of singular points are generated in the upper wafer W, the rotation and movement of the holding disc 400 (lapped wafer T) are repeated, and thereby the thickness measurement at each singular point can be sequentially performed.

[0154] Further, in the case where the thickness Hw of the upper wafer W at the singular point is measured in the second thickness measuring device 53 as such, the setting position of the second thickness measuring device 53 is not limited to the present embodiment. The measurement can also be performed after the wet etching process in the step E14, and therefore the second thickness measuring device 53 can also be provided, for example, to the first processing block Gl or the like.

[0155] Further, in the above embodiment, as Figure 3 and Figure 18As shown, the wafer processing system 1 has a structure in which the loading and unloading station 2 and the first to third processing blocks G1 to G3 are arranged sequentially along the X-axis direction, but the structure of the wafer processing system 1 is not limited to this.

[0156] Specifically, such as ​ As with the wafer processing system 500 in other embodiments shown, the first processing block G1 may be omitted. More specifically, as with the wafer processing system 500, the etching processing device 30 and the wafer transport device 40 may be omitted, and the etching process of the polished overlapping wafer T may be performed outside the wafer processing system 500. In this case, a wafer transport device 510 is provided in the second processing block G2, which is configured to transport the overlapping wafer T to the cassette C of the cassette stage 10, the first cleaning device 50, the second cleaning device 51, the first thickness measuring device 52, the second thickness measuring device 53, and the processing device 70.

[0157] In this case, the wafer transport device 510 has a transport arm 41 that can transfer overlapping wafers T to and from the cassette C, for example, holding and transporting overlapping wafers T, and a transport arm 61 that has an adsorption holding surface (not shown) of overlapping wafers T that can transfer overlapping wafers T to and from the first cleaning device 50, the second cleaning device 51, the first thickness measuring device 52, the second thickness measuring device 53 and the processing device 70.

[0158] Furthermore, since the wafer transport device 40 is omitted in the wafer processing system 500, the overlapping wafer T is transported only by the wafer transport device 510 for the first cleaning device 50, the second cleaning device 51, the first thickness measuring device 52, and the second thickness measuring device 53. In other words, in the wafer processing system 500, the first gate 350 and drive mechanism 351 on the side of the negative X-axis direction are omitted in the first thickness measuring device 52 and the second thickness measuring device 53, while the second gate 360 ​​and drive mechanism 361 on the side of the negative Y-axis direction are provided.

[0159] Alternatively, two conveying arms 61 can be provided in the wafer conveying device 510, and the conveying arm 61 used for conveying the overlapping wafer T before grinding and the conveying arm 61 used for conveying the overlapping wafer T after grinding can be used separately.

[0160] It should be considered that all points in the embodiments disclosed herein are illustrative rather than restrictive. The above embodiments may be omitted, substituted, or modified in various ways without departing from the appended claims and their spirit.

[0161] Explanation of reference numerals in the attached figures

[0162] 1: wafer processing system; 52: first thickness measuring device; 53: second thickness measuring device; 70: processing device; Ht: overall thickness; Hw: thickness of (upper wafer); S: lower wafer; T: coinciding wafer; W: upper wafer.

Claims

1. A substrate processing system that processes a laminated substrate in which a first substrate and a second substrate are bonded, the substrate processing system comprising: a processing device that performs grinding on the first substrate; a first thickness measuring device that measures a thickness of the first substrate before the grinding by the processing device and a total thickness of the laminated substrate including the first substrate; and a second thickness measuring device that measures a thickness of the first substrate after the grinding by the processing device, wherein the first thickness measuring device and the second thickness measuring device are provided outside the processing device.

2. The substrate processing system according to claim 1, wherein the first thickness measuring device comprises: a first substrate holding portion that holds the laminated substrate; a first measuring portion that measures the thickness of the first substrate held by the first substrate holding portion; and a total thickness measuring portion that measures the total thickness of the laminated substrate held by the first substrate holding portion, wherein a notch portion extending radially from a center portion of the first substrate holding portion to an outer end portion is formed in the first substrate holding portion, and the total thickness measuring portion is relatively movable in the notch portion, the second thickness measuring device comprises: a second substrate holding portion that holds the laminated substrate; and a second measuring portion that measures the thickness of the first substrate held by the second substrate holding portion.

3. The substrate processing system according to claim 2, wherein a diameter of the first substrate holding portion is smaller than a diameter of the second substrate holding portion.

4. The substrate processing system according to claim 2 or 3, wherein the first thickness measuring device comprises: a first driving portion that moves and rotates the first substrate holding portion in a horizontal direction; and a first position detecting portion that detects a horizontal position of the laminated substrate before the grinding by the processing device, wherein the first position detecting portion is disposed at the same position as the first measuring portion in a moving direction of the first substrate holding portion. wherein 5. The substrate processing system according to claim 2 or 3, wherein the second thickness measuring device comprises: a second driving portion that moves and rotates the second substrate holding portion in a horizontal direction; and a second position detecting portion that detects a horizontal position of the laminated substrate after the grinding, wherein the second position detecting portion is disposed at the same position as the second measuring portion in a moving direction of the second substrate holding portion.

6. The substrate processing system according to any one of claims 1 to 5, comprising: a first substrate conveyance device that conveys the laminated substrate to a cassette capable of accommodating a plurality of the laminated substrates; and a second substrate conveyance device that conveys the laminated substrate to the processing device, wherein a first conveyance opening for the first substrate conveyance device to enter is formed in the first thickness measuring device, and a second conveyance opening for the second substrate conveyance device to enter is not formed in the first thickness measuring device, and a first conveyance opening for the first substrate conveyance device to enter is formed in the second thickness measuring device, and a second conveyance opening for the second substrate conveyance device to enter is not formed in the second thickness measuring device. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 6. The substrate processing system according to any one of claims 1 to 3, characterized by, ​ ​ ​ ​ ​ 7. The substrate processing system according to any one of claims 1 to 3, wherein a carrying-in and carrying-out area in which a cassette capable of housing a plurality of the bonded substrates is placed, a processing area in which the first thickness measuring device and the second thickness measuring device are provided, and a processing area in which the processing device is provided are formed, the substrate processing system includes a control device that controls the internal pressure of the carrying-in and carrying-out area to be higher than the internal pressure of the processing area, and controls the internal pressure of the processing area to be higher than the internal pressure of the processing area.

8. The substrate processing system according to claim 7, wherein the control device controls the internal pressure of the first thickness measuring device and the second thickness measuring device to be lower than the internal pressure of the carrying-in and carrying-out area and higher than the internal pressure of the processing area.

9. The substrate processing system of any of claims 1 to 3, wherein, Further comprising: a first cleaning device that cleans the bonded substrate before grinding by the processing device; and a second cleaning device that cleans the bonded substrate after grinding by the processing device, wherein the first cleaning device, the second cleaning device, the first thickness measuring device, and the second thickness measuring device are arranged in layers.

10. A substrate processing method of processing a bonded substrate in which a first substrate and a second substrate are joined, in a substrate processing system, the substrate processing method comprising: measuring the thickness of the first substrate before grinding by a first thickness measuring device; measuring the overall thickness of the bonded substrate before grinding by a first thickness measuring device; grinding the first substrate by a processing device; and measuring the thickness of the first substrate after grinding by a second thickness measuring device, wherein the first thickness measuring device and the second thickness measuring device are provided outside the processing device. including:

11. The substrate processing method according to claim 10, wherein calculating the thickness of the second substrate based on the overall thickness of the bonded substrate before grinding and the thickness of the first substrate before grinding; and adjusting the relative inclination between the holding surface of the third substrate holding portion of the processing device and the grinding surface of the grinding tool with respect to the bonded substrate before grinding of the first substrate, based on the calculated thickness of the second substrate.

12. The substrate processing method according to claim 10 or 11, wherein a plurality of bonded substrates are processed continuously in the substrate processing system, the relative inclination between the holding surface of the third substrate holding portion of the processing device and the grinding surface of the grinding tool with respect to the bonded substrate is adjusted based on the thickness of the first substrate after grinding measured by one substrate before grinding of the first substrate in the bonded substrate to be processed next. including: detecting the horizontal position of the bonded substrate before grinding by a first thickness measuring device; and 13. The substrate processing method according to claim 10 or 11, wherein detecting the horizontal position of the bonded substrate after grinding by a second thickness measuring device.

14. The substrate processing method according to claim 13, wherein ​ ​ ​ In the first thickness measuring device and the second thickness measuring device, the thickness of the first substrate is measured at a plurality of points in the radial direction, The measurement of the thickness at the center portion of the first substrate is performed at the same position as the detection of the horizontal direction position.

15. The substrate processing method according to claim 10 or 11, wherein The substrate processing system is provided with: a first substrate conveyance device that conveys the stacked substrates to a cassette that can accommodate a plurality of the stacked substrates; and a second substrate conveyance device that conveys the stacked substrates to the processing device, wherein the first substrate conveyance device and the second substrate conveyance device are caused to enter the first thickness measuring device, only the first substrate conveyance device is caused to enter the second thickness measuring device, and the second substrate conveyance device is not caused to enter the second thickness measuring device.

16. The substrate processing method according to claim 10 or 11, wherein a load-in / out area in which a cassette that can accommodate a plurality of the stacked substrates is placed, a processing area in which the first thickness measuring device and the second thickness measuring device are provided, and a processing area in which the processing device is provided are formed in the substrate processing system, wherein the internal pressure of the load-in / out area is controlled to be higher than the internal pressure of the processing area, and the internal pressure of the processing area is controlled to be higher than the internal pressure of the processing area.

17. The substrate processing method according to claim 16, wherein the internal pressure of the first thickness measuring device and the second thickness measuring device is controlled to be lower than the internal pressure of the load-in / out area and higher than the internal pressure of the processing area.

18. The substrate processing method according to claim 10 or 11, wherein before the thickness of the first substrate is measured by the first thickness measuring device, the stacked substrates before grinding are cleaned by a first cleaning device; and before the thickness of the first substrate is measured by the second thickness measuring device, the stacked substrates after grinding are cleaned by a second cleaning device. ​

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