Grinding device and grinding method

Abstract

Provided is a device for grinding a substrate by using a grinding tool that includes a grinding wheel. The device includes: a grinding chamber formed inside a grinding chamber cover in which the grinding tool is accommodated; and an information processing unit that receives grinding stone information of the grinding wheel, such information detected by a grinding stone detection unit provided above the upper surface of the grinding chamber.

Description

Grinding device and grinding method

[0001] The present disclosure relates to a grinding apparatus and a grinding method.

[0002] Patent Document 1 discloses a setup method for storing the position of a processing tool. The setup involves a confirmation process to confirm that a first block gauge can enter the gap between the holding surface of the chuck table and the tip of the processing tool, but a second block gauge cannot. Next, the processing tool is moved closer to the holding surface by a distance equal to half the difference in thickness between the two block gauges, forming a second gap between the holding surface and the tip of the processing tool. If the first block gauge can enter the second gap, the position of the processing tool at this time is stored in a memory unit. If the first block gauge cannot enter the second gap, the position of the processing tool determined in the confirmation process is stored in the memory unit.

[0003] Japan Patent Publication No. 2021-154396

[0004] The technology according to the present disclosure appropriately controls the position of the grinding wheel after the grinding wheel is replaced.

[0005] One aspect of the present disclosure is an apparatus for grinding a substrate with a grinding tool equipped with a grinding wheel, comprising: a grinding chamber formed inside a grinding chamber cover that houses the grinding tool; and an information processing unit that receives grinding wheel information of the grinding wheel detected by a grinding wheel detection unit provided above the top surface of the grinding chamber.

[0006] According to the present disclosure, the position of the grinding wheel after replacement can be appropriately controlled.

[0007] FIG. 1 is a plan view showing an outline of the configuration of a wafer processing system according to this embodiment. FIG. 2 is a cross-sectional view showing an outline of the configuration of a grinding unit, a grinding chamber cover, and a grinding wheel detection unit. FIG. 3 is a plan view showing an outline of the configuration of the grinding wheel detection unit. FIG. 4 is a plan view and a side view showing an outline of the configuration of a dressing board. FIG. 5 is a flow diagram showing an example of main steps of wafer processing in the wafer processing system. FIG. 6 is an explanatory diagram showing the state of grinding processing in the grinding unit. FIG. 7 is an explanatory diagram showing a method for calculating the amount of wear of a grinding wheel. FIG. 8 is a flow diagram showing an example of main steps of a maintenance method performed using a wafer processing system and an exchange device. FIG. 9 is an explanatory diagram showing the state of replacing a grinding wheel and setting the setup position of the replaced grinding wheel. FIG. 10 is an explanatory diagram showing a method for calculating the correction amount of the setup position. FIG. 11 is an explanatory diagram showing the state of dressing the replaced grinding wheel. FIG. 12 is a side view of a replaced grinding wheel in another embodiment.

[0008] In the manufacturing process of semiconductor devices, for example, a semiconductor substrate (hereinafter referred to as a wafer) having a plurality of devices such as electronic circuits formed on its surface is thinned by grinding the back surface of the wafer.

[0009] Wafer grinding is performed, for example, by lowering a grinding wheel onto a wafer held in a chuck and rotating the grinding wheel to bring it into contact with the backside of the wafer. Repeated wafer grinding wears the grinding wheel, causing it to thin. Therefore, the grinding wheel is replaced after a set number of wafers have been ground.

[0010] After replacing the grinding wheel, the reference position of the grinding wheel relative to the chuck, for example, the setup position, is adjusted. The setup position is a position where the position of the bottom surface (grinding surface) of the grinding wheel coincides with the position of the top surface of the chuck or is a predetermined distance away from the position of the top surface of the chuck.

[0011] For example, in the setup method disclosed in the aforementioned Patent Document 1, a first block gauge and a second block gauge are used to adjust the setup position of a processing tool (grinding wheel). However, because the operator manually adjusts the setup position, there is a risk of the setup position varying depending on the operator. Furthermore, in order to prevent the formation of localized concave defects (so-called dimples) on the surface of the wafer during grinding and to prevent contamination of the grinding chamber, there is a demand to avoid mounting any items, such as block gauges, that are not used for wafer grinding on the upper surface of the chuck.

[0012] In this regard, it is conceivable to automatically adjust the setup position (auto-setup). For example, instead of a gauge block, a switch could be provided on the top surface of the chuck. The grinding wheel is then automatically lowered, and the setup position is adjusted by clamping the switch between the cutting edge of the grinding wheel and the chuck. In such a case, to prevent the switch from interfering with wafer grinding except when setup is being performed, the switch is retracted to a position where it does not interfere with grinding. Specifically, for example, a moving mechanism equipped with a swivel arm or the like is installed in the grinding chamber, and the switch is held and moved at the tip of the swivel arm.

[0013] However, with the above auto-setup, there is a risk of malfunction because the moving mechanism and switch are installed in the grinding chamber where contamination such as foreign matter occurs during grinding. In addition, the cutting edge of the grinding wheel and the chuck come into direct contact with the switch, which may cause dimples on the wafer or contamination of the grinding chamber, and may even damage the cutting edge of the grinding wheel or the chuck.

[0014] The technology disclosed herein has been developed in consideration of the above circumstances, and appropriately controls the position of a grinding wheel after replacement without causing dimples on the wafer or contamination of the grinding chamber. Hereinafter, a grinding apparatus and a grinding method according to the present embodiment will be described with reference to the drawings. Note that in this specification and the drawings, elements having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0015] In the technology of the present disclosure, "grinding" of the wafer W includes so-called "polishing." Therefore, although the following description will be given using a "grinding apparatus" as an example, the technology according to the present disclosure may also be applied to a "polishing apparatus."

[0016] In the wafer processing system 1 shown in FIG. 1, a wafer W serving 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. A device layer including an electronic circuit may be formed on the front surface of the wafer W. The back surface of the wafer W opposite the front surface is the grinding surface that is ground in the wafer processing system 1. The wafer W may be a glass substrate. The wafer W may also be a laminated substrate formed by bonding multiple substrates together.

[0017] The wafer processing system 1 has a configuration in which a loading / unloading station 2 and a processing station 3 are integrally connected. The loading / unloading station 2 loads / unloads a cassette C, which can accommodate a plurality of wafers W, between the loading / unloading station 2 and the outside, for example. The processing station 3 is equipped with various processing devices that perform desired processing on the wafers W.

[0018] The loading / unloading station 2 is provided with a cassette mounting table 10. In the illustrated example, a plurality of cassettes C, for example, two cassettes C, can be freely mounted on the cassette mounting table 10 in a line in the Y-axis direction. Note that the number of cassettes C mounted on the cassette mounting table 10 is not limited to that in this embodiment and can be determined arbitrarily.

[0019] For example, three processing blocks G1 to G3 are provided in the processing station 3. The first processing block G1, the second processing block G2, and the third processing block G3 are arranged in this order from the negative side of the X axis (the loading / unloading station 2 side) to the positive side.

[0020] The first processing block G1 is provided with, for example, an etching processing device 20 and a wafer transfer device 30. The etching processing devices 20 are provided, for example, stacked in two stages in the vertical direction. The wafer transfer device 30 is disposed on the positive side of the etching processing device 20 in the Y-axis direction. Note that the number and arrangement of the etching processing devices 20 and wafer transfer devices 30 are not limited to this.

[0021] The etching processing device 20 etches the back surface of the wafer W after grinding. At this time, grinding marks are removed, and cleaning processes such as particle removal and metal component removal are also performed. For example, an etching solution is supplied to the back surface of the wafer W, and the back surface is wet-etched. The etching solution may be, for example, FPM, HF, or HNO. ３ , H ３ P.O. ４ , TMAH, Choline, KOH, etc. are used.

[0022] The wafer transfer device 30 has, for example, two transfer arms 31 that hold and transfer the wafer W. Each transfer arm 31 is configured to be movable horizontally, vertically, around a horizontal axis, and around a vertical axis. The wafer transfer device 30 is configured to be able to transfer the wafer W between the cassette C on the cassette mounting table 10, the etching processing device 20, a first cleaning device 40 (described later), a second cleaning device 41 (described later), and an alignment device 42 (described later).

[0023] The second processing block G2 is provided with, for example, a first cleaning apparatus 40, a second cleaning apparatus 41, an alignment apparatus 42, and a wafer transfer apparatus 50. The first cleaning apparatus 40, the second cleaning apparatus 41, and the alignment apparatus 42 are stacked in this order from the top. The wafer transfer apparatus 50 is disposed on the negative Y-axis side of the first cleaning apparatus 40, the second cleaning apparatus 41, and the alignment apparatus 42. Note that the number and arrangement of the first cleaning apparatus 40, the second cleaning apparatus 41, the alignment apparatus 42, and the wafer transfer apparatus 50 are not limited to this.

[0024] The first cleaning device 40 cleans the back surface of the wafer W before grinding in the grinding device 60, which will be described later. In this case, it is possible to prevent foreign matter from getting caught between the chuck 80 of the grinding device 60 and the wafer W, and to grind the wafer W flat. Note that the thickness of the wafer W may be measured in the first cleaning device 40.

[0025] The second cleaning device 41 cleans the back surface of the wafer W after grinding in the grinding device 60 (described later) to remove particles such as grinding debris and metal components. Note that the thickness of the wafer W may be measured in the second cleaning device 41.

[0026] In this embodiment, a distinction is made between the first cleaning apparatus 40 that processes the wafer W before grinding and the second cleaning apparatus 41 that processes the wafer W after grinding, but either the first cleaning apparatus 40 or the second cleaning apparatus 41 may process the wafer W either after grinding or before grinding.

[0027] The alignment device 42 aligns the center of the wafer W before grinding in the grinding device 60, which will be described later, with the center of the chuck 80 of the grinding device 60. The alignment device 42 also adjusts the horizontal orientation and position of the wafer W before grinding. Specifically, the alignment device 42 detects the notch portion of the wafer W and adjusts the horizontal orientation and position of the wafer W. The alignment device 42 may also measure the thickness of the wafer W.

[0028] The wafer transfer device 50 has, for example, two transfer arms 51 that transfer the wafer W by suction and holding it on a suction holding surface (not shown). Each transfer arm 51 is configured to be movable horizontally, vertically, around a horizontal axis, and around a vertical axis. The wafer transfer device 50 is configured to be able to transfer the wafer W between the first cleaning device 40, the second cleaning device 41, the alignment device 42, and a grinding device 60 (described later). In this embodiment, the wafer transfer device 50 is also configured to be able to transfer a dress board 131 (described later) and functions as a transfer device for the dress board 131.

[0029] The third processing block G3 is provided with, for example, one grinding device 60. However, the number and arrangement of the grinding devices 60 are not limited to this.

[0030] The grinding device 60 includes, for example, a rotary table 70, four chucks 80, three grinding sections 90 (first grinding section 90a, second grinding section 90b, third grinding section 90c), four thickness measurement sections 100, 101 (thickness measurement section 100, first thickness measurement section 101a, second thickness measurement section 101b, third thickness measurement section 101c), a grinding chamber cover 110, a grinding wheel detection section 120 (see Figure 2), a dress board storage section 130, a dress board thickness measurement section 134, and an exterior cover 140.

[0031] The turntable 70 is configured to be rotatable about a vertical rotation centerline R1 by a rotation mechanism (not shown). Four chucks 80 are provided on the turntable 70 as substrate holders that suction-hold the wafer W. The four chucks 80 are provided at equal intervals around the periphery of the turntable 70. A porous chuck, for example, is used as the holding surface of the chucks 80 that holds the wafer W, and suction-holds the surface of the wafer W. The surface of the chucks 80, i.e., the holding surface of the wafer W, has a convex shape in which the center protrudes compared to the edges in a side view. Note that because this protrusion in the center is slight, the convex shape of the chucks 80 is omitted in the illustrations in the following description.

[0032] The four chucks 80 can be moved to the delivery position A0 and the processing positions A1 to A3 by the rotation of the rotary table 70. Each of the four chucks 80 is configured to be rotatable about a rotation center line R2 (see FIG. 2) by a rotation mechanism (not shown). Furthermore, the chucks 80 are configured to be tiltable by a tilt adjustment unit (not shown). This allows the relative tilt between the surface of the chuck 80 and a grinding wheel E (described below) provided in the grinding unit 90 to be adjusted.

[0033] At the transfer position A0, the wafer W is transferred by the wafer transfer device 50. A first grinding unit 90a is disposed at the processing position A1 and performs primary grinding of the wafer W. A second grinding unit 90b is disposed at the processing position A2 and performs secondary grinding of the wafer W. A third grinding unit 90c is disposed at the processing position A3 and performs tertiary grinding of the wafer W. The first grinding unit 90a, the second grinding unit 90b, and the third grinding unit 90c have the same configuration except for the grinding wheel F described below, and may be collectively referred to as the grinding unit 90 in the following description.

[0034] 2, the grinding unit 90 has a movable part 91 to which a grinding tool D is attached. The grinding tool D comes into contact with the wafer W and grinds the wafer W. The grinding tool D has, for example, a disk-shaped grinding wheel E and a plurality of grinding stones F attached to the underside of the grinding wheel E in a ring shape. The grain size of the abrasive grains of the grinding stones F in the first grinding unit 90a decreases in this order, followed by the grain size of the abrasive grains of the grinding stones F in the second grinding unit 90b and the third grinding unit 90c.

[0035] The movable part 91 has a spindle shaft 92 to which the grinding tool D is attached, and a spindle motor 93 that rotates the spindle shaft 92. The grinding tool D is replaceably attached to the underside of the spindle shaft 92 by a fastener (not shown), such as a bolt. The spindle motor 93 supports the upper surface of the spindle shaft 92 and rotates the spindle shaft 92 and the grinding tool D attached to the spindle shaft 92 about a rotation center line R3.

[0036] The grinding unit 90 further includes an elevator unit 94 that raises and lowers the movable unit 91. The elevator unit 94 includes, for example, a Z-axis guide 95 extending in the vertical direction, a Z-axis slider 96 that moves along the Z-axis guide 95, and a Z-axis motor 97 that moves the Z-axis slider 96. The movable unit 91 is fixed to the Z-axis slider 96, and the movable unit 91 and grinding tool D rise and fall together with the Z-axis slider 96. The elevator unit 94 raises and lowers the movable unit 91 between a grinding position P1 where the grinding tool D grinds the wafer W and an exchange position P2 where the grinding tool D is exchanged.

[0037] The lifting unit 94 further has a grinding tool detection unit 98 that detects the position of the grinding tool D. The grinding tool detection unit 98 detects, for example, the rotation of the Z-axis motor 97 to detect the position of the grinding tool D. Information on the position of the grinding tool D acquired by the grinding tool detection unit 98 (hereinafter referred to as grinding tool information) is transmitted to the control device 150, which will be described later.

[0038] 1 , a thickness measurement unit 100 that measures the thickness of a wafer W is provided at the transfer position A0. The thickness measurement unit 100 may have any configuration, but may include, for example, a non-contact sensor (not shown) and a calculation unit (not shown). Furthermore, three thickness measurement units 101 (a first thickness measurement unit 101a, a second thickness measurement unit 101b, and a third thickness measurement unit 101c) that measure the thickness of a wafer W are provided at each of the processing positions A1 to A3. The thickness measurement units 101 may also have any configuration, but may include, for example, a non-contact sensor (not shown) and a calculation unit (not shown).

[0039] 1 and 2 , the grinding chamber cover 110 defines a grinding chamber 111 therein. The grinding chamber cover 110 prevents particles, such as grinding debris, generated in the grinding chamber 111 from escaping to the outside. The grinding chamber 111 is equipped with a rotary table 70, four chucks 80, parts of three grinding units 90, and four thickness measurement units 100 and 101. The grinding position P1 described above is a position within the grinding chamber cover 110 where the wafer W is ground, and the grinding tool D, spindle shaft 92, and part of the spindle motor 93 are disposed within the grinding chamber cover 110. The replacement position P2 is a position outside the grinding chamber cover 110 where the grinding tool D is replaced, and the grinding tool D and the movable unit 91 are disposed outside the grinding chamber cover 110.

[0040] An opening 113 through which the grinding tool D passes is formed in the top plate 112 of the grinding chamber cover 110. The diameter of the opening 113 is larger than the diameters of the grinding tool D and the spindle shaft 92. Note that, for example, a cylindrical cover (not shown) may be provided around the opening 113 on the top plate 112. A loading / unloading port (not shown) for loading and unloading the wafer W is formed on the side surface of the grinding chamber cover 110 on the transfer position A0 side. A shutter (not shown) for opening and closing the loading / unloading port is provided at the loading / unloading port.

[0041] The grinding wheel detector 120 is provided on the upper surface of the top plate 112 of the grinding chamber cover 110. When the grinding wheel F of the grinding tool D passes through the opening 113, the grinding wheel detector 120 detects the position of the lower surface (the cutting edge position) of the grinding wheel F.

[0042] The grinding wheel detection unit 120 has, for example, a laser sensor 121 as a light-projecting unit that projects laser light, and a light-receiving sensor 122 as a light-receiving unit that receives the laser light from the laser sensor 121. The laser sensor 121 and the light-receiving sensor 122 are arranged in opposing positions across the opening 113. The grinding wheel detection unit 120 detects the position of the underside of the grinding wheel F using the laser light projected from the laser sensor 121 toward the light-receiving sensor 122. Specifically, the grinding wheel detection unit 120 detects the boundary between the position where the laser light is blocked by the grinding wheel F and the position where the laser light passes below the grinding wheel F, as the underside position of the grinding wheel F. Information on the underside position of the grinding wheel F obtained by the light-receiving sensor 122 (hereinafter referred to as grinding wheel information) is transmitted to the control device 150, which will be described later.

[0043] If the laser optical axis passes between adjacent grinding wheels F, the grinding wheel detection unit 120 will not be able to detect the position of the bottom surface of the grinding wheel F. Therefore, as shown in Figure 3, the laser sensor 121 and the light-receiving sensor 122 are positioned so that the axis of the laser light L from the laser sensor 121 (laser optical axis) is horizontal and tangential to the grinding wheel F. In this case, if a grinding wheel F is present in the opening 113, the laser light L will be blocked by that grinding wheel F, and the grinding wheel detection unit 120 will be able to reliably detect the position of the bottom surface of the grinding wheel F.

[0044] As shown in FIG. 1 , the dress board storage unit 130 is located outside the grinding chamber cover 110, between the transfer position A0 and the wafer transfer device 50 of the second processing block G2. The dress board storage unit 130 stores a dress board 131 used to dress the grinding wheel F. The dress board 131 is transported between the dress board storage unit 130 and the transfer position A0 by the wafer transfer device 50. As shown in FIG. 4 , the dress board 131 includes a disk-shaped dressing wheel 132 and a disk-shaped pedestal 133 that is provided on the underside of the dressing wheel 132 and supports the dressing wheel 132. The grinding wheel F comes into contact with the dress board 131 and is ground, thereby adjusting the surface condition of the grinding wheel F.

[0045] The dress board thickness measuring unit 134 is stacked on the dress board storage unit 130. The dress board thickness measuring unit 134 measures the thickness of the dress board 131. The thickness measurement of the dress board 131 may be performed inside the dress board storage unit 130 or on the chuck 80.

[0046] As shown in FIG. 1 , the exterior cover 140 prevents particles such as grinding chips generated inside the exterior cover 140 from escaping to the outside. The interior of the exterior cover 140 contains a rotary table 70, four chucks 80, three grinding units 90, four thickness measurement units 100, 101, a grinding chamber cover 110, a grinding wheel detection unit 120, a dressing board storage unit 130, and a dressing board thickness measurement unit 134. Three passage openings 141 are formed on the side of the exterior cover 140, through which the replacement device 200 (described later) passes when entering or exiting the interior of the exterior cover 140. The three passage openings 141 are formed at positions corresponding to the three grinding units 90 (first grinding unit 90a, second grinding unit 90b, and third grinding unit 90c). Each passage opening 141 is provided with a shutter 142 that opens and closes the passage opening 141 using a moving mechanism (not shown). The shutter 142 normally closes the passage opening 141 and opens the passage opening 141 when the exchange device 200 passes through.

[0047] The wafer processing system 1 described above is provided with a control device 150. The control device 150 is a computer equipped with, for example, a CPU, a storage medium such as a memory, and the like. The storage medium stores programs that control various processes executed in the wafer processing system 1. The storage medium may be temporary or non-temporary.

[0048] The control device 150 has an information processing unit 151 that processes information received from each device in the wafer processing system 1 and further transmits the processed information. In this embodiment, the control device 150 (information processing unit 151) is provided for the entire wafer processing system 1, but for example, a control unit including an information processing unit may be provided individually for each device in the wafer processing system 1 (for example, the grinding device 60).

[0049] Next, wafer processing performed using the wafer processing system 1 configured as above will be described.

[0050] First, a cassette C containing a plurality of wafers W is placed on the cassette mounting table 10 of the transfer station 2. Next, the wafers W in the cassette C are removed by the wafer transfer device 30 and transferred to the first cleaning device 40.

[0051] In the first cleaning device 40, the back surface of the wafer W before grinding is cleaned (S1 in FIG. 5).

[0052] Next, the wafer W is transferred by the wafer transfer device 30 to the alignment device 42. The alignment device 42 detects the center of the wafer W before grinding and adjusts the center position of the wafer W. The alignment device 42 also detects the notch portion of the wafer W before grinding and adjusts the horizontal orientation and position of the wafer W (S2 in FIG. 5).

[0053] Next, the wafer W is transferred by the wafer transfer device 50 to the transfer chamber 81 of the grinding device 60 and transferred to the chuck 80 at the transfer position A0. At the transfer position A0, the thickness of the wafer W before grinding is measured at multiple points by the thickness measuring unit 100 (S3 in FIG. 5). The measured thickness information is transmitted to, for example, the control device 150.

[0054] Next, the wafer W held by the chuck 80 is moved to the processing position A1. At the processing position A1, the back surface of the wafer W is primarily ground by the first grinding unit 90a (S4 in FIG. 5). In S4, the grinding tool D (grinding wheel F and grinding wheel E) is first lowered at high speed from the standby position P0 to the air-cut start position P11 (Q0 to Q1 in FIG. 6), as shown in FIG. 6. The standby position P0 is a position higher than the grinding position P1 within the space of the grinding chamber 111 (inside the grinding chamber cover 110), where the grinding tool D waits. At this time, the grinding tool D is lowered at high speed to improve throughput. However, if the high-speed grinding wheel F were to come into contact with the wafer W, there is a concern that the grinding wheel F would be broken or the wafer W would be damaged. Therefore, the lowering speed of the grinding wheel F is reduced at the air cut start position P11, and the grinding wheel F is lowered at a low speed to the contact position P12 with the wafer W (air cut from Q1 to Q2 in FIG. 6).

[0055] The height position (air cut start position P11) of the lower surface (cutting edge) Fa of the grinding wheel F when air cutting is started, as shown in FIG. 6, is set by adding the thickness of the wafer W before grinding and the air cut amount to the setup position (described later). The air cut amount is set in advance in a recipe and is the distance the grinding wheel F descends from the air cut start position P11 to the contact position P12 shown in FIG. 6. In this case, in order to shorten the processing time, the air cut start position P11 is set so that the grinding wheel F does not collide with the wafer W but the air cut amount is as small as possible. The thickness of the wafer W before grinding used to adjust the air cut start position P11 may be measured by the thickness measuring unit 100 at the transfer position A0 described above, or may be obtained by measuring the thickness of the wafer W before grinding by the first thickness measuring unit 101a at the processing position A1. The measured thickness information is transmitted to, for example, the control device 150.

[0056] After the grinding wheel F is lowered and contacts the wafer W, the grinding wheel F is further lowered to grind the wafer W to a grinding end position P13 (the target thickness of the wafer W in S4) in the first grinding section 90a (Q2 to Q5 in FIG. 6: grinding step). Note that in the grinding step, the lowering speed of the grinding wheel F may be changed stepwise between Q2 and Q5 (for example, Q3 and Q4 in FIG. 6), or the lowering speed may be controlled to a constant value.

[0057] When the grinding wheel F reaches the grinding end position P13 and stops descending, the grinding wheel F is held at the grinding end position P13 for a certain period of time (Q5 to Q6 in FIG. 6: spark out). In the spark out state, the grinding wheel F continues to rotate. At this time, the position of the grinding tool D measured by the grinding tool detector 98, specifically the boundary position (Z position) between the bottom surface of the spindle shaft 92 and the top surface of the grinding wheel E, is measured. Information on the measured position of the grinding tool D (hereinafter referred to as grinding tool information) is sent to, for example, the control device 150.

[0058] After the spark-out is completed, the grinding wheel F starts to rise while continuing to rotate (Q6 to Q7 in FIG. 6: escape cut). In the escape cut state, the grinding wheel F is raised at a low speed to prevent wheel marks from remaining on the back surface of the wafer W when the wafer W and the grinding wheel F are separated from each other.

[0059] After the wafer W and the grinding wheel F are separated from each other, the upward movement speed of the grinding wheel F is accelerated to move the grinding wheel F to the standby position P0 (from Q7 onwards), thereby completing the primary grinding of the back surface of the wafer W in the first grinding section 90a. The air-cut start position P11, the contact position P12 and the grinding end position P13 are collectively referred to as the grinding position P1.

[0060] Next, the first thickness measuring unit 101a measures the thickness of the wafer W after the primary grinding (S5 in FIG. 5). The measured thickness information is transmitted to, for example, the control device 150. Note that the thickness measurement of the wafer W by the first thickness measuring unit 101a is also performed during the grinding process by the first grinding unit 90a.

[0061] Next, based on the thickness of the wafer W after grinding measured by the first thickness measuring unit 101a, the reference position of the grinding wheel F relative to the chuck 80, that is, the so-called setup position, is adjusted (S6 in FIG. 5). This setup position adjustment is performed to adjust the setup position for the grinding process of the next wafer W in the first grinding unit 90a. The setup position is a position where the position of the lower surface (grinding surface) Fa of the grinding wheel F coincides with the position of the upper surface (holding surface) of the chuck 80, or is a predetermined distance away from the position of the upper surface (holding surface) of the chuck 80. This predetermined distance from the upper surface of the chuck 80 can be set arbitrarily. The method for adjusting the setup position will be described in detail later.

[0062] In this embodiment, the setup position adjustment (S6) is performed immediately after the thickness measurement (S5) of the wafer W, but the timing of the setup position adjustment is not limited to this. Specifically, the setup position adjustment may be performed at least before the grinding process of the next wafer W in the first grinding unit 90a.

[0063] Next, the wafer W held by the chuck 80 is moved to the processing position A2. At the processing position A2, the second grinding unit 90b performs secondary grinding on the back surface of the wafer W (S7 in FIG. 5). Thereafter, the second thickness measuring unit 101b measures the thickness of the wafer W after the secondary grinding (S8 in FIG. 5), and adjusts the setup position of the grinding wheel F relative to the chuck 80 (S9 in FIG. 5). Note that steps S7 to S9 at the processing position A2 are the same as steps S4 to S6 at the processing position A1 described above, respectively.

[0064] Next, the wafer W held by the chuck 80 is moved to processing position A3. At processing position A3, the back surface of the wafer W is tertiary ground by the third grinding unit 90c (S10 in FIG. 5). Thereafter, the thickness of the wafer W after the tertiary grinding is measured by the third thickness measuring unit 101c (S11 in FIG. 5), and the setup position of the grinding wheel F relative to the chuck 80 is adjusted (S12 in FIG. 5). Note that steps S10 to S12 at processing position A3 are the same as steps S4 to S6 at processing position A1 described above, respectively.

[0065] Next, the wafer W held by the chuck 80 is moved to the transfer position A0. At the transfer position A0, the thickness of the wafer W after the tertiary grinding is measured at multiple points by the thickness measuring unit 100 to obtain the in-plane thickness distribution of the wafer W and the flatness of the wafer W (S13 in FIG. 3). The obtained information on the thickness distribution and flatness is transmitted to, for example, the control device 150.

[0066] Next, the wafer W is transferred by the wafer transfer device 50 to the second cleaning device 41. In the second cleaning device 41, the back surface of the wafer W after grinding is cleaned to remove particles such as grinding debris (S14 in FIG. 5).

[0067] Next, the wafer W is transferred by the wafer transfer device 30 to the etching processing device 20. In the etching processing device 20, a wet etching process (cleaning process) is performed on the rear surface of the wafer W to remove, for example, grinding marks (S15 in FIG. 3).

[0068] Thereafter, the wafer W that has been subjected to all the processes is transferred by the wafer transfer device 30 to the cassette C on the cassette mounting table 10. In this way, a series of wafer processes in the wafer processing system 1 is completed.

[0069] Next, the above-mentioned method for adjusting the setup position (S6, S9, S12) will be described. While the method for adjusting the setup position in the first grinding unit 90a will be described below, the same method applies to the second grinding unit 90b and the third grinding unit 90c.

[0070] FIG. 7 is an explanatory diagram showing a method for calculating the amount of wear of the grinding wheel F. The setup position is adjusted based on this amount of wear, as described below. FIG. 7( a) shows the state of spark-out during primary grinding of the backside of the first wafer W1, and FIG. 7( b) shows the state of spark-out during primary grinding of the backside of the second wafer W2. In FIG. 7, Z1 and Z2 respectively represent the position of the grinding tool D (the position of the grinding wheel F detected by the grinding tool detector 98; more specifically, the boundary position between the bottom surface of the spindle shaft 92 and the top surface of the grinding wheel E). H1 and H2 respectively represent the length of the grinding wheel F including the grinding wheel E. L1 and L2 respectively represent the thicknesses of the wafers W1 and W2 after primary grinding.

[0071] As described above, the grinding stone F of the first grinding section 90a wears and becomes thinner as it repeatedly grinds the wafer W. α shown in FIG. 7 is the amount of wear of the grinding stone F caused by grinding the wafer W (grinding the back surface of the wafer W in the illustrated example), and can be expressed by the following formula (1): α=H1-H2 (1)

[0072] At this time, if the distance from the home position of the grinding tool D to the holding surface of the chuck 80 is constant as shown in FIG. 7, for example, by aligning the height of the upper surface of the chuck 80, the following equation (2) is established: Z1+H1+L1=Z2+H2+L2 (2)

[0073] Then, based on this wear amount α, the first grinding unit 90a adjusts the setup position for the grinding process of the next wafer W. That is, in order to control the position of the grinding surface of the grinding wheel F relative to the holding surface of the chuck 80 to be constant during the grinding process of the wafer W, the grinding wheel F is moved closer to the chuck 80 by the amount of wear amount α of the grinding wheel F, and this position is set as the setup position for the grinding process of the next wafer W. In other words, the amount of movement of the grinding wheel F for updating the setup position corresponds to the wear amount α of the grinding wheel F.

[0074] As described above, the setup positions of the first grinding unit 90 a, the second grinding unit 90 b, and the third grinding unit 90 c are adjusted. By appropriately adjusting the setup positions, even if the grinding wheel F is worn, the grinding wheel F can be appropriately positioned before grinding. Therefore, grinding of the back surface of the wafer W (primary grinding, secondary grinding, and tertiary grinding) can be appropriately performed.

[0075] Furthermore, for example, when the grinding wheel F wears, the air cut start position P11 becomes higher, and it takes time for the grinding wheel F to reach the wafer W. In this regard, according to this embodiment, even if the grinding wheel F wears, the setup position is appropriately adjusted to appropriately adjust the air cut start position P11, thereby shortening the time required for air cut and improving throughput.

[0076] By repeatedly grinding the wafers W as described above, the grinding wheel F wears down and becomes thinner. Therefore, after a predetermined number of wafers W have been ground, the grinding wheel F is replaced. In this embodiment, the grinding wheel F is replaced using an exchange device 200, which will be described later.

[0077] 1 , an exchange device 200 for exchanging a grinding tool D of the grinding device 60 is provided outside the wafer processing system 1. The exchange device 200 removes a used grinding tool D from the spindle shaft 92 of the grinding unit 90 and attaches an unused grinding tool D to the spindle shaft 92. The exchange device 200 is, for example, a self-propelled robot, and is configured to be able to access three passage openings 141 in the exterior cover 140 of the grinding device 60. The exchange device 200 enters the interior of the exterior cover 140 from the outside and exchanges a grinding tool D inside the exterior cover 140.

[0078] A storage facility (not shown) for storing the replacement device 200 and a storage unit (not shown) for storing the grinding tool D may be provided outside the wafer processing system 1. The replacement device 200 waits in the storage facility except when replacing the grinding tool D. The storage unit stores both used and unused grinding tools D.

[0079] The replacement device 200 has, for example, a replacement unit 201, a moving mechanism 202, and a traveling mechanism 203. The replacement unit 201 attaches the grinding tool D to the spindle shaft 92 of the grinding unit 90 or removes the grinding tool D from the spindle shaft 92. The replacement unit 201 is configured to be movable horizontally, vertically, around the horizontal axis, and around the vertical axis. The replacement unit 201 may hold the grinding tool D or may hold a container (not shown) that contains the grinding tool D. The replacement unit 201 also has an operating mechanism (not shown) that tightens or loosens a fastener (not shown) that fastens the grinding tool D to the spindle shaft 92.

[0080] The moving mechanism 202 moves the replacement part 201 into or out of the interior of the exterior cover 140 through the passage 141 of the exterior cover 140. The moving mechanism 202 is, for example, an articulated arm, and holds the replacement part 201 at one end and is connected to a traveling mechanism 203 at the other end. The traveling mechanism 203 supports the moving mechanism 202 and causes the moving mechanism 202 to travel.

[0081] The exchange device 200 includes a control device (not shown). The control device is a computer including, for example, a CPU, a storage medium such as a memory, and the like. The storage medium stores a program that controls the processing executed by the exchange device 200. The storage medium may be temporary or non-temporary.

[0082] Next, a maintenance method performed using the wafer processing system 1 and replacement device 200 configured as described above, specifically a method for replacing the grinding tool D, will be described. Below, a method for replacing the grinding tool D in the first grinding unit 90a will be described, but the methods for replacing the grinding tool D in the second grinding unit 90b and the third grinding unit 90c are similar. In the following description, the grinding tool D, grinding wheel E, and grinding wheel F before replacement (after use) will be referred to as the pre-replacement grinding tool D1, pre-replacement wheel E1, and pre-replacement grinding wheel F1, respectively. The replaced (unused) grinding tool D, grinding wheel E, and grinding wheel F will be referred to as the replaced grinding tool D2, the replaced wheel E2, and the replaced grinding wheel F2, respectively.

[0083] After grinding a predetermined number of wafers W, when it is time to replace the grinding wheel F in the first grinding unit 90a, the information processing unit 151 of the control device 150 sends a replacement command for the pre-replacement grinding tool D1 to the first grinding unit 90a (T1 in FIG. 8). At this time, the information processing unit 151 has acquired information on the setup position of the pre-replacement grinding wheel F1. The information processing unit 151 may also send a replacement command for the pre-replacement grinding tool D1 to the replacement device 200 simultaneously with T1. In other words, T1 and T4, which will be described later, may be performed simultaneously.

[0084] In the first grinding section 90a, the elevator 94 raises the pre-replacement grinding tool D1, for example, from the standby position P0 to the replacement position P2, as shown in FIG. 9(a) (T2 in FIG. 8). At this time, the laser sensor 121 in the grinding wheel detection section 120 projects a laser beam L toward the light-receiving sensor 122. When the pre-replacement grinding tool D1 passes through the opening 113 of the grinding chamber cover 110, the light-receiving sensor 122 detects the position of the underside of the pre-replacement grinding wheel F1 (T3 in FIG. 8). Information regarding the position of the underside of the pre-replacement grinding wheel F1 acquired by the light-receiving sensor 122 (hereinafter referred to as pre-replacement grinding wheel information) is transmitted from the light-receiving sensor 122 to the control device 150 (information processing section 151). After passing through the opening 113, the pre-replacement grinding tool D1 rises to the replacement position P2.

[0085] When the information processing unit 151 receives the pre-replacement grinding wheel information from the light receiving sensor 122, it transmits a command to replace the pre-replacement grinding tool D1 to the replacement device 200 (T4 in FIG. 8). As described above, T4 may be performed simultaneously with T1. Furthermore, when it is determined that the grinding wheel length of the pre-replacement grinding wheel F1 has reached the replacement time during the grinding process of the wafer W, a command to replace the pre-replacement grinding tool D1 may be transmitted to the replacement device 200 during the grinding process of the wafer W.

[0086] When the replacement device 200 waiting in the storage facility receives a replacement command for the pre-replacement grinding tool D1, it acquires an unused post-replacement grinding tool D2 from the storage unit and travels to the first grinding unit 90a while holding the post-replacement grinding tool D2. The replacement device 200 then removes the used pre-replacement grinding tool D1 from the spindle shaft 92 as shown in FIG. 9(b), and then attaches the post-replacement grinding tool D2 to the spindle shaft 92 as shown in FIG. 9(c). The replacement device 200 thus replaces the pre-replacement grinding tool D1 with the post-replacement grinding tool D2 (T5 in FIG. 8). Information indicating that the replacement of the grinding tool D has been completed (hereinafter referred to as replacement completion information) is transmitted from the replacement device 200 to the information processing unit 151.

[0087] At T5, when the exchange device 200 enters the interior of the exterior cover 140 or exits from the interior of the exterior cover 140, the shutter 142 opens the passage opening 141.

[0088] Next, in the first grinding unit 90a, the lifting unit 94 lowers the replaced grinding tool D2 from the replacement position P2 toward the grinding position P1 as shown in FIG. 9(d) (T6 in FIG. 8). At this time, the laser sensor 121 in the grinding wheel detection unit 120 projects a laser beam L toward the light-receiving sensor 122. Then, when the replaced grinding tool D2 passes through the opening 113 of the grinding chamber cover 110, the light-receiving sensor 122 detects the position of the bottom surface of the replaced grinding wheel F2 (T7 in FIG. 8). Information on the position of the bottom surface of the replaced grinding wheel F2 acquired by the light-receiving sensor 122 (hereinafter referred to as replaced grinding wheel information) is transmitted from the light-receiving sensor 122 to the control device 150 (information processing unit 151).

[0089] The information processing unit 151 sets the setup position of the replaced grinding wheel F2 using the setup position information of the replaced grinding wheel F1 acquired at T1, the before-replacement grinding wheel information received at T3, and the after-replacement grinding wheel information received at T7 (T8 in FIG. 8). That is, as shown in equation (3), the setup position SP2 of the replaced grinding wheel F2 is the setup position SP1 of the before-replacement grinding wheel F1 plus a correction amount C. Also, as shown in FIG. 10, the correction amount C is the difference between the bottom surface position B2 of the replaced grinding wheel F2, which is the after-replacement grinding wheel information, and the bottom surface position B1 of the before-replacement grinding wheel F1, which is the before-replacement grinding wheel information, and is calculated using the following equation (4). In other words, the correction amount C is the difference between the length of the replaced grinding wheel F2 and the length of the before-replacement grinding wheel F1. SP2=SP1+C (3) C=B2-B1 (4)

[0090] After setting the setup position of the post-exchange grindstone F2, the information processing unit 151 transmits a transfer command to the wafer transfer device 50 to transfer the dress board 131 (T9 in FIG. 8).

[0091] The dress board 131 stored in the dress board storage unit 130 is removed by the wafer transfer device 50 and transferred to the chuck 80 at the transfer position A0. At this time, the thickness of the dress board 131 is measured by the dress board thickness measurement unit 134. The height of the transfer arm 51 of the wafer transfer device 50 when the transfer arm 51 suction-holds the dress board 131 is controlled based on the measured thickness of the dress board 131. Furthermore, based on the measured thickness of the dress board 131 and the setup position SP2 of the replaced grinding wheel F2, an air-cut position for dressing the replaced grinding wheel F2 at T10 (described later) is set. Next, the dress board 131 held by the chuck 80 is moved to the processing position A1.

[0092] At the processing position A1, as shown in FIG. 11 , the replaced grinding wheel F2 is dressed using the dressing board 131 (T10 in FIG. 8 ). Specifically, the replaced grinding wheel F2 is moved vertically downward relative to the dressing board 131, and the replaced grinding wheel F2 is brought into contact with the dressing board 131. Then, the replaced grinding wheel F2 and the dressing board 131 are rotated, and the replaced grinding wheel F2 is further moved vertically downward. This grinds and dresses the surface of the replaced grinding wheel F2. In other words, the surface condition of the replaced grinding wheel F2 is appropriately adjusted.

[0093] As described above, the pre-replacement grinding tool D1 (pre-replacement grinding wheel F1) is replaced with the post-replacement grinding tool D2 (post-replacement grinding wheel F2). Thereafter, the post-replacement grinding wheel F2 is moved from the spark-out position after dressing to the setup position set at T8, and primary grinding of the back surface of the wafer W by the first grinding unit 90a is started in S4 described above.

[0094] According to the above embodiment, the setup position of the replaced grinding wheel F2 is automatically set. When the operator manually sets the setup position as in the conventional case, there is a risk that the operator may become dirty. However, according to the present embodiment, such operator dirt can be prevented.

[0095] Furthermore, according to this embodiment, the replacement of the grinding tool D1 with the grinding tool D2, the setting of the setup position of the grinding wheel F2, and the dressing of the grinding wheel F2 are all performed automatically. This simplifies the maintenance work of the grinding device 60 and reduces downtime. It also prevents the operator from getting dirty, which is a conventional manual operation.

[0096] As described above, conventionally, the setup of the grinding wheel is performed manually by an operator, which can lead to variations in the setup position depending on the operator. Also, there is a risk that localized concave defects (so-called dimples) may be formed on the surface of the wafer W during grinding, or that the grinding chamber 111 may be contaminated.

[0097] In this regard, in the present embodiment, since the setup position of the replaced grinding wheel F2 is automatically set, the setup position can always be set appropriately. Furthermore, dimples on the wafer W during conventional grinding can be suppressed, and contamination of the grinding chamber 111 can be suppressed.

[0098] Furthermore, according to this embodiment, the laser sensor 121 and the light receiving sensor 122 of the grinding wheel detection unit 120 are provided on the upper surface of the top plate 112 of the grinding chamber cover 110, i.e., outside the grinding chamber cover 110. Therefore, compared to when the grinding wheel detection unit 120 is provided inside the grinding chamber cover 110, the detection accuracy of the grinding wheel F is higher and the grinding wheel detection unit 120 is easier to maintain.

[0099] Furthermore, if the grinding wheel detector 120 were provided inside the grinding chamber cover 110, the grinding chamber 111 would be contaminated with particles such as grinding dust, which could cause malfunctions of the laser sensor 121 and the light receiving sensor 122. In this regard, this embodiment makes it possible to avoid such malfunctions.

[0100] Furthermore, if the grinding wheel detection unit 120 were provided inside the grinding chamber cover 110, it would be possible to move the laser sensor 121 and the light receiving sensor 122 using a movement mechanism (not shown) to avoid the above-mentioned malfunction, but there is a risk that the movement mechanism would also malfunction. In this regard, in this embodiment, the laser sensor 121 and the light receiving sensor 122 can be provided outside the grinding chamber cover 110, and a movement mechanism is not necessary, thereby improving the reliability of the device.

[0101] Furthermore, according to this embodiment, the setup position of the replaced grinding wheel F2 is set in a non-contact manner using the laser sensor 121 and the light receiving sensor 122 of the grinding wheel detection unit 120, so that the replaced grinding wheel F2 and the chuck 80 are not affected.

[0102] Furthermore, according to this embodiment, it is only necessary to calculate the difference between the bottom surface position B2 of the replaced grinding wheel F2, which is the post-replacement grinding wheel information, and the bottom surface position B1 of the pre-replacement grinding wheel F1, which is the pre-replacement grinding wheel information, as long as the laser sensor 121 and the light-receiving sensor 122 are installed so that the axis of the laser light L is horizontal. In other words, even if the installation positions of the laser sensor 121 and the light-receiving sensor 122 are shifted in the vertical direction (height direction), this does not affect the calculation of the difference. Therefore, the laser sensor 121 and the light-receiving sensor 122 can be installed in a simple manner.

[0103] In the above embodiment, the replacement of the pre-replacement grinding tool D1 with the post-replacement grinding tool D2, the setting of the setup position of the post-replacement grinding wheel F2, and the dressing of the post-replacement grinding wheel F2 were all performed automatically, but the replacement of the pre-replacement grinding tool D1 with the post-replacement grinding tool D2 and the dressing of the post-replacement grinding wheel F2 may also be performed manually by an operator.

[0104] In the above embodiment, when the setup position of the replaced grinding wheel F2 is set in T8, the difference (B2 - B1) between the bottom surface position B2 of the replaced grinding wheel F2 and the bottom surface position B1 of the previous grinding wheel F1 is used as the setup position correction amount C. Here, as shown in FIG. 12 , in the replaced grinding tool D2, the lengths of the multiple replaced grinding wheels F2 attached to the replaced wheel E2 may vary, that is, there may be a variation V in the bottom surface positions of the multiple replaced grinding wheels F2. This variation V is, for example, approximately ±0.1 mm. Therefore, this variation V may also be taken into account in the correction amount C. Specifically, as shown in the following equation (5), the correction amount C may be calculated by adding the variation V to the difference between the bottom surface position B2 of the replaced grinding wheel F2, which is the replaced grinding wheel information, and the bottom surface position B1 of the previous grinding wheel F1, which is the previous grinding wheel information. C = B2 - B1 + V (5)

[0105] Alternatively, the variation V may be absorbed by the accuracy (margin) of the laser sensor 121 of the grindstone detection unit 120. The configuration of the grindstone detection unit 120 is arbitrary, and other sensors may be used instead of the laser sensor 121. However, as described above, it is preferable to use a sensor having a detection accuracy high enough to absorb the variation V.

[0106] Furthermore, in order to eliminate the influence of the variation V, the replaced grinding tool D2 may be rotated by the spindle motor 93 when the replaced grinding tool D2 is lowered to pass through the opening 113 of the grinding chamber cover 110. In this case, the grinding wheel detection unit 120 detects the lowest lower surface position B2 of the multiple replaced grinding wheels F2. This makes it possible to eliminate the influence of the variation V.

[0107] When the replaced grinding tool D2 is lowered while rotating, the rotation speed of the replaced grinding tool D2 may be low. In this case, the grinding wheel detection unit 120 can detect the lower surface positions B2 of the multiple replaced grinding wheels F2 regardless of the specifications of the spindle motor 93.

[0108] Alternatively, the replaced grinding tool D2 may be raised and lowered to pass through the opening 113 multiple times. Then, by changing the horizontal orientation of the replaced grinding tool D2 each time, the grinding wheel detection unit 120 can detect the lower surface position B2 of the replaced grinding wheel F2 multiple times. For example, by repeatedly passing the replaced grinding wheel F2 through the opening 113 and rotating the replaced grinding wheel F2 by 90 degrees, the lower surface position B2 of the replaced grinding wheel F2 can be detected four times.

[0109] Furthermore, a plurality of grinding wheel detectors 120 may be provided on the upper surface of the grinding chamber cover 110. In such a case, the plurality of grinding wheel detectors 120 can detect the lower surface positions B2 of a plurality of replaced grinding wheels F2, thereby eliminating the influence of the variation V.

[0110] Here, for example, before the grinding process of the wafer W, the upper surface of the chuck 80 may be ground by the grinding unit 90 to improve the parallelism between the grinding unit 90 (grinding wheel F) and the upper surface of the chuck 80, a process known as chuck grounding (self-grinding). In such a case, the height of the upper surface of the chuck 80 changes. Therefore, when calculating the correction amount C of the setup position in T8, the difference in height of the upper surface of the chuck 80 before and after chuck grounding may be added. Specifically, the thickness measurement unit 100 measures the height of the upper surface of the chuck 80 before and after chuck grounding, and the information processing unit 151 calculates the difference X in height of the upper surface of the chuck 80. Then, as shown in the following equation (6), the correction amount C is calculated by adding the difference X in height of the upper surface of the chuck 80 before and after chuck grounding to the difference between the lower surface position B2 of the replaced grinding wheel F2, which is the replaced grinding wheel information, and the lower surface position B1 of the previous grinding wheel F1, which is the previous grinding wheel information. C=B2-B1+X (6)

[0111] In the above embodiment, the grinding wheel detection unit 120 is provided on the upper surface of the grinding chamber cover 110, but the installation position of the grinding wheel detection unit 120 is not limited to this. For example, the grinding wheel detection unit 120 may be provided in the replacement device 200. The configuration of the grinding wheel detection unit 120 is arbitrary, but for example, it detects the position of the lower surface of the grinding wheel F using laser light. Then, the information processing unit 151 sets the setup position of the replaced grinding wheel F2 based on the pre-replacement grinding wheel information and the post-replacement grinding wheel information detected by the grinding wheel detection unit 120. The setup position of the replaced grinding wheel F2 is set for each chuck 80.

[0112] In such cases, the following falls within the scope of the present invention: A grinding device for grinding a substrate, comprising: a grinding tool having a grinding wheel and a grinding stone attached to the underside of the grinding wheel; and an information processing unit that receives grinding stone information detected by a grinding stone detection unit provided in an exchange device that exchanges the grinding tool.

[0113] In the above embodiment, a so-called three-axis grinding device 60 is employed in which three grinding units 90 (first grinding unit 90a, second grinding unit 90b, and third grinding unit 90c) are arranged in the grinding device 60, but the configuration of the grinding device 60 is not limited to this. For example, the grinding device 60 may have a single-axis configuration in which only one grinding unit 90 is arranged, or a two-axis configuration in which two grinding units 90 are arranged.

[0114] In the above embodiment, the dress board storage unit 130 is provided inside the grinding apparatus 60, but the dress board storage unit 130 may be omitted and the dress board 131 may be transported from outside the grinding apparatus 60. For example, the dress board 131 may be stored in a dress board storage unit provided in the first processing block G1 or the second processing block G2, or may be transported from outside the wafer processing system 1. In this case, the dress board thickness measurement unit 134 is also provided outside the grinding apparatus 60.

[0115] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. For example, the components of the above-described embodiments may be arbitrarily combined. Such an arbitrary combination naturally provides the functions and effects of each of the components involved in the combination, and also provides other functions and effects that are apparent to those skilled in the art from the description of this specification.

[0116] Furthermore, the effects described herein are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that are apparent to those skilled in the art from the description of this specification, in addition to or in place of the above-described effects.

[0117] 60 Grinding device 110 Grinding chamber cover 111 Grinding chamber 120 Grinding stone detection unit 151 Information processing unit D Grinding tool E Grinding wheel F Grinding stone W Wafer

Claims

1. An apparatus for grinding a substrate with a grinding tool equipped with a grinding wheel, comprising: a grinding chamber formed inside a grinding chamber cover that houses the grinding tool; and an information processing unit that receives grinding wheel information of the grinding wheel detected by a grinding wheel detection unit provided above the upper surface of the grinding chamber.

2. A grinding device as described in claim 1, wherein the information processing unit sets a reference position of the replaced grindstone using pre-replacement grindstone information of the pre-replacement grindstone received from the grindstone detection unit and post-replacement grindstone information of the replaced grindstone received from the grindstone detection unit.

3. A grinding device as described in claim 2, wherein the pre-replacement grinding wheel information includes information on the underside position of the pre-replacement grinding wheel, the post-replacement grinding wheel information includes information on the underside position of the post-replacement grinding wheel, and the information processing unit sets the reference position of the post-replacement grinding wheel by adding the difference between the underside position of the pre-replacement grinding wheel and the underside position of the post-replacement grinding wheel to the reference position of the pre-replacement grinding wheel.

4. A grinding apparatus as described in claim 2, wherein the reference position is a position where the position of the lower surface of the grinding wheel coincides with the position of the upper surface of a substrate holding part that holds a substrate, or a position that is a predetermined set distance away from the position of the upper surface of the substrate holding part.

5. The grinding device described in claim 2, wherein the information processing unit, after setting a reference position for the replaced grinding wheel, sends a transport command for the dress board to a transport device capable of transporting a dress board for dressing the replaced grinding wheel.

6. The grinding device according to claim 2, wherein the information processing unit transmits a command to replace the grinding wheel to a replacement device that replaces the grinding wheel when it is determined that the length of the previous grinding wheel has reached the time to replace it.

7. The grinding device according to claim 6, wherein said information processing section receives said post-replacement grinding wheel information from said grinding wheel detection section after receiving information indicating completion of replacement of said grinding wheel from said replacement device.

8. The grinding device according to claim 1, wherein the grindstone detection unit is provided on an upper surface of the grinding chamber.

9. The grinding device according to claim 8, wherein the grindstone detection unit includes a laser sensor, and the grindstone detection unit is positioned so that a laser optical axis from the laser sensor is positioned horizontally and tangentially to the grinding wheel.

10. A grinding device as described in claim 1, further comprising a grinding tool detection unit provided in a lifting unit that raises and lowers the grinding tool, wherein the information processing unit receives grinding tool information detected by the grinding tool detection unit and uses the grinding tool information to set a reference position for the grinding wheel.

11. A method for grinding a substrate, comprising: grinding a substrate using a grinding wheel provided in a grinding chamber formed inside a grinding chamber cover; receiving, when replacing the grinding wheel, grinding wheel information of the grinding wheel detected by a grinding wheel detection unit provided above an upper surface of the grinding chamber; and setting a reference position of the replaced grinding wheel using the pre-replacement grinding wheel information of the pre-replacement grinding wheel received from the grinding wheel detection unit and the post-replacement grinding wheel information of the replaced grinding wheel received from the grinding wheel detection unit.

12. A grinding method as described in claim 11, wherein the pre-replacement grinding wheel information includes information on the underside position of the pre-replacement grinding wheel, and the post-replacement grinding wheel information includes information on the underside position of the post-replacement grinding wheel, and the reference position of the post-replacement grinding wheel is set by adding the difference between the underside position of the pre-replacement grinding wheel and the underside position of the post-replacement grinding wheel to the reference position of the pre-replacement grinding wheel.

13. A grinding method as described in claim 11, wherein the reference position is a position where the position of the lower surface of the grinding wheel coincides with the position of the upper surface of a substrate holding part that holds a substrate, or a position that is a predetermined set distance away from the position of the upper surface of the substrate holding part.

14. The grinding method according to claim 11, further comprising the step of: after setting a reference position for the replaced grindstone, transmitting a command to transport the dress board to a transport device capable of transporting a dress board for dressing the replaced grindstone.

15. The grinding method according to claim 11, further comprising the step of: transmitting a command to replace the grinding wheel to a replacement device that replaces the grinding wheel when it is determined that the length of the grinding wheel before replacement has reached the time for replacement.

16. The grinding method according to claim 15, further comprising receiving the post-replacement grindstone information from the grindstone detection unit after receiving information indicating completion of replacement of the grindstone from the replacement device.

17. A grinding method according to claim 11, further comprising receiving grinding tool information detected by a grinding tool detection unit provided in a lifting unit that raises and lowers the grinding tool, and using the grinding tool information to set a reference position for the grinding wheel.

Images