WO2019124032A1

WO2019124032A1 - Substrate processing system, substrate processing method, and computer storage medium

Info

Publication number: WO2019124032A1
Application number: PCT/JP2018/044366
Authority: WO
Inventors: 宗久児玉
Original assignee: 東京エレクトロン株式会社
Priority date: 2017-12-22
Filing date: 2018-12-03
Publication date: 2019-06-27
Also published as: TWI806935B; CN111479654A; KR102604525B1; CN111479654B; TW201929078A; JPWO2019124032A1; JP6968201B2; KR20200099565A

Abstract

A substrate processing system that machines a machining face of a substrate on which a protective material is provided on a non-machining face has: a grinding unit that grinds the machining face of the substrate in a plurality of steps; a protective material thickness measuring unit that measures the thickness of the protective material before grinding the substrate machining face with the grinding unit; and a controlling unit that calculates, on the basis of the protective material thickness measured by the protective material thickness measuring unit, a first grinding amount during a first grinding step so that a second grinding amount during a second grinding step after the first grinding step, in which the machining face of the substrate is ground with the grinding unit, is constant for each substrate.

Description

Substrate processing system, substrate processing method and computer storage medium

(Cross-reference to related applications)
Priority is claimed on Japanese Patent Application No. 2017-246732, filed Dec. 22, 2017, the content of which is incorporated herein by reference.

The present invention relates to a substrate processing system for processing a processed surface of a substrate provided with a protective material on a non-processed surface, a substrate processing method using the substrate processing system, and a computer storage medium.

In recent years, in the semiconductor device manufacturing process, the back surface of a wafer may be ground to thin the wafer with respect to a semiconductor wafer (hereinafter referred to as a wafer) on which devices such as a plurality of electronic circuits are formed on the surface. It has been done. Further, as described in, for example, Patent Document 1 and Patent Document 2, for example, a protective tape is provided on the surface of the wafer before grinding as a protective material for protecting the device.

Grinding of the back surface of the wafer is performed using, for example, a grinding apparatus described in Patent Document 1 and Patent Document 2. The grinding apparatus includes, for example, a rotatable chuck that holds the front surface of the wafer, and a grinding wheel that is annularly rotatably configured and includes a grinding wheel that grinds the back surface of the wafer held by the chuck. Then, in this grinding apparatus, rough grinding and finish grinding are sequentially performed on the back surface of the wafer. Specifically, in each grinding process, the back surface of the wafer is ground by bringing the grinding wheel into contact with the back surface of the wafer while rotating the chuck (wafer) and the grinding wheel (grinding wheel). In addition, during this grinding, the wafer is finished to a target thickness by measuring the thickness of the wafer with a thickness measurement gauge.

Further, for example, in Patent Document 2, the above-described thickness measurement gauge is a contact type, and includes a reference height gauge and a wafer height gauge, and a value obtained by subtracting the measurement value of the reference height gauge from the measurement value of the wafer height gauge. It is stated that the thickness of the wafer is measured on the basis of. In this case, since the protective tape is attached to the surface of the wafer, the thickness of the wafer is calculated in consideration of the thickness of the protective tape.

Further, for example, Patent Document 2 describes using a non-contact type finish thickness measuring device in finish grinding. The finished thickness measuring device has a plurality of thickness sensors, and measures the thickness of the wafer at a plurality of points. In this case, the thickness of only the wafer excluding the protective tape is measured.

Japan JP 2012-187654 Japanese Patent Application Laid-Open No. 2008-264913

By the way, the thickness of the protective tape may vary from wafer to wafer. In such a case, as in the conventional case, the overall thickness of the wafer and the protective tape is measured by rough grinding using a contact-type thickness measurement meter, and the thickness of the wafer is measured using a non-contact-type thickness measurement meter by finish grinding The amount of grinding in rough grinding and finish grinding varies from wafer to wafer.

When grinding while measuring the total thickness including the thickness of the wafer and the thickness of the protective tape using a contact-type thickness measurement meter, if the thickness of the protective tape differs for each wafer, the thickness of each wafer after grinding is It will be different. Then, in order to grind the wafers having different thicknesses to the same thickness, the amount of grinding at the time of the subsequent grinding will vary from wafer to wafer.

It is not preferable that the grinding amount varies in this way. Particularly in finish grinding, since the wafer is ground to the final finished thickness, the amount of grinding needs to be strictly controlled, and it is necessary that the amount of grinding be constant regardless of variations in the thickness of the protective tape. Become.

The present invention has been made in view of the above circumstances, and in grinding and processing a processed surface of a substrate provided with a protective material on a non-processed surface, the substrate is properly made with a constant grinding amount for each substrate. The purpose is to grind.

One aspect of the present invention for solving the above problems is a substrate processing system for processing a processing surface of a substrate having a protective material provided on a non-processing surface, and a grinding unit for grinding the processing surface of the substrate in a plurality of steps. And before grinding the processed surface of the substrate in the grinding unit, based on the protective material thickness measurement unit that measures the thickness of the protective material and the protective material thickness measured by the protective material thickness measurement unit. In the first grinding process, the second grinding amount in the second grinding process after the first grinding process for grinding the machined surface of the substrate in the grinding unit is constant for each substrate. And a control unit that calculates a grinding amount of 1.

According to one aspect of the present invention, the thickness of the protective material is measured before grinding the machined surface of the substrate, and the first grinding amount in the first grinding process step is calculated using the measurement result. Thus, since the first grinding amount is calculated in consideration of the thickness of the protective material, even if the thickness of the protective material varies from substrate to substrate, the substrate after being ground in the first grinding process step Can be made constant for each substrate. Then, the second grinding amount in grinding the machined surface of the substrate in the second grinding process can be made constant, and the substrate can be ground appropriately.

One embodiment of the present invention according to another aspect is a substrate processing method for processing a processed surface of a substrate provided with a protective material on a non-processed surface, the protective material thickness measuring step of measuring the thickness of the protective material; Thereafter, a plurality of grinding processing steps of grinding the processed surface of the substrate, and among the plurality of grinding processing steps based on the protective material thickness measured in the protective material thickness measuring step, The first grinding amount in the first grinding process is calculated so that the second grinding amount in the second grinding process after the first grinding process for grinding the machined surface becomes constant for each substrate. Do.

According to an aspect of the present invention according to another aspect, a readable program storing a program that operates on a computer of a control unit that controls the substrate processing system so as to cause the substrate processing system to execute the substrate processing method It is a computer storage medium.

According to one aspect of the present invention, in grinding and processing the machined surface of the substrate having the protective material provided on the non-machined surface, the substrate can be properly ground with a constant amount of grinding for each substrate. .

It is a top view which shows typically the outline | summary of a structure of the substrate processing system concerning this embodiment. It is a side view which shows the outline of a structure of a protection wafer. It is a top view which shows the outline of a structure of a processing apparatus. It is a side view which shows the outline of a structure of a protective tape thickness measurement unit. It is a side view showing an outline of composition of whole thickness measurement unit. It is a side view which shows the outline of a structure of a wafer main body thickness measurement unit. It is a flowchart which shows the main process of wafer processing. It is explanatory drawing which shows a mode that the process surface of a wafer is ground. It is an explanatory view showing a grinding amount of each grinding processing about a protection wafer from which thickness of a protection tape and thickness of a wafer before grinding processing differ.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and the drawings, elements having substantially the same functional configuration will be assigned the same reference numerals and redundant description will be omitted.

<Substrate processing system>
First, the configuration of a substrate processing system according to the present embodiment will be described. FIG. 1 is a plan view schematically showing the outline of the configuration of a substrate processing system 1. In the following, in order to clarify the positional relationship, the X-axis direction, the Y-axis direction, and the Z-axis direction orthogonal to one another are defined, and the Z-axis positive direction is the vertically upward direction.

In the substrate processing system 1 of the present embodiment, the wafer W as a substrate is thinned. Hereinafter, as shown in FIG. 2, in the wafer W, the surface to be processed (ground) is referred to as “processing surface W1”, and the surface on the opposite side to the processing surface W1 is referred to as “non-processing surface W2”. The wafer W is, for example, a semiconductor wafer such as a silicon wafer or a compound semiconductor wafer. The wafer W includes a wafer main body M as a substrate main body, and a device D formed on the non-processing surface side of the wafer main body M. The surface of the wafer main body M constitutes a processing surface W1, and the surface of the device D constitutes a non-processing surface W2 of the wafer W. On the non-processed surface W2 of the wafer W, a protective material for protecting the device D, for example, a protective tape P is attached. In the following description, the entire wafer W to which the protective tape P is attached is referred to as a protective wafer Wp.

As shown in FIG. 1, the substrate processing system 1 stores the protected wafer Wp before processing in the cassette C, and transfers the plurality of protected wafers Wp from the outside into the substrate processing system 1 in cassette units, and processing A loading station 3 for storing the subsequent wafer W (wafer W in which the protective tape P has been peeled from the protective wafer Wp) in the cassette C and unloading the plurality of wafers W from the substrate processing system 1 in cassette units, A processing apparatus 4 for processing and thinning the wafer Wp, a post-processing apparatus 5 for performing post-processing of the protected wafer Wp after processing, protection between the loading station 2, the processing apparatus 4 and the post-processing apparatus 5 And a transfer station 6 for transferring the wafer Wp. The loading station 2, the transfer station 6, and the processing device 4 are arranged in this order in the Y-axis direction on the X-axis negative direction side. The unloading station 3 and the post-processing device 5 are arranged side by side in this order in the Y-axis direction on the X-axis positive direction side.

A cassette mounting table 10 is provided at the loading station 2. In the illustrated example, a plurality of, for example, two cassettes C can be mounted on the cassette mounting table 10 in a row in the X-axis direction.

The unloading station 3 also has the same configuration as the loading station 2. A cassette mounting table 20 is provided at the unloading station 3, and for example, two cassettes C can be mounted on the cassette mounting table 20 in a row in the X-axis direction. The loading station 2 and the unloading station 3 may be integrated into one loading and unloading station, and in such a case, the loading and unloading station is provided with a common cassette mounting table.

In the processing apparatus 4, processing such as grinding and cleaning is performed on the protected wafer Wp. The configuration of the processing device 4 will be described later.

In the post-processing apparatus 5, post-processing is performed on the protected wafer Wp processed by the processing apparatus 4. As the post-processing, for example, a mounting process of holding the protective wafer Wp on a dicing frame via a dicing tape, a peeling process of peeling the protective tape P attached to the wafer W in the protective wafer Wp, and the like are performed. Then, the post-processing apparatus 5 carries the post-processing and carries the wafer W held by the dicing frame to the cassette C of the unloading station 3. A known device is used for the mounting process and the peeling process performed by the post-processing device 5 respectively.

The transfer station 6 is provided with a wafer transfer area 30. In the wafer transfer area 30, a wafer transfer apparatus 32 movable on the transfer path 31 extending in the X-axis direction is provided. The wafer transfer apparatus 32 has a transfer fork 33 and a transfer pad 34 as a wafer holding unit for holding the protective wafer Wp. The tip of the transfer fork 33 branches into two, and the protective wafer Wp is held by suction. The transfer fork 33 transfers the protected wafer Wp before the grinding process. The transfer pad 34 has a circular shape with a diameter longer than the diameter of the protective wafer Wp in plan view, and adsorbs and holds the protective wafer Wp. The transfer pad 34 transfers the protective wafer Wp after the grinding process. The transfer fork 33 and the transfer pad 34 are configured to be movable in the horizontal direction, the vertical direction, around the horizontal axis, and around the vertical axis, respectively.

As shown in FIG. 1, a control unit 40 is provided in the substrate processing system 1. The control unit 40 is, for example, a computer and has a program storage unit (not shown). The program storage unit stores a program that controls processing of the protected wafer Wp (wafer W) in the substrate processing system 1. The program storage unit also stores a program for realizing the below-described wafer processing in the substrate processing system 1 by controlling the operation of drive systems such as the above-described various processing apparatuses and transport apparatuses. The program is recorded on a computer readable storage medium H such as a computer readable hard disk (HD), a flexible disk (FD), a compact disc (CD), a magnet optical desk (MO), a memory card, etc. And may be installed in the control unit 40 from the storage medium H.

<Processing device>
Next, the structure of the processing apparatus 4 mentioned above is demonstrated. As shown in FIGS. 3 to 6, the processing apparatus 4 includes a rotary table 100, a transport unit 110, an alignment unit 120, a first cleaning unit 130, a second cleaning unit 140, a rough grinding unit 150 as a grinding unit, and grinding Middle grinding unit 160 as a part, finish grinding unit 170 as a grinding part, protective tape thickness measuring unit 180 as a protective material thickness measuring part, overall thickness measuring unit 190 as a total thickness measuring part, and substrate body thickness measuring part The wafer body thickness measurement unit 200 of FIG. In the present embodiment, the rough grinding unit 150 corresponds to a first grinding portion in the present invention, and the middle grinding unit 160 and the finish grinding unit 170 respectively correspond to a second grinding portion in the present invention.

The rotary table 100 is configured to be rotatable by a rotation mechanism (not shown). On the rotating table 100, four chucks 101 for attracting and holding the protective wafer Wp are provided. The chucks 101 are arranged uniformly on the same circumference as the rotary table 100, that is, every 90 degrees. The four chucks 101 are movable to the delivery position A0 and the processing positions A1 to A3 by rotation of the rotary table 100.

In this embodiment, the delivery position A0 is a position on the X-axis positive direction side and the Y-axis negative direction side of the rotary table 100, and the second cleaning unit 140 and the alignment unit are on the Y-axis negative direction side of the delivery position A0. 120 and the first cleaning unit 130 are arranged side by side. The alignment unit 120 and the first cleaning unit 130 are stacked and arranged in this order from above. The first processing position A1 is a position on the X-axis positive direction side and the Y-axis positive direction side of the rotary table 100, and the rough grinding unit 150 is disposed. The second processing position A2 is a position on the X axis negative direction side and the Y axis positive direction side of the rotary table 100, and the middle grinding unit 160 is disposed. The third processing position A3 is a position on the X axis negative direction side and the Y axis negative direction side of the rotary table 100, and the finish grinding unit 170 is disposed.

The chuck 101 is held by a chuck base 102. The chuck 101 and the chuck base 102 are configured to be rotatable by a rotation mechanism (not shown).

The transport unit 110 is an articulated robot including a plurality of, for example, three arms 111 to 113. The three arms 111 to 113 are connected by joints (not shown), and by these joints, the first arm 111 and the second arm 112 are configured to be pivotable around their respective proximal ends. Of the three arms 111 to 113, a transfer pad 114 for attracting and holding the protective wafer Wp is attached to the first arm 111 at the tip. Further, among the three arms 111 to 113, the third arm 113 at the proximal end is attached to a vertical movement mechanism 115 for moving the arms 111 to 113 in the vertical direction. Then, the transfer unit 110 having such a configuration can transfer the protective wafer Wp to the delivery position A0, the alignment unit 120, the first cleaning unit 130, and the second cleaning unit 140.

The alignment unit 120 adjusts the horizontal direction of the protective wafer Wp before the grinding process. For example, the position of the notch portion of the wafer W is adjusted by detecting the position of the notch portion of the wafer W while detecting the position of the notch portion of the wafer W while rotating the protective wafer Wp held by the spin chuck (not shown). The horizontal orientation of the protective wafer Wp is adjusted.

In the first cleaning unit 130, the processing surface W1 of the wafer W after the grinding processing is cleaned, more specifically, spin-cleaned. For example, while rotating the protective wafer Wp (wafer W) held by the spin chuck (not shown), the cleaning liquid is supplied from the cleaning liquid nozzle (not shown) to the processing surface W1 of the wafer W. Then, the supplied cleaning liquid diffuses on the processing surface W1, and the processing surface W1 is cleaned.

The second cleaning unit 140 cleans the non-processed surface W2 of the wafer W in a state where the protective wafer Wp after the grinding processing is held by the transfer pad 114, that is, the protective tape P attached to the non-processed surface W2. , Cleaning the transfer pad 114.

In the rough grinding unit 150, the processing surface W1 of the wafer W is roughly ground. The rough grinding unit 150 has a rough grinding portion 151 having an annular shape and a rotatable rough grinding wheel (not shown). The rough grinding portion 151 is configured to be movable in the vertical direction and the horizontal direction along the support column 152. Then, while the processing surface W1 of the wafer W held by the chuck 101 is in contact with the rough grinding wheel, the processing surface W1 of the wafer W is roughly ground by rotating the chuck 101 and the rough grinding wheel respectively.

In the middle grinding unit 160, the processing surface W1 of the wafer W is middle ground. The middle grinding unit 160 has a middle grinding portion 161 having an annular shape and a rotatable middle grinding wheel (not shown). In addition, the middle grinding portion 161 is configured to be movable in the vertical direction and the horizontal direction along the support column 162. The grain size of the abrasive grains of the medium grinding wheel is smaller than the grain size of the abrasive grains of the rough grinding stone. Then, while the processing surface W1 of the wafer W held by the chuck 101 is in contact with the middle grinding stone, the processing surface W1 is middle-grounded by rotating the chuck 101 and the middle grinding wheel, respectively.

In the finish grinding unit 170, the processing surface W1 of the wafer W is finish ground. The finish grinding unit 170 has a finish grinding portion 171 provided with a ring-shaped rotatable finish grinding wheel (not shown). The finish grinding unit 171 is configured to be movable in the vertical direction and the horizontal direction along the support 172. The grain size of the abrasive grains of the finish grinding wheel is smaller than the grain size of the abrasive grains of the medium grinding wheel. Then, in a state where the processing surface W1 of the wafer W held by the chuck 101 is in contact with the finish grinding wheel, the processing surface W1 is finish-ground by rotating the chuck 101 and the finish grinding wheel respectively.

As shown in FIGS. 1 and 3, the protective tape thickness measurement unit 180 is provided, for example, above the alignment unit 120. As shown in FIG. 4, the protective tape thickness measurement unit 180 measures the thickness of the protective tape P with respect to the protective wafer Wp held by the transfer pad 114 of the transfer unit 110. The protective tape thickness measurement unit 180 measures the thickness of the protective tape P of the protective wafer Wp being transported from the alignment unit 120 to the delivery position A0.

The protective tape thickness measurement unit 180 includes a sensor 181 and a calculation unit 182. For the sensor 181, a sensor that measures the thickness of the protective tape P without contacting the protective tape P is used, and for example, a white confocal (confocal) optical system sensor is used. The sensor 181 irradiates the protective tape P with light having a predetermined wavelength band, and further receives the reflected light reflected from the surface P1 of the protective tape P and the reflected light reflected from the back surface P2. The calculation unit 182 calculates the thickness of the protective tape P based on the both reflected lights received by the sensor 181.

In the present embodiment, a white confocal optical system sensor is used as the sensor 181 of the protective tape thickness measurement unit 180, but the configuration of the protective tape thickness measurement unit 180 is not limited thereto. Any measuring device can be used as long as it measures thickness. Also, a plurality of sensors 181 may be provided.

The entire thickness measurement unit 190 is provided to each of the rough grinding unit 150 and the middle grinding unit 160. As shown in FIG. 5, the entire thickness measurement unit 190 includes a chuck side height gauge 191, a wafer side height gauge 192, and a calculation unit 193. The chuck side height gauge 191 includes a probe 194, and the tip end of the probe 194 contacts the upper surface 102a of the chuck base 102 to measure the height position of the upper surface 102a. The upper surface 102 a of the chuck base 102 is flush with the upper surface of the chuck 101 that holds the protective wafer Wp. The wafer side height gauge 192 includes a probe 195, and the tip of the probe 195 contacts the processing surface W1 of the wafer W, and measures the height position of the processing surface W1. The calculation unit 193 subtracts the chuck side height gauge 191 from the measurement value of the wafer side height gauge 192 to calculate the entire thickness of the protective wafer Wp. The total thickness is the sum of the thickness of the wafer W (the sum of the thickness of the wafer main body M and the thickness of the device D) and the thickness of the protective tape P.

Wafer body thickness measurement unit 200 is provided in finish grinding unit 170. As shown in FIG. 6, the wafer body thickness measurement unit 200 includes a sensor 201 and a calculation unit 202. As the sensor 201, a sensor that measures the thickness of the wafer body M without contacting the wafer body M is used, and for example, a white confocal (confocal) optical system sensor is used. The sensor 201 irradiates the wafer main body M with light having a predetermined wavelength band, and further receives the reflected light reflected from the front surface of the wafer main body M and the reflected light reflected from the back surface. The calculation unit 202 calculates the thickness of the wafer main body M based on the both reflected lights received by the sensor 201.

The sensor 201 according to the present embodiment can measure the thickness without contacting the wafer main body M, so that the wafer main body M can be prevented from being scratched. In particular, in the finish grinding unit 170, the wafer W (wafer main body M) is ground and thinned, and is easily scratched. Therefore, it is useful to be able to measure the thickness of the wafer main body M without contact.

In the present embodiment, a white confocal optical system sensor is used as the sensor 201 of the wafer body thickness measurement unit 200, but the configuration of the wafer body thickness measurement unit 200 is not limited to this. Any measuring device can be used as long as it measures thickness. In addition, a plurality of sensors 201 may be provided.

<Wafer processing>
Next, wafer processing performed using the substrate processing system 1 configured as described above will be described according to the flowchart of FIG.

FIG. 8 is an explanatory view showing a state in which the processing surface W1 of the wafer W is ground in the substrate processing system 1 (processing apparatus 4). As shown in FIG. 8A, before grinding, the total thickness of the protective wafer Wp is Twp0, the thickness of the wafer body M is Tm0, the thickness of the device D is Td, and the thickness of the protective tape P is Tp. It is. Then, the rough grinding in FIG. 8B, the intermediate grinding in FIG. 8C, and the finish grinding in FIG. 8D are sequentially performed, and the wafer W is thinned. The grinding amounts of the processing surface W1 of the wafer W in rough grinding, middle grinding and finish grinding are G1, G2 and G3, and the target thicknesses of the wafer W after grinding are H1, H2 and H3.

In the substrate processing system 1, first, the cassette C containing a plurality of protective wafers Wp is placed on the cassette mounting table 10 of the loading station 2. In the cassette C, in order to suppress the deformation of the protective tape P, the protective wafer Wp is stored such that the non-processed surface W2 of the wafer W to which the protective tape P is attached is directed upward.

Next, the protected wafer Wp in the cassette C is taken out by the transfer fork 33 of the wafer transfer apparatus 32 and transferred to the processing apparatus 4. At this time, the front and back surfaces are reversed such that the processing surface W1 of the wafer W is directed upward by the transfer fork 33.

The protected wafer Wp transferred to the processing apparatus 4 is delivered to the alignment unit 120. Then, in the alignment unit 120, the horizontal direction of the protective wafer Wp is adjusted (Step S1 in FIG. 7).

Next, while the protective wafer Wp is being transported by the transport unit 110, the thickness Tp of the protective tape P shown in FIG. 8A is measured by the protective tape thickness measurement unit 180 (step S2 in FIG. 7). The measurement result of the protective tape thickness measurement unit 180 is output from the calculation unit 182 to the control unit 40.

Next, the protected wafer Wp is transported by the transport unit 110 from the alignment unit 120 to the delivery position A0 and delivered to the chuck 101 at the delivery position A0. Thereafter, the rotary table 100 is rotated 90 degrees counterclockwise to move the chuck 101 to the first processing position A1.

Next, before the rough grinding by the rough grinding unit 150, the whole thickness Twp0 of the protective wafer Wp shown in FIG. 8A is measured by the whole thickness measuring unit 190 (Step S3 in FIG. 7). The measurement result of the entire thickness measurement unit 190 is output from the calculation unit 193 to the control unit 40.

In the control unit 40, the rough grinding amount G1 of the processing surface W1 of the wafer W in the rough grinding unit 150 is determined based on the thickness Tp of the protective tape P measured in step S2 and the total thickness Twp0 measured in step S3. Calculate (step S4 in FIG. 7). Specifically, first, a target thickness H1 of the wafer W to be left after the rough grinding shown in FIG. 8B is set. Then, the rough grinding amount G1 is calculated using the following equation (1). The rough grinding amount G1 corresponds to the first grinding amount in the present invention.
G1 = Twp0-Tp-H1 ・・・・・ (1)

Next, the processing surface W1 of the wafer W is roughly ground as shown in FIG. 8B by the rough grinding unit 150 based on the rough grinding amount G1 calculated in step S4 (step S5 in FIG. 7).

Next, the rotary table 100 is rotated 90 degrees counterclockwise to move the chuck 101 to the second processing position A2. Then, before middle grinding by middle grinding unit 160, total thickness Twp1 of protective wafer Wp shown in FIG. 8B is measured by total thickness measurement unit 190 (step S6 in FIG. 7). The measurement result of the entire thickness measurement unit 190 is output from the calculation unit 193 to the control unit 40.

In control unit 40, based on thickness Tp of protective tape P measured in step S2 and overall thickness Twp1 measured in step S6, middle grinding amount G2 of processing surface W1 of wafer W in middle grinding unit 160 is determined. Calculate (step S7 in FIG. 7). Specifically, first, a target thickness H2 of the wafer W to be left after the middle grinding shown in FIG. 8C is set. Then, the middle grinding amount G2 is calculated using the following equation (2). The middle grinding amount G2 corresponds to the second grinding amount in the present invention.
G2 = Twp1-Tp-H2 ... (2)

Next, on the basis of the middle grinding amount G2 calculated in step S7, the middle grinding unit 160 middle-grinds the processing surface W1 of the wafer W as shown in FIG. 8C (step S8 in FIG. 7).

Next, the rotary table 100 is rotated 90 degrees counterclockwise to move the chuck 101 to the third processing position A3. Then, before the finish grinding by the finish grinding unit 170, the thickness Tm2 of the wafer body M shown in FIG. 8C is measured by the wafer body thickness measurement unit 200 (step S9 in FIG. 7). The measurement result of the wafer body thickness measurement unit 200 is output from the calculation unit 202 to the control unit 40.

The control unit 40 calculates the finish grinding amount G3 of the processing surface W1 of the wafer W in the finish grinding unit 170 based on the thickness Tm2 of the wafer main body M measured in step S9 and the thickness Td of the device D (FIG. Step S10 of 7). Specifically, first, a target thickness H3 of the wafer W to be left after finish grinding shown in FIG. 8D is set. Then, the finish grinding amount G3 is calculated using the following equation (3). The finish grinding amount G3 corresponds to the second grinding amount in the present invention.
G3 = Tm2 + Td-H3 ・・・・・ (3)

The thickness Td of the device D used in step S10 may or may not be known in advance before wafer processing. If the thickness Td of the device D is known in advance before the wafer processing, the equation (3) may be entered as it is.

On the other hand, when the thickness Td of the device D is not known before wafer processing, it can be calculated from the thickness Tm2 of the wafer main body M measured in step S9. In such a case, there are, for example, two methods of calculating the thickness Td of the device D. As a first calculation method, the thickness Td of the device D can be calculated by subtracting the thickness Tm2 of the wafer main body M from the target thickness H2 of the wafer W after middle grinding.

As a second calculation method, for example, the total thickness measurement unit 190 is also provided to the finish grinding unit 170, and before the finish grinding by the finish grinding unit 170, the entire thickness Twp2 of the protected wafer Wp shown in FIG. Do. Then, the thickness Td of the device D can be calculated using the following equation (4).
Td = Twp2-Tm2-Tp (4)

Next, based on the finish grinding amount G3 calculated in step S10, the finish grinding unit 170 performs finish grinding on the processing surface W1 of the wafer W as shown in FIG. 8 (d) (step S11 in FIG. 7).

Here, when it is not necessary to consider the thickness Td of the device D, the target thickness H3 of the wafer W is the same as the target thickness of the wafer main body M. In this case, the processing surface W1 of the wafer W is finish ground until the thickness of the wafer main body M changes from Tm3 to H3.

Next, the rotary table 100 is rotated 90 degrees counterclockwise, or the rotary table 100 is rotated 270 degrees clockwise to move the chuck 101 to the delivery position A0. Here, the processing surface W1 of the wafer W is roughly cleaned by the cleaning liquid using the cleaning liquid nozzle (not shown) (step S12 in FIG. 7). In this step S12, cleaning is performed to remove dirt on the processing surface W1 to a certain extent.

Next, the protection wafer Wp is transferred by the transfer unit 110 from the delivery position A0 to the second cleaning unit 140. Then, in the second cleaning unit 140, the non-processed surface W2 (protective tape P) of the wafer W is cleaned and dried in a state where the protected wafer Wp is held by the transfer pad 114 (step S13 in FIG. 7). .

Next, the protective wafer Wp is transferred by the transfer unit 110 from the second cleaning unit 140 to the first cleaning unit 130. Then, in the first cleaning unit 130, the processing surface W1 of the wafer W is finish-cleaned with the cleaning liquid using the cleaning liquid nozzle (not shown) (step S14 in FIG. 7). In step S14, the processing surface W1 is cleaned and dried to a desired degree of cleanliness.

Thereafter, the protected wafer Wp is transferred by the wafer transfer apparatus 32 from the first cleaning unit 130 to the post-processing apparatus 5. Then, in the post-processing apparatus 5, post-processing such as mounting processing for holding the protective wafer Wp on the dicing frame and peeling processing for peeling the protective tape P attached to the protective wafer Wp is performed (step S15 in FIG. 7). ).

Thereafter, the wafer W subjected to all the processes is transferred to the cassette C of the cassette mounting table 20 of the unloading station 3. Thus, a series of wafer processing in the substrate processing system 1 is completed.

According to the above embodiment, in one substrate processing system 1, a series of processing can be continuously performed on a plurality of protected wafers Wp, and the throughput of wafer processing can be improved.

Further, according to the present embodiment, by measuring the thickness Tp of the protective tape P with the protective tape thickness measurement unit 180, even if the thickness Tp of the protective tape P varies among the protective wafers Wp, at least the middle grinding unit The middle grinding amount G2 at 160 and the finishing grinding amount G3 at the finishing grinding unit 170 can be made constant. And grinding of processing side W1 of wafer W can be performed appropriately.

Hereinafter, the effect of the present embodiment will be described based on FIG. FIG. 9A shows a protective wafer Wpa as a reference. FIG. 9B shows a protective wafer Wpb in which the thickness of the protective tape P is different from that of the protective wafer Wpa. FIG. 9C shows a protected wafer Wpc in which the thickness of the wafer W before the grinding process is different from that of the protected wafer Wpa.

As described above, the grinding amounts G1, G2 and G3 in rough grinding, middle grinding and finish grinding are calculated by the following formulas (1), (2) and (3), respectively.
G1 = Twp0-Tp-H1 ・・・・・ (1)
G2 = Twp1-Tp-H2 ... (2)
G3 = Tm2 + Td-H3 ・・・・・ (3)

In such a case, first, protected wafers Wpa and Wpb shown in FIGS. 9A and 9B will be described. In these protective wafers Wpa and Wpb, the thicknesses of the protective tapes Pa and Pb are Tpa and Tpb, respectively, and the thickness Tpb is larger than the thickness Tpa. The thicknesses of the wafer bodies Ma and Mb before the grinding process are the same for Tma0 and Tmb0, respectively, and the thicknesses for the devices Da and Db are the same for Tda and Tdb, respectively.

The rough grinding amount G1 in the rough grinding is calculated by the above equation (1), but (Twpa0-Tpa) in the protected wafer Wpa and (Twpb0-Tpb) in the protected wafer Wpb are the same. Then, rough grinding amount Ga1 for protected wafer Wpa and rough grinding amount Gb1 for protected wafer Wpb become equal.

Similarly, with regard to the medium grinding amount G2 in the middle grinding, the middle grinding amount Ga2 for the protection wafer Wpa and the middle grinding amount Gb2 for the protection wafer Wpb are the same from the above equation (2). Further, with regard to the finish grinding amount G3 in the finish grinding, the finish grinding amount Ga3 for the protection wafer Wpa and the finish grinding amount Gb3 for the protection wafer Wpb are the same from the above equation (3).

As described above, according to the present embodiment, the rough grinding amounts Ga1 and Gb1, the middle grinding amounts Ga2 and Gb2, and the finish grinding for each of the protection wafers Wpa and Wpb, even if the thicknesses Tpa and Tpb of the protection tapes Pa and Pb are different. The amounts Ga3 and Gb3 can be made the same.

Next, protection wafers Wpa and Wpc shown in FIGS. 9A and 9C will be described. In the protected wafers Wpa and Wpc, the thicknesses of the wafer bodies Ma and Mc before the grinding process are Tma0 and Tmc0, respectively, and the thickness Tmc0 is larger than the thickness Tma0. The thicknesses of the protective tapes Pa and Pb are the same for Tpa and Tpb, respectively, and the thicknesses of the devices Da and Db are also the same for Tda and Tdb, respectively.

In such a case, since the overall thickness Twpa0 of the protected wafer Wpa and the overall thickness Twpc0 of the protected wafer Wpc are different, the rough grinding amounts Ga1 and Gc1 in the rough grinding, which are calculated from the above equation (1), are different.

However, the overall thicknesses Twpa1 and Twpc1 after rough grinding can be made the same. Then, with regard to the medium grinding amount G2 in the middle grinding, according to the above equation (2), the middle grinding amount Ga2 for the protective wafer Wpa and the middle grinding amount Gc2 for the protective wafer Wpc become the same. Further, with regard to the finish grinding amount G3 in the finish grinding, the finish grinding amount Ga3 for the protection wafer Wpa and the finish grinding amount Gc3 for the protection wafer Wpc are the same from the above equation (3).

As described above, according to the present embodiment, when the thicknesses Tma0 and Tmc0 of the wafer bodies Ma and Mc before the grinding process are different, the middle grinding amounts Ga2 and Gb2 and the finish grinding amounts Ga3 and Gb3 are set for each of the protection wafers Wpa and Wpb. It can be the same. Here, in rough grinding, a damaged layer is formed. When the thickness of the damaged layer changes, the subsequent processing becomes uneven. In this respect, as in the present embodiment, the overall thicknesses Twpa1 and Twpc1 after rough grinding are the same, the middle grinding amounts Ga2 and Gb2, and the finish grinding amounts Ga3 and Gb3 are also the same, that is, the remaining damage layer is the same. Because the subsequent processing (medium grinding, finish grinding) will be the same conditions. As a result, uniform processing can be performed for each of the protected wafers Wpa and Wpb.

Other Embodiments
In the above embodiment, the rough grinding in step S5 may be divided into a plurality of steps. The rough grinding in step S5 is divided into, for example, steps from air cutting to lower the rough grinding portion 151 (coarse grinding wheel) at low speed, to step S51 to perform rough grinding at high speed, and to step S52 to perform rough grinding to low speed. It will be.

As described above, when the thickness of the wafer main body M before the grinding process is different among the plurality of protection wafers Wp, the rough grinding amount G1 is different for each of the protection wafers Wp. On the other hand, in the low speed step S52, it is preferable that the grinding amount G12 be a grinding amount that does not apply a stress to the wafer W, and be a fixed value common to a plurality of wafers W.

Therefore, the grinding amount G11 in the high-speed step S51 is set as a fluctuation value that fluctuates for each of the protection wafers Wp. Specifically, after the rough grinding amount G1 is calculated for each protection wafer Wp, the grinding amount G12 (fixed value) of each step S52 is subtracted from the rough grinding amount G1, and the grinding amount G11 of step S51 is calculated. calculate.

In such a case, although the grinding amount G11 of the high-speed step S51 is different for each protection wafer Wp, the grinding amount G12 of the low-speed step S52 can be fixed. Then, in the second half process of the rough grinding, the stress applied to the wafer W can be reduced as compared with the first half process, and the rough grinding can be appropriately performed.

Step S52 may be further divided into a plurality of steps. Further, depending on the thickness of the wafer W, step S51 is omitted, and grinding is performed only with the grinding amount G12 (fixed value) of step S52. For example, even when there are a plurality of fixed values of the grinding amount in a plurality of steps, the first half of the plurality of steps may be omitted and grinding may be performed only with the grinding amount of the fixed value.

In the above embodiment, the entire thickness of the protection wafer Wp is measured by the contact total thickness measurement unit 190 in the middle grinding in step S8, but the total thickness of the protection wafer Wp is measured in the first half processing of the middle grinding. In some cases, the thickness of the wafer main body M may be measured in the second half process. For example, when the thickness of the wafer W is large to a certain extent at the start of the middle grinding, the entire thickness of the protective wafer Wp can be measured by the contact total thickness measurement unit 190 (first half process). Then, when the thickness of the wafer W reaches a predetermined thickness, the thickness of the wafer main body M is measured by the non-contact type wafer main body thickness measurement unit 200 (second half process).

In this case, when the middle grinding amount G2 is calculated, the middle grinding amount G21 in the first half processing and the second grinding amount G22 in the second half processing are divided and calculated. Specifically, in the first half process, based on the total thickness Twp1 of the protective wafer Wp measured by the entire thickness measurement unit 190, the thickness Tp of the protective tape P measured in step S2, and the predetermined thickness (H2) The front half grinding amount G21 is calculated using the above equation (2).

In the latter half process, the thickness Tm2 of the wafer body M measured by the wafer body thickness measurement unit 200, the thickness Td of the device D calculated from the thickness Tm2, and the target thickness H3 after finish grinding, for example, The second half grinding amount G22 is calculated using the equation (3). And based on these first half grinding amount G21 and second half grinding amount G22, it is possible to appropriately carry out middle grinding of the processing surface W1 of the wafer W. Note that a value input in advance may be used as the thickness Td of the device D.

Also in the finish grinding in step S11, the overall thickness of the protected wafer Wp may be measured in the first half process, and the thickness of the wafer main body M may be measured in the second half process. Even in this case, similarly to the above-mentioned middle grinding amount G2, the finish grinding amount G3 is divided and calculated into the first half grinding amount G31 and the second half grinding amount G32.

In the substrate processing system 1 according to the above embodiment, the protective tape thickness measurement unit 180 measures the thickness of the protective tape P with respect to the protective wafer Wp being transported by the transport unit 110. As long as the processing surface W1 of the wafer W is not roughly ground, it can be disposed at an arbitrary position. That is, the protective tape thickness measurement unit 180 can be disposed between the loading station 2 and the rough grinding unit 150. Specifically, the protective tape thickness measurement unit 180 may be provided inside the alignment unit 120 or may be provided inside the loading station 2.

In the substrate processing system 1 of the above embodiment, the processing apparatus 4 includes the rough grinding unit 150, the middle grinding unit 160, and the finish grinding unit 170, but the configuration of the unit is not limited to this. The rough grinding unit 150 may be disposed at the first processing position A1, the finish grinding unit 170 may be disposed at the second processing position A2, and the polishing unit (not shown) may be disposed at the third processing position A3. . Even in such a case, it is possible to appropriately grind the processing surface W1 of the wafer W by calculating the rough grinding amount G1 in the rough grinding unit 150 and the finishing grinding amount G3 in the finishing grinding unit 170 as in the above embodiment. it can.

In the above embodiment, the protective tape P is attached to the non-processed surface W2 of the wafer W in order to protect the device D, but the protective material of the device D is not limited to this. For example, a support substrate such as a support wafer or a glass substrate may be bonded to the non-processed surface W2 of the wafer W, and the present invention can be applied even in such a case.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this example. It is apparent that those skilled in the art can conceive of various modifications or alterations within the scope of the technical idea described in the claims, and they are naturally also within the technical scope of the present invention. It is understood that it belongs.

Reference Signs List 1 substrate processing system 2 loading station 3 unloading station 4 processing device 5 post-processing device 6 transfer station 40 control unit 150 rough grinding unit 160 middle grinding unit 170 finish grinding unit 180 protective tape thickness measurement unit 190 overall thickness measurement unit 200 wafer body thickness Measurement unit D Device M Wafer body P Protective tape W Wafer W1 Processed surface W2 Non-processed surface Wp Protective wafer

Claims

A substrate processing system for processing a processing surface of a substrate having a protective material provided on a non-processing surface, the substrate processing system comprising:
A grinding unit that grinds a processed surface of the substrate in a plurality of steps;
A protective material thickness measurement unit that measures the thickness of the protective material before grinding the processed surface of the substrate in the grinding unit;
The second grinding amount in the second grinding process step after the first grinding process step of grinding the processed surface of the substrate in the grinding unit based on the protective material thickness measured in the protective material thickness measurement unit is And a control unit that calculates a first grinding amount in the first grinding process step so as to be constant for each substrate.
In the substrate processing system according to claim 1,
It has an overall thickness measurement unit that measures the overall thickness of the substrate and the protective material,
The control unit is configured to measure the overall thickness measured by the overall thickness measurement unit before the substrate is ground in the first grinding process, the protective material thickness measured by the protective material thickness measurement unit, and A first grinding amount in the first grinding process is calculated based on the target thickness of the substrate after being ground in the first grinding process.
In the substrate processing system according to claim 2,
In the first grinding process step, the processing surface of the substrate is ground divided into a plurality of steps,
The control unit
Of the plurality of steps of grinding, the amount of grinding in the second step after the first step of grinding the processed surface of the substrate is set,
The first step based on the overall thickness measured in the overall thickness measurement unit, the protective material thickness measured in the protective material thickness measurement unit, and the grinding amount set in the second step Calculate the grinding amount at
In the substrate processing system according to claim 1,
It has an overall thickness measurement unit that measures the overall thickness of the substrate and the protective material,
The control unit is configured to measure the overall thickness measured by the overall thickness measurement unit before the substrate is ground in the second grinding process, the protective material thickness measured by the protective material thickness measurement unit, and A second grinding amount in the second grinding process is calculated based on the target thickness of the substrate after being ground in the second grinding process.
In the substrate processing system according to claim 1,
The substrate processing system
An overall thickness measurement unit that measures the overall thickness until the overall thickness of the substrate and the protective material reaches a predetermined thickness;
And a substrate thickness measurement unit that measures the thickness of the substrate after the entire thickness reaches the predetermined thickness.
The control unit
Based on the total thickness measured in the total thickness measurement unit before the substrate is ground in the second grinding process step, the protective material thickness measured in the protective material thickness measurement unit, and the predetermined thickness Calculating a second front half grinding amount in the second grinding process step;
Thereafter, after the entire thickness reaches the predetermined thickness, grinding is performed to a target thickness of the substrate after being ground in the second grinding process based on the substrate thickness measured by the substrate thickness measurement unit. Control the grinding unit.
In the substrate processing system according to claim 1,
The substrate includes a substrate body, and a device formed on the non-processed surface side of the substrate body and protected by the protective material.
The substrate processing system has a substrate body thickness measurement unit that measures the thickness of the substrate body,
The control unit is configured to measure the substrate body thickness measured by the substrate body thickness measurement unit before the substrate is ground in the second grinding process, and the device thickness calculated from the substrate body thickness. A second grinding amount in the second grinding process is calculated based on the target thickness of the substrate after being ground in the second grinding process.
In the substrate processing system according to claim 1,
The grinding unit includes a first grinding unit that performs the first grinding process and a second grinding unit that performs the second grinding process.
A substrate processing method for processing a processing surface of a substrate having a protective material provided on a non-processing surface,
A protective material thickness measurement step of measuring the thickness of the protective material;
And a plurality of grinding processing steps of grinding the machined surface of the substrate.
Of the plurality of grinding processes based on the thickness of the protective material measured in the process of measuring the thickness of the protective material, a second grinding process after the first grinding process which grinds the processed surface of the substrate The first grinding amount in the first grinding process step is calculated so that the grinding amount of 2 is constant for each substrate.
In the substrate processing method according to claim 8,
And a first overall thickness measuring step of measuring the overall thickness of the substrate and the protective material in the first grinding process step;
Before the substrate is ground in the first grinding process, the overall thickness measured in the first overall thickness measurement process, the protective material thickness measured in the protective material thickness measurement process, and the first thickness The first grinding amount in the first grinding process is calculated based on the target thickness of the substrate after being ground in the grinding process.
In the substrate processing method according to claim 9,
In the first grinding process step, the processing surface of the substrate is ground divided into a plurality of steps,
Of the plurality of steps of grinding, the amount of grinding in the second step after the first step of grinding the processed surface of the substrate is set,
The first on the basis of the overall thickness measured in the first overall thickness measurement step, the protective material thickness measured in the protective material thickness measurement step, and the grinding amount set in the second step Calculate the grinding amount in step 1.
In the substrate processing method according to claim 8,
And a second overall thickness measurement step of measuring the overall thickness of the substrate and the protective material in the second grinding process step,
Before the substrate is ground in the second grinding process, the overall thickness measured in the second overall thickness measurement process, the protective material thickness measured in the protective material thickness measurement process, and the second thickness The second grinding amount in the second grinding process is calculated based on the target thickness of the substrate after being ground in the grinding process.
In the substrate processing method according to claim 8,
The substrate processing method is
A second overall thickness measurement step of measuring the overall thickness until the overall thickness of the substrate and the protective material reaches a predetermined thickness in the second grinding process step;
A substrate thickness measurement step of measuring the thickness of the substrate after the entire thickness reaches the predetermined thickness in the second grinding process step;
The entire thickness measured in the second overall thickness measurement step before the substrate is ground in the second grinding step, the protective material thickness measured in the protective material thickness measurement step, and the predetermined thickness Calculating a second front half grinding amount in the second grinding process, based on
Thereafter, after the entire thickness reaches the predetermined thickness, grinding is performed to a target thickness of the substrate after being ground in the second grinding process based on the substrate thickness measured in the substrate thickness measuring step.
In the substrate processing method according to claim 8,
The substrate includes a substrate body, and a device formed on the non-processed surface side of the substrate body and protected by the protective material.
The substrate processing method includes a substrate body thickness measuring step of measuring the thickness of the substrate body in the second grinding step.
Before the substrate is ground in the second grinding process step, the substrate body thickness measured in the substrate body thickness measuring step, the thickness of the device calculated from the substrate body thickness, and the second grinding A second grinding amount in the second grinding process step is calculated based on the target thickness of the substrate after being ground in the processing step.
A reading that stores a program that operates on a computer of a control unit that controls the substrate processing system so that the substrate processing system executes a substrate processing method of processing the processed surface of a substrate provided with a protective material on a non-processed surface Computer storage medium,
The substrate processing method is
A protective material thickness measurement step of measuring the thickness of the protective material;
And a plurality of grinding processing steps of grinding the machined surface of the substrate.
Of the plurality of grinding processes based on the thickness of the protective material measured in the process of measuring the thickness of the protective material, a second grinding process after the first grinding process which grinds the processed surface of the substrate The first grinding amount in the first grinding process step is calculated so that the grinding amount of 2 is constant for each substrate.