KR102604525B1 - Substrate processing system, substrate processing method, and computer storage medium - Google Patents

Abstract

A substrate processing system for processing the machined surface of a substrate on which a protective material is provided on the unprocessed surface includes a grinding unit for grinding the machined surface of the substrate in a plurality of processes, and before grinding the machined surface of the substrate in the grinding unit, A protective material thickness measuring unit that measures the thickness of the protective material, and a second grinding process after the first grinding process that grinds the machined surface of the substrate in the grinding unit based on the protective material thickness measured by the protective material thickness measuring unit. It has a control unit that calculates the first grinding amount in the first grinding process so that the second grinding amount in is constant for each substrate.

Description

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

(Cross-reference to related applications)

This application claims priority based on Patent Application No. 2017-246732 filed in Japan on December 22, 2017, and uses the content here.

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

Recently, in the manufacturing process of semiconductor devices, the back side of a semiconductor wafer (hereinafter referred to as "wafer") on which a plurality of devices such as electronic circuits are formed on the surface is ground to thin the wafer. . Additionally, as described in, for example, Patent Document 1 and Patent Document 2, a protective tape, for example, is provided on the surface of the wafer before grinding as a protective material to protect the device.

Grinding of the back side of the wafer is performed using, for example, a grinding device described in Patent Document 1 and Patent Document 2. The grinding device includes, for example, a chuck that holds the surface of the wafer and is rotatable, a grinding wheel that grinds the back side of the wafer held in the chuck, and a grinding wheel configured to rotate in an annular manner. And in this grinding device, rough grinding and final grinding are sequentially performed on the back side of the wafer. Specifically, in each grinding process, the back side of the wafer is ground by rotating the chuck (wafer) and the grinding wheel (grinding wheel) and bringing the grinding wheel into contact with the back side of the wafer. Also, during this grinding, the thickness of the wafer is measured using a thickness measurement gauge, so that the wafer is finished to the target thickness.

Also, for example, in Patent Document 2, the above-mentioned thickness measurement gauge is a contact type, and is provided with a reference height gauge and a wafer side height gauge, and the measurement value of the reference side height gauge is subtracted from the measurement value of the wafer side height gauge. It is described that the thickness of the wafer is measured based on the value. In this case, since a protective tape is attached to the surface of the wafer, the thickness of the wafer is calculated by taking into account the thickness of the protective tape.

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

Japanese Patent Publication No. 2012-187654 Japanese Patent Publication No. 2008-264913

However, the thickness of the protective tape may be uneven for each wafer. In this case, as in the past, the overall thickness of the wafer and protective tape is measured using a contact-type thickness measuring meter during rough grinding, and the thickness of the wafer is measured using a non-contact thickness measuring meter during finish grinding. The amount of grinding in grinding is uneven for each wafer.

When grinding while measuring the entire thickness including the thickness of the wafer and the thickness of the protective tape using a contact-type thickness measuring meter, if the thickness of the protective tape is different for each wafer, the thickness of each wafer after grinding will be different. Then, in order to grind wafers of different thicknesses to the same thickness, the amount of grinding during subsequent grinding becomes non-uniform for each wafer.

It is undesirable for the grinding amount to be non-uniform in this way. In particular, in final grinding, since the wafer is ground to the final finished thickness, the grinding amount must be strictly controlled, and the grinding amount must be constant regardless of the unevenness of the thickness of the protective tape.

The present invention has been made in consideration of the above circumstances, and its purpose is to grind and process the machined surface of a substrate on which a protective material is provided on the unprocessed side, by maintaining a constant grinding amount for each substrate and grinding the substrate appropriately.

One aspect of the present invention that solves the above problem is a substrate processing system for processing the machined surface of a substrate on which a protective material is provided on the unprocessed surface, comprising a grinding unit for grinding the machined surface of the substrate through a plurality of processes, and the grinding unit. Before grinding the machined surface of the substrate, a protective material thickness measuring unit that measures the thickness of the protective material, and grinding the processed surface of the substrate in the grinding unit based on the protective material thickness measured in the protective material thickness measuring unit. It has a control unit that calculates the first grinding amount in the first grinding process so that the second grinding amount in the second grinding process after the first grinding process is constant for each substrate.

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 measurement result is used to calculate the first grinding amount in the first grinding process. In this way, since the first grinding amount is calculated in consideration of the thickness of the protective material, even if the thickness of the protective material is non-uniform for each substrate, the thickness of the substrate after grinding in the first grinding process can be made constant for each substrate. Then, the second grinding amount can be kept constant when grinding the machined surface of the substrate in the second grinding process, and the substrate can be ground appropriately.

One aspect of the present invention according to another aspect is a substrate processing method of processing the machined surface of a substrate provided with a protective material on the unprocessed side, comprising a protective material thickness measurement process of measuring the thickness of the protective material, and thereafter, processing of the substrate. A plurality of grinding processes for grinding the surface, based on the protective material thickness measured in the protective material thickness measurement process, a first grinding process after the first grinding process for grinding the machined surface of the substrate among the plurality of grinding processing processes. 2. The first grinding amount in the first grinding process is calculated so that the second grinding amount in the grinding process is constant for each substrate.

In addition, according to one aspect of the present invention according to another aspect, there is a readable computer storage medium storing a program that runs on a computer of a control unit that controls the substrate processing system so that the substrate processing method is executed by the substrate processing system. .

According to one aspect of the present invention, when grinding and processing the processed surface of a substrate on which a protective material is provided on the non-processed surface, the grinding amount for each substrate can be kept constant, so that the substrate can be properly ground.

1 is a plan view schematically showing the outline of the configuration of a substrate processing system according to this embodiment.
Figure 2 is a side view schematically showing the structure of the protection wafer.
Figure 3 is a plan view schematically showing the structure of the processing device.
Figure 4 is a side view schematically showing the configuration of the protective tape thickness measurement unit.
Figure 5 is a side view schematically showing the configuration of the overall thickness measurement unit.
Figure 6 is a side view schematically showing the configuration of the wafer body thickness measurement unit.
Figure 7 is a flowchart showing the main processes of wafer processing.
Figure 8 is an explanatory diagram showing how the processing surface of the wafer is ground.
Fig. 9 is an explanatory diagram showing the grinding amount of each grinding process for protection wafers with different thicknesses of the protection tape and the thickness of the wafer before the grinding process.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention will be described with reference to the drawings. Additionally, in this specification and drawings, elements having substantially the same functional structure are assigned the same reference numerals to omit duplicate descriptions.

<Substrate processing system>

First, the configuration of the substrate processing system according to this embodiment will be described. 1 is a plan view schematically showing the outline of the configuration of the substrate processing system 1. In addition, in the following, in order to clarify the positional relationship, the

In the substrate processing system 1 of this embodiment, the wafer W serving 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 the 'processed surface W1', and the surface opposite to the processed surface W1 is referred to as the 'unprocessed surface W2'. It is said. The wafer W is a semiconductor wafer, for example, 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 unprocessed surface side of the wafer main body M. Then, the surface of the wafer body M constitutes the processed surface W1, and the surface of the device D constitutes the unprocessed surface W2 of the wafer W. A protective material, such as a protective tape P, for protecting the device D is attached to the unprocessed surface W2 of the wafer W. In addition, in the following description, the entire wafer W to which the protection tape P is attached is referred to as the protection wafer Wp.

As shown in FIG. 1, the substrate processing system 1 stores a protection wafer Wp before processing in a cassette C, and supplies a plurality of protection wafers Wp to the substrate processing system 1 from the outside in units of cassettes. A loading station 2 to be loaded, a processed wafer W (a wafer W with the protective tape P peeled from the protective wafer Wp) are stored in a cassette C, and a plurality of wafers W are stored in the cassette C. A carrying station 3 that carries out the substrate processing system 1 in units of cassettes, a processing device 4 that processes the protection wafer Wp to make it thinner, and a processing device 4 that processes the protection wafer Wp to make it thinner. A configuration in which a post-processing device 5 that performs post-processing, and a transfer station 6 that transfers the protection wafer Wp between the loading station 2, the processing device 4, and the post-processing device 5 are connected. has. The loading station 2, the conveying 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 carrying out station 3 and the post-processing device 5 are arranged in this order in the Y-axis direction on the positive X-axis direction side.

The loading station 2 is provided with a cassette placement table 10. In the example shown, a plurality of cassettes C, for example, two cassettes C, can be arranged in a row on the cassette placement table 10 in the X-axis direction.

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

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

In the post-processing device 5, post-processing is performed on the protection wafer Wp processed in the processing device 4. Post-processing includes, for example, a mounting process in which the protection wafer Wp is held on a dicing frame via a dicing tape, and peeling off the protection tape P attached to the wafer W in the protection wafer Wp. Peeling treatment and the like are performed. Then, the post-processing device 5 transfers the wafer W that has undergone post-processing and is held in the dicing frame to the cassette C of the unloading station 3. Known devices are used for the mount processing and peeling processing performed in the post-processing device 5, respectively.

The transfer station 6 is provided with a wafer transfer area 30. The wafer transfer area 30 is provided with a wafer transfer device 32 capable of moving on a transfer path 31 extending in the X-axis direction. The wafer transfer device 32 is a wafer holding portion that holds the protection wafer Wp and has a transfer fork 33 and a transfer pad 34. The transport fork 33 has its tip divided into two to adsorb and hold the protection wafer Wp. The transport fork 33 transports the protection wafer Wp before the grinding process. The transfer pad 34 has a circular shape with a diameter longer than the diameter of the protection wafer Wp when viewed in plan, and adsorbs and holds the protection wafer Wp. The transport pad 34 transports the protection wafer Wp after the grinding process. And these transport forks 33 and transport pads 34 are configured to be movable in the horizontal direction, vertical direction, around the horizontal axis, and around the vertical axis, respectively.

As shown in FIG. 1, the substrate processing system 1 is provided with a control unit 40. The control unit 40 is, for example, a computer and has a program storage unit (not shown). In the program storage unit, a program that controls processing of the protection wafer Wp (wafer W) in the substrate processing system 1 is stored. Also stored in the program storage unit is a program for controlling the operation of drive systems such as the various processing devices and transfer devices described above to realize the later-described wafer processing in the substrate processing system 1. In addition, the program can be stored on a computer-readable storage medium (H) such as a computer-readable hard disk (HD), flexible disk (FD), compact disk (CD), magnet optical disk (MO), or memory card. It may be something that has been recorded or installed in the control unit 40 from the storage medium H.

<Processing equipment>

Next, the configuration of the processing device 4 described above will be described. 3 to 6, the processing device 4 includes a rotary table 100, a transfer unit 110, an alignment unit 120, a first cleaning unit 130, a second cleaning unit 140, Coarse grinding unit 150 as a grinding unit, intermediate grinding unit 160 as a grinding unit, finish grinding unit 170 as a grinding unit, protective tape thickness measuring unit 180 as a protective material thickness measuring unit, and overall as a full thickness measuring unit. It has a thickness measurement unit 190 and a wafer body thickness measurement unit 200 as a substrate body thickness measurement unit. In addition, in this embodiment, the rough grinding unit 150 corresponds to the first grinding unit in the present invention, and the intermediate grinding unit 160 and the finish grinding unit 170 each correspond to the second grinding unit in the present invention. Equivalent to

The rotary table 100 is configured to be rotatable by a rotary mechanism (not shown). Four chucks 101 are provided on the rotary table 100 to adsorb and hold the protection wafer Wp. The chuck 101 is arranged evenly, that is, at intervals of 90 degrees, on the same circumference as the rotary table 100. The four chucks 101 can be moved to the delivery position A0 and the processing positions A1 to A3 by rotating the rotary table 100.

In this embodiment, the delivery position A0 is a position on the The alignment unit 120 and the first cleaning unit 130 are arranged in an array. The alignment unit 120 and the first cleaning unit 130 are stacked and arranged in this order from the top. The first machining 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 machining 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 intermediate grinding unit 160 is disposed. The third machining position A3 is a position on the negative X-axis 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 on the chuck base 102. The chuck 101 and the chuck base 102 are configured to be rotatable by a rotation mechanism (not shown).

The transfer unit 110 is an articulated robot with a plurality of arms, 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 each configured to be able to rotate about the proximal end. . Among the three arms 111 to 113, the first arm 111 at the tip is equipped with a transfer pad 114 for adsorbing and holding the protection wafer Wp. Additionally, among the three arms 111 to 113, the third arm 113 at the base is attached to a vertical movement mechanism 115 that moves the arms 111 to 113 in the vertical direction. And, the transfer unit 110 having this configuration transfers the protection wafer Wp to the transfer position A0, the alignment unit 120, the first cleaning unit 130, and the second cleaning unit 140. can do.

The alignment unit 120 adjusts the horizontal direction of the protection wafer Wp before the grinding process. For example, while rotating the protection wafer Wp held on the spin chuck (not shown), the position of the notch part of the wafer W is detected by a detection unit (not shown), thereby adjusting the position of the notch part to protect the wafer. Adjust the horizontal direction of (Wp).

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

In the second cleaning unit 140, the protection wafer Wp after the grinding process is attached to the unprocessed surface W2 of the wafer W held on the transfer pad 114, that is, the unprocessed surface W2. The protective tape P is cleaned, and the transport pad 114 is also cleaned.

In the rough grinding unit 150, the processing surface W1 of the wafer W is rough ground. The rough grinding unit 150 has a rough grinding unit 151 equipped with a rough grinding wheel (not shown) that can rotate in an annular shape. In addition, the rough grinding portion 151 is configured to be movable in the vertical and horizontal directions along the support 152. Then, while the processing surface W1 of the wafer W held in the chuck 101 is brought into contact with the rough grinding wheel, the chuck 101 and the rough grinding wheel are each rotated to grind the processing surface of the wafer W ( W1) is subjected to rough grinding.

In the intermediate grinding unit 160, the processing surface W1 of the wafer W is intermediately ground. The intermediate grinding unit 160 has an intermediate grinding unit 161 provided with an intermediate grinding wheel (not shown) that can rotate in an annular shape. In addition, the intermediate grinding portion 161 is configured to be movable in the vertical and horizontal directions along the support column 162. Additionally, the grain size of the abrasive grains of the intermediate grinding wheel is smaller than that of the coarse grinding wheel. Then, with the processing surface W1 of the wafer W held in the chuck 101 in contact with the intermediate grinding wheel, the processing surface W1 is intermediately ground by rotating the chuck 101 and the intermediate grinding wheel, respectively. .

In the final grinding unit 170, the processing surface W1 of the wafer W is subjected to final grinding. The finishing grinding unit 170 has a finishing grinding unit 171 equipped with a finishing grinding wheel (not shown) that can rotate in an annular shape. In addition, the finish grinding unit 171 is configured to be movable in the vertical and horizontal directions along the support column 172. Additionally, the grain size of the abrasive grains of the finishing grinding wheel is smaller than that of the intermediate grinding wheel. Then, with the machining surface W1 of the wafer W held in the chuck 101 in contact with the finishing grinding wheel, the chuck 101 and the finishing grinding wheel are each rotated to perform final grinding of the machining surface W1. .

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

The protective tape thickness measurement unit 180 has a sensor 181 and a calculation unit 182. As the sensor 181, a sensor that measures the thickness of the protective tape P without contacting the protective tape P is used, for example, a white confocal optical sensor is used. The sensor 181 radiates light having a predetermined wavelength band to the protective tape P, and also receives reflected light reflected from the surface P1 of the protective tape P and reflected light reflected from the back surface P2. . The calculation unit 182 calculates the thickness of the protective tape P based on the positive reflected light received by the sensor 181.

In addition, in this embodiment, a white confocal optical 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 to this, and the protective tape (P ), any measuring device can be used as long as the thickness is measured. Additionally, a plurality of sensors 181 may be provided.

The total thickness measuring unit 190 is provided in each of the coarse grinding unit 150 and the intermediate grinding unit 160. As shown in FIG. 5 , the total thickness measurement unit 190 has a chuck side height gauge 191, a wafer side height gauge 192, and a calculation unit 193. The chuck side height gauge 191 is provided with a probe 194, and the tip 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 102a of the chuck base 102 is flush with the upper surface of the chuck 101 holding the protection wafer Wp. The wafer-side height gauge 192 is provided with a probe 195, and the tip of the probe 195 contacts the processing surface W1 of the wafer W to measure the height position of the processing surface W1. The calculation unit 193 calculates the total thickness of the protection wafer Wp by subtracting the measured value of the thumb side height gauge 191 from the measured value of the wafer side height gauge 192. Additionally, this total thickness is the sum of the thickness of the wafer W (the sum of the thickness of the wafer body M and the thickness of the device D) plus the thickness of the protective tape P.

The wafer body thickness measurement unit 200 is provided in the finishing grinding unit 170. As shown in FIG. 6 , the wafer body thickness measurement unit 200 has 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, for example, a white confocal optical sensor is used. The sensor 201 radiates light having a predetermined wavelength band to the wafer body M, and also receives reflected light reflected from the surface of the wafer body M and reflected light reflected from the back surface. The calculation unit 202 calculates the thickness of the wafer body M based on the positive reflected light received by the sensor 201.

Since the sensor 201 of this embodiment can measure the thickness without contacting the wafer body M, it is possible to prevent the wafer body M from being scratched. In particular, in the final grinding unit 170, the wafer W (wafer body M) is ground to become thinner and is prone to scratches, so it is useful to be able to measure the thickness of the wafer body M in a non-contact manner in this way. do.

In addition, in this embodiment, a white confocal optical 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, and the wafer body thickness measurement unit (M ), any measuring device can be used as long as the thickness is measured. Additionally, a plurality of sensors 201 may be provided.

<Wafer processing>

Next, wafer processing performed using the substrate processing system 1 configured as above will be explained according to the flowchart in FIG. 7.

FIG. 8 is an explanatory diagram showing how the processing surface W1 of the wafer W is ground in the substrate processing system 1 (processing device 4). As shown in Figure 8 (a), before grinding, the total thickness of the protection wafer Wp is Twp0, the thickness of the wafer body M is Tm0, the thickness of the device D is Td, and the protection tape ( The thickness of P) is Tp. Then, the rough grinding in Figure 8(b), the intermediate grinding in Figure 8(c), and the final grinding in Figure 8(d) are sequentially performed to thin the wafer W. The grinding amounts of the processing surface W1 of the wafer W in rough grinding, intermediate grinding, and finish grinding are G1, G2, and G3, and the target thicknesses of the wafer W after each grinding are H1, H2, and H3. .

In the substrate processing system 1, first, a cassette C containing a plurality of protection wafers Wp is placed on the cassette placement table 10 of the loading station 2. In order to prevent the protection tape P from being deformed, the cassette C is provided with a protection wafer Wp so that the unprocessed surface W2 of the wafer W to which the protection tape P is attached faces upward. It is stored.

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

The protection wafer (Wp) transported to the processing device 4 is transferred to the alignment unit 120. Then, in the alignment unit 120, the horizontal direction of the protection wafer Wp is adjusted (step S1 in FIG. 7).

Next, while the protection wafer Wp is being transferred by the transfer unit 110, the thickness Tp of the protection tape P shown in FIG. 8(a) is measured by the protection tape thickness measurement unit 180. (Step (S2) in FIG. 7). The measurement results of the protective tape thickness measurement unit 180 are output from the calculation unit 182 to the control unit 40.

Next, the protection wafer Wp is transported from the alignment unit 120 to the transfer position A0 by the transport unit 110, and is transferred to the chuck 101 at the transfer position A0. Afterwards, the rotary table 100 is rotated 90 degrees counterclockwise to move the chuck 101 to the first machining position A1.

Next, before rough grinding by the rough grinding unit 150, the total thickness Twp0 of the protection wafer Wp shown in (a) of FIG. 8 is measured by the total thickness measurement unit 190 (FIG. 7 Step (S3)). The measurement results of the total thickness measurement unit 190 are output from the calculation unit 193 to the control unit 40.

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

G1 = Twp0 - Tp - H1 ···· (1)

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

Next, the rotary table 100 is rotated 90 degrees counterclockwise to move the chuck 101 to the second machining position A2. Then, before intermediate grinding by the intermediate grinding unit 160, the total thickness Twp1 of the protection wafer Wp shown in (b) of FIG. 8 is measured by the total thickness measurement unit 190 (FIG. 7 Step (S6)). The measurement results of the total thickness measurement unit 190 are output from the calculation unit 193 to the control unit 40.

In the control unit 40, based on the thickness Tp of the protective tape P measured in step S2 and the total thickness Twp1 measured in step S6, the The intermediate grinding amount G2 of the processing surface W1 of the wafer W is calculated (step S7 in FIG. 7). Specifically, first, the target thickness H2 of the wafer W to be left after intermediate grinding, shown in (c) of FIG. 8, is set. Then, the intermediate grinding amount (G2) is calculated using the following formula (2). In addition, the intermediate grinding amount G2 corresponds to the second grinding amount in the present invention.

G2 = Twp1 - Tp - H2 ···· (2)

Next, based on the intermediate grinding amount G2 calculated in step S7 by the intermediate grinding unit 160, the processing surface W1 of the wafer W is intermediate as shown in FIG. 8(c). It is ground (step S8 in FIG. 7).

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

The control unit 40 determines the wafer W in the finish grinding unit 170 based on the thickness Tm2 of the wafer body M and the thickness Td of the device D measured in step S9. ) of the machined surface W1 is calculated (step S10 in FIG. 7 ). Specifically, first, the target thickness H3 of the wafer W to be left after final grinding, shown in (d) of FIG. 8, is set. Then, the final grinding amount (G3) is calculated using the following formula (3). In addition, the final grinding amount G3 corresponds to the second grinding amount in the present invention.

G3 = Tm2＋Td - H3 ···· (3)

Additionally, 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 wafer processing, it can be directly substituted into equation (3) above.

Meanwhile, if the thickness (Td) of the device (D) is not known before wafer processing, it can be calculated from the thickness (Tm2) of the wafer body (M) measured in step S9. In this case, there are, for example, two methods for 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 body M from the target thickness H2 of the wafer W after intermediate grinding.

As a second calculation method, for example, a total thickness measurement unit 190 is provided in the finish grinding unit 170, and before finish grinding by the finish grinding unit 170, the protection shown in FIG. 8(c) is measured. Measure the total thickness (Twp2) of the wafer (Wp). And the thickness (Td) of the device (D) can be calculated using the following equation (4).

Td = Twp2 - Tm2 - Tp ···· (4)

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

Here, when there is no need to consider the thickness Td of the device D, the target thickness H3 of the wafer W becomes the same as the target thickness of the wafer body M. In this case, the processing surface W1 of the wafer W is finish ground until the thickness of the wafer body M becomes from Tm2 to H3.

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

Next, the protection wafer Wp is transported from the transfer position A0 to the second cleaning unit 140 by the transport unit 110 . Then, in the second cleaning unit 140, while the protection wafer Wp is held on the transfer pad 114, the unprocessed surface W2 (protection tape P) of the wafer W is cleaned, It is dried (step (S13) of FIG. 7).

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

Afterwards, the protection wafer Wp is transferred from the first cleaning unit 130 to the post-processing device 5 by the wafer transfer device 32 . In the post-processing device 5, post-processing such as a mount process for holding the protection wafer Wp on the dicing frame and a peeling process for peeling off the protection tape P attached to the protection wafer Wp are performed. (Step (S15) in FIG. 7).

Afterwards, the wafer W on which all processes have been performed is transferred to the cassette C on the cassette placement table 20 of the unloading station 3. In this way, the series of wafer processing in the substrate processing system 1 ends.

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

Furthermore, according to this embodiment, by measuring the thickness Tp of the protective tape P in the protective tape thickness measurement unit 180, the thickness Tp of the protective tape P is non-uniform for each protective wafer Wp. Even so, at least the intermediate grinding amount G2 in the intermediate grinding unit 160 and the finish grinding amount G3 in the finish grinding unit 170 can be kept constant. Then, the processing surface W1 of the wafer W can be appropriately ground.

Hereinafter, the effects of this embodiment will be explained based on FIG. 9. Figure 9(a) shows a reference protection wafer (Wpa). FIG. 9B shows a protection wafer Wpb whose thickness of the protection tape P is different from that of the protection wafer Wpa. FIG. 9(c) shows a protection wafer Wpc whose thickness is different from the protection wafer Wpa of the wafer W before grinding treatment.

As described above, the grinding amounts (G1, G2, G3) in rough grinding, intermediate grinding, and finish grinding are calculated using the following equations (1), (2), and (3), respectively.

G1 = Twp0 - Tp - H1 ···· (1)

G2 = Twp1 - Tp - H2 ···· (2)

G3 = Tm2＋Td - H3 ···· (3)

In this case, the protection wafers Wpa and Wpb shown in Figures 9 (a) and (b) will first be described. In these protection wafers (Wpa, Wpb), the thicknesses of the protection tapes (Pa, Pb) are Tpa and Tpb, respectively, and the thickness (Tpb) is greater than the thickness (Tpa). In addition, the thicknesses of the wafer bodies (Ma, Mb) before the grinding process are the same as Tma0 and Tmb0, respectively, and the thicknesses of the devices (Da, Db) are also the same as Tda and Tdb, respectively.

In addition, the rough grinding amount G1 in rough grinding is calculated by the above equation (1), and (Twpa0 - Tpa) in the protection wafer Wpa and (Twpb0 - Tpb) in the protection wafer Wpb. becomes the same. Then, the rough grinding amount Ga1 for the protection wafer Wpa and the rough grinding amount Gb1 for the protection wafer Wpb become the same.

Similarly, regarding the intermediate grinding amount G2 in intermediate grinding, from the above equation (2), the intermediate grinding amount Ga2 with respect to the protection wafer Wpa and the intermediate grinding amount Gb2 with respect to the protection wafer Wpb. ) becomes the same. Also, regarding the finish grinding amount G3 in finish grinding, from the above equation (3), the finish grinding amount Ga3 for the protection wafer Wpa and the finish grinding amount Gb3 for the protection wafer Wpb. ) becomes the same.

In this way, according to this embodiment, even if the thicknesses (Tpa, Tpb) of the protective tapes (Pa, Pb) are different, the rough grinding amounts (Ga1, Gb1), the intermediate grinding amounts (Ga2, Gb2) and finish grinding amounts (Ga3, Gb3) can be made the same.

Next, the protection wafers Wpa and Wpc shown in FIGS. 9A and 9C will be described. In these protection wafers (Wpa, Wpc), the thicknesses of the wafer bodies (Ma, Mc) before the grinding process are Tma0 and Tmc0, respectively, and the thickness Tmc0 is greater than the thickness Tma0. The thicknesses of the protective tapes (Pa, Pc) are the same as Tpa and Tpc, respectively, and the thicknesses of the devices (Da, Dc) are also the same as Tda and Tdc, respectively.

In this case, since the total thickness (Twpa0) of the protection wafer (Wpa) and the total thickness (Twpc0) of the protection wafer (Wpc) are different, the rough grinding amount (Ga1) in rough grinding is calculated from the above equation (1). , Gc1) are different.

However, the overall thickness (Twpa1, Twpc1) after rough grinding can be made the same. Then, regarding the intermediate grinding amount G2 in intermediate grinding, from the above equation (2), the intermediate grinding amount Ga2 with respect to the protection wafer Wpa and the intermediate grinding amount Gc2 with respect to the protection wafer Wpc ) becomes the same. Also, regarding the finish grinding amount G3 in finish grinding, from the above equation (3), the finish grinding amount Ga3 for the protection wafer Wpa and the finish grinding amount Gc3 for the protection wafer Wpc. ) becomes the same.

According to this embodiment, when the thicknesses (Tma0, Tmc0) of the wafer bodies (Ma, Mc) before the grinding process are different, the intermediate grinding amount (Ga2, Gc2) and the final grinding amount for each protection wafer (Wpa, Wpc). (Ga3, Gc3) can be made the same. Here, a damage layer is formed in rough grinding. And if the thickness of the damage layer changes, subsequent processing becomes uneven. In this regard, as in the present embodiment, the total thickness (Twpa1, Twpc1) after rough grinding becomes the same, and the intermediate grinding amounts (Ga2, Gb2) and final grinding amounts (Ga3, Gb3) also become the same, that is, the remainder of the damage layer. Since is the same, subsequent processing (intermediate grinding, final grinding) has the same conditions. As a result, uniform processing can be performed for each protection wafer (Wpa, Wpc).

<Other embodiments>

In the above embodiment, the rough grinding in step S5 may be divided into multiple steps. The rough grinding in step S5 includes, for example, an air cut that lowers the rough grinding portion 151 (coarse grinding wheel) at a low speed, a step of performing rough grinding at a high speed (S51), and a step of performing rough grinding at a low speed. It is divided into steps such as (S52).

As described above, in the plurality of protection wafers Wp, when the thickness of the wafer body M before the grinding process is different, the rough grinding amount G1 is different for each protection wafer Wp. Meanwhile, in the low-speed step S52, the grinding amount G12 is preferably set to a common fixed value for a plurality of wafers W in order to be a grinding amount that does not apply stress to the wafer W. .

Therefore, the grinding amount G11 in the high-speed step S51 is set to a variable value that varies for each protection wafer Wp. Specifically, after calculating the rough grinding amount G1 for each protection wafer Wp, the grinding amount G12 (fixed value) of each step S52 is subtracted from the rough grinding amount G1, Calculate the grinding amount (G11) of (S51).

In this case, the grinding amount G11 in the high-speed step S51 is different for each protection wafer Wp, but the grinding amount G12 in the low-speed step S52 can be fixed. Then, in the latter half of the rough grinding process, the stress along the wafer W can be reduced compared to the first half process, and rough grinding can be performed appropriately.

Additionally, step S52 may be further divided into a plurality of steps. Additionally, depending on the thickness of the wafer W, step S51 is omitted, and grinding is performed only with the grinding amount G12 (fixed value) in 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 fixed value of the grinding amount.

In addition, in the above embodiment, in the intermediate grinding of step S8, the total thickness of the protection wafer (Wp) was measured by the contact-type overall thickness measurement unit 190, but in the overall processing of the intermediate grinding, the total thickness of the protection wafer (Wp) was measured. ) and sometimes measure the thickness of the wafer body (M) in post-processing. For example, at the start of intermediate grinding, if the thickness of the wafer W is relatively large, the total thickness of the protection wafer Wp can be measured by the contact-type total thickness measurement unit 190 (overall processing) ). Then, when the thickness of the wafer W reaches a predetermined thickness, the thickness of the wafer body M is measured by the non-contact wafer body thickness measurement unit 200 (post-processing).

In this case, when calculating the intermediate grinding amount G2, it is divided into the first half grinding amount G21 in the first half process and the second half grinding amount G22 in the second half process. Specifically, in the overall processing, the total thickness Twp1 of the protection wafer Wp measured in the total thickness measurement unit 190, the thickness Tp of the protection tape P measured in step S2, and Based on the determined thickness H2, the overall grinding amount G21 is calculated using the above equation (2).

In addition, in the post-processing, 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, for example, and Based on the target thickness H3 after final grinding, the latter grinding amount G22 is calculated using the above equation (3). Then, based on these first-half grinding amounts G21 and latter-half grinding amounts G22, intermediate grinding of the processing surface W1 of the wafer W can be appropriately performed. Additionally, a pre-input value may be used for the thickness Td of the device D.

Also, regarding the final grinding in step S11, there are cases where the entire thickness of the protection wafer Wp is measured in the first half process and the thickness of the wafer body M is measured in the second half process. In this case as well, like the intermediate grinding amount G2, the finish grinding amount G3 is calculated by dividing it into the first half grinding amount G31 and the second half grinding amount G32.

In the substrate processing system 1 of the above embodiment, the protective tape thickness measurement unit 180 was measuring the thickness of the protective tape P with respect to the protective wafer Wp being transported by the transportation unit 110. The rough grinding unit 150 can be placed at any position as long as the processing surface W1 of the wafer W is not subjected to rough grinding. That is, the protective tape thickness measuring unit 180 can be placed 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 device 4 has a rough grinding unit 150, an intermediate grinding unit 160, and a finish grinding unit 170, but the configuration of the units is not limited to this. No. A rough grinding unit 150 is disposed at the first machining position A1, a finish grinding unit 170 is disposed at the second machining position A2, and a polishing unit (not shown) is disposed at the third machining position A3. ) may be placed. In this case as well, as in the above embodiment, by calculating the rough grinding amount G1 in the rough grinding unit 150 and the finish grinding amount G3 in the finish grinding unit 170, the wafer W The processing surface (W1) of can be appropriately ground.

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

Although embodiments of the present invention have been described above, the present invention is not limited to these examples. It is obvious to those skilled in the art that various changes or modifications can be made within the scope of the technical idea described in the claims, and it is understood that they naturally fall within the technical scope of the present invention.

delete

Claims (14)

A substrate processing system that processes the processed surface of a substrate provided with a protective material on the unprocessed surface, comprising:
A protective material thickness measuring unit that measures the thickness of the protective material,
a total thickness measuring unit that measures the total thickness of the substrate and the protective material;
a grinding unit that grinds the machined surface of the substrate in a plurality of grinding processes after measuring the thickness of the protective material and the overall thickness;
control unit
With
The control unit,
Among the plurality of grinding processes, before the substrate is ground in the first grinding process, the first grinding amount in the first grinding process is the protective material thickness measured by the protective material thickness measurement unit, and the total Based on the total thickness measured by the thickness measurement unit and the target thickness of the substrate after grinding in the first grinding process, the second grinding amount in the second grinding process after the first grinding process is the substrate Executing control to make the calculation constant each time,
Substrate handling system. delete According to claim 1,
In the first grinding process, the processing surface of the substrate is divided into a plurality of steps,
The control unit,
Among the plurality of stages of grinding, setting a grinding amount in a second stage after the first stage of grinding the machined surface of the substrate,
Control for calculating the grinding amount in the first step based on the total thickness measured by the total thickness measuring unit, the protective material thickness measured by the protective material thickness measuring unit, and the grinding amount set in the second step. Implementing a substrate processing system. According to claim 1,
The control unit determines the total thickness measured by the total 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 the total thickness of the protective material ground in the second grinding process. A substrate processing system that executes control to calculate a second grinding amount in the second grinding process based on the target thickness of the substrate later. According to claim 1,
The total thickness measuring unit measures the total thickness of the substrate and the protective material until the total thickness reaches a predetermined thickness,
The substrate processing system,
After the total thickness reaches the predetermined thickness, it has a substrate thickness measuring unit that measures the thickness of the substrate,
The control unit,
Based on the total thickness measured by the total thickness measuring unit before the substrate is ground in the second grinding process, the protective material thickness measured by the protective material thickness measuring unit, and the determined thickness, the second grinding processing process Calculate the second overall grinding amount in
Thereafter, after the total thickness reaches the predetermined thickness, the grinding unit is controlled to grind the substrate to the target thickness after grinding in the second grinding process, based on the substrate thickness measured by the substrate thickness measuring unit. A substrate processing system. According to claim 1,
The substrate includes a substrate main body and a device formed on an unprocessed surface side of the substrate main 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 control the substrate body thickness measured by the substrate body thickness measurement unit before the substrate is ground in the second grinding process, the thickness of the device calculated from the substrate body thickness, and the second grinding process. A substrate processing system that executes control to calculate a second grinding amount in the second grinding process based on a target thickness of the substrate after grinding. According to claim 1,
A substrate processing system wherein 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 the processed surface of a substrate provided with a protective material on the unprocessed surface, comprising:
A protective material thickness measurement process of measuring the thickness of the protective material,
A total thickness measurement process of measuring the total thickness of the substrate and the protective material,
After measuring the thickness of the protective material and the total thickness, a plurality of grinding processes are performed to grind the machined surface of the substrate,
Among the plurality of grinding processes, before the substrate is ground in the first grinding process, the first grinding amount in the first grinding process, the protective material thickness measured in the protective material thickness measurement step, and the total Based on the total thickness measured in the thickness measurement process and the target thickness of the substrate after grinding in the first grinding process among the plurality of grinding process processes, in the second grinding process after the first grinding process, Calculating the second grinding amount to be constant for each substrate,
A substrate processing method comprising performing the first grinding treatment process on the machined surface of the substrate with the calculated first grinding amount. delete According to claim 8,
In the first grinding process, the processing surface of the substrate is divided into a plurality of steps,
Among the plurality of stages of grinding, setting a grinding amount in a second stage after the first stage of grinding the machined surface of the substrate,
A substrate that calculates the grinding amount in the first step based on the total thickness measured in the total thickness measurement process, the protective material thickness measured in the protective material thickness measurement process, and the grinding amount set in the second step. How to handle it. According to claim 8,
In the second grinding process, there is a second total thickness measurement process for measuring the total thickness of the substrate and the protective material,
Before the substrate is ground in the second grinding process, the total thickness measured in the second overall thickness measurement process, the protective material thickness measured in the protective material thickness measurement process, and the protective material thickness measured in the protective material thickness measurement process, and the above after grinding in the second grinding treatment process. A substrate processing method, wherein a second grinding amount in the second grinding process is calculated based on the target thickness of the substrate. According to claim 8,
The substrate processing method is,
A second total thickness measurement process of measuring the total thickness of the substrate and the protective material until the total thickness of the substrate and the protective material reaches a predetermined thickness in the second grinding process;
After the total thickness reaches the predetermined thickness in the second grinding process, there is a substrate thickness measurement process of measuring the thickness of the substrate,
Based on the total thickness measured in the second total thickness measurement process before the substrate is ground in the second grinding treatment process, the protective material thickness measured in the protective material thickness measurement process, and the determined thickness, the second grinding process Calculate the second overall grinding amount in the treatment process,
Thereafter, after the total thickness reaches the predetermined thickness, the substrate processing method grinds the substrate to a target thickness after grinding in the second grinding process, based on the substrate thickness measured in the substrate thickness measurement process. . According to claim 8,
The substrate includes a substrate main body and a device formed on an unprocessed surface side of the substrate main body and protected by the protective material,
The substrate processing method has a substrate main body thickness measurement step of measuring the thickness of the substrate main body in the second grinding process,
The substrate main body thickness measured in the substrate main body thickness measurement process before the substrate is ground in the second grinding process, the thickness of the device calculated from the substrate main body thickness, and the thickness of the device after grinding in the second grinding process. A substrate processing method, wherein a second grinding amount in the second grinding process is calculated based on the target thickness of the substrate. A readable computer storage medium storing a program that runs on a computer of a control unit that controls the substrate processing system so that a substrate processing method for processing the processed surface of a substrate provided with a protective material on the unprocessed surface is executed by the substrate processing system. ,
The substrate processing method is,
A protective material thickness measurement process of measuring the thickness of the protective material,
A total thickness measurement process of measuring the total thickness of the substrate and the protective material,
After measuring the thickness of the protective material and the total thickness, a plurality of grinding processes are performed to grind the machined surface of the substrate,
Among the plurality of grinding processes, before the substrate is ground in the first grinding process, the first grinding amount in the first grinding process, the protective material thickness measured in the protective material thickness measurement step, and the total Based on the total thickness measured in the thickness measurement process and the target thickness of the substrate after grinding in the first grinding process among the plurality of grinding process processes, in the second grinding process after the first grinding process, Calculating the second grinding amount to be constant for each substrate,
A computer storage medium comprising performing the first grinding treatment process on the machined surface of the substrate with the calculated first grinding amount.

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