Patent Application
20200139503
This application claims the benefit of Japanese Patent Application No. 2017-121183 filed on Jun. 21, 2017, the entire disclosures of which are incorporated herein by reference.
The various aspects and embodiments described herein pertain generally to a substrate processing system configured to thin a substrate having a protective tape attached on a surface thereof, a substrate processing method using the substrate processing system, and a computer-readable recording medium.
Recently, in a manufacturing process for a semiconductor device, a semiconductor wafer (hereinafter, simply referred to as “wafer”) having devices such as a plurality of electronic circuits formed on a front surface thereof is thinned by grinding a rear surface of the wafer.
The grinding of the rear surface of the wafer is performed in a grinding apparatus which is equipped with a chuck configured to hold, for example, the front surface of the wafer; and a grinding device such as a grinding whetstone configured to grind the rear surface of the wafer held by the chuck. In this grinding apparatus, if the front surface of the wafer is directly held by the chuck, the devices on the front surface of the wafer may be damaged.
Thus, in Patent Document 1, for example, a protective tape is provided on the front surface of the wafer to protect this front surface. After the protective tape is attached, while the protective tape is being held by the chuck, the rear surface of the wafer is ground by the grinding whetstone.
However, a thickness of the protective tape itself may be non-uniform within a surface thereof. Further, since a tension gets non-uniform when the protective tape is attached to the wafer, the thickness of the protective tape may be non-uniform within the surface thereof. In the grinding method disclosed in Patent Document 1, however, this non-uniformity of the thickness of the protective tape is not considered. In such a case, if the rear surface of the wafer is ground, a relative thickness which is a sum of a thickness of the wafer and the thickness of the protective tape becomes uniform within the surface. As a result, the thickness of the wafer after the grinding may become non-uniform. In view of this, there is still a room for improvement in the conventional method of grinding the rear surface of the wafer.
In view of the foregoing, exemplary embodiments provide a technique of thinning a substrate into a uniform thickness within a surface of the substrate by appropriately grinding a rear surface of the substrate having a protective tape attached on a front surface thereof.
In one exemplary embodiment, there is provided a substrate processing system configured to thin a substrate having a protective tape attached on a front surface thereof. The substrate processing system includes a substrate holder configured to hold the substrate; a grinder configured to perform a grinding of a rear surface of the substrate held by the substrate holder; and a tape thickness measurement device configured to measure a thickness of the protective tape before the rear surface of the substrate is ground in the grinder.
According to the exemplary embodiment, since the thickness of the protective tape is measured before the rear surface of the substrate is ground, the contact manner of the grinder to the rear surface of the substrate may be adjusted by using this measurement result. By way of example, if the thickness of the protective tape is non-uniform within a surface thereof, the way of contact between the rear surface of the substrate and the grinder is adjusted based on a thickness distribution of the protective tape. Accordingly, the substrate can be thinned into a uniform thickness within a surface of the substrate.
In another exemplary embodiment, there is provided a substrate processing method of thinning a substrate having a protective tape attached on a front surface thereof. The substrate processing method includes measuring a thickness of the protective tape; and grinding, by using a grinder, a rear surface of the substrate held by a substrate holder.
In still another exemplary embodiment, there is provided a computer-readable recording medium having stored thereon computer-executable instructions that, in response to execution, cause a substrate processing system to perform a substrate processing method.
According to the exemplary embodiments, by investigating the thickness of the protective tape before the grinding, the grinder can be brought into contact with the rear surface of the substrate appropriately even if the thickness of the protective tape is non-uniform within the surface thereof. Therefore, the substrate can be thinned to have the uniform thickness within the surface thereof.
Hereinafter, exemplary embodiments will be described with reference to the accompanying drawings. In the specification and the drawings, parts having substantially same functions and configurations will be assigned same reference numerals, and redundant description thereof will be omitted.
<Substrate Processing System>
First, a configuration of a substrate processing system according to an exemplary embodiment will be described.
In the substrate processing system 1 according to the present exemplary embodiment, a wafer Was a substrate, shown in
The substrate processing system 1 includes a carry-in/out station 2 and a processing station 3 connected as a single body. The carry-in/out station 2 is configured as a carry-in/out section in which a cassette C, which is capable of accommodating therein a plurality of wafers W, is carried in/out from/to the outside. The processing station 3 is equipped with various kinds of processing apparatuses configured to perform preset processings on the wafer W.
The carry-in/out station 2 is equipped with a cassette placing table 10. In the shown example, the cassette placing table 10 is configured to be capable of holding a plurality of, for example, four cassettes C in series in the X-axis direction.
Further, the carry-in/out station 2 includes a wafer transfer area 20 provided adjacent to the cassette placing table 10. A wafer transfer device 22 configured to be movable on a transfer path 21 extending in the X-axis direction is provided in the wafer transfer area 20. The wafer transfer device 22 is equipped with a transfer arm 23 configured to be movable in the horizontal direction and the vertical direction and pivotable around a horizontal axis and a vertical axis (θ direction), and is capable of transferring, with this transfer arm 23, the wafers W between the cassette C on each cassette placing plate 11 and respective apparatuses 30 and 31 of the processing station 3 to be described later. That is, the carry-in/out station 2 is configured to be capable of carrying the wafers W into/from the processing station 3.
Within the processing station 3, the processing apparatus 30 configured to perform various processings such as grinding and polishing on the wafer W to thin the wafer W and the cleaning apparatus 31 configured to clean the wafer W processed by the processing apparatus 30 are arranged toward the positive X-axis direction from the negative X-axis direction.
The processing apparatus 30 includes a turntable 40, a transfer unit 50, an alignment unit 60, a cleaning unit 70, a rough grinding unit 80 as a rough grinder, a fine grinding unit 90 as a finishing grinder, a gettering layer forming unit 100, a tape thickness measuring unit 110 as a tape thickness measurer and a relative thickness measuring unit 120 as a relative thickness measurer.
(Turntable)
The turntable 40 is configured to be rotated by a rotating device (not shown). Four chucks 200 as substrate holders each configured to attract and hold the wafer W are provided on the turntable 40. The chucks 200 are arranged on a circle concentric with the turntable 40 at a regular distance, that is, an angular distance of 90 degrees therebetween. The four chucks 200 can be moved to four processing positions P1 to P4 as the turntable 40 is rotated.
In the present exemplary embodiment, the first processing position P1 is a position at a positive X-axis and negative Y-axis side of the turntable 40, and the cleaning unit 70 is disposed thereat. Further, the alignment unit 60 is disposed at a negative Y-axis side of the first processing position P1. The second processing position P2 is a position at a positive X-axis and positive Y-axis side of the turntable 40, and the rough grinding unit 80 is disposed thereat. The third processing position P3 is a position at a negative X-axis and positive Y-axis side of the turntable 40, and the fine grinding unit 90 is disposed thereat. The fourth processing position P4 is a position at a negative X-axis and negative Y-axis side of the turntable 40, and the gettering layer forming unit 100 is disposed thereat.
(Chuck)
As depicted in
By way of example, a porous chuck is used as the chuck 200. A porous 201 as a porous body having a multiple number of holes therein is provided on the surface of the chuck 200. The porous 201 may be made of various kinds of materials as long as they are porous. By way of non-limiting example, the porous 201 may be made of carbon, alumina, silicon carbide, or the like. By suctioning the wafer W via the porous 201 with a suction mechanism (not shown), the wafer W is attracted to and held by the chuck 200.
The chuck 200 is held on a chuck table 202. The chuck 200 and the chuck table 202 are supported on a base 203. The base 203 is equipped with a rotating device 204 configured to rotate the chuck 200, the chuck table 202 and the base 203; and an adjusting device 205 as an adjuster configured to adjust an inclination of the chuck 200, the chuck table 202 and the base 203.
The rotating device 204 is equipped with: a rotation shaft 210 configured to rotate the chuck 200; a driving unit 220 configured to apply a rotational driving force when rotating the chuck 200; and a driving force transmitter 230 configured to transmit the rotational driving force applied by the driving unit 220 to the rotation shaft 210. The rotation shaft 210 is fixed at a central portion of a bottom of the base 203. Further, the rotation shaft 210 is rotatably supported at a supporting table 211. The chuck 200 is rotated around this rotation shaft 210.
The driving unit 220 is provided independently from the rotation shaft 210. The driving unit 220 is equipped with a driving shaft 221; and a motor 222 configured to rotate the driving shaft 221.
As shown in
The driven pulley 231 is divided into an inner driven pulley 231a fixed at an outer surface of the rotation shaft 210 and an outer driven pulley 231b provided at an outside of the inner driven pulley 231a. An inner magnet 234 as a first driving force transmitter is provided on an outer surface of the inner driven pulley 231a, and an outer magnet 235 as a second driving force transmitter is provided on an inner surface of the outer driven pulley 231b. A hollow portion 236 is formed between the inner magnet 234 and the outer magnet 235. With this configuration, the driving force transmitter 230 transmits the rotational driving force by the driving unit 220 to the rotation shaft 210 through a non-contact type magnet drive mechanism. That is, the rotation shaft 210 at the driven side and the driving unit 220 at the driving side are separated and configured to be independent from each other.
Further, by providing the hollow portion 236 as mentioned above, vibration and heat of the motor 222 are not delivered to the chuck 200 to affect it. In such a case, the wafer W held on the chuck 200 can be appropriately ground.
As depicted in
Further, the number and the layout of the adjustment shafts 241 are not limited to the shown example as long as two or more adjustment shafts are provided. By way of example, the fixed shaft 240 may be omitted, and only the adjustment shafts 241 may be provided. Furthermore, the configuration of the adjusting device 205 is not limited to the shown example. Instead of the adjustment shaft 241 implemented by the ball screw and the motor 242, a piezoelectric element, for example, may be used.
As illustrated in
An operation of the rotating device 204 when the chuck 200 is tilted by the adjusting device 205 as stated above will be further explained in comparison with a conventional example.
As shown in
In contrast, in the present exemplary embodiment shown in
Moreover, if the belt 506 and the rotation shaft 501 are directly connected as shown in
(Transfer Unit)
As illustrated in
The alignment unit 60 is configured to adjust a direction of the wafer W before being processed in the horizontal direction. The alignment unit 60 is equipped with a base 260, a spin chuck 261 configured to hold and rotate the wafer W; and a detector 262 configured to detect a notch of the wafer W. A position of the notch of the wafer W is detected by the detector 262 while the wafer W held by the spin chuck 261 is being rotated, and by adjusting the position of the notch, the direction of the wafer W in the horizontal direction is adjusted.
(Cleaning Unit)
The cleaning unit 70 is configured to clean the rear surface W2 of the wafer W. The cleaning unit 70 is disposed above the chuck 200, and is equipped with a nozzle 270 configured to supply a cleaning liquid, for example, pure water onto the rear surface W2 of the wafer W. The cleaning liquid is supplied from the nozzle 270 while the wafer W held by the chuck 200 is being rotated. The supplied cleaning liquid is diffused on the rear surface W2 of the wafer W, so that the rear surface W2 is cleaned. Further, the cleaning unit 70 may further have a function of cleaning the chuck 200. In such a case, the cleaning unit 70 may be equipped with, for example, a nozzle (not shown) configured to supply the cleaning liquid to the chuck 200 and a stone (not shown) configured to come into contact with the chuck 200 and clean the chuck 200 physically.
(Rough Grinding Unit)
The rough grinding unit 80 is configured to grind the rear surface W2 of the wafer W roughly. As depicted in
(Fine Grinding Unit)
The fine grinding unit 90 is configured to grind the rear surface W2 of the wafer W finely. A configuration of the fine grinding unit 90 is substantially the same as the configuration of the rough grinding unit 80, and the find grinding unit 90 is equipped with the grinding whetstone 290, a base 291, a spindle 292 and a driver 293. Here, however, a particle size of the grinding whetstone 290 for the fine grinding is smaller than that of the grinding whetstone 280 for the rough grinding. By respectively rotating the chuck 200 and the grinding whetstone 290 while supplying the grinding liquid onto the rear surface W2 of the wafer W held by the chuck 200 in the state that the rear surface W2 of the wafer W is in contact with the ¼ arc portion of the grinding whetstone 290, the rear surface W2 of the wafer W is ground. Like the grinding member for the rough grinding, the grinding member for the fine grinding is not limited to the grinding whetstone 290.
(Gettering Layer Forming Unit)
The gettering layer forming unit 100 is configured to form a gettering layer on the rear surface W2 of the wafer W while removing, through a stress relief processing, a damage layer which is formed on the rear surface W2 of the wafer W when the rough grinding and the fine grinding are performed on the rear surface W2 of the wafer W. A configuration of this gettering layer forming unit 100 is substantially the same as that of the rough grinding unit 80 or the fine grinding unit 90. The gettering layer forming unit 100 is equipped with a polishing whetstone 300, a base 301, a spindle 302 and a driver 303. Here, however, a particle size of the polishing whetstone 300 is smaller than those of the grinding whetstones 280 and 290. By rotating the chuck 200 and the polishing whetstone 300 respectively while keeping the rear surface W2 of the wafer W held by the chuck 200 in contact with a ¼ arc portion of the polishing whetstone 300, the rear surface W2 of the wafer W is polished.
Further, though dry polishing is performed in the gettering layer forming unit 100 according to the present exemplary embodiment, the exemplary embodiment is not limited thereto. By way of example, the rear surface W2 may be polished while supplying a polishing liquid, for example, water to the rear surface W2 of the wafer W.
(Tape Thickness Measuring Unit)
As shown in
As the tape thickness measuring unit 100, a measurement device configured to measure the thickness of the protective tape B without coming into contact with the protective tape B is used. For example, a spectral interferometer may be used. As shown in
As depicted in
Further, as shown in
Furthermore, though the spectral interferometer is used as the tape thickness measuring unit 110 in the present exemplary embodiment, the configuration of the tape thickness measuring unit 110 is not limited thereto, and any of various kinds of measurement devices may be used as long as the thickness of the protective tape B can be measured.
Here, the purpose of measuring the thickness of the protective tape B by the tape thickness measuring unit 110 in the present exemplary embodiment will be explained. As shown in
In these cases, if the rear surface W2 of the wafer W is ground and polished in the rough grinding unit 80, the fine grinding unit 90 and the gettering layer forming unit 100 in sequence, a relative thickness which is a sum of a thickness of the wafer W and the thickness of the protective tape B becomes uniform within the surface thereof. As a result, the thickness of the wafer W becomes non-uniform within the surface thereof.
Thus, prior to performing the rough grinding of the rear surface W2 of the wafer W in the rough grinding unit 80, the thickness of the protective tape B is measured in the tape thickness measuring unit 110. Then, based on a measurement result, the inclination of the chuck 200 is adjusted by the adjusting device 205. At this time, the inclination of the chuck 200 in the rough grinding unit 80, the inclination of the chuck 200 in the fine grinding unit 90 and the inclination of the chuck 200 in the gettering layer forming unit 100 are respectively adjusted.
Below, an example where the inclination of the chuck 200 is adjusted in the rough grinding unit 80 will be elaborated. By way of example, for the protective tape B shown in
(Relative Thickness Measuring Unit)
The relative thickness measuring unit 120 is provided in each of the rough grinding unit 80, the fine grinding unit 90, and the gettering layer forming unit 100. In the following, the relative thickness measuring unit 120 provided in the rough grinding unit 80 will be explained.
As depicted in
By way of example, a laser displacement meter may be used as the first sensor 320. The first sensor 320 does not come into contact with the chuck 200 and is configured to measure a position (height) of a front surface of the chuck 200 where no porous 201 is provided. Here, if laser light is irradiated to the porous 201, the laser light is absorbed by the porous 201 and not to be reflected. This is why the position where no porous 201 is provided is measured. This surface of the chuck 200 is regarded as a reference surface.
The second sensor 321 may also be a laser displacement meter, for example. The second sensor 321 does not come into contact with the wafer W and is configured to measure a position (height) of the rear surface W2 of the wafer W. In the present exemplary embodiment, although the first sensor 320 and the second sensor 321 are the laser displacement meters, the present exemplary embodiment is not limited thereto, and any of various kinds of measurement device capable of measuring a position of a measurement target in a non-contact manner can be used.
The calculator 322 is configured to calculate the relative thickness by subtracting the position of the front surface of the chuck 200 measured by the first sensor 320 from the position of the rear surface W2 of the wafer W measured by the second sensor 321.
The relative thickness is measured by the relative thickness measuring unit 120 while the rear surface W2 of the wafer W is being roughly ground in the rough grinding unit 80. A measurement result of the relative thickness measuring unit 120 is outputted from the calculator 322 to a controller 340 to be described later. The controller 340 monitors the relative thickness measured in the relative thickness measuring unit 120 and controls the rough grinding unit 80 such that the rough grinding is stopped when the relative thickness reaches a preset thickness. By using the relative thickness measuring unit 120 in this way, an end point (termination time) of the rough grinding can be found.
Further, as mentioned above, the relative thickness measuring unit 120 is provided in the fine grinding unit 90 and the gettering layer forming unit 100 as well. The relative thickness measuring unit 120 measures the relative thickness in each unit and is thus capable of finding an end point of the fine grinding and an end point of the polishing in the gettering layer formation.
Further, the relative thickness measuring unit 120 of the present exemplary embodiment is capable of measuring the relative thickness without coming into contact with the wafer W and the chuck 200. Here, if a contact type measurement device is used as in conventional cases, that is, if the relative thickness is measured in a state that the measurement device is in contact with the rear surface W2 of the wafer W, the contract portion is rubbed to have a flaw. Further, depending on a device formed on the front surface of the wafer W, such a contact type measurement device may not be used. On this ground, the relative thickness measuring unit 120 of the present exemplary embodiment has advantages.
Here, in the rough grinding unit 80 and the fine grinding unit 90, the rear surface W2 of the wafer W is ground while supplying water as a grinding liquid onto the rear surface W2. Accordingly, a water layer D is formed on the rear surface W2 of the wafer W, as depicted in
Thus, it is desirable to provide a nozzle 323 as a fluid supply at a bottom surface of the second sensor 321. The nozzle 323 is configured to jet, for example, air A as a fluid along an optical path P of the laser light from the second sensor 321 to surround the optical path P. In such a case, the air A serves as a wall and blows the water layer D away, so that a spot (optical axis spot) of the rear surface W2 where the laser light is irradiated to and reflected from can be set in a dry environment. Thus, without being affected by the water layer D, the position of the rear surface W2 can be measured by the second sensor 321 more accurately.
Furthermore, the fluid jetted from the nozzle 323 may not be limited to the air. For example, water, which is the same as the water layer D, may be used. In such a case, a column of water is formed from the second sensor 321 to the rear surface W2. Since a refractive index of the laser light does not change between the water jetted from the nozzle 323 and the water layer D, the position of the rear surface W2 can be measured more accurately.
(Cleaning Apparatus)
The cleaning apparatus 31 shown in
(Controller)
The above-described substrate processing system 1 is equipped with the controller 340 as shown in
(Wafer Processing)
Now, a wafer processing performed by using the substrate processing system 1 having the above-described configuration will be discussed.
First, a cassette C accommodating therein a plurality of wafers W is placed on the cassette placing table 10 of the carry-in/out station 2. To suppress a deformation of the protective tape B, each wafer W is accommodated in the cassette C such that the front surface of the wafer W to which the protective tape B is attached faces upwards.
Then, a wafer W is taken out of the cassette C and transferred into the processing apparatus 30 of the processing station 3 by the wafer transfer device 22. At this time, the front surface and the rear surface of the wafer W are inverted by the transfer arm 23 such that the rear surface W2 of the wafer W faces upwards.
The wafer W transferred into the processing apparatus 30 is delivered onto the spin chuck 261 of the alignment unit 60. Then, a direction of the wafer Win the horizontal direction is adjusted by the alignment unit 60 (process S1 of
Subsequently, while the wafer W is being transferred by the transfer unit 50, the thickness of the protective tape B is measured by the tape thickness measuring unit 110 (process S2 of
By way of example, for the protective tape B shown in
Further, in the present exemplary embodiment, though the inclination of the chuck 200 of each of the rough grinding unit 80, the fine grinding unit 90 and the gettering layer forming unit 100 is adjusted, the inclination of the chuck 200 of only the rough grinding unit 80 may be adjusted.
Subsequently, the wafer W is delivered onto the chuck 200 at the first processing position P1 by the transfer unit 50. Thereafter, by rotating the turntable 40 by 90 degrees in the counterclockwise direction, the chuck 200 is moved to the second processing position P2. Then, the rear surface W2 of the wafer W is roughly ground by the rough grinding unit 80 (process S4 of
Thereafter, the turntable 40 is further rotated by 90 degrees in the counterclockwise direction, and the chuck 200 is moved to the third processing position P3. Then, the rear surface W2 of the wafer W is finely ground by the fine grinding unit 90 (process S5 of
Thereafter, by further rotating the turntable 40 by 90 degrees in the counterclockwise direction, the chuck 200 is moved to the fourth processing position P4. Then, while performing the stress relief processing, the gettering layer is formed on the rear surface W2 of the wafer W by the gettering layer forming unit 100 (process S6 of
Afterwards, by further rotating the turntable 40 by 90 degrees in the counterclockwise direction or 270 degrees in the clockwise direction, the chuck 200 is moved to the first processing position P1. Then, the rear surface W2 of the wafer W is cleaned by the cleaning liquid in the cleaning unit 70 (process S7 of
Subsequently, the wafer W is transferred into the cleaning apparatus 31 by the wafer transfer device 22. In the cleaning apparatus 31, the rear surface W2 of the wafer W is cleaned by the cleaning liquid (process S8 of
Then, the wafer W after being subjected to all the required processings is transferred back into the cassette C on the cassette placing table 10 by the wafer transfer device 22. Then, a series of the wafer processings in the substrate processing system 1 is ended.
According to the present exemplary embodiment as described above, since the thickness of the protective tape B is measured in the tape thickness measuring unit 110 before the rear surface W2 of the wafer W is roughly ground in the rough grinding unit 80, the inclination of the chuck 200 is adjusted based on this measurement result, and the way how the grinding whetstones 280 and 290 and the polishing whetstone 300 come into contact with the rear surface W2 of the wafer W can be adjusted. Thus, even if the thickness of the protective tape B is non-uniform within the surface thereof, the thickness of the wafer W after being subject to the grinding and the polishing can be uniform within the surface thereof.
Conventionally, to uniform the thickness of the wafer W, a feedback control, in which the thickness of the wafer W is actually measured after the fine grinding and a processing condition for the grinding processing is corrected based on the measurement result, has been performed. In such a case, however, the grinding whetstone 290 needs to be separated from the fine grinding unit 90, and a sensor for measuring the thickness needs to be installed. Thus, it takes time to complete the grinding processing. In the present exemplary embodiment, however, since the thickness of the protective tape B is measured and the inclination of the chuck 200 is adjusted before the grinding processing, the time for the grinding processing can be shortened. Accordingly, the throughput of the wafer processing can be improved.
Furthermore, even if the inclination of the chuck 200 is adjusted as stated above, the rotation shaft 210 at the driven side and the driving unit 220 at the driving side are operated independently because the hollow portion 236 is formed in the driven pulley 231 of the rotating device 204. That is, though the rotational driving force by the driving unit 220 is appropriately delivered to the rotation shaft 210, the inclination of the chuck 200 (inclination of the rotation shaft 210) is not delivered to the driving unit 220. Therefore, the chuck 200 can be rotated appropriately.
Further, since the relative thickness is individually measured by the relative thickness measuring unit 120 during the rough grinding in the rough grinding unit 80, during the fine grinding in the fine grinding unit 90 and during the polishing in the gettering layer forming unit 100, the end points of the rough grinding, the fine grinding and the polishing can be found. Therefore, the wafer W can be ground and polished to have the appropriate thickness.
Moreover, according to the above-described exemplary embodiment, the rough grinding of the rear surface of the wafer W in the rough grinding unit 80, the fine grinding of the rear surface of the wafer Win the fine grinding unit 90, the formation of the gettering layer in the gettering layer forming unit 100, and the cleaning of the rear surface of the wafer Win the cleaning unit 70 and the cleaning apparatus 31 can be performed on a plurality of wafers W continuously in the single substrate processing system 1. Therefore, the wafer processing can be performed efficiently within the single substrate processing system 1, so that a throughput can be improved.
<Other Examples of Tape Thickness Measuring Unit>
Now, other examples of the tape thickness measuring unit 110 will be described. The tape thickness measuring unit 110 can be placed at any position as long as it is capable of performing the thickness measurement before the rear surface W2 of the wafer W is roughly ground in the rough grinding unit 80. That is, the tape thickness measuring unit 110 can be placed at any position in a wafer transfer path ranging from the carry-in/out station 2 to the rough grinding unit 80.
As depicted in
The first sensor 400 may be, by way of example, a laser displacement meter. The first sensor 400 is configured to measure a position (height) of a front surface of the base 260. This front surface of the base 260 is regarded as a reference surface.
The second sensor 401 may also be, for example, a laser displacement meter. The second sensor 401 is configured to measure a position (height) of the rear surface W2 of the wafer W. Further, in the present exemplary embodiment, though the laser displacement meters are used as the first sensor 400 and the second sensor 401, the present exemplary embodiment is not limited thereto, and any of various kinds of measurement devices capable of measuring a position of a measurement target in a non-contact manner can be used.
The calculator 402 calculates the thickness of the protective tape B by subtracting, from the position of the rear surface W2 of the wafer W measured by the second sensor 401, the position of the front surface of the base 260 measured by the first sensor 400 and a sum of a previously investigated thickness of the wafer W and a distance between a front surface of the spin chuck 261 and the front surface of the base 260.
Further, in the present first modification example, the second sensor 401 may measure a position of the rear surface W2 of the wafer W after measuring a position of the front surface of the spin chuck 261, for example. In the calculator 402, the relative thickness is calculated by subtracting the position of the front surface of the spin chuck 261 from the position of the rear surface W2 of the wafer W, and the thickness of the protective tape B is calculated by subtracting the previously investigated thickness of the wafer W from the relative thickness. In such a case, however, it is desirable that the spin chuck 261 has the same size as the wafer W when viewed from the top.
Moreover, though the thickness of the protective tape B is measured by using the first sensor 400, the second sensor 401 and the calculator 402 in the first modification example, the thickness of the protective tape B may be directly measured by using, for example, a spectral interferometer. In such a case, light having a wavelength range capable of penetrating the wafer W, for example, infrared light is used.
The tape thickness measuring unit 110 may be provided at an outside of the processing apparatus 30. In such a configuration, the tape thickness measuring unit 110 is connected to, for example, the wafer transfer area 20. As depicted in
In any of the above-described first and second modification examples, since the thickness of the protective tape B can be measured before the rough grinding in the rough grinding unit 80 is performed, the same effects as obtained in the above-described exemplary embodiment can be achieved.
<Other Examples of Chuck Rotating Device>
In the above-described exemplary embodiment shown in
The flexible member 420 is not particularly limited as long as it delivers the rotational driving force by the driving unit 220 to the rotation shaft 210 but does not deliver the inclination of the rotation shaft 210 to the driving unit 220. By way of non-limiting example, a plurality of pins having flexibility may be used as the flexible member 420, or a diaphragm (membrane) may be used as the flexible member 420 and this diaphragm may be transformed. By using the flexible member 420, the same effects as obtained in the above-described exemplary embodiments can be achieved.
Moreover, in the rotating device 204 according to the above-described exemplary embodiments, the rotation shaft 210 and the driving unit 220 are provided independent. However, a driving unit (not shown) of a direct drive type, for example, may be provided at the supporting table 211 of the rotation shaft 210.
<Other Examples of Chuck Adjusting Device>
In the above-described exemplary embodiment shown in
<Other Exemplary Embodiments of Substrate Processing System>
In the substrate processing system 1 according to the above-described exemplary embodiment shown in
From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting. The scope of the inventive concept is defined by the following claims and their equivalents rather than by the detailed description of the exemplary embodiments. It shall be understood that all modifications and embodiments conceived from the meaning and scope of the claims and their equivalents are included in the scope of the inventive concept.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017-121183 | Jun 2017 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2018/021873 | 6/7/2018 | WO | 00 |
