WO2020129730A1

WO2020129730A1 - Substrate processing device and substrate processing method

Info

Publication number: WO2020129730A1
Application number: PCT/JP2019/048087
Authority: WO
Inventors: 弘明森; 隼斗田之上
Original assignee: 東京エレクトロン株式会社
Priority date: 2018-12-21
Filing date: 2019-12-09
Publication date: 2020-06-25
Also published as: JP7287982B2; TW202044379A; TWI814960B; JPWO2020129730A1

Abstract

This substrate processing device for processing a substrate has: a holding part for holding, in a superposed substrate in which a first substrate and a second substrate are joined, the second substrate; an inner surface reforming part for emitting a laser beam for an inner surface along a surface direction to the inside of the first substrate held by the holding part so as to form an inner surface reformed layer; and a movement mechanism for relatively moving the holding part and the inner surface reforming part, wherein the inner surface reformed layer is formed by moving the laser beam for an inner surface from a radially outer side to a radially inner side in the first substrate by means of the movement mechanism.

Description

Substrate processing apparatus and substrate processing method

The present disclosure relates to a substrate processing apparatus and a substrate processing method.

Patent Document 1 discloses a method for manufacturing a stacked semiconductor device. In this manufacturing method, two or more semiconductor wafers are stacked to manufacture a stacked semiconductor device. At this time, each semiconductor wafer is laminated on another semiconductor wafer and then backside ground to have a desired thickness.

JP 2012-69736 A

The technology according to the present disclosure efficiently performs pretreatment for substrate thinning.

One aspect of the present disclosure is a substrate processing apparatus for processing a substrate, comprising: a holding unit that holds the second substrate in a superposed substrate in which a first substrate and a second substrate are joined; and a holding unit that holds the second substrate. Inside of the held first substrate, an internal surface reforming unit that irradiates an internal surface laser beam along a surface direction to form an internal surface reforming layer, the holding unit and the internal surface reforming A moving mechanism for relatively moving the inner surface of the first substrate by the moving mechanism to move the laser light for the inner surface from the outer side to the inner side in the radial direction inside the first substrate. To form.

According to the present disclosure, pretreatment for thinning a substrate can be efficiently performed.

It is a top view which shows typically the outline of a structure of the wafer processing system concerning this embodiment. It is a side view which shows the outline of a structure of an overlapping wafer. It is a side view which shows the outline of a part of structure of an overlapping wafer. It is a top view which shows the outline of a structure of a reformer. It is a side view which shows the outline of a structure of a reformer. It is a top view which shows the outline of a structure of a peripheral edge removal apparatus. It is a side view which shows the outline of a structure of a peripheral edge removal apparatus. It is a longitudinal cross-sectional view which shows the outline of a structure of a transfer arm. It is a flowchart which shows the main processes of wafer processing. It is explanatory drawing of the main processes of wafer processing. It is explanatory drawing of the main processes of a modification process. It is explanatory drawing which shows a mode that a peripheral modified layer is formed in a process wafer. It is explanatory drawing which shows a mode that the peripheral modified layer was formed in the processed wafer. It is explanatory drawing which shows a mode that a division|segmentation modification layer is formed in a process wafer. It is explanatory drawing which shows a mode that the division|segmentation modification layer was formed in the process wafer. It is explanatory drawing which shows a mode that an internal surface modification layer is formed in a process wafer. It is explanatory drawing which shows a mode that an internal surface modification layer is formed in a process wafer. It is explanatory drawing which shows the stress which acts on the inside of a process wafer at the time of formation of an internal surface modification layer. It is explanatory drawing which shows a mode that a peripheral part is removed. It is explanatory drawing which shows a mode that a back surface wafer is separated from a process wafer. It is a top view which shows the outline of a structure of the reforming apparatus concerning other embodiment. It is explanatory drawing which shows a mode that a peripheral modified layer is formed in the process wafer in other embodiment. It is explanatory drawing which shows a mode that an internal surface modification layer is formed in a process wafer in other embodiment. It is explanatory drawing of the main processes of the wafer processing concerning other embodiment.

In the manufacturing process of a semiconductor device, for example, as in the method disclosed in Patent Document 1, a semiconductor wafer (hereinafter, referred to as a wafer) having a plurality of devices such as electronic circuits formed on the front surface is attached to the back surface of the wafer. The wafer is thinned by grinding.

Grinding of the back surface of the wafer is performed, for example, by rotating the wafer and the grinding wheel with the grinding wheel in contact with the back surface and further lowering the grinding wheel. In such a case, the grinding wheel is worn and needs to be replaced regularly. Further, in the grinding process, it is necessary to use grinding water and treat the waste liquid. Therefore, a conventional wafer thinning process requires running costs.

Normally, the peripheral edge of the wafer is chamfered, but when the back surface of the wafer is ground as described above, the peripheral edge of the wafer becomes a sharply pointed shape (so-called knife edge shape). Then, chipping may occur at the peripheral edge of the wafer and the wafer may be damaged. Therefore, so-called edge trim is performed in advance to remove the peripheral portion of the wafer before the grinding process. Then, for example, in the method disclosed in Patent Document 1, the peripheral portion of the wafer is partially ground or cut to perform this edge trim.

The technology according to the present disclosure efficiently performs pretreatment for wafer thinning processing. Hereinafter, a wafer processing system as a substrate processing apparatus and a wafer processing method as a substrate processing method according to the present embodiment will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configuration are designated by the same reference numerals, and duplicate description is omitted.

First, the configuration of the wafer processing system according to this embodiment will be described. FIG. 1 is a plan view schematically showing the outline of the configuration of the wafer processing system 1.

In the wafer processing system 1, as shown in FIGS. 2 and 3, a processed wafer W as a first substrate and a support wafer S as a second substrate are bonded to a superposed wafer T as a superposed substrate. Perform predetermined processing. Then, in the wafer processing system 1, the peripheral edge portion We of the processed wafer W is removed, and the processed wafer W is further thinned. Hereinafter, in the processed wafer W, a surface bonded to the support wafer S is referred to as a front surface Wa, and a surface opposite to the front surface Wa is referred to as a back surface Wb. Similarly, in the support wafer S, the surface bonded to the processing wafer W is referred to as the front surface Sa, and the surface opposite to the front surface Sa is referred to as the back surface Sb.

The processing wafer W is, for example, a semiconductor wafer such as a silicon wafer, and has a device layer (not shown) including a plurality of devices formed on the front surface Wa. Further, an oxide film F, for example, a SiO ₂ film (TEOS film) is further formed on the device layer. The peripheral edge We of the processed wafer W is chamfered, and the thickness of the cross section of the peripheral edge We decreases toward the tip thereof. The peripheral edge portion We is a portion to be removed in the edge trim, and is, for example, within a range of 1 mm to 5 mm in the radial direction from the outer end portion of the processed wafer W.

Note that the oxide film F is not shown in FIG. 2 in order to avoid the complexity of the drawing. Similarly, in other drawings used in the following description, illustration of the oxide film F may be omitted.

The support wafer S is a wafer that supports the processing wafer W, and is, for example, a silicon wafer. An oxide film (not shown) is formed on the surface Sa of the support wafer S. Further, the support wafer S functions as a protective material that protects the device on the front surface Wa of the processing wafer W. When a plurality of devices are formed on the front surface Sa of the support wafer S, a device layer (not shown) is formed on the front surface Sa similarly to the processed wafer W.

Here, if the processing wafer W and the supporting wafer S are bonded to each other at the peripheral edge portion We of the processing wafer W, the peripheral edge portion We may not be removed properly. Therefore, at the interface between the processing wafer W and the supporting wafer S, a bonding region Aa where the oxide film F and the surface Sa of the supporting wafer S are bonded and an unbonded region Ab which is a region radially outside the bonding region Aa are provided. Form. The presence of the unbonded region Ab in this way allows the peripheral edge portion We to be appropriately removed. It should be noted that, although the details will be described later, it is preferable that the outer end of the joining region Aa is located slightly outside in the radial direction from the inner end of the peripheral edge We to be removed.

As shown in FIG. 1, the wafer processing system 1 has a configuration in which a loading/unloading station 2 and a processing station 3 are integrally connected. The loading/unloading station 2 loads/unloads a cassette Ct capable of accommodating a plurality of overlapped wafers T with the outside, for example. The processing station 3 includes various processing devices that perform predetermined processing on the overlapped wafer T.

The cassette loading table 10 is provided in the loading/unloading station 2. In the illustrated example, a plurality of, for example, three cassettes Ct can be mounted on the cassette mounting table 10 in a line in the Y-axis direction. The number of cassettes Ct mounted on the cassette mounting table 10 is not limited to this embodiment, and can be arbitrarily determined.

At the loading/unloading station 2, a wafer transfer device 20 is provided adjacent to the cassette mounting table 10 on the X axis negative direction side of the cassette mounting table 10. The wafer transfer device 20 is configured to be movable on a transfer path 21 extending in the Y-axis direction. Further, the wafer transfer device 20 has, for example, two

transfer arms

22, 22 that hold and transfer the overlapped wafer T. Each transfer arm 22 is configured to be movable in the horizontal direction, the vertical direction, around the horizontal axis, and around the vertical axis. The configuration of the transfer arm 22 is not limited to this embodiment, and may have any configuration. The wafer transfer device 20 is configured to be able to transfer the overlapped wafer T to the cassette Ct of the cassette mounting table 10 and the transition device 30 described later.

The loading/unloading station 2 is provided with a transition device 30 for transferring the overlapped wafer T, adjacent to the wafer transfer device 20 on the X-axis negative direction side of the wafer transfer device 20.

The processing station 3 is provided with, for example, three processing blocks G1 to G3. The first processing block G1, the second processing block G2, and the third processing block G3 are arranged side by side in this order from the X-axis positive direction side (the loading/unloading station 2 side) to the negative direction side.

The first processing block G1 is provided with an etching device 40, a cleaning device 41, and a wafer transfer device 50. The etching device 40 and the cleaning device 41 are arranged in layers. The number and arrangement of the etching device 40 and the cleaning device 41 are not limited to this. For example, the etching device 40 and the cleaning device 41 may extend in the X-axis direction and may be placed side by side in parallel in a plan view. Further, each of the etching device 40 and the cleaning device 41 may be laminated.

The etching device 40 performs an etching process on the back surface Wb of the processing wafer W ground by the processing device 80 described later. For example, a chemical solution (etching solution) is supplied to the back surface Wb, and the back surface Wb is wet-etched. For example, HF, HNO ₃ , H ₃ PO ₄ , TMAH, Choline, KOH or the like is used as the chemical liquid.

The cleaning device 41 cleans the back surface Wb of the processed wafer W ground by the processing device 80 described later. For example, a brush is brought into contact with the back surface Wb to scrub and clean the back surface Wb. Note that a pressurized cleaning liquid may be used for cleaning the back surface Wb. Further, the cleaning device 41 may have a configuration for cleaning the back surface Sb of the support wafer S together with the back surface Wb of the processing wafer W.

The wafer transfer device 50 is arranged, for example, on the Y axis negative direction side with respect to the etching device 40 and the cleaning device 41. The wafer transfer device 50 has, for example, two

transfer arms

51, 51 for holding and transferring the overlapped wafer T. Each transfer arm 51 is configured to be movable in the horizontal direction, the vertical direction, around the horizontal axis, and around the vertical axis. The configuration of the transfer arm 51 is not limited to this embodiment, and may have any configuration. The wafer transfer device 50 is configured to transfer the superposed wafer T to the transition device 30, the etching device 40, the cleaning device 41, and the reforming device 60 described later.

The second processing block G2 is provided with a reforming device 60, a peripheral edge removing device 61, and a wafer transfer device 70. The reforming device 60 and the peripheral edge removing device 61 are arranged in layers. The number and arrangement of the reforming device 60 and the peripheral edge removing device 61 are not limited to this.

The reforming device 60 irradiates the inside of the processed wafer W with laser light to form a peripheral reforming layer, a split reforming layer, and an inner surface reforming layer. The specific configuration of the reformer 60 will be described later.

The peripheral edge removing device 61 removes the peripheral edge portion We of the processed wafer W with the peripheral edge modified layer formed by the reforming device 60 as a starting point. The specific configuration of the peripheral edge removing device 61 will be described later.

The wafer transfer device 70 is arranged, for example, on the Y axis positive direction side with respect to the reforming device 60 and the peripheral edge removing device 61. The wafer transfer device 70 has, for example, two

transfer arms

71, 71 for holding and transferring the overlapped wafer T. Each transfer arm 71 is supported by an articulated arm member 72, and is configured to be movable in a horizontal direction, a vertical direction, a horizontal axis, and a vertical axis. The specific configuration of the transfer arm 71 will be described later. The wafer transfer device 70 is configured to transfer the superposed wafer T to the cleaning device 41, the reforming device 60, the peripheral edge removing device 61, and the processing device 80 described later.

A processing device 80 is provided in the third processing block G3. Note that the number and arrangement of the processing devices 80 are not limited to this embodiment, and a plurality of processing devices 80 may be arranged arbitrarily.

The processing device 80 grinds the back surface Wb of the processed wafer W. Then, on the back surface Wb on which the inner surface reforming layer is formed, the inner surface reforming layer is removed and the peripheral edge reforming layer is further removed. Specifically, the processing device 80 rotates the processing wafer W and the grinding wheel, respectively, in a state where the back surface Wb of the processing wafer W held by the chuck 81 is in contact with a grinding wheel (not shown), and the back surface Wb is rotated. To grind. A known grinding device (polishing device) is used as the processing device 80, and for example, the device described in JP 2010-69601 A is used.

The wafer processing system 1 described above is provided with the control device 90. The control device 90 is, for example, a computer and has a program storage unit (not shown). The program storage unit stores a program for controlling the processing of the overlapped wafer T in the wafer processing system 1. The program storage unit also stores a program for controlling the operation of drive systems such as the above-described various processing devices and transfer devices so as to realize substrate processing to be described later in the wafer processing system 1. The program may be recorded in a computer-readable storage medium H and may be installed in the control device 90 from the storage medium H.

Next, the reformer 60 described above will be described. FIG. 4 is a plan view showing the outline of the configuration of the reformer 60. FIG. 5 is a side view showing the outline of the configuration of the reformer 60.

The reforming device 60 has a chuck 100 as a holding unit that holds the superposed wafer T on its upper surface. The chuck 100 sucks and holds the support wafer S in a state where the processing wafer W is on the upper side and the support wafer S is on the lower side. The chuck 100 is supported by the slider table 102 via an air bearing 101. A rotating mechanism 103 is provided on the lower surface side of the slider table 102. The rotation mechanism 103 incorporates, for example, a motor as a drive source. The chuck 100 is configured to be rotatable about a vertical axis by a rotating mechanism 103 via an air bearing 101. The slider table 102 is configured to be movable along a rail 105 provided on the base 106 and extending in the Y-axis direction by a moving mechanism 104 provided on the lower surface side. The drive source of the moving mechanism 104 is not particularly limited, but a linear motor is used, for example.

A laser head 110 is provided above the chuck 100. The laser head 110 has a lens 111. The lens 111 is a cylindrical member provided on the lower surface of the laser head 110, and irradiates the processing wafer W held by the chuck 100 with laser light. In addition, in this embodiment, the peripheral edge reforming portion and the inner surface reforming portion have the common laser head 110.

The laser head 110 further has an LCOS (Liquid Crystal on Silicon) not shown. The LCOS is a spatial light modulator that modulates and outputs laser light. Specifically, the LCOS can control the focal position and phase of the laser light, and can adjust the shape and number (branch number) of the laser light with which the processing wafer W is irradiated.

The laser head 110 emits high-frequency pulsed laser light oscillated from a laser light oscillator (not shown) having a wavelength that is transparent to the processing wafer W inside the processing wafer W. The light is condensed and irradiated at a predetermined position. As a result, the portion where the laser light is focused inside the processed wafer W is modified, and the peripheral modified layer, the split modified layer, and the inner surface modified layer are formed.

The laser head 110 is supported by the support member 120. The laser head 110 is configured to be movable up and down by a lifting mechanism 130 along a rail 121 extending in the vertical direction. Further, the laser head 110 is configured to be movable in the Y-axis direction by the moving mechanism 131. The elevating mechanism 130 and the moving mechanism 131 are supported by the support columns 132, respectively.

A macro camera 140 and a micro camera 150 are provided above the chuck 100 and on the Y axis positive direction side of the laser head 110. For example, the macro camera 140 and the micro camera 150 are integrally formed, and the macro camera 140 is arranged on the Y-axis positive direction side of the micro camera 150. The macro camera 140 and the micro camera 150 are configured to be movable up and down by a lifting mechanism 160, and are further configured to be movable in the Y-axis direction by a moving mechanism 161.

The macro camera 140 images the outer edge of the processed wafer W (overlapping wafer T). The macro camera 140 includes, for example, a coaxial lens, emits visible light, for example, red light, and further receives reflected light from an object. Note that, for example, the imaging magnification of the macro camera 140 is 2 times.

The micro camera 150 images the peripheral portion of the processed wafer W and the boundary between the bonded area Aa and the unbonded area Ab. The micro camera 150 includes, for example, a coaxial lens, irradiates infrared light (IR light), and further receives reflected light from an object. Note that, for example, the imaging magnification of the micro camera 150 is 10 times, the field of view is about ⅕ of the macro camera 140, and the pixel size is about ⅕ of the macro camera 140.

Next, the peripheral edge removing device 61 described above will be described. FIG. 6 is a plan view showing the outline of the configuration of the peripheral edge removing device 61. FIG. 7 is a side view showing the outline of the configuration of the peripheral edge removing device 61.

The peripheral edge removing device 61 has a chuck 170 for holding the overlapped wafer T on its upper surface. The chuck 170 sucks and holds the support wafer S in a state where the processing wafer W is on the upper side and the support wafer S is on the lower side. The chuck 170 is configured to be rotatable about a vertical axis by a rotating mechanism 171.

A pad 180 for holding and transferring the peripheral edge portion We of the processing wafer W is provided above the chuck 170. A suction mechanism (not shown) such as a vacuum pump is connected to the pad 180, and the pad 180 sucks and holds the peripheral edge portion We on the lower surface thereof. The pad 180 is provided with an elevating mechanism 181 for vertically elevating the pad 180 and a moving mechanism 182 for moving the pad 180 in the horizontal direction (X-axis direction and Y-axis direction).

Above the chuck 170, a detection unit 190 for confirming whether or not the peripheral edge portion We has been removed from the processing wafer W is provided. The detection unit 190 detects the presence or absence of the peripheral edge We in the processed wafer W held by the chuck 170 and having the peripheral edge We removed. A sensor is used for the detection unit 190, for example. The sensor is, for example, a line type laser displacement meter, and detects the presence or absence of the peripheral edge portion We by irradiating the peripheral edge portion of the overlapped wafer T (processed wafer W) with a laser to measure the thickness of the overlapped wafer T. .. Note that the detection method of the presence or absence of the peripheral edge portion We by the detection unit 190 is not limited to this. For example, a line camera may be used as the detection unit 190, and the presence or absence of the peripheral edge portion We may be detected by imaging the overlapped wafer T (processed wafer W).

A recovery unit (not shown) that recovers the peripheral edge portion We transferred by the pad 180 is provided below the chuck 170. The recovery unit accommodates and recovers the peripheral edge We that is suction-held by the pad 180.

Next, the transfer arm 71 of the wafer transfer device 70 described above will be described. FIG. 8 is a vertical cross-sectional view showing the outline of the configuration of the transfer arm 71.

The transfer arm 71 has a disk-shaped suction plate 200 having a larger diameter than the overlapped wafer T. A holding unit 210 that holds the central portion Wc of the processing wafer W is provided on the lower surface of the suction plate 200.

A suction pipe 211 for sucking the central portion Wc is connected to the holding portion 210, and the suction pipe 211 communicates with a suction mechanism 212 such as a vacuum pump. The suction pipe 211 is provided with a pressure sensor 213 that measures suction pressure. The configuration of the pressure sensor 213 is arbitrary, but for example, a diaphragm type pressure gauge is used.

A rotation mechanism 220 that rotates the suction plate 200 around a vertical axis is provided on the upper surface of the suction plate 200. The rotation mechanism 220 is supported by the support member 221. The support member 221 (rotation mechanism 220) is supported by the arm member 72.

Next, wafer processing performed using the wafer processing system 1 configured as described above will be described. FIG. 9 is a flowchart showing the main steps of wafer processing. FIG. 10 is an explanatory diagram of main steps of wafer processing. In the present embodiment, the processing wafer W and the supporting wafer S are bonded to each other in the bonding apparatus (not shown) outside the wafer processing system 1 to form the overlapped wafer T in advance.

First, the cassette Ct containing a plurality of overlapped wafers T shown in FIG. 10A is placed on the cassette placing table 10 of the loading/unloading station 2.

Next, the overlapped wafer T in the cassette Ct is taken out by the wafer transfer device 20 and transferred to the transition device 30. Subsequently, the wafer transfer device 50 takes out the overlapped wafer T of the transition device 30 and transfers it to the reforming device 60. In the reforming apparatus 60, as shown in FIG. 10B, the peripheral reforming layer M1 and the divided reforming layer M2 are sequentially formed inside the processing wafer W (steps A1 and A2 in FIG. 9), and further in FIG. As shown in c), the inner surface modified layer M3 is formed (step A3 in FIG. 9). The peripheral edge modifying layer M1 serves as a base point for removing the peripheral edge We in the edge trim. The divided reformed layer M2 serves as a base point for making the removed peripheral edge portion We into small pieces. The inner surface modified layer M3 serves as a base point for thinning the processed wafer W.

FIG. 11 is an explanatory diagram of main steps of the reforming process in the reforming device 60. First, as shown in FIG. 11A, the chuck 100 (slider table 102) is moved to the loading/unloading position P1. Then, the superposed wafer T is loaded from the wafer transfer device 50 and held by the chuck 100.

Next, the chuck 100 is moved to the macro alignment position P2 as shown in FIG. 11(b). The macro alignment position P2 is a position where the macro camera 140 can capture an image of the outer edge of the processing wafer W.

Next, the macro camera 140 captures an image of the outer edge of the processed wafer W in the circumferential direction of 360 degrees. The captured image is output from the macro camera 140 to the control device 90.

The controller 90 calculates the first eccentricity amount of the center Cc of the chuck 100 and the center Cw of the processed wafer W from the image of the macro camera 140. Further, the control device 90 calculates the movement amount of the chuck 100 based on the first eccentricity amount so as to correct the Y-axis component of the first eccentricity amount. The chuck 100 moves in the Y-axis direction based on the calculated movement amount, and moves the chuck 100 to the micro alignment position P3 as shown in FIG. 11(c). The micro alignment position P3 is a position where the micro camera 150 can capture an image of the peripheral portion of the processing wafer W. Here, as described above, the field of view of the micro camera 150 is as small as about 1/5 of that of the macro camera 140. Therefore, if the Y-axis component of the first eccentricity is not corrected, the peripheral portion of the processing wafer W is the micro camera. The micro camera 150 may not be able to capture an image because it does not enter the angle of view of 150. Therefore, the correction of the Y-axis component based on the first amount of eccentricity can also be said to be for moving the chuck 100 to the micro alignment position P3.

Next, the micro camera 150 images the boundary between the bonded area Aa and the unbonded area Ab of the processed wafer W in the circumferential direction of 360 degrees. The captured image is output from the micro camera 150 to the control device 90.

The controller 90 calculates the second eccentricity amount between the center Cc of the chuck 100 and the center Ca of the bonding area Aa from the image of the micro camera 150. Further, the controller 90 determines the position of the chuck 100 with respect to the peripheral modified layer M1 based on the second eccentricity so that the center of the bonding area Aa and the center of the chuck 100 coincide with each other. As described above, the unbonded area Ab is formed before the processing wafer W and the supporting wafer S are bonded. The center of the unbonded area Ab (center Ca of the bonding area Aa) and the center of the processed wafer W are formed. There is a case that it is misaligned. In this regard, by adjusting the position of the chuck 100 with respect to the peripheral modified layer M1 based on the second eccentric amount as in the present embodiment, the deviation of the unbonded region Ab is corrected.

Next, as shown in FIG. 11D, the chuck 100 is moved to the reforming position P4. The modification position P4 is a position where the laser head 110 irradiates the processing wafer W with laser light to form the peripheral modification layer M1. In the present embodiment, the modified position P4 is the same as the micro alignment position P3.

Next, as shown in FIGS. 12 and 13, laser light L1 (peripheral laser light L1) is emitted from the laser head 110, and the peripheral edge modifying layer M1 is formed at the boundary between the peripheral edge We and the central portion Wc of the processing wafer W. Are formed (step A1 in FIG. 9). The shape and number of the laser light L1 are adjusted by the LCOS. Specifically, the laser light L1 is controlled in its focal position and phase so as to form a peripheral modified layer M1 described later, and its shape is adjusted. Further, in the present embodiment, the number of laser beams L1 is one.

The peripheral edge modified layer M1 formed by the laser beam L1 is stretched in the thickness direction and has a vertically long aspect ratio. The lower end of the peripheral modified layer M1 is located above the target surface (dotted line in FIG. 12) of the thinned processed wafer W. That is, the distance H1 between the lower end of the peripheral modified layer M1 and the surface Wa of the processed wafer W is larger than the target thickness H2 of the thinned processed wafer W. In such a case, the peripheral modified layer M1 does not remain on the processed wafer W after thinning. Inside the processed wafer W, cracks C1 have propagated from the peripheral modified layer M1 and have reached the front surface Wa and the back surface Wb.

The peripheral modified layer M1 is formed radially inward of the outer end of the bonding area Aa. When the peripheral edge modifying layer M1 is formed by the laser light L1 from the laser head 110, even if the peripheral edge modifying layer M1 is formed deviating from the outer end of the bonding area Aa due to, for example, a processing error, the peripheral edge modifying layer M1 is changed. It is possible to suppress the quality layer M1 from being formed radially outward from the outer end portion of the bonding area Aa. Here, when the peripheral edge modified layer M1 is formed radially outward from the outer end of the bonding area Aa, the processed wafer W floats on the support wafer S after the peripheral edge We is removed. I will end up. In this respect, in the present embodiment, the state of the processed wafer W can be reliably suppressed.

The inventors of the present invention have diligently studied and confirmed that the peripheral edge We can be appropriately removed if the distance D between the peripheral edge modified layer M1 and the outer end of the bonding area Aa is sufficiently small. The distance D is preferably within 500 μm, more preferably within 50 μm.

Here, as described above, the control device 90 determines the position of the chuck 100 based on the second amount of eccentricity. In step A1, the chuck 100 is rotated by the rotating mechanism 103 and the chuck 100 is moved by the moving mechanism 104 so that the center of the bonding area Aa and the center of the chuck 100 coincide with each other in accordance with the determined position of the chuck 100. Move in the Y-axis direction. At this time, the rotation of the chuck 100 and the movement in the Y-axis direction are synchronized. By performing the complete synchronization control in this manner, the movement of the chuck 100 can be appropriately followed by the determined position with a small error.

Then, while rotating and moving the chuck 100 (processing wafer W) in this way, the laser light L1 is irradiated from the laser head 110 to the inside of the processing wafer W. That is, the peripheral edge modified layer M1 is formed while correcting the second eccentricity amount. Then, the peripheral modified layer M1 is annularly formed concentrically with the bonding area Aa. That is, the distance D between the peripheral modified layer M1 and the outer end of the bonding area Aa shown in FIG. 12 can be made constant. Therefore, in the peripheral edge removing device 61, the peripheral edge portion We can be appropriately removed with the peripheral edge modifying layer M1 as a base point.

In this example, when the second amount of eccentricity has an X-axis component, the chuck 100 is rotated in the Y-axis direction and the chuck 100 is rotated to correct the X-axis component. On the other hand, when the second amount of eccentricity does not include the X-axis component, it is sufficient to move the chuck 100 in the Y-axis direction without rotating it.

Next, the laser head 110 is moved in the Y-axis direction, and laser light L2 (division laser light L2) is emitted from the laser head 110 as shown in FIGS. The divided modified layer M2 is formed on the outside in the direction (step A2 in FIG. 9). At this time, the laser light emitted from the laser head 110 is switched from the laser light L1 to the laser light L2 by the LCOS, and the shape and number of the laser light L2 are adjusted. Specifically, the laser beam L2 is controlled in its focal position and phase to adjust its shape so as to form a split modification layer M2 described later. In addition, in the present embodiment, the number of laser beams L2 is one.

Similarly to the peripheral modified layer M1, the divided modified layer M2 is also stretched in the thickness direction and has a vertically long aspect ratio. In the present embodiment, the divided reformed layer M2 is formed at the same height as the peripheral reformed layer M1. Further, the crack C2 has propagated from the divided reformed layer M2 and reaches the front surface Wa and the back surface Wb.

Further, by forming a plurality of divided modified layers M2 and cracks C2 at a pitch of several μm in the radial direction, one line of the divided modified layers extending radially outward from the peripheral modified layer M1 as shown in FIG. The layer M2 is formed. In the illustrated example, the divided reformed layers M2 of the line extending in the radial direction are formed at eight locations, but the number of divided reformed layers M2 is arbitrary. If at least the divided modified layer M2 is formed at two locations, the peripheral edge portion We can be removed. In such a case, when the peripheral edge We is removed in the edge trim, the peripheral edge We is divided into a plurality of pieces by the division modified layer M2 while separating from the annular peripheral modified layer M1 as a base point. Then, the removed peripheral edge We is made into small pieces, which can be removed more easily.

Although the laser head 110 is moved in the Y-axis direction in forming the divided modified layer M2 in the present embodiment, the chuck 100 may be moved in the Y-axis direction.

Next, as shown in FIGS. 16 and 17, laser light L3 (laser light L3 for inner surface) is emitted from the laser head 110 to form an inner surface modified layer M3 along the surface direction (FIG. 9). Step A3). At this time, the laser light emitted from the laser head 110 is switched from the laser light L2 to the laser light L3 by the LCOS, and the shape and number of the laser light L3 are adjusted. Specifically, the laser beam L3 is controlled in its focal position and phase to adjust its shape so as to form an internal surface reforming layer M3 described later. In addition, in the present embodiment, the number of laser beams L3 is one. The black arrow shown in FIG. 17 indicates the rotation direction of the chuck 100, and the same applies to the following description.

The lower end of the inner surface modified layer M3 is located slightly above the target surface (dotted line in FIG. 16) of the processed wafer W after thinning. That is, the distance H3 between the lower end of the inner surface modified layer M3 and the front surface Wa of the processed wafer W is slightly larger than the target thickness H2 of the thinned processed wafer W. In addition, inside the processed wafer W, a crack C3 propagates in the surface direction from the inner surface modified layer M3.

In Step A3, the chuck 100 (processed wafer W) is rotated, and the laser head 110 is moved from the outer peripheral portion of the processed wafer W toward the central portion in the Y-axis direction while being moved from the laser head 110 to the inside of the processed wafer W. The laser light L3 is emitted. Then, the inner surface modified layer M3 is formed in a spiral shape from the outer side to the inner side in the surface of the processing wafer W.

In step A3, the inner surface modification layer M3 is thus formed by irradiating the processing wafer W with the laser beam L3 from the outer side to the inner side in the radial direction. The reason for this will be described with reference to FIG. FIG. 18A shows a case where the inner surface modified layer M3 is formed from the inner side to the outer side as a comparative example, and FIG. 18B shows a case where the inner surface modified layer M3 is formed from the outer side to the inner side according to the present embodiment. Indicates. As shown in FIG. 18A, when the inner surface modified layer M3 is first formed in the central portion of the processed wafer W, the stress R acting along with the formation of the inner surface modified layer M3 causes Staying away from the inside. Then, the stress R damages the inside of the processed wafer W, and the crack C3 does not propagate. On the other hand, as shown in FIG. 18B, when the inner surface modified layer M3 is first formed on the outer peripheral portion of the processed wafer W, the stress R can be released to the outside of the processed wafer W. Therefore, the inside of the processed wafer W is not damaged, and the crack C3 can also propagate in the surface direction.

Although the laser head 110 is moved in the Y-axis direction in forming the inner surface modified layer M3 in the present embodiment, the chuck 100 may be moved in the Y-axis direction. Although the chuck 100 is rotated in forming the inner surface modified layer M3, the laser head 110 may be moved to rotate the laser head 110 relative to the chuck 100.

Next, when the inner surface modified layer M3 is formed on the processed wafer W, the chuck 100 is moved to the loading/unloading position P1 as shown in FIG. 11(e). Then, the overlapped wafer T is unloaded by the wafer transfer device 70.

Next, the overlapped wafer T is transferred to the peripheral edge removing device 61 by the wafer transfer device 70. In the peripheral edge removing device 61, as shown in FIG. 10D, the peripheral edge portion We of the processing wafer W is removed from the peripheral edge modified layer M1 as a base point (step A4 in FIG. 9). In step A4, as shown in FIG. 19, the lifting mechanism 181 lowers the pad 180 to suck and hold the peripheral edge portion We, and then raises the pad 180 further. Then, the peripheral edge portion We held by the pad 180 is separated from the processed wafer W with the peripheral edge modified layer M1 as a base point. At this time, the peripheral edge portion We is divided into small pieces based on the divided reformed layer M2. The removed peripheral edge portion We is recovered from the pad 180 to a recovery unit (not shown).

Next, the overlapped wafer T is transferred to the processing device 80 by the wafer transfer device 70. In the processing device 80, first, when transferring the overlapped wafer T from the transfer arm 71 to the chuck 81, as shown in FIG. 10E, the back surface Wb side of the processed wafer W (hereinafter , Back wafer Wb1) is separated (step A5 in FIG. 9).

In step A5, as shown in FIG. 20A, the processing wafer W is suction-held by the suction plate 200 of the transfer arm 71, while the supporting wafer S is suction-held by the chuck 81. Then, the suction plate 200 is rotated, and the back surface wafer Wb1 is cut along the boundary of the inner surface reforming layer M3. After that, as shown in FIG. 20B, in a state where the suction plate 200 sucks and holds the back surface wafer Wb1, the suction plate 200 is lifted to separate the back surface wafer Wb1 from the processing wafer W. At this time, the pressure sensor 213 measures the pressure with which the backside wafer Wb1 is sucked, whereby the presence or absence of the backside wafer Wb1 can be detected, and it can be confirmed whether or not the backside wafer Wb1 is separated from the processed wafer W. When the backside wafer Wb1 can be separated only by raising the suction plate 200 as shown in FIG. 20B, the rotation of the suction plate 200 shown in FIG. 20A may be omitted. The separated backside wafer Wb1 is collected outside the wafer processing system 1.

Subsequently, as shown in FIG. 10F, the back surface Wb of the processed wafer W held by the chuck 81 is ground to remove the inner surface modification layer M3 and the peripheral modification layer M1 remaining on the back surface Wb (FIG. 10F). Step A6 of 9). In step A6, the back surface Wb is ground by rotating the processing wafer W and the grinding wheel while the back surface Wb is in contact with the grinding wheel. After that, the back surface Wb of the processed wafer W may be cleaned with the cleaning liquid using a cleaning liquid nozzle (not shown).

Next, the overlapped wafer T is transferred to the cleaning device 41 by the wafer transfer device 70. In the cleaning device 41, the back surface Wb, which is the ground surface of the processed wafer W, is scrubbed and cleaned (step A7 in FIG. 9). In the cleaning device 41, the back surface Sb of the support wafer S may be cleaned together with the back surface Wb of the processing wafer W.

Next, the overlapped wafer T is transferred to the etching device 40 by the wafer transfer device 50. In the etching apparatus 40, the back surface Wb of the processed wafer W is wet-etched with a chemical solution (step A8 in FIG. 9). A grinding mark may be formed on the back surface Wb ground by the processing device 80 described above. In this step A8, the grinding marks can be removed by wet etching, and the back surface Wb can be smoothed.

After that, the superposed wafer T that has undergone all the processes is transferred to the transition device 30 by the wafer transfer device 50, and further transferred to the cassette Ct of the cassette mounting table 10 by the wafer transfer device 20. In this way, a series of wafer processing in the wafer processing system 1 is completed.

According to the above embodiment, in step A3, the laser light L3 is moved from the outer side to the inner side in the radial direction of the processing wafer W to form the inner surface reforming layer M3 from the outer side to the inner side in the radial direction. Therefore, the stress R generated due to the formation of the inner surface modified layer M3 can be released to the outside of the processed wafer W. As a result, the inside of the processed wafer W is not damaged, and the crack C3 can be propagated in the surface direction. As described above, in this embodiment, the pretreatment for the thinning process of the processed wafer W can be efficiently performed.

Further, according to the present embodiment, the peripheral edge portion We is removed from the peripheral edge modified layer M1 as a base point to perform edge trim, and the back surface wafer Wb1 is separated from the internal surface modified layer M3 as a base point to process the processed wafer W. We are thinning it. The laser head 110 used for forming the peripheral modified layer M1 and the internal modified layer M3 is less likely to deteriorate with time and the consumables are reduced, so that the maintenance frequency can be reduced. Further, since it is a dry process using a laser, it is not necessary to process grinding water or waste water. Therefore, the running cost can be reduced. Therefore, the running cost can be suppressed as compared with the conventional edge trimming by grinding or thinning processing by grinding.

In the present embodiment, the back surface Wb is ground in step A6, but this grinding may be performed by removing the inner surface modified layer M3 and the peripheral modified layer M1, and the grinding amount is about several tens of μm. Few. On the other hand, when the back surface Wb is ground to thin the processed wafer W as in the conventional case, the grinding amount is large, for example, 700 μm or more, and the degree of wear of the grinding wheel is large. Therefore, in the present embodiment, the maintenance frequency can be reduced.

Further, according to the present embodiment, by adjusting the shapes of the laser beams L1 to L3 using one laser head 110, the peripheral edge modified layer M1, the split modified layer M2, and the internal surface modified layer M3 are formed. Can be formed. That is, even if the direction in which the modified layer is stretched and the required processing quality are different, it is possible to use one laser head 110 to select an appropriate shape of the laser beam. Since the modified layer having an arbitrary shape can be formed in this manner, the degree of freedom in forming the modified layer is improved. Further, the area occupied by the device (footprint) can be reduced, and space saving can be realized. Further, since the device configuration is simple, the device cost can be reduced. As described above, in this embodiment, the thinning process of the processed wafer W and the pre-process of the edge trim can be efficiently performed.

Here, a preferable interval (pitch) of the inner surface modified layer M3 (laser light L3) when forming the inner surface modified layer M3 in step A3 will be described. As shown in FIGS. 16 and 17, the inner surface reforming layer M3 is formed in a spiral shape from the outer side to the inner side in the radial direction of the processed wafer W. In the following description, this spiral may be called a processing line for convenience.

The following two intervals are included in the interval of the above-mentioned inner surface modified layer M3. The first interval is the interval Q1 in the circumferential direction of the inner surface modified layer M3 on the processing line shown in FIG. The second interval is the radial interval Q2 of the inner surface modified layer M3 between the adjacent processing lines shown in FIG.

Explain the first interval Q1. When the internal surface modified layer M3 is formed in step A3, it is preferable to keep the interval Q1 between the internal surface modified layers M3 constant in order to propagate the crack C3. Further, when the processed wafer W is separated from the inner surface reforming layer M3 as a starting point in step A5, the interval Q1 of the inner surface reforming layer M3 is set to be constant in order to perform this separation uniformly in the wafer surface. Is preferred.

When adjusting the circumferential interval Q1 of the inner surface modified layer M3, the rotation speed of the chuck 100 is controlled. That is, when the radial position of the laser head 110 (irradiation position of the laser beam L3) is on the outer peripheral portion, the rotation speed is slowed, and when the radial position of the laser head 110 is at the central portion, the rotation speed is increased. doing. Specifically, for example, when the diameter of the processed wafer W is 300 mm, the rotation speed is 30 rpm to 60 rpm in the outer peripheral portion of the processed wafer W (for example, in the range of 120 mm to 150 mm in the radial direction). On the other hand, in the central portion of the processed wafer W (for example, in the range of 0 mm (center point) to 20 mm in the radial direction), the rotation speed is 500 rpm to 3000 rpm. In the range of 20 mm to 120 mm in the radial direction of the processed wafer W, the rotation speed linearly changes from 60 rpm to 500 rpm. In this case, the peripheral speed of the laser beam L3 becomes constant, and the interval Q1 can be made constant in the circumferential direction.

In addition, in order to rotate the laser beam L3 with respect to the processing wafer W as described above, the laser head 110 may be moved instead of rotating the chuck 100.

The frequency of the laser beam L3 may be further controlled when adjusting the circumferential interval Q1 of the inner surface modified layer M3. That is, the frequency is increased when the radial position of the laser head 110 (the irradiation position of the laser light L3) is on the outer peripheral portion, and the frequency is decreased when the radial position of the laser head 110 is on the central portion. Even in this case, when the radial position of the laser head 110 is on the outer peripheral portion, the rotation speed is slowed, and when the radial position of the laser head 110 is on the central portion, the rotation speed is increased. However, since the frequency of the laser light L3 is adjusted as described above, the adjustment range of the rotation speed of the laser head 110 can be reduced.

Explain the second interval Q2. When the processed wafer W is separated from the inner surface modification layer M3 in step A5 as a starting point, in order to perform this separation uniformly in the wafer surface, the inner surface modification layer M3 formed in step A3 is formed in the radial direction. It is preferable to keep the interval Q2 constant.

When adjusting the radial distance Q2 of the inner surface reforming layer M3, the moving speed of the laser head 110 is controlled. That is, when the radial position of the laser head 110 (the irradiation position of the laser beam L3) is on the outer peripheral portion, the moving speed is slowed, and when the radial position of the laser head 110 is on the central portion, the moving speed is fast. doing. In such a case, the interval Q2 can be made constant in the radial direction.

In addition, in order to move the laser beam L3 with respect to the processing wafer W as described above, the chuck 100 may be moved in addition to moving the laser head 110.

In the above embodiment, the laser beams L1 to L3 having different shapes are emitted by one laser head 110. However, the laser head 110 does not carry the processed wafer T to be processed into the reforming apparatus 60. Is preferably calibrated. More specifically, it is preferable to calibrate the laser head 110 before the overlapped wafer T is held on the chuck 100. In such a case, it is not necessary to calibrate the laser head 110 during the reforming process for one processed wafer W, and the time required for switching the laser beams L1 to L3 can be shortened. As a result, the throughput of wafer processing can be improved.

Further, in the above embodiment, when the peripheral modified layer M1 is formed, one laser beam L1 is emitted from the laser head 110 into the inside of the processing wafer W, but a plurality of laser beams L1 may be emitted. In such a case, the time for forming the peripheral modified layer M1 can be shortened, and the throughput of wafer processing can be further improved. Similarly, when the internal surface reforming layer M3 is formed, one laser beam L3 is emitted from the laser head 110 to the inside of the processing wafer W, but a plurality of laser beams L3 may be emitted. Even in such a case, the time for forming the inner surface modified layer M3 can be shortened, and the throughput of wafer processing can be further improved.

Although one laser head 110 is provided in the reformer 60 of the above embodiment, a plurality of laser heads 110, 300, for example, may be provided as shown in FIG. In this embodiment, for convenience of description, the laser head 110 is referred to as a first laser head 110, and the laser head 300 is referred to as a second laser head 300. The number of laser heads is not limited to this embodiment. Further, in FIG. 21, the macro camera 140 and the micro camera 150 are not shown in order to avoid complexity of the drawing.

The second laser head 300 is provided on the Y-axis positive direction side of the first laser head 110. The configuration of the second laser head 300 is similar to that of the first laser head 110. That is, the second laser head 300 has the lens 301 and the LCOS (not shown).

The supporting structure of the second laser head 300 is similar to the supporting structure of the first laser head 110. That is, the second laser head 300 is supported by the support member 310, the rail 311, the elevating mechanism 320, and the moving mechanism 321. The second laser head 300 is configured to be movable up and down and movable in the Y-axis direction.

In such a case, when forming the peripheral modified layer M1, the first laser head 110 and the second laser head 300 are concentrically arranged on the outer peripheral portion of the processed wafer W as shown in FIG. Then, while rotating the processing wafer W, the laser beam L11 is emitted from the first laser head 110 and the laser beam L12 is emitted from the second laser head 300. Then, the laser light L11 forms the peripheral modified layer M11, and the laser light L12 forms the peripheral modified layer M12. The peripheral edge modified layers M11 and M12 are respectively formed over a half circumference of the processed wafer W, and the peripheral edge modified layers M1 and M12 are combined to form the peripheral edge modified layer M1 in an annular shape. That is, in the present embodiment, the processed wafer W only needs to be rotated 180 degrees when forming the peripheral modified layer M1. Therefore, the time for forming the peripheral modified layer M1 can be shortened, and as a result, the throughput of wafer processing can be further improved.

In the above example, the laser light L11 from the first laser head 110 and the laser light L12 from the second laser head 300 are irradiated to the same depth inside the processing wafer W to modify the peripheral edge. The layer M11 and the peripheral modified layer M12 were formed at the same depth. In this regard, the laser light L11 and the laser light L12 may be irradiated to different depths to form the peripheral modified layer M11 and the modified peripheral layer M12 at different depths.

Further, when forming the inner surface modified layer M3, as shown in FIG. 23, the first laser head 110 and the second laser head 300 are arranged concentrically on the outer peripheral portion of the processed wafer W. Then, while rotating the processing wafer W, the first laser head 110 and the second laser head 300 are moved in the Y-axis direction from the outer peripheral portion of the processing wafer W toward the central portion. That is, the first laser head 110 is moved in the Y-axis positive direction, and the second laser head 300 is moved in the Y-axis negative direction. During the rotation of the processing wafer W and the movement of the laser heads 110 and 300, the first laser head 110 irradiates the inside of the processing wafer W with the laser light L31, and the second laser head 300 emits the laser light into the inside of the processing wafer W. The light L32 is emitted. Then, the laser light L31 forms the inner surface reforming layer M31, and the laser light L32 forms the inner surface reforming layer M32. The inner surface modified layers M31 and M32 are each formed in a spiral shape, and the inner surface modified layer M3 is formed on the entire surface of the processed wafer W. By simultaneously forming the inner surface modified layers M31 and M32 in this manner, the time for forming the inner surface modified layer M3 can be shortened, and as a result, the throughput of wafer processing can be further improved.

In the above-described embodiment, the divided reformed layer M2 is formed by using the laser head 110 used in the reformer 60 to form the other peripheral reformed layer M1 and the inner surface reformed layer M3. Alternatively, a separate laser head (not shown) may be used. Further, in the reforming device 60, the peripheral reforming layer M1, the divided reforming layer M2, and the inner surface reforming layer M3 may be formed using different laser heads (not shown).

In the above embodiments, the peripheral edge We is removed by holding the peripheral edge We with the pad 180 in the peripheral edge removing device 61, but the removing method is not limited to this. For example, the peripheral edge portion We may be removed by applying physical impact or ultrasonic waves.

Further, in the above embodiment, the backside wafer Wb1 is separated from the processed wafer W when the overlapping wafer T is transferred from the transfer arm 71 of the wafer transfer device 70 to the chuck 81 of the processing device 80. Is not limited to this. For example, a separating device (not shown) may be provided in the same device as the peripheral edge removing device 61, or a separating device (not shown) may be provided separately.

Further, in the above embodiment, after the peripheral edge portion We of the processing wafer W is removed, the back surface wafer Wb1 of the processing wafer W is thinned by separating it from the internal surface reforming layer M3 as a base point. And the thinning of the processed wafer W may be performed at the same time.

For example, as shown in FIG. 24A, an annular peripheral modified layer M1 is formed inside the processed wafer W, and an internal surface modified layer M3 is formed along the surface direction of the processed wafer W. At this time, the upper end of the peripheral modified layer M1 is made to substantially coincide with the height at which the internal modified layer M3 is formed. The peripheral modified layer M1 and the internal surface modified layer M3 may be formed in any order.

Thereafter, as shown in FIG. 24B, the back surface Wb side of the processed wafer W is separated from the peripheral edge modified layer M1 and the internal surface modified layer M3 as base points. In this way, the processed wafer W can be thinned by separating the back surface Wb side from the inner surface modified layer M3 as a base point. At this time, the peripheral edge portion We is removed integrally with the wafer on the back surface Wb side.

In such a case, since the peripheral edge We is removed and the processed wafer W is thinned at the same time, the throughput of wafer processing can be further improved.

The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The above-described embodiments may be omitted, replaced, or modified in various forms without departing from the scope and spirit of the appended claims.

For example, in the above embodiment, the unbonded region Ab is formed at the interface between the processing wafer W and the supporting wafer S before bonding, but the unbonded region Ab may be formed after bonding. For example, by irradiating the outer peripheral portion of the oxide film F with laser light after bonding, it is possible to reduce the bonding strength and form the unbonded region Ab.

1 Wafer Processing System 60 Reforming Device 100 Chuck 104 Moving Mechanism 110 Laser Head S Support Wafer T Overlapping Wafer W Processed Wafer

Claims

A substrate processing apparatus for processing a substrate, comprising:
A holding unit for holding the second substrate in the superposed substrate in which the first substrate and the second substrate are joined,
Inside the first substrate held by the holding unit, an internal surface reforming unit that irradiates a laser beam for an internal surface along a surface direction to form an internal surface reforming layer,
A moving mechanism that relatively moves the holding portion and the inner surface reforming portion,
A substrate processing apparatus wherein the moving mechanism moves the laser light for inner surface from the outer side to the inner side in the radial direction inside the first substrate to form the inner surface reforming layer.
A rotation mechanism that relatively rotates the holding portion and the inner surface reforming portion,
By the moving mechanism and the rotating mechanism, the inner surface laser light is spirally moved from the radially outer side to the inner side inside the first substrate to form the inner surface reforming layer,
The speed of rotation by the rotating mechanism is higher when the laser light for the inner surface is irradiated to the inner side of the first substrate than when the laser light is irradiated to the inner side of the first substrate, in the radial direction. The substrate processing apparatus described.
In the internal surface reforming section, the frequency of the internal surface laser light that is irradiated to the outside in the radial direction inside the first substrate is higher than the frequency of the internal surface laser light that is irradiated to the inside. The substrate processing apparatus according to claim 2, wherein the laser light for the inner surface is irradiated as described above.
The moving speed of the laser light for the inner surface by the moving mechanism is higher when the laser light for the inner surface is irradiated to the inside than when the laser light for the inner surface is irradiated to the outer side in the radial direction inside the first substrate. The substrate processing apparatus according to claim 1, which is fast.
Inside the first substrate held by the holding portion, a peripheral edge modifying portion that irradiates a peripheral edge laser beam along the boundary between the peripheral edge portion and the central portion to be removed to form a peripheral edge modifying layer is provided. Have,
The peripheral edge modifying section and the internal surface modifying section have a common laser head,
The substrate processing apparatus according to claim 1, wherein the laser head switches between the peripheral edge laser light and the internal surface laser light.
The substrate processing apparatus according to claim 5, comprising a plurality of the laser heads.
The substrate processing apparatus according to claim 5, wherein the laser head is configured to be vertically movable and horizontally movable.
A substrate processing method for processing a substrate, comprising:
Holding the second substrate in a holding portion in a superposed substrate in which the first substrate and the second substrate are joined,
Irradiating the inside surface of the first substrate held by the holding portion from the inside surface reforming portion with a laser beam for the inside surface to form an inside surface reforming layer. ,
When the inner surface reforming layer is formed, the holding unit and the inner surface reforming unit are relatively moved by a moving mechanism so that the laser light for inner surface is radially outside inside the first substrate. Substrate processing method of moving from inside to inside.
When forming the inner surface reforming layer, the holding mechanism and the inner surface reforming portion are relatively moved by the moving mechanism while the holding portion and the inner surface reforming portion are relatively moved by the moving mechanism. Rotating to move the laser light for the inner surface in a spiral shape from the outer side to the inner side in the radial direction inside the first substrate,
9. The speed of rotation by the rotating mechanism is higher when the laser light for the inner surface is irradiated to the inner side of the first substrate than when the laser light is irradiated to the inner side of the first substrate, in the radial direction. The substrate processing method described.
In the internal surface reforming section, the frequency of the internal surface laser light that is irradiated to the outside in the radial direction inside the first substrate is higher than the frequency of the internal surface laser light that is irradiated to the inside. 10. The substrate processing method according to claim 9, wherein the inner surface laser light is irradiated as described above.
The moving speed of the laser light for the inner surface by the moving mechanism is higher when the laser light for the inner surface is irradiated to the inside than when the laser light for the inner surface is irradiated to the outer side in the radial direction inside the first substrate. The substrate processing method according to any one of claims 8 to 10, which is fast.
Inside the first substrate held by the holding portion from the peripheral edge modifying portion, a peripheral edge laser beam is irradiated along the boundary between the peripheral edge portion and the central portion to be removed to form a peripheral edge modifying layer. Have that
The peripheral edge modifying section and the internal surface modifying section have a common laser head,
The substrate processing method according to claim 8, wherein the laser head switches between the peripheral edge laser light and the internal surface laser light.
A plurality of the laser heads are provided,
The substrate processing method according to claim 12, wherein the plurality of laser heads simultaneously irradiate the inside of the first substrate with the laser light for peripheral edge when forming the peripheral edge modifying layer.
A plurality of the laser heads are provided,
The substrate processing method according to claim 12, wherein the plurality of laser heads simultaneously irradiate the inside surface of the first substrate with the laser light for inside surface when forming the inside surface modification layer.