JP2021015832A - Separation device and separation method - Google Patents

Abstract

To provide a separation device and a separation method, capable of appropriately separate an object to be processed into first and second separated bodies.SOLUTION: A separation device is configured to separate an object to be processed into first and second separated bodies, the object to be processed including a modified layer that is formed by irradiation with a laser beam. The separation device includes: a first holding part holding the first separated body; a second holding part holding the second separated body; and a movement part relatively moving the first holding part and the second holding part. The second holding part holds inside the outer edge of the second separated body.SELECTED DRAWING: Figure 17

Description

The present disclosure relates to a separation device and a separation method.

Patent Document 1 discloses a method for processing a laminated wafer in which a first wafer is laminated on a second wafer. In this processing method, the focusing point of the laser beam is positioned inside the first wafer, and the first wafer is moved relative to the focusing point in the horizontal direction while irradiating the laser beam. After forming a modified surface inside the wafer, a part of the first wafer is separated from the laminated wafer with the modified surface as a boundary.

JP-A-2015-32690

The technique according to the present disclosure appropriately separates the object to be processed into a first separated body and a second separated body.

One aspect of the present disclosure is a separation device that separates a processing target body on which a modified layer is formed by irradiation with laser light into a first separation body and a second separation body, wherein the first separation body is used. It has a first holding portion for holding, a second holding portion for holding the second separated body, and a moving portion for relatively moving the first holding portion and the second holding portion. Then, the second holding portion holds the inside of the outer end portion of the second separating body.

According to the present disclosure, the processed object can be appropriately separated into a first separated body and a second separated body.

It is a top view which shows the outline of the structure of the wafer processing system which concerns on this embodiment schematically. It is a side view which shows typically the outline of the structure of the wafer processing system which concerns on this Embodiment. It is a side view which shows the outline of the structure of a polymerization wafer. It is a side view which shows the outline of the structure of a part of a polymerization wafer. It is a top view which shows the outline of the structure of the separation device. It is a top view which shows the outline of the structure of the separation processing part. It is a side view which shows the outline of the structure of the separation processing part. It is a side view which shows the outline of the structure of the separation processing part and the transport part. It is a flow chart which shows the main process of a wafer processing. It is explanatory drawing of the main process of a wafer processing. It is explanatory drawing which shows the state of modifying the outer peripheral part of the device layer of a processing wafer. It is explanatory drawing which shows the state of forming the peripheral modification layer on the processed wafer. It is explanatory drawing which shows the appearance which the peripheral modification layer was formed on the processed wafer. It is explanatory drawing which shows the state of forming the internal surface modification layer on the processed wafer. It is explanatory drawing which shows the state of forming the internal surface modification layer on the processed wafer. It is explanatory drawing of the main process of a separation process. It is explanatory drawing which shows how the 2nd holding part holds a processed wafer. It is explanatory drawing of the main process of the carry-out processing of the 2nd separation wafer. It is explanatory drawing which shows the positional relationship of the transfer pad of a transfer part, and the transfer arm of a wafer transfer device. It is explanatory drawing of the main process of the carry-out processing of the 1st separation wafer. It is explanatory drawing which shows how the 2nd holding part holds a processed wafer in another embodiment. It is a side view which shows the outline of the structure of the separation processing part which concerns on other embodiment. It is a side view which shows the outline of the structure of the separation processing part which concerns on other embodiment. It is a side view which shows the outline of the structure of the separation processing part which concerns on other embodiment. It is explanatory drawing of the main process of the separation process which concerns on other embodiment.

In the process of manufacturing a semiconductor device, the wafer is thinned with respect to a semiconductor wafer (hereinafter referred to as a wafer) in which a plurality of devices are formed on the surface. There are various methods for thinning the wafer. For example, a method of grinding the back surface of the wafer or a modified surface (modified layer) by irradiating the inside of the wafer with a laser beam (laser beam) as disclosed in Patent Document 1. ) Is formed, and the wafer is separated from the modified layer as a base point.

Here, when the wafer is separated from the modified layer as a base point as described above, for example, both sides of the wafer are sucked and held by chucks (vacuum chucks) to separate the chucks. Then, a force acts on the wafer in the direction in which the chucks are separated, and the wafers are separated.

However, the wafer irradiated with the laser beam may be partially peeled off or warped. In such a case, it becomes difficult to suck and hold the wafer with the chuck. In addition, the wafer may be damaged by the load when the wafer is sucked by the chuck. Therefore, there is room for improvement in the conventional wafer separation process.

The technique according to the present disclosure appropriately separates the objects to be processed. Hereinafter, a wafer processing system including the separation device according to the present embodiment and a wafer processing method will be described with reference to the drawings. In the present specification and the drawings, elements having substantially the same functional configuration are designated by the same reference numerals to omit duplicate description.

First, the configuration of the wafer processing system according to the present embodiment will be described. FIG. 1 is a plan view schematically showing an outline of the configuration of the wafer processing system 1. FIG. 2 is a side view schematically showing an outline of the configuration of the wafer processing system 1.

In the wafer processing system 1, as shown in FIGS. 3 and 4, processing is performed on the polymerized wafer T in which the processing wafer W as the processing target and the support wafer S are joined. Then, in the wafer processing system 1, the processing wafer W is thinned while removing the peripheral portion We of the processing wafer W. Hereinafter, in the processed wafer W, the surface bonded to the support wafer S is referred to as a front surface Wa, and the 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 processed wafer W is referred to as a front surface Sa, and the surface opposite to the front surface Sa is referred to as a back surface Sb.

The processed wafer W is a semiconductor wafer such as a silicon substrate, and a device layer D including a plurality of devices is formed on the surface Wa. Further, an oxide film Fw, for example, a SiO ₂ film (TEOS film) is further formed on the device layer D. The peripheral edge portion We of the processed wafer W is chamfered, and the cross section of the peripheral edge portion We becomes thinner toward the tip thereof. Further, the peripheral edge portion We is a portion that is removed in the edge trim, and is, for example, in the range of 1 mm to 5 mm in the radial direction from the outer end portion of the processed wafer W. The edge trim is a process for preventing the peripheral edge portion We of the processed wafer W from becoming a sharply pointed shape (so-called knife edge shape) after the processed wafer W is separated as described later.

In the wafer processing system 1 of the present embodiment, the processing wafer W in the polymerization wafer T is separated. In the following description, the separated processed wafer W on the front surface Wa side is referred to as the first separated wafer W1 as the first separator, and the separated processed wafer W on the back surface Wb side is referred to as the second separator. The second separation wafer W2 of the above. The first separation wafer W1 has a device layer D and is commercialized. The second separation wafer W2 is reused. In the following description, the first separation wafer W1 indicates a processed wafer W in a state of being supported by the support wafer S, and may be referred to as a first separation wafer W1 including the support wafer S. Further, the surface separated on the first separation wafer W1 is referred to as a separation surface W1a, and the surface separated on the second separation wafer W2 is referred to as a separation surface W2a.

The support wafer S is a wafer that supports the processed wafer W, and is, for example, a silicon wafer. An oxide film Fs, for example, a SiO ₂ film (TEOS film) is formed on the surface Sa of the support wafer S. When a plurality of devices on the surface Sa of the support wafer S are formed, a device layer (not shown) is formed on the surface Sa in the same manner as the processing wafer W.

In FIG. 3, the device layer D and the oxide films Fw and Fs are not shown in order to avoid the complexity of the illustration. Similarly, in other drawings used in the following description, the illustration of the device layer D and the oxide films Fw and Fs may be omitted.

As shown in FIG. 1, the wafer processing system 1 has a configuration in which the loading / unloading station 2 and the processing station 3 are integrally connected. The carry-in / out station 2 and the processing station 3 are arranged side by side from the negative X-axis side to the control direction side. In the carry-in / out station 2, for example, cassettes Ct, Cw1 and Cw2 capable of accommodating a plurality of polymerization wafers T, a plurality of first separation wafers W1 and a plurality of second separation wafers W2 are carried in / out from the outside. Is done. The processing station 3 is provided with various processing devices for performing desired processing on the polymerization wafer T, the separation wafers W1 and W2.

In the present embodiment, the cassette Ct and the cassette Cw1 are provided separately, but the same cassette may be used. That is, the cassette accommodating the polymerized wafer T before processing and the first separation wafer W1 cassette after processing may be used in common.

The loading / unloading station 2 is provided with a cassette mounting stand 10. In the illustrated example, a plurality of cassettes, for example, three cassettes Ct, Cw1 and Cw2 can be freely mounted in a row in the Y-axis direction on the cassette mounting table 10. The number of cassettes Ct, Cw1 and Cw2 mounted on the cassette mounting table 10 is not limited to this embodiment and can be arbitrarily determined.

The loading / unloading station 2 is provided with a wafer transfer region 20 adjacent to the cassette mounting table 10 on the X-axis positive direction side of the cassette mounting table 10. The wafer transfer region 20 is provided with a wafer transfer device 22 that is movable on a transfer path 21 extending in the Y-axis direction. The wafer transfer device 22 has two transfer arms 23, 23 that hold and transfer the polymerized wafer T and the separated wafers W1 and W2. Each transport arm 23 is configured to be movable in the horizontal direction, the vertical direction, the horizontal axis, and the vertical axis. The configuration of the transport arm 23 is not limited to this embodiment, and any configuration can be adopted. The wafer transfer device 22 is configured to be able to transfer the polymerization wafer T and the separation wafers W1 and W2 to the cassettes Ct, Cw1, Cw2 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 delivering the polymerized wafer T, the separated wafers W1 and W2 on the X-axis positive direction side of the wafer transport region 20 adjacent to the wafer transport region 20. There is.

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 negative direction side of the X axis (the loading / unloading station 2 side) to the positive 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 apparatus 40 is provided in two rows in the X-axis direction and three stages in the vertical direction on the loading / unloading station 2 side of the first processing block G1. That is, in this embodiment, six etching devices 40 are provided. The cleaning device 41 is provided in three stages in the vertical direction on the X-axis positive direction side of the etching device 40. The wafer transfer device 50 is arranged on the Y-axis positive direction side of the etching device 40 and the cleaning device 41. The number and arrangement of the etching device 40, the cleaning device 41, and the wafer transfer device 50 are not limited to this.

The etching apparatus 40 etches the separation surface W1a of the first separation wafer W1 or the separation surface W2a of the second separation wafer W2. For example, etching (chemical solution) is supplied to the separation surface W1a or the separation surface W2a, and the separation surface W1a or the separation surface W2a is wet-etched. As the etching solution, for example, HF, HNO ₃ , H ₃ PO ₄ , TMAH, Choline, KOH and the like are used.

The cleaning device 41 cleans the separation surface W1a of the first separation wafer W1 or the separation surface W2a of the second separation wafer W2. For example, the brush is brought into contact with the separation surface W1a or the separation surface W2a, and the separation surface W1a or the separation surface W2a is scrubbed. A pressurized cleaning liquid may be used for cleaning the separation surface W1a or the separation surface W2a. Further, when cleaning the separation surface W1a or the separation surface W2a, the back surface Sb or the back surface Wb on the opposite side may also be cleaned.

The wafer transfer device 50 has two transfer arms 51 and 51 that hold and transfer the polymerized wafer T and the separated wafers W1 and W2. Each transport arm 51 is configured to be movable in the horizontal direction, the vertical direction, the horizontal axis, and the vertical axis. The configuration of the transport arm 51 is not limited to this embodiment, and any configuration can be adopted. The wafer transfer device 50 is movable on a transfer path 52 extending in the X-axis direction. The wafer transfer device 50 is configured to be able to transfer the polymerization wafer T, the separation wafers W1 and W2 to each of the processing devices of the transition device 30, the first processing block G1 and the second processing block G2. ..

The second processing block G2 is provided with an alignment device 60, a separation device 61, and a wafer transfer device 70. The alignment device 60 and the separation device 61 are provided so as to be laminated vertically from above to below. The wafer transfer device 70 is arranged on the Y-axis negative direction side of the alignment device 60 and the separation device 61. The number and arrangement of the alignment device 60, the separation device 61, and the wafer transfer device 70 are not limited to this.

The alignment device 60 adjusts the horizontal orientation and the center position of the processed wafer W before laser processing. For example, while rotating the processing wafer W held by the spin chuck (not shown), the position of the notch portion of the processing wafer W is detected by the detection unit (not shown) to adjust the position of the notch portion. The horizontal orientation and center position of the processing wafer W are adjusted.

The separation device 61 separates the processed wafer W into the first separation wafer W1 and the second separation wafer W2 based on the peripheral reforming layer and the internal surface reforming layer formed by the internal reforming device 81 described later. .. The specific configuration of the separation device 61 will be described later.

The wafer transfer device 70 has two transfer arms 71 and 71 that hold and transfer the polymerized wafer T and the separated wafers W1 and W2. Each transport arm 71 is configured to be movable in the horizontal direction, the vertical direction, the horizontal axis, and the vertical axis. The configuration of the transport arm 71 is not limited to this embodiment, and any configuration can be adopted. Further, the number of transfer arms 71 in the wafer transfer device 70 is not limited to this embodiment, and any number of transfer arms 71 can be provided, for example, one may be provided. Then, the polymerization wafer T and the separation wafers W1 and W2 can be conveyed to each processing apparatus of the first processing block G1 to the third processing block G3.

The surface reforming device 80 and the internal reforming device 81 are provided in the third processing block G3. The surface reforming device 80 and the internal reforming device 81 are provided so as to be laminated vertically from above to below. The number and arrangement of the surface reformer 80 and the internal reformer 81 are not limited to this.

The surface modification device 80 irradiates the outer peripheral portion of the device layer D of the processing wafer W with laser light to modify the outer peripheral portion. As the laser light, a laser light (CO ₂ laser) having a wavelength that is transparent to the processed wafer W is used.

The internal reformer 81 irradiates the inside of the processed wafer W with a laser beam to form a peripheral reforming layer and an internal surface reforming layer. As the laser light, a laser light (YAG laser) having a wavelength that is transparent to the processed wafer W is used. The peripheral modification layer and the internal surface modification layer serve as base points for separating the processed wafer W into the separation surface W1a of the first separation wafer W1 and the second separation wafer W2.

The wafer processing system 1 described above is provided with a control device 90. The control device 90 is, for example, a computer equipped with a CPU, a memory, or the like, and has a program storage unit (not shown). The program storage unit stores a program for controlling the processing of the polymerization wafer T, the separation wafers W1 and W2 in the wafer processing system 1. Further, the program storage unit also stores a program for controlling the operation of the drive system of the above-mentioned various processing devices and transfer devices to realize the wafer processing described later in the wafer processing system 1. The program may be recorded on a computer-readable storage medium H and may be installed on the control device 90 from the storage medium H.

Next, the separation device 61 described above will be described. FIG. 5 is a plan view showing an outline of the configuration of the separation device 61.

The separation device 61 has a processing container 100 whose inside can be closed. A carry-in outlet (not shown) for the polymerization wafer T and the separation wafers W1 and W2 is formed on the side surface of the processing container 100, and an opening / closing shutter (not shown) is provided at the carry-in outlet.

A separation processing unit 110, a pad cleaning unit 111, and a transport unit 112 are provided inside the separation device 61. The separation processing unit 110 separates the processing wafer W into the first separation wafer W1 and the second separation wafer W2. The pad cleaning unit 111 cleans the transport pad 192, which will be described later, of the transport unit 112. The transfer unit 112 transfers the second separation wafer W2 between the separation processing unit 110 and the wafer transfer device 70.

FIG. 6 is a plan view showing an outline of the configuration of the separation processing unit 110. FIG. 7 is a side view showing an outline of the configuration of the separation processing unit 110. FIG. 8 is a side view showing an outline of the configuration of the separation processing unit 110 and the transport unit 112.

The separation processing unit 110 includes a first holding unit 120, a second holding unit 121, a load cell 130, a stage 140, a support pin 150, a blade 160, a separation surface cleaning unit 170, and a delivery unit 180.

The first holding portion 120 is provided below the second holding portion 121. The first holding portion 120 and the second holding portion 121 hold the polymerized wafer T before the processed wafer W is separated in a state where the processed wafer W faces upward. That is, the first holding portion 120 sucks and holds the first separation wafer W1 (support wafer S), and the second holding portion 121 sucks and holds the second separation wafer W2.

The first holding portion 120 is a chuck having a substantially disk shape, and communicates with a suction device (not shown) such as a vacuum pump. The first holding portion 120 has a diameter larger than that of the first separation wafer W1, and sucks and holds the first separation wafer W1 on the entire upper surface thereof.

The second holding portion 121 is a chuck having a substantially disk shape, and communicates with a suction device (not shown) such as a vacuum pump. The second holding portion 121 has a diameter smaller than that of the second separation wafer W2, and specifically, as will be described later, has a diameter smaller than that of the peripheral modification layer formed on the processed wafer W. Then, the second holding portion 121 adsorbs and holds the inside of the peripheral modification layer of the second separation wafer W2 on the lower surface thereof.

The lower surface of the first holding portion 120 is supported by the stage 140 via a load cell 130 as a load measuring portion. The load cell 130 detects a force (load) acting on the first holding portion 120. The load cells 130 are a plurality of load cells 130 at equal intervals on the concentric circles of the first holding portion 120 at the outer peripheral portion of the first holding portion 120. For example, three are provided. The number and arrangement of the load cells 130 are not limited thereto. For example, the load cell 130 may be provided at the center of the first holding portion 120.

The load cell 130 measures the load when separating the processed wafer W as described later, but may be used when setting up the separation device 61. For example, the first holding portion 120 and the second holding portion 121 are brought into contact with each other in a state where the first holding portion 120 and the second holding portion 121 do not hold the polymerization wafer T (processed wafer W, support wafer S). The position where the load is measured by the load cell 130 is set as the reference position (zero point position).

The stage 140 is supported by the support member 141. The stage 140 (first holding portion 120) is configured to be vertically elevated by an elevating mechanism 143 along a rail 142 extending in the vertical direction. The elevating mechanism 143 includes, for example, a motor (not shown), a ball screw (not shown), a guide (not shown), and the like. In the present embodiment, the rail 142 and the elevating mechanism 143 correspond to the moving portion in the present disclosure.

A support pin 150 extending in the vertical direction is provided on the bottom surface of the separation processing unit 110. Three support pins 150 are provided, for example, by inserting the through holes 120a of the first holding portion 120 and the through holes 140a of the stage 140. When the stage 140 is raised, the tip of the support pin 150 projects upward from the upper surface of the first holding portion 120, and the support pin 150 supports the first separation wafer W1 (support wafer S). .. Further, when the stage 140 is lowered, the tip end portion of the support pin 150 is located below the upper surface of the first holding portion 120.

In the present embodiment, the first separation wafer W1 is delivered to the support pin 150 by moving the stage 140 up and down, but the support pin 150 may move up and down. Further, instead of the support pin 150, a pad (not shown) that attracts and holds the first separation wafer W1 may be used.

A blade 160 as an insertion portion inserted between the first holding portion 120 and the second holding portion 121 into the polymerization wafer T (the interface between the processed wafer W and the support wafer S as described in detail later). Is provided. A plurality, for example, three blades 160 are provided on the side of the second holding portion 121 on the concentric circles of the second holding portion 121 at equal intervals. Further, the blade 160 is moved in the horizontal direction and the vertical direction by a moving mechanism (not shown), and is configured to be able to move back and forth on the outer surface of the polymerization wafer T held by the first holding portion 120 and the second holding portion 121. Has been done. The number and arrangement of the blades 160 are not limited to this. Further, the method of moving the blade 160 is also arbitrary. Further, for example, when the first separation wafer W1 and the second separation wafer W2 can be separated without inserting the blade 160, the blade 160 may be omitted.

A separation surface cleaning unit 170 for cleaning the separation surface W1a of the first separation wafer W1 and the separation surface W2a of the second separation wafer W2 is provided between the first holding unit 120 and the second holding unit 121. ing. The separation surface cleaning unit 170 has a cleaning nozzle 171 and a suction nozzle 172. The cleaning nozzle 171 supplies, for example, air as a cleaning fluid. The suction nozzle 172 sucks the air supplied from the cleaning nozzle 171. The cleaning nozzle 171 and the suction nozzle 172 move in the horizontal direction and the vertical direction by a moving mechanism (not shown), respectively, and are configured to be able to move forward and backward with respect to the space between the first holding portion 120 and the second holding portion 121, respectively. Has been done.

In the present embodiment, air is used as the cleaning fluid, but the present invention is not limited to this, and for example, a cleaning liquid such as pure water or two fluids may be used. Further, when the separation surfaces W1a and W2a are cleaned with the cleaning liquid, the first holding portion 120 and the second holding portion 121 may be rotated to shake off the cleaning liquid remaining after the cleaning and dry it.

Between the first holding portion 120 and the second holding portion 121, a delivery portion 180 for delivering the second separation wafer W2 from the second holding portion 121 to the transport portion 112 is provided. At the upper end of the delivery portion 180, a tapered portion 180a whose diameter decreases in a tapered shape from the upper end to the lower side is formed. At the lower end of the delivery portion 180, a step portion 180b protruding inward in the radial direction is formed. The inner diameter of the upper end of the tapered portion 180a is larger than the diameter of the second separation wafer W2, and the inner diameter of the lower end of the tapered portion 180a is substantially the same as the diameter of the second separation wafer W2. Further, the inner diameter of the step portion 180b is smaller than the diameter of the second separation wafer W2. Then, the second separation wafer W2 is dropped from the second holding portion 121, guided by the tapered portion 180a, and placed on the step portion 180b. In this way, the second separation wafer W2 is held by the delivery portion 180 while the center position is adjusted (centered) by the delivery portion 180. The delivery portion 180 is moved in the horizontal direction and the vertical direction by a moving mechanism (not shown), and is configured to be able to move forward and backward with respect to the space between the first holding portion 120 and the second holding portion 121. ..

The transport unit 112 is an articulated robot provided with a plurality of, for example, two arms 190 and 191. Of the two arms 190 and 191, the first arm 190 at the tip is attached with a transport pad 192 that attracts and holds the central portion of the second separation wafer W2. Further, the second arm 191 at the base end is attached to the moving mechanism 193. By the moving mechanism 193, the arms 190 and 191 and the transport pad 192 are configured to be movable in the horizontal and vertical directions, and the transport pad 192 is configured to be rotatable around the axes of the arms 190 and 191. In the present embodiment, one transport pad 192 is provided for the first arm 190, but two transport pads 192 may be provided on both sides of the first arm 190. Further, in the present embodiment, the delivery unit 180 and the transport unit 112 correspond to the rotating unit in the present disclosure. Further, in the present embodiment, the transport unit 112 is an articulated robot, but the present invention is not limited to this, and any configuration can be adopted.

The pad cleaning unit 111 cleans the transport pad 192 of the transport unit 112. The pad cleaning unit 111 has a cleaning tool such as a stone cleaning tool (not shown) or a brush cleaning tool (not shown). Then, the cleaning tool is brought into contact with the suction surface of the transport pad 192 to clean the transport pad 192. The cleaning method of the transport pad 192 in the pad cleaning unit 111 is not limited to this. For example, the transport pad 192 may be cleaned by supplying air, a cleaning liquid, two fluids, or the like to the suction surface of the transport pad 192.

Next, the wafer processing performed by using the wafer processing system 1 configured as described above will be described. FIG. 9 is a flow chart showing a main process of wafer processing. FIG. 10 is an explanatory diagram of a main process of wafer processing. In the present embodiment, the processing wafer W and the support wafer S are bonded to each other in an external bonding device (not shown) of the wafer processing system 1 to form a polymerized wafer T in advance.

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

Next, the wafer transfer device 22 takes out the polymerized wafer T in the cassette Ct and transfers it to the transition device 30. Subsequently, the wafer transfer device 50 takes out the polymerized wafer T of the transition device 30 and transfers it to the alignment device 60. In the alignment device 60, the horizontal orientation and the center position of the processed wafer W on the polymerized wafer T are adjusted (step A1 in FIG. 9).

Next, the polymerized wafer T is transferred to the surface modification device 80 by the wafer transfer device 70. In the surface modifier 80, as shown in FIG. 11, the laser head (not shown) irradiates the outer peripheral portion De of the device layer D with the laser beam L1 to modify the outer peripheral portion De (step A2 in FIG. 9). ). More specifically, the interface between the processing wafer W and the device layer D is modified. In the present embodiment, the interface side of the outer peripheral portion De with the processed wafer W is modified, but the entire outer peripheral portion De of the device layer D may be modified, or the oxide film Fw may be modified. ..

When the outer peripheral portion De is modified in step A2, the bonding strength decreases, and at the interface between the processed wafer W and the device layer D, the bonding region Aa to which the oxide film Fw and the oxide film Fs are bonded and the bonding region Aa in the radial direction An unbonded region Ab, which is an outer region, is formed. In the processing wafer W separation step described later, the peripheral edge We is removed from the first separated wafer W1 as an edge trim, and the presence of the unbonded region Ab in this way appropriately removes the peripheral edge We. it can. The outer end portion of the joint region Aa is located slightly radially outward from the inner end portion of the peripheral edge portion We to be removed.

Next, the polymerized wafer T is transferred to the internal reformer 81 by the wafer transfer device 70. In the internal reformer 81, the peripheral reforming layer M1 is formed inside the processed wafer W as shown in FIG. 10B (step A3 in FIG. 9), and further, as shown in FIG. 10C, the internal surface is formed. The reformed layer M2 is formed (step A4 in FIG. 9). The peripheral edge modification layer M1 serves as a base point when the peripheral edge portion We is removed in the edge trim. The internal surface modification layer M2 serves as a base point for separating and thinning the processed wafer W.

The internal reformer 81 first irradiates the laser beam L2 (peripheral laser beam L2) from the laser head (not shown) as shown in FIGS. 12 and 13, and then irradiates the peripheral portion We and the central portion of the processing wafer W. A peripheral modification layer M1 is formed at the boundary of Wc (step A3 in FIG. 9). Specifically, for example, the annular peripheral modification layer M1 is formed by irradiating the laser beam L2 while rotating the processed wafer W. Inside the processed wafer W, the crack C1 from the peripheral modification layer M1 extends only to the front surface Wa and does not reach the back surface Wb.

Next, as shown in FIGS. 14 and 15, laser light L3 (internal surface laser light L3) is irradiated from a laser head (not shown) to form an internal surface modification layer M2 along the surface direction. (Step A4 in FIG. 9). Specifically, for example, the laser beam L3 is irradiated while rotating the processing wafer W, and the laser beam L3 is irradiated while rotating the processing wafer W once (360 degrees) to form an annular internal surface modification layer M2. After forming, the laser head is moved inward in the radial direction of the processing wafer W. The formation of the annular inner surface modification layer M2 and the movement of the laser head inward in the radial direction are repeatedly performed to form the inner surface modification layer M2 in the surface direction. Inside the processed wafer W, cracks C2 grow in the plane direction from the internal surface modification layer M2. The crack C2 grows only inside the peripheral modification layer M1.

In the present embodiment, after the outer peripheral portion De of the device layer D is modified in step A2, the peripheral modification layer M1 and the inner surface modification layer M2 are formed in steps A3 and A4, but the order may be reversed. good. That is, after forming the peripheral modification layer M1 and the inner surface modification layer M2, the outer peripheral De may be modified.

Next, the polymerized wafer T is transferred to the separation device 61 by the wafer transfer device 70. In the separation device 61, as shown in FIG. 10D, the processed wafer W is separated into the first separation wafer W1 and the second separation wafer W2 with the peripheral modification layer M1 and the inner surface modification layer M2 as base points. (Step A5 in FIG. 9). At this time, the peripheral portion We is also removed from the first separation wafer W1.

In the separation device 61, first, the polymerized wafer T is delivered from the transfer arm 71 of the wafer transfer device 70 to the support pin 150. Subsequently, the first holding portion 120 is raised via the stage 140, and the polymerized wafer T is transferred from the support pin 150 to the first holding portion 120 and is adsorbed and held. Further, the first holding portion 120 is raised, and as shown in FIG. 16A, the support wafer S (second separation wafer W2 side) is sucked and held by the first holding portion 120 of the polymerized wafer T. At the same time, the processing wafer W (first separation wafer W1 side) is sucked and held by the second holding portion 121.

At this time, as shown in FIG. 17, the second holding portion 121 adsorbs and holds the inside of the peripheral modification layer M1 formed on the processed wafer W. In the present embodiment, the outer end portion of the second holding portion 121 is maintained inside the peripheral modification layer M1. That is, the diameter of the second holding portion 121 is smaller than the diameter of the peripheral modification layer M1. Here, in the processed wafer W irradiated with the laser beams L2 and L3, the peripheral edge portion We may be warped. In such a case, it becomes difficult for the second holding portion 121 to suck and hold the processed wafer W on the entire surface. Further, the processing wafer W may be damaged by the load when the processing wafer W is adsorbed by the second holding portion 121. In particular, in the present embodiment, since a step is formed on the second separation wafer W2 by the peripheral modification layer M1 and the internal surface modification layer M2, this step portion may be damaged. In this respect, since the inside of the peripheral edge modifying layer M1 (inside of the peripheral edge We) where the warp of the second holding portion 121 is generated is adsorbed and held as in the present embodiment, the processed wafer W can be appropriately held. It can also suppress damage to the processed wafer W. Even if the outer end portion of the second holding portion 121, that is, the outer end portion of the second holding portion 121 with respect to the processed wafer W held by the second holding portion 121 coincides with the peripheral modification layer M1. Good.

Further, when the polymerized wafer T is adsorbed and held by the first holding portion 120 and the second holding portion 121 in this way, the polymerized wafer T is pressed and a load acts on the polymerized wafer T. In the present embodiment, the load cell 130 is used to measure and monitor the load applied to the first holding portion 120 and the second holding portion 121. Then, the load applied to the polymerized wafer T can be kept within an allowable range, and the polymerized wafer T can be prevented from being damaged. Further, since a plurality of load cells 130 are provided, the load distribution in the wafer plane can be measured, and it can be confirmed whether or not the processed wafer W is uniformly pressed in the plane. As described above, the reference position (zero point position) of the first holding portion 120 is determined at the time of setup, and the height when raising the first holding portion 120 is controlled, but the load cell 130 The height of the first holding portion 120 may be controlled by using the load measurement result of.

Further, pressure sensors (not shown) provided in each of the first holding portion 120 and the second holding portion 121 measure and monitor the pressure. Then, it can be confirmed whether or not the polymerized wafer T can be appropriately adsorbed and held by each of the first holding portion 120 and the second holding portion 121.

Next, as shown in FIG. 16B, the blade 160 is inserted at the interface between the processing wafer W and the support wafer S, and the first separation wafer is set with the peripheral modification layer M1 and the inner surface modification layer M2 as base points. The W1 and the second separation wafer W2 are trimmed.

Next, as shown in FIG. 16C, the first holding portion 120 is lowered and held by the first separation wafer W1 held by the first holding portion 120 and the second holding portion 121. The second separation wafer W2 is separated.

When the processed wafer W is separated in this way, the load cell 130 is used to measure and monitor the load applied to the first holding portion 120 and the second holding portion 121. Then, the load applied to the processing wafer W can be kept within an allowable range, and the processing wafer W can be suppressed from being damaged. Further, since a plurality of load cells 130 are provided, the load distribution in the wafer plane can be measured, and it can be confirmed whether or not the processed wafer W can be uniformly separated in the plane.

Further, pressure sensors (not shown) provided in each of the first holding portion 120 and the second holding portion 121 measure and monitor the pressure. Then, each of the first holding portion 120 and the second holding portion 121 detects the presence or absence of the first separation wafer W1 and the second separation wafer W2, and separates the first separation wafer W1 and the second separation wafer W1. It can be confirmed whether or not the wafer W2 is separated.

Next, as shown in FIG. 16D, the cleaning nozzle 171 and the suction nozzle 172 are moved and arranged between the first holding portion 120 and the second holding portion 121. Subsequently, air is supplied from the cleaning nozzle 171 and air is sucked from the suction nozzle 172. Then, an air flow from the cleaning nozzle 171 to the suction nozzle 172 is formed between the first separation wafer W1 and the second separation wafer W2. With this air, dust and debris (particles) adhering to the separation surfaces W1a and W2a are removed, and the separation surfaces W1a and W2a are washed (step A6 in FIG. 9).

When cleaning the separation surfaces W1a and W2a in step A6, it is preferable to make the space between the separation surfaces W1a and W2a as small as possible. In such a case, the flow velocity of the air flowing through the space can be increased, and the space can be filled with air. Therefore, the separation surfaces W1a and W2a can be cleaned more efficiently.

Next, the separated first separation wafer W1 and the second separation wafer W2 are carried out from the separation device 61. As described above, the separation surfaces W1a and W2a are washed in step A6, but in the present embodiment, in order to more reliably avoid contamination in the apparatus, the first separation wafer without holding the separation surfaces W1a and W2a. The W1 and the second separation wafer W2 are conveyed.

FIG. 18 is an explanatory diagram showing a step of carrying out the second separation wafer W2 from the separation device 61. First, as shown in FIG. 18A, the delivery portion 180 is moved between the first holding portion 120 and the second holding portion 121 and arranged below the second separation wafer W2. Subsequently, the suction holding of the second separated wafer W2 by the second holding portion 121 is stopped, and the second separated wafer W2 is delivered from the second holding portion 121 to the delivery portion 180 (step A7 in FIG. 9). ).

Next, as shown in FIG. 18B, after lowering the delivery unit 180 holding the second separation wafer W2, the transfer pad 192 of the transfer unit 112 is between the second holding unit 121 and the delivery unit 180. To move. Then, the transfer pad 192 sucks and holds the central portion of the back surface Wb of the second separation wafer W2. After that, as shown in FIG. 18C, the transport pad 192 is retracted from below the second holding portion 121, and further, as shown in FIG. 18D, the transport pad 192 is used to retract the front and back surfaces of the second separation wafer W2. Is inverted (step A8 in FIG. 9). That is, the separation surface W2a of the second separation wafer W2 is directed upward.

Next, as shown in FIG. 18D, the transfer arm 71 of the wafer transfer device 70 is moved below the transfer pad 192. After that, as shown in FIG. 18E, the transfer arm 71 is raised, and the second separation wafer W2 is transferred from the transfer pad 192 to the transfer arm 71 (step A9 in FIG. 9). At this time, the transfer pad 192 may be lowered to transfer the second separation wafer W2 from the transfer pad 192 to the transfer arm 71. In this way, the second separation wafer W2 is carried out from the separation device 61 by the wafer transfer device 70.

Here, as shown in FIG. 19, the transport arm 71 has a fork shape branched from the base end portion 71a to two tip portions 72b and 72b. A suction pad 72 for sucking and holding the second separation wafer W2 is provided on each of the base end portion 71a and the tip portions 72b and 72b. Then, in the present embodiment, the transport pad 192 and the first arm 190 are accommodated between the two tip portions 72b and 72b in a plan view. Therefore, when the second separation wafer W2 is delivered in step A9, the transfer unit 112 and the transfer arm 71 do not interfere with each other.

In the present embodiment, in step A9, the second separation wafer W2 is directly delivered from the transfer pad 192 to the transfer arm 71. For example, the second separation wafer W2 is directly delivered from the transfer pad 192 to the standby unit (not shown). After the W2 is once placed, the transfer arm 71 may receive it. However, if the second separation wafer W2 is directly delivered from the transfer pad 192 to the transfer arm 71, the deviation of the second separation wafer W2 can be suppressed.

FIG. 20 is an explanatory diagram showing a process of carrying out the first separation wafer W1 from the separation device 61. First, as shown in FIG. 20A, the first holding portion 120 is lowered, and the first separation wafer W1 is delivered from the first holding portion 120 to the support pin 150 (FIG. 9 step A10).

Next, as shown in FIG. 20B, the transfer arm 71 of the wafer transfer device 70 is moved below the first separation wafer W1. After that, as shown in FIG. 20C, the transfer arm 71 is raised, and the first separation wafer W1 is delivered from the support pin 150 to the transfer arm 71 (step A11 in FIG. 9). In this way, the first separation wafer W1 is carried out from the separation device 61 by the wafer transfer device 70.

Next, subsequent processing is performed on the second separation wafer W2 and the first separation wafer W1 carried out from the separation device 61 as described above.

That is, the second separated wafer W2 is transferred to the cleaning device 41 by the wafer transfer device 70. In the cleaning device 41, the separation surface W2a of the second separation wafer W2 is scrub-cleaned as shown in FIG. 10 (e) (step A12 in FIG. 9).

In step A12, while the second separation wafer W2 is rotationally held by the spin chuck (not shown), a scrub cleaning tool 200 such as a brush is brought into contact with the separation surface W2a from above, and the scrub cleaning tool 200 is brought into contact with the separation surface W2a. For example, pure water is supplied from. Then, the separation surface W2a is washed, and particles are removed from the separation surface W2a. Then, after the scrub cleaning tool 200 is retracted, the second separation wafer W2 is further rotated to spin-dry the separation surface W2a. In step A12, the back surface Wb of the second separation wafer W2 can also be cleaned to further purify the second separation wafer W2.

Next, the second separated wafer W2 is transferred to the etching device 40 by the wafer transfer device 50. In the etching apparatus 40, as shown in FIG. 10 (f), the separation surface W2a of the second separation wafer W2 is wet-etched by the etching solution E (step A13 in FIG. 9).

In step A13, in a state where the second separation wafer W2 is rotationally held by the spin chuck (not shown), the etching solution is applied to the central portion of the separation surface W2a from the nozzle 210 arranged above the second separation wafer W2. Supply E. The separation surface W2a is etched by this etching solution E, and the peripheral surface modification layer M1 and the internal surface modification layer M2 remaining on the separation surface W2a are removed. Further, since the peripheral modification layer M1 and the internal surface modification layer M2 remain in the scrub cleaning in step A5, particles may be generated again in this state, but this is caused by the etching in this step A13. Particles are also removed.

In step A13, after etching the separation surface W2a in this way, the supply of the etching solution E from the nozzle 210 is stopped, the separation surface W2a is further washed with pure water, and then the second separation wafer W2 is used. Further rotation is performed to spin dry the separation surface W2a.

After that, the second separated wafer W2 that has been subjected to all the processing is conveyed to the transition device 30 by the wafer transfer device 50, and further transferred to the cassette Cw2 of the cassette mounting table 10 by the wafer transfer device 22.

On the other hand, the same processing is performed on the first separation wafer W1. That is, the first separated wafer W1 is transported to the cleaning device 41 by the wafer transfer device 70. In the cleaning device 41, as shown in FIG. 10 (g), the separation surface W1a of the first separation wafer W1 is scrubbed (step A14 in FIG. 9). In step A14, as in step A12, pure water is supplied with the scrub cleaning tool 200 in contact with the separation surface W1a from above to clean the separation surface W1a. Further, the back surface Sb on the opposite side of the separation surface W1a may also be cleaned.

Next, the first separated wafer W1 is transferred to the etching device 40 by the wafer transfer device 50. In the etching apparatus 40, as shown in FIG. 10 (h), the separation surface W1a of the first separation wafer W1 is wet-etched by the etching solution E (step A15 in FIG. 9). In step A15, the peripheral modification layer M1 and the internal modification layer M2 remaining on the separation surface W1a are removed. Further, in step A15, the separation surface W1a is etched so that the first separation wafer W1 is thinned to a desired thickness.

After that, the first separated wafer W1 that has been subjected to all the processing is conveyed to the transition device 30 by the wafer transfer device 50, and further transferred to the cassette Cw1 of the cassette mounting table 10 by the wafer transfer device 22. At this time, when the cassette Ct is empty, the first separation wafer W1 may be conveyed to the cassette Ct. In this way, a series of wafer processing in the wafer processing system 1 is completed.

According to the above embodiment, when the processed wafer W is separated in step A5, the second holding portion 121 is inside the peripheral modification layer M1 formed on the processed wafer W as shown in FIG. Adsorbs and holds. As described above, the peripheral portion We of the processed wafer W irradiated with the laser beams L2 and L3 may be warped. Even if the processed wafer W is in such a state, the second holding portion 121 adsorbs the inside of the peripheral modification layer M1 where warpage occurs (the inside of the peripheral edge We), so that the processed wafer W can be appropriately used. It can be held and damage to the processed wafer W can be suppressed.

In the present embodiment, the second holding portion 121 has a substantially disk shape, but the shape of the second holding portion 121 is not limited to this. The second holding portion 121 may have a structure for holding the inside of the peripheral modification layer M1. For example, as shown in FIG. 21, the second holding portion 121 has a structure in which the upper layer 122 and the lower layer 123 are laminated, and the suction surface 123a of the processing wafer W of the lower layer 123 is inside the peripheral modification layer M1. You may. That is, the outer end portion of the lower layer 123 on the processing wafer W (second separation wafer W2) side is located inside the peripheral modification layer M1. On the other hand, the outer end of the upper layer 122 opposite to the processed wafer W (second separation wafer W2) is located outside the peripheral modification layer M1 and is located outside the processed wafer W in the present embodiment. .. In the present embodiment, the second holding portion 121 is arranged above the first holding portion 120, but the arrangement of the first holding portion 120 and the second holding portion 121 may be upside down. ..

Further, in the present embodiment, as shown in FIG. 16A in step A5, when the polymerized wafer T is adsorbed and held by the first holding portion 120 and the second holding portion 121, the load cell 130 is used to hold the polymerized wafer T. The load applied to the holding portion 120 of 1 and the holding portion 121 of 2 is measured and monitored. Then, the load applied to the polymerized wafer T can be kept within an allowable range, and the polymerized wafer T can be prevented from being damaged. Further, since a plurality of load cells 130 are provided, the load distribution in the wafer plane can be measured, and it can be confirmed whether or not the processed wafer W is uniformly pressed in the plane.

Further, in the present embodiment, when the processed wafer W is separated as shown in FIG. 16C in step A5, the load applied to the first holding portion 120 and the second holding portion 121 by using the load cell 130 is used. To measure and monitor. Then, the load applied to the processing wafer W can be kept within an allowable range, and the processing wafer W can be suppressed from being damaged. Further, since a plurality of load cells 130 are provided, the load distribution in the wafer plane can be measured, and it can be confirmed whether or not the processed wafer W can be uniformly separated in the plane.

Although the processing wafer W is separated in the wafer processing system 1 as described above, the separation surface W2a side of the second separated wafer W2 to be reused outside the wafer processing system 1 is ground, and the peripheral portion W2e Is removed. Then, the separation surface W2a is washed and particles are removed from the ground second separation wafer W2, and then the separation surface W2a is further etched to remove grinding marks. Then, when the second separation wafer W2 is reused as, for example, a product wafer, the separation surface W2a is further polished (CMP). On the other hand, when the second separation wafer W2 is reused as a support wafer for supporting the product wafer, for example, it is used as it is.

Further, outside the wafer processing system 1, the separation surface W1a of the first separation wafer W1 to be commercialized is polished (CMP). In the present embodiment, since the first separation wafer W1 is etched to a desired thickness in step A15 as described above, it is only necessary to polish the separation surface W1a. However, for example, when the first separation wafer W1 does not have a desired thickness in step A8, the separation surface W1a is ground to a desired thickness outside the wafer processing system 1. After that, the separated surface W1a is cleaned, the separated surface W1a is etched, and the separated surface W1a is polished on the ground first separated wafer W1.

Further, the wafer processing system 1 of the above embodiment may be further provided with a grinding device (not shown). The grinding device may be provided adjacent to, for example, the surface reforming device 80 and the internal reforming device 81 of the third processing block G3. In such a case, for example, between steps A9 and A12, the separation surface W2a of the second separation wafer W2 is ground by the grinding device. Further, for example, between steps A11 and A14, the separation surface W1a of the first separation wafer W1 is ground to a desired thickness in the grinding apparatus. After that, the separated surface W1a in step A14 is washed and the separation surface W1a in step A15 is etched on the ground first separated wafer W1 in sequence.

In the separation device 61 of the present embodiment, the first holding portion 120 moves up and down, but the second holding portion 121 may move up and down, or the first holding portion 120 and the second holding portion 121 may move up and down. Both may go up and down.

In the separation device 61 of the above embodiment, when the processed wafer W is separated in step A5, the load cell 130 is used to measure the load applied to the first holding portion 120 and the second holding portion 121. Therefore, the operation of the first holding unit 120 and the second holding unit 121 may be controlled by using the load measurement result by the load cell 130.

For example, as shown in FIG. 22, a drive unit 250 for raising and lowering the first holding unit 120 may be provided between the load cell 130 and the stage 140. The drive unit 250 is attached to the load cell 130, and is provided with, for example, three.

In such a case, when the polymerized wafer T is adsorbed and held by the first holding portion 120 and the second holding portion 121 as shown in FIG. 16A in step A5, the stage 140 is raised to perform the first. The holding portion 120 of the above is raised to a predetermined height. At this time, the height of the first holding portion 120 may be determined by using the load measurement result of each load cell 130. After that, each driving unit 250 raises the first holding unit 120 to separate the processed wafer W. At this time, each drive unit 250 is controlled by using the load measurement result of each load cell 130. Specifically, each drive unit 250 is controlled so that the load applied to the first holding unit 120 becomes uniform. Then, the processed wafer W can be uniformly pressed in the wafer surface. As a result, it is possible to prevent the processed wafer W (polymerized wafer T) from being excessively loaded and to prevent the processed wafer W from being damaged. Further, it is also possible to control the timing at which the separation of the processed wafer W is completed by using the load measurement result of each load cell 130.

After that, when the processed wafer W is separated as shown in FIG. 16C, the load applied to the first holding portion 120 and the second holding portion 121 is measured by using the load cell 130. Then, each driving unit 250 lowers the first holding unit 120 to separate the processed wafer W. At this time, each drive unit 250 is controlled by using the load measurement result of each load cell 130. Specifically, each drive unit 250 is controlled so that the load applied to the first holding unit 120 becomes uniform. Then, the processed wafer W can be uniformly separated in the wafer surface.

Further, for example, as shown in FIG. 23, a plurality of drive units 260 for raising and lowering the second holding unit 121 may be provided on the upper surface of the second holding unit 121. For example, three drive units 260 are provided at positions corresponding to the load cells 130.

In such a case, when the processed wafer W is separated as shown in FIG. 16C in step A5, the load applied to the first holding portion 120 and the second holding portion 121 is measured by using the load cell 130. Then, each driving unit 260 raises the second holding unit 121 to separate the processed wafer W. At this time, each drive unit 260 is controlled by using the load measurement result of each load cell 130. Specifically, each drive unit 260 is controlled so that the load applied to the second holding unit 121 becomes uniform. Then, the processed wafer W can be uniformly separated in the wafer surface.

When the processing wafer W is separated by individually controlling each drive unit 260, the first separation wafer W1 and the second separation wafer W2 can be separated on the entire surface as in the present embodiment, but the separation is performed. The method is not limited to this. For example, when the processed wafer W has a portion that is easily separated, the load balance in the wafer surface of the processed wafer W may be intentionally made non-uniform, and separation may be started from the portion that is easily separated. Alternatively, for example, the peripheral edge portion We of the processed wafer W may be separated prior to the central portion Wc, and the peripheral edge portion We may be warped and separated.

In the separation device 61 of the above embodiment, as shown in FIG. 16A, the load applied to the processed wafer W when the polymerized wafer T is adsorbed and held by the first holding portion 120 and the second holding portion 121. It may have a structure that absorbs.

For example, as shown in FIG. 24, a plurality of springs 270 as elastic bodies are provided on the upper surface of the second holding portion 121. Further, a plurality of T-shaped members 271 are provided on the upper surface of the second holding portion 121. The T-shaped member 271 has a head portion 271a having a relatively large diameter and a shaft portion 271b extending downward from the head portion 271a. The spring 270 is provided at the lower end of the shaft portion 271b of the T-shaped member 271. Also. A support plate 272 is provided above the second holding portion 121 in parallel with the second holding portion 121 in a side view. The shaft portion 271b of the T-shaped member 271 is inserted into the support plate 272, and the head 271a is locked to the support plate 272.

In such a case, in step A5, first, as shown in FIG. 25A, the first holding portion 120 is raised, and the first holding portion 120 and the second holding portion 121 adsorb and hold the polymerized wafer T. At this time, the polymerization wafer T is pressed and a load acts on the second holding portion 121 side, and this load is absorbed by the spring 270. Therefore, the load applied to the processed wafer W can be reduced, and the processed wafer W can be prevented from being damaged.

Next, as shown in FIG. 25B, the first holding portion 120 is lowered and held by the first separation wafer W1 held by the first holding portion 120 and the second holding portion 121. The second separation wafer W2 is separated. At this time, the second holding portion 121 is also pulled downward, but the T-shaped member 271 is formed on the support plate 272, and the second holding portion 121 does not descend. Therefore, the processed wafer W can be appropriately separated.

The elastic spring 270 may be provided in the first holding portion 120. Specifically, for example, it may be provided between the lower surface of the first holding portion 120 and the load cell 130.

In the wafer processing system 1 of the above embodiment, when the processing wafer W is separated in step A5, the processing wafer W is separated from the peripheral surface modification layer M1 and the inner surface modification layer M2, but the processing wafer W is separated. The base point to be used is not limited to this. For example, the peripheral surface modification layer M1 may be omitted, an internal surface modification layer M2 may be formed on the entire inner surface of the processing wafer W, and the processing wafer W may be separated from the internal surface modification layer M2 as a base point.

Even in such a case, the peripheral portion We of the processed wafer W (polymerized wafer T) may be warped due to the irradiation of the laser beam. Further, the inner surface modification layer M2 also has minute irregularities, and if the inner surface modification layer M2 is pressed against the inner surface modification layer M2, internal damage may progress.

Therefore, in the present embodiment, the second holding portion 121 attracts and holds the inside of the peripheral edge portion We. Then, the processed wafer W can be appropriately held by the second holding portion 121, and damage to the processed wafer W can be suppressed. In other words, the second holding portion 121 may suck and hold the inside of the warped portion of the processed wafer W.

In the wafer processing system 1 of the above embodiment, when the processing wafer W is separated in step A5, the peripheral portion We is removed from the first separation wafer W1, but the method for separating the processing wafer W is not limited to this. For example, after removing the peripheral edge portion We, the processed wafer W may be separated into a first separation wafer W1 and a second separation wafer W2.

Further, in the wafer processing system 1 of the above embodiment, the processing wafer W is separated from the peripheral modification layer M1 and the internal surface modification layer M2 as the base points in step A5, but the base point for separating the processing wafer W is limited to this. Not done. For example, the modified layer may be formed by irradiating the entire inside of the oxide film Fw or the oxide film Fs with a laser beam, and the processed wafer W may be separated from the modified layer as a starting point. Further, for example, in the processed wafer W before processing in the wafer processing system 1, an oxide film (not shown) is formed between the processed wafer W and the device layer D, and laser light is applied to the entire inside of the oxide film. The modified wafer W may be separated by irradiating the wafer to form a modified layer and starting from the modified layer. Further, for example, an adhesive layer (not shown) is further formed at the interface between the processed wafer W and the support wafer S, and the entire inside of the adhesive layer is irradiated with laser light to form a modified layer, and the modified layer is formed. The processing wafer W may be separated from the starting point.

For example, when a modified layer is formed on the oxide film Fw, the peripheral portion We of the processed wafer W (polymerized wafer T) may be warped by irradiation with laser light. In such a case, it becomes difficult for the second holding portion 121 to suck and hold the processed wafer W on the entire surface. Further, the processing wafer W may be damaged by the load when the processing wafer W is adsorbed by the second holding portion 121. Therefore, in the present embodiment, the second holding portion 121 may adsorb and hold the inside of the peripheral edge portion We. Then, the processed wafer W can be appropriately held by the second holding portion 121, and damage to the processed wafer W can be suppressed.

In the wafer processing system 1 of the above embodiment, the outer peripheral portion De of the device layer D is modified to form the unbonded region Ab in step A2, but the unbonded region Ab is formed outside the wafer processing system 1. You may. For example, before joining the processed wafer W and the supporting wafer S, a treatment is performed on the outer peripheral portion of the oxide film Fw to reduce the bonding strength with respect to the surface Sa of the supporting wafer S. Specifically, the surface layer of the outer peripheral portion may be removed by polishing, wet etching, or the like. Alternatively, the surface of the outer peripheral portion may be made hydrophobic or roughened with a laser.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The above-described embodiment may be omitted, replaced, or changed in various forms without departing from the scope of the appended claims and the gist thereof.

61 Separation device 120 1st holding part 121 2nd holding part W processing wafer W1 1st separation wafer W2 2nd separation wafer

Claims (18)

It is a separation device that separates a processing target body on which a modified layer is formed by irradiation with laser light into a first separation body and a second separation body.
A first holding portion for holding the first separated body and
A second holding portion for holding the second separated body and
It has a first holding portion and a moving portion that relatively moves the second holding portion.
The second holding portion is a separating device that holds the inside of the outer end portion of the second separating body. The separation device according to claim 1, wherein the first holding portion holds the entire surface of the first separation body. Inside the treatment target body, a peripheral modification layer, which is the modification layer, is formed along the boundary between the peripheral portion and the central portion of the treatment target body.
The separation device according to claim 1 or 2, wherein the second holding portion holds the inside of the peripheral modification layer in the second separator. The separation device according to claim 3, wherein the outer end portion of the second holding portion is located inside the peripheral modification layer in the second separator. The diameter of the second holding portion is smaller than the diameter of the second separator.
The separation device according to claim 4, wherein the diameter of the first holding portion is equal to or larger than the diameter of the first separator. The separation device according to any one of claims 1 to 5, further comprising a load measuring unit for measuring a load applied to the first holding unit and the second holding unit. The separation device according to claim 6, wherein a plurality of the load measuring units are provided. The separation device according to claim 6 or 7, further comprising a driving unit that relatively moves the first holding unit and the second holding unit at a position corresponding to the load measuring unit. The separation device according to any one of claims 1 to 8, wherein an elastic body is provided in the first holding portion or the second holding portion. It is a separation method for separating a processing object having a modified layer formed by irradiation with laser light into a first separation body and a second separation body.
The first separator held in the first holding portion and the second separator held in the second holding portion are relatively moved and separated.
A separation method in which the second holding portion holds the inside of the outer end portion of the second separating body. The separation method according to claim 10, wherein the first holding portion holds the entire surface of the first separated body. Inside the treatment target body, a peripheral modification layer, which is the modification layer, is formed along the boundary between the peripheral portion and the central portion of the treatment target body.
The separation method according to claim 10 or 11, wherein the second holding portion holds the inside of the peripheral modification layer in the second separator. The separation method according to any one of claims 10 to 12, wherein when the body to be processed is separated, the load applied to the first holding portion and the second holding portion is measured by the load measuring unit. The separation method according to claim 13, wherein a plurality of the load measuring units are provided. The separation method according to claim 13 or 14, wherein the timing for ending the separation of the processing target body is controlled based on the load measurement result by the load measuring unit. Based on the measurement results of the load distribution by the plurality of load measuring units, the first holding unit and the second holding unit are placed at positions corresponding to the load measuring units so that the load distribution becomes uniform. The separation method according to claim 14, wherein the object to be processed is separated by moving them relatively. Based on the measurement results of the load distribution by the plurality of load measuring units, the first holding unit and the second holding unit are located at positions corresponding to the load measuring units so that the load distribution becomes non-uniform. The separation method according to claim 14, wherein the object to be processed is separated by relatively moving the body. An elastic body is provided on the first holding portion or the second holding portion.
The separation method according to any one of claims 10 to 17, wherein when the body to be processed is separated, the elastic body absorbs the load applied to the first holding portion and the second holding portion.

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