WO2020184178A1

WO2020184178A1 - Processing device and processing method

Info

Publication number: WO2020184178A1
Application number: PCT/JP2020/007697
Authority: WO
Inventors: 弘明森; 義広川口
Original assignee: 東京エレクトロン株式会社
Priority date: 2019-03-08
Filing date: 2020-02-26
Publication date: 2020-09-17
Also published as: JP7129549B2; TWI832975B; JPWO2020184178A1; TW202040673A

Abstract

A processing device according to the present invention has: a modification unit which forms a modified layer by irradiating the interior of a workpiece retained by a retaining part with a laser beam; a measurement unit which measures the output of the laser beam; a moving part which moves the retaining part between a first position, where the workpiece is transported into and out of the retaining part, and a second position where the modified layer is formed by the modification unit; and a control unit which controls the retaining part, the modification unit, the measurement unit, and the moving part. The control unit controls the retaining part, the measurement unit, and the moving part such that the output of the laser beam is measured by the measurement unit while the retaining part is waiting at the first position.

Description

Processing equipment and processing method

This disclosure relates to a processing apparatus and a processing method.

Patent Document 1 discloses a method for producing a wafer from a hexagonal single crystal ingot. In this generation method, the focusing point of the laser beam having a wavelength that is transparent to the hexagonal single crystal ingot is positioned at a depth corresponding to the thickness of the wafer generated from the surface of the ingot. The surface of the ingot is irradiated with a laser beam by moving the condensing point and the hexagonal single crystal ingot relatively, and cracks are formed from the modified layer parallel to the surface and the modified layer to form a separation starting point. .. Then, the wafer is peeled from the hexagonal single crystal ingot.

Japanese Unexamined Patent Publication No. 2016-146448

The technique according to the present disclosure shortens the time required for the treatment when the modified layer is formed by irradiating the inside of the treated body with a laser beam.

One aspect of the present disclosure is an apparatus for processing a processed body, in which a holding portion for holding the processed body and the inside of the processed body held by the holding portion are irradiated with laser light to form a modified layer. The modified layer is formed by the modified portion for forming the modified portion, the measuring portion for measuring the output of the laser beam, the first position for loading and unloading the processed material with respect to the holding portion, and the modified portion. The control unit has a moving unit for moving the holding unit and a control unit for controlling the holding unit, the modifying unit, the measuring unit, and the moving unit. Controls the holding unit, the measuring unit, and the moving unit so that the measuring unit measures the output of the laser beam when the holding unit stands by at the first position.

According to the present disclosure, when the modified layer is formed by irradiating the inside of the processed body with a laser beam, the time required for the processing can be shortened.

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 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 reformer. It is a side view which shows the outline of the structure of the reformer. It is a top view which shows the outline of the structure of the peripheral edge removal device. It is a side view which shows the outline of the structure of the peripheral edge removal device. It is explanatory drawing which shows the outline of the structure of the peripheral edge removal device schematically. It is a vertical cross-sectional view which shows the outline of the structure of the transport arm. It is a flow chart which shows the main process of the wafer processing which concerns on this Embodiment. It is explanatory drawing of the main process of the wafer processing which concerns on this embodiment. It is a flow chart which shows the main process of the reforming process. It is explanatory drawing of the main process of a reforming process. It is explanatory drawing which shows the timing which performs the focus adjustment with respect to the elevating and lowering of a micro camera. It is explanatory drawing which shows a mode that a macro camera takes an image of the outer end portion of a processing wafer. It is explanatory drawing which shows a mode that a micro camera images the boundary of the bonded region and the unbonded region of a processed 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 typically the method of forming a plurality of peripheral modification layers. It is explanatory drawing which shows the appearance of forming a plurality of peripheral modification layers. It is explanatory drawing which shows the appearance of forming a plurality of peripheral modification layers. It is explanatory drawing which shows the state of forming the peripheral modification layer of one layer. It is explanatory drawing which shows the periphery of the notch part in forming a peripheral modification layer on a processed wafer. It is explanatory drawing which shows the state of forming the division modification layer on the processing wafer. It is explanatory drawing which shows the appearance which the division modification layer was formed on the processing wafer. It is explanatory drawing which shows the state of forming the division modification layer in a comparative example. It is explanatory drawing which shows the state of forming the division modification layer in this embodiment. 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.

In the manufacturing process of a semiconductor device, the wafer is thinned with respect to a wafer in which devices such as a plurality of electronic circuits 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 method of irradiating the inside of the wafer with laser light to form a modified layer and separating the wafer from the modified layer as a base point. and so on.

The wafer generation method disclosed in Patent Document 1 described above is the same technique as the wafer thinning described above in that the wafer is peeled from the hexagonal single crystal ingot. Here, when irradiating the inside of the wafer with a laser beam, it is necessary to confirm whether or not the output (power) of the laser beam is appropriate (power check). Further, it is appropriate to perform this power check for each wafer to be processed. However, Patent Document 1 does not disclose that the power check is performed, much less shortening the processing time of the power check is not considered at all. Therefore, there is room for improvement in the conventional method.

The technique according to the present disclosure shortens the processing time and efficiently performs the formation of the modified layer using the laser beam. Hereinafter, a wafer processing system including a reformer as a processing device according to the present embodiment for efficiently performing wafer processing and a wafer processing method as a 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 this embodiment will be described. FIG. 1 is a plan view schematically showing an outline of the configuration of the wafer processing system 1.

In the wafer processing system 1, as shown in FIGS. 2 and 3, the processing wafer W as the first substrate and the support wafer S as the second substrate are bonded to the polymerization wafer T as the polymerization substrate. Perform the desired treatment. Then, in the wafer processing system 1, the peripheral portion We of the processed wafer W is removed, and the processed wafer W is further thinned. 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 wafer, and a device layer (not shown) including a plurality of devices is formed on the 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 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. The peripheral edge portion We is a portion that is removed in the so-called 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.

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

The support wafer S is a wafer that supports the processed 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 for protecting the device on the surface Wa of the processing wafer W. 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.

Here, in the peripheral portion We of the processed wafer W, if the processed wafer W and the supporting wafer S are joined, there is a possibility that the peripheral portion We cannot be properly removed. Therefore, at the interface between the processed wafer W and the support wafer S, a bonding region Aa to which the oxide film F and the surface Sa of the support wafer S are bonded and an unbonded region Ab which is a region outside the bonding region Aa in the radial direction are provided. Form. With the presence of the unbonded region Ab in this way, the peripheral portion We can be appropriately removed. 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.

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 carries in / out a cassette Ct capable of accommodating a plurality of polymerized wafers T with, for example, the outside. The processing station 3 includes various processing devices that perform desired processing on the polymerized wafer T.

The loading / unloading station 2 is provided with a cassette mounting stand 10. In the illustrated example, a plurality of, for example, three cassettes Ct can be freely mounted in a row on the cassette mounting table 10 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.

The loading / unloading station 2 is provided with a wafer transfer device 20 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 and 22 that hold and transfer the polymerized wafer T. Each transport arm 22 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 22 is not limited to this embodiment, and any configuration can be adopted. The wafer transfer device 20 is configured to be able to transfer the polymerized 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 delivering the polymerized 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 (import / export 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 apparatus 40 and the cleaning apparatus 41 are arranged in a laminated manner. The number and arrangement of the etching apparatus 40 and the cleaning apparatus 41 are not limited to this. For example, the etching apparatus 40 and the cleaning apparatus 41 may be extended in the X-axis direction and placed side by side in parallel in a plan view. Further, the etching apparatus 40 and the cleaning apparatus 41 may be laminated respectively.

The etching apparatus 40 etches the back surface Wb of the processed wafer W ground by the processing apparatus 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. As the chemical solution, for example, HF, HNO ₃ , H ₃ PO ₄ , TMAH, Choline, KOH and the like are used.

The cleaning device 41 cleans the back surface Wb of the processed wafer W ground by the processing device 80 described later. For example, the back surface Wb is brought into contact with the brush to scrub clean the back surface Wb. 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 on the Y-axis negative direction side with respect to the etching device 40 and the cleaning device 41, for example. The wafer transfer device 50 has, for example, two

transfer arms

51, 51 that hold and transfer the polymerized wafer T. 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 configured to be able to transfer the polymerized 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 reformer 60, a peripheral edge removing device 61, and a wafer transfer device 70. The reformer 60 and the peripheral edge removing device 61 are arranged in a laminated manner. The number and arrangement of the reformer 60 and the peripheral edge removing device 61 are not limited to this.

The reformer 60 irradiates the inside of the processed wafer W with laser light to form a peripheral reforming layer, a split reforming layer, and an internal 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 from the peripheral edge reforming layer formed by the reforming device 60 as a base point. The specific configuration of the peripheral edge removing device 61 will be described later.

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

transfer arms

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

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

The processing apparatus 80 grinds the back surface Wb of the processed wafer W. Then, on the back surface Wb on which the inner surface modification layer is formed, the inner surface modification layer is removed, and further, the peripheral modification layer is removed.

The processing device 80 has a rotary table 81. The rotary table 81 is rotatably configured around a vertical rotation center line 82 by a rotation mechanism (not shown). Two chucks 83 for sucking and holding the polymerized wafer T are provided on the rotary table 81. The chucks 83 are evenly arranged on the same circumference as the rotary table 81. The two chucks 83 can be moved to the delivery position A0 and the processing position A1 by rotating the rotary table 81. Further, each of the two chucks 83 is configured to be rotatable around a vertical axis by a rotation mechanism (not shown).

At the delivery position A0, the polymerization wafer T is delivered. At the machining position A1, the grinding unit 84 is arranged. The grinding unit 84 grinds the back surface Wb of the processed wafer W. The grinding unit 84 has a grinding unit 85 having an annular shape and a rotatable grinding wheel (not shown). Further, the grinding portion 85 is configured to be movable in the vertical direction along the support column 86. Then, in a state where the back surface Wb of the processed wafer W held by the chuck 83 is in contact with the grinding wheel, the chuck 83 and the grinding wheel are each rotated to grind the back surface Wb.

The above wafer processing system 1 is provided with a control device 90 as a control unit. The control device 90 is, for example, a computer and has a program storage unit (not shown). The program storage unit stores a program that controls the processing of the polymerized wafer T 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 storage medium H that can be read by a computer, and may be installed from the storage medium H on the control device 90.

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

The reformer 60 has a chuck 100 as a holding portion that holds the polymerized wafer T on the upper surface. The chuck 100 attracts 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 arranged on the lower side. The chuck 100 is supported by the slider table 102 via an air bearing 101. A rotation mechanism 103 as a rotating portion is provided on the lower surface side of the slider table 102. The rotation mechanism 103 has, for example, a built-in motor as a drive source. The chuck 100 is rotatably configured around a vertical axis by a rotation 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 as a moving portion provided on the lower surface side thereof. The drive source of the moving mechanism 104 is not particularly limited, but for example, a linear motor is used.

The slider table 102 is provided with a power meter 107 as a measuring unit for measuring the output (power) of the laser light emitted from the laser head 110, which will be described later. The power meter 107 is provided at the Y-axis negative end of the slider table 102. Then, as will be described later, at the first position P1, the power meter 107 is arranged below the lens of the laser head 110. The power of the laser beam measured by the power meter 107 is output to the control device 90. The power of the laser beam is set in the control device 90 according to the processing recipe, and it is confirmed whether or not the measured power of the laser beam is appropriate (power check). This power check is performed for each processing wafer W to be processed, for example.

A laser head 110 as a reforming portion is provided above the chuck 100. The laser head 110 has a lens 111 and a piezo actuator 112. The lens 111 is provided on the lower surface of the laser head 110 and irradiates the processing wafer W held by the chuck 100 with laser light. The piezo actuator 112 raises and lowers the lens 111.

Further, the laser head 110 is provided with a sensor 113 for measuring the position of the laser beam emitted from the lens 111. The sensor 113 is provided coaxially with the laser beam emitted from the lens 111, and is, for example, an AF sensor, which measures the height of the back surface Wb of the processing wafer W. The height of the back surface Wb measured by the sensor 113 is output to the control device 90. The control device 90 calculates the irradiation position of the laser beam emitted to the inside of the processing wafer W based on the height of the back surface Wb.

Further, the laser head 110 is further provided with a sensor 114 and a camera 115 for adjusting the irradiation position (focus) of the laser light emitted from the lens 111. The sensor 114 is provided on a different axis from the laser beam emitted from the lens 111, and is, for example, an AF sensor, which measures the height of the back surface Wb of the processing wafer W and searches for the back surface Wb. As the sensor 114, an AF sensor capable of measuring a wider range than the sensor 113 is used. Further, the camera 115 is provided coaxially with the laser beam emitted from the lens 111, and images the back surface Wb of the processed wafer W. The height of the back surface Wb measured by the sensor 114 and the image of the back surface Wb captured by the camera 115 are output to the control device 90, respectively. As will be described later, the control device 90 calculates the irradiation position of the laser beam emitted to the inside of the processed wafer W based on the height of the back surface Wb and the image.

Further, the laser head 110 further has a spatial light modulator (not shown). The spatial light modulator modulates and outputs the laser beam. Specifically, the spatial light modulator can control the focal position and phase of the laser beam, and can adjust the shape and number (number of branches) of the laser beam irradiated to the processing wafer W.

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

The laser head 110 is supported by the support member 116. The laser head 110 is configured to be vertically elevated by an elevating mechanism 118 along a rail 117 extending in the vertical direction. Further, the laser head 110 is configured to be movable in the Y-axis direction by the moving mechanism 119. The elevating mechanism 118 and the moving mechanism 119 are each supported by the support pillar 120.

Above the chuck 100 and on the Y-axis positive direction side of the laser head 110, a macro camera 121 as a first imaging unit and a micro camera 122 as a second imaging unit are provided. For example, the macro camera 121 and the micro camera 122 are integrally configured, and the macro camera 121 is arranged on the Y-axis positive direction side of the micro camera 122. The macro camera 121 and the micro camera 122 are configured to be vertically movable by the elevating mechanism 123, and further configured to be movable in the Y-axis direction by the moving mechanism 124.

The macro camera 121 images the outer end of the processed wafer W (polymerized wafer T). The macro camera 121 includes, for example, a coaxial lens, irradiates visible light, for example, red light, and further receives reflected light from an object. For example, the imaging magnification of the macro camera 121 is 2 times.

The micro camera 122 images the peripheral edge of the processed wafer W and images the boundary between the bonded region Aa and the unbonded region Ab. The microcamera 122 includes, for example, a coaxial lens, irradiates infrared light (IR light), and further receives reflected light from an object. For example, the imaging magnification of the micro camera 122 is 10 times, the field of view is about 1/5 of that of the macro camera 121, and the pixel size is about 1/5 of that of the macro camera 121.

Next, the peripheral removal device 61 described above will be described. FIG. 6 is a plan view showing an outline of the configuration of the peripheral edge removing device 61. FIG. 7 is a side view showing an outline of the configuration of the peripheral edge removing device 61. FIG. 8 is an explanatory diagram schematically showing an outline of the configuration of the peripheral edge removing device 61.

The peripheral edge removing device 61 has a chuck 130 that holds the polymerized wafer T on the upper surface. The chuck 130 holds the support wafer S in a state where the processing wafer W is on the upper side and the support wafer S is arranged on the lower side. Further, the chuck 130 is configured to be rotatable around a vertical axis by a rotation mechanism 131.

On the side of the chuck 130, a peripheral edge removing portion 140 for removing the peripheral edge portion We of the processed wafer W is provided. The peripheral edge removing portion 140 applies an impact to the peripheral edge portion We to remove the peripheral edge portion We. The peripheral edge removing portion 140 has a wedge roller 141 and a support roller 142.

The wedge roller 141 has a wedge shape with a sharp tip when viewed from the side. The wedge roller 141 is inserted from the outer end portion of the processing wafer W and the support wafer S into the interface between the processing wafer W and the support wafer S. Then, the peripheral portion We is pushed up by the inserted wedge roller 141, separated from the processed wafer W, and removed.

The support roller 142 penetrates the center of the wedge roller 141 and supports the wedge roller 141. The support roller 142 is configured to be movable in the horizontal direction by a moving mechanism (not shown), and the wedge roller 141 also moves when the support roller 142 moves. Further, the support roller 142 is configured to be rotatable around a vertical axis, and the wedge roller 141 also rotates when the support roller 142 rotates. In the present embodiment, the support roller 142 uses a so-called free roller that rotates in response to the rotation of the chuck 130 as described later. However, the support roller 142 may be positively rotated by a rotation mechanism (not shown).

In the present embodiment, the wedge roller 141 is used as the insertion member, but the insertion member is not limited to this. For example, the insertion member may have a shape in which the width becomes smaller toward the outside in the radial direction in the side view, and a knife-shaped insertion member having a sharpened tip may be used.

Nozzles

150 and 151 for supplying the cleaning liquid to the processing wafer W are provided above and below the chuck 130, respectively. For example, pure water is used as the cleaning liquid. When the peripheral edge removing portion 140 is used to apply an impact to the peripheral edge portion We to remove the peripheral edge portion We, dust (particles) is generated along with the removal. Therefore, in the present embodiment, the cleaning liquid is supplied from the

nozzles

150 and 151 to suppress the scattering of the dust.

The upper nozzle 150 is arranged above the chuck 130, and supplies the cleaning liquid from above the processing wafer W to the back surface Wb. The cleaning liquid from the upper nozzle 150 can suppress the scattering of dust generated when the peripheral edge portion We is removed, and further suppress the scattering of dust on the processing wafer W. Specifically, the cleaning liquid causes dust to flow to the outer peripheral side of the processing wafer W. Further, the lower nozzle 151 is arranged below the chuck 130, and supplies the cleaning liquid to the processing wafer W from the support wafer S side. The cleaning liquid from the lower nozzle 151 can more reliably suppress the scattering of dust. Further, the cleaning liquid from the lower nozzle 151 can prevent dust and broken material of the peripheral portion We from wrapping around to the support wafer S side.

The number and arrangement of the

nozzles

150 and 151 are not limited to this embodiment. For example, a plurality of

nozzles

150 and 151 may be provided respectively. Further, the lower nozzle 151 can be omitted.

The method of suppressing the scattering of dust is not limited to the supply of cleaning liquid. For example, a suction mechanism (not shown) may be provided to suck and remove the generated dust.

Above the chuck 130, a detection unit 160 for confirming whether or not the peripheral portion We has been removed from the processing wafer W is provided. The detection unit 160 detects the presence or absence of the peripheral edge portion We on the processed wafer W held by the chuck 130 and from which the peripheral edge portion We has been removed. For example, a sensor is used for the detection unit 160. The sensor is, for example, a line-type laser displacement meter, and detects the presence or absence of the peripheral portion We by irradiating the peripheral portion of the polymerized wafer T (processed wafer W) with a laser and measuring the thickness of the polymerized wafer T. .. The method of detecting the presence or absence of the peripheral portion We by the detection unit 160 is not limited to this. For example, the detection unit 160 may detect the presence or absence of the peripheral portion We by photographing the polymerization wafer T (processed wafer W) using, for example, a line camera.

Below the chuck 130, a recovery unit (not shown) for collecting the peripheral edge portion We removed by the peripheral edge removing portion 140 is provided.

Next, the transfer arm 71 of the wafer transfer device 70 described above will be described. FIG. 9 is a vertical cross-sectional view showing an outline of the configuration of the transport arm 71.

The transport arm 71 has a disc-shaped suction plate 170 having a diameter larger than that of the polymerized wafer T. A holding portion 180 for holding the central portion Wc of the processed wafer W is provided on the lower surface of the suction plate 170.

A suction pipe 181 for sucking the central portion Wc is connected to the holding portion 180, and the suction pipe 181 communicates with a suction mechanism 182 such as a vacuum pump, for example. The suction tube 181 is provided with a pressure sensor 183 that measures the suction pressure. The configuration of the pressure sensor 183 is arbitrary, but for example, a diaphragm type pressure gauge is used.

On the upper surface of the suction plate 170, a rotation mechanism 190 for rotating the suction plate 170 around a vertical axis is provided. The rotation mechanism 190 is supported by the support member 191. Further, the support member 191 (rotation mechanism 190) is supported by the arm member 72.

Next, the wafer processing performed by using the wafer processing system 1 configured as described above will be described. FIG. 10 is a flow chart showing a main process of wafer processing. FIG. 11 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. 11A is placed on the cassette mounting table 10 of the loading / unloading station 2.

Next, the polymerized 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 polymerized wafer T of the transition device 30 and transfers it to the reformer 60. In the reformer 60, as shown in FIG. 11B, the peripheral reforming layer M1 and the split reforming layer M2 are sequentially formed inside the processed wafer W (steps A1 and A2 in FIG. 10), and further in FIG. As shown in c), the internal surface reforming layer M3 is formed (step A3 in FIG. 10). The peripheral edge modification layer M1 serves as a base point when the peripheral edge portion We is removed in the edge trim. The split modified layer M2 serves as a base point for the peripheral portion We to be removed to be fragmented. The internal surface modification layer M3 serves as a base point for thinning the processed wafer W.

FIG. 12 is a flow chart showing the main steps of the reforming process in the reformer 60. FIG. 13 is an explanatory diagram of the main steps of the reforming process. In the present embodiment, as shown in FIG. 13, the chuck 100 is arranged at the first position P1 and the second position P2, and each process is performed.

In the reformer 60, before the polymerization wafer T is carried in, the chuck 100 (slider table 102) is moved to the first position P1 as shown in FIG. 13A and is made to stand by. While the chuck 100 is on standby, the power meter 107 is arranged below the lens 111 of the laser head 110. The power meter 107 measures the output (power) of the laser beam emitted from the laser head 110. The power of the laser beam measured by the power meter 107 is output to the control device 90, and the power check is performed by the control device 90. Further, while the chuck 100 is on standby, the optical system of the laser head 110 is calibrated (calibration) (step B1 in FIG. 12).

Here, for example, when the power meter 107 is located away from the first position P1, it is necessary to move the chuck 100 from the first position P1 for power check, and the device becomes large. On the other hand, in the present embodiment, since the power meter 107 is arranged below the laser head 110 at the first position P1, the power check can be performed without moving the chuck 100. As a result, the occupied area (footprint) of the reformer 60 can be reduced, and the space can be saved. Further, since the power check and the calibration can be performed while the chuck 100 is on standby, the reforming processing time can be shortened and the wafer processing throughput can be improved. The power check and calibration may be performed when the polymerized wafer T is carried in in step B2 described later.

Next, the polymerized wafer T is carried in from the wafer transfer device 50 in a state where the chuck 100 is arranged at the first position as shown in FIG. 13 (b) (step B2 in FIG. 12). The carried-in polymerized wafer T is held by the chuck 100.

Next, macro alignment is performed using the macro camera 121 with the chuck 100 arranged at the first position P1. At the first position P1, the macro camera 121 is arranged at a position where the outer end portion of the processing wafer W can be imaged. Then, in the macro alignment, after adjusting the focus of the macro camera 121 (step B3 in FIG. 12), the outer end portion of the processed wafer W is imaged (step B4 in FIG. 12).

First, in step B3, the focus of the macro camera 121 is adjusted with respect to a plurality of points in the height direction of the processing wafer W. At this time, the chuck 100 is not rotated. Then, the macro camera 121 is raised or lowered by the elevating mechanism 123 to adjust the focus of the macro camera 121 with respect to a plurality of points in the height direction of the processing wafer W.

The focus adjustment of this embodiment will be described. FIG. 14 is an explanatory diagram showing the timing of adjusting the focus with respect to the elevating and lowering of the macro camera 121, where the vertical axis represents the elevating speed and the horizontal axis represents the time. Further, Q1 to Q4 in FIG. 14 indicate the first to fourth focus adjustments, respectively. In FIG. 14, (a) shows a comparative example, and (b) shows an example of the present embodiment.

As shown in FIG. 14A, in the comparative example, the macro camera 121 is moved up and down, and then the focus adjustments Q1 to Q4 are performed in a state where the macro camera 121 is stopped at a desired height. That is, every time the macro camera 121 is moved up and down, acceleration and deceleration are repeated. Then, it is determined whether or not the focus value is appropriate for each focus adjustment Q1 to Q4. Therefore, it takes time.

On the other hand, as shown in FIG. 14B, in the present embodiment, focus adjustments Q1 to Q4 are performed while raising and lowering the macro camera 121. That is, the macro camera 121 is not stopped when the focus is adjusted. Therefore, acceleration and deceleration of the comparative example are unnecessary, time can be omitted, and the suitability of the focus values in the focus adjustments Q1 to Q4 can be collectively determined. Therefore, the time for focus adjustment can be shortened. In the example of FIG. 14, the time that can be shortened is t1.

Next, in step B4, the outer end portion of the processing wafer W is imaged with respect to a plurality of points in the circumferential direction of the processing wafer W. At this time, the macro camera 121 is fixed without being moved up and down. Then, the chuck 100 is rotated to image the outer end portion R1 (dotted line in FIG. 15) of the processed wafer W with respect to a plurality of points in the circumferential direction of the processed wafer W as shown in FIG.

Also in the imaging of the outer end portion of the processed wafer W, in the same manner as the focus adjustment shown in FIG. 14 described above, in the comparative example, the chuck 100 is rotated and then the imaging is performed in a state where the chuck 100 is stopped at a desired position. On the other hand, in the present embodiment, the outer end portion of the processed wafer W is imaged while rotating the chuck 100. That is, the rotation of the chuck 100 is not stopped when the image is taken. Therefore, the imaging time can be shortened. Further, by shortening the imaging time in this way, it is possible to increase the number of imaging times, and as a result, macro alignment can be appropriately performed.

In this way, the macro camera 121 captures an image of the outer end portion of the processed wafer W at 360 degrees in the circumferential direction. The captured image is output from the macro camera 121 to the control device 90.

The control device 90 calculates the first eccentricity of the center Cc of the chuck 100 and the center Cw of the processing wafer W from the image of the macro camera 121. Further, the control device 90 calculates the movement amount of the chuck 100 so as to correct the Y-axis component of the first eccentric amount based on the first eccentric 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. The micro-alignment position is a position where the micro camera 122 can image the peripheral edge of the processing wafer W. Here, as described above, the field of view of the micro camera 122 is as small as about 1/5 of that of the macro camera 121. Therefore, unless the Y-axis component of the first eccentric amount is corrected, the peripheral portion of the processing wafer W is the micro camera. It may not be possible to take an image with the micro camera 122 because it does not fit in the angle of view of 122. Therefore, it can be said that the correction of the Y-axis component based on the first eccentricity amount is for moving the chuck 100 to the micro-alignment position.

In the macro alignment using the macro camera 121, the amount of light is also adjusted before the focus adjustment. The light amount adjustment may be performed for each polymerization wafer T, for each lot, or for each processing condition (processing recipe). The light amount adjustment is performed on one point or a plurality of points of the processing wafer W. In such a case, the rotation of the chuck 100 is stopped and the light amount adjustment is performed. While the rotation of the chuck 100 is stopped, the amount of light is changed a plurality of times to perform imaging.

Further, as described above, the macro alignment is performed to move the chuck 100 to the micro alignment position, but such macro alignment can be omitted. That is, when the alignment is not performed in two stages of macro and micro and is performed in only one stage of micro, macro alignment is omitted.

Next, as shown in FIG. 13 (c), the chuck 100 is moved to the second position P2 (step B5 in FIG. 12).

Next, micro-alignment is performed using the micro camera 122 with the chuck 100 arranged at the second position P2. At the second position P2, the microcamera 122 is arranged at a position where the boundary between the bonded region Aa and the unbonded region Ab of the processed wafer W can be imaged. Then, in the micro-alignment, after adjusting the focus of the micro camera 122 (step B6 in FIG. 12), the boundary between the bonded region Aa and the unjunction region Ab is imaged (step B7 in FIG. 12).

First, in step B6, the focus of the micro camera 122 is adjusted with respect to a plurality of points in the height direction of the processing wafer W. The focus adjustment of the micro camera 122 is performed while moving the micro camera 122 up and down by the elevating mechanism 123. Therefore, the time for focus adjustment can be shortened. Since the focus adjustment of the micro camera 122 is the same as the focus adjustment of the macro camera 121 in step B3, the description thereof will be omitted.

Next, in step B7, the boundary between the bonded region Aa and the unbonded region Ab of the processed wafer W is imaged at a plurality of points in the circumferential direction of the processed wafer W. At this time, the macro camera 121 is fixed without being moved up and down. Then, the chuck 100 is rotated to image the boundary R2 (dotted line in FIG. 16) between the bonded region Aa and the unbonded region Ab with respect to a plurality of points in the circumferential direction of the processed wafer W as shown in FIG. ..

In the imaging of the boundary between the bonded region Aa and the unbonded region Ab, the chuck 100 was rotated and then stopped at a desired position in the comparative example as in the imaging of the outer end portion of the processed wafer W in step B3. Take an image in the state. On the other hand, in the present embodiment, the boundary between the bonded region Aa and the unbonded region Ab is imaged while rotating the chuck 100. That is, the rotation of the chuck 100 is not stopped when the image is taken. Therefore, the imaging time can be shortened. Further, by shortening the imaging time in this way, it is possible to increase the number of imaging times, and as a result, micro-alignment can be appropriately performed.

In this way, the microcamera 122 captures an image of the boundary between the bonded region Aa and the unbonded region Ab at 360 degrees in the circumferential direction of the processed wafer W. The captured image is output from the micro camera 122 to the control device 90.

The control device 90 calculates the second eccentric amount of the center Cc of the chuck 100 and the center Ca of the junction region Aa from the image of the micro camera 122. Further, the control device 90 determines the position of the chuck 100 with respect to the peripheral modification layer M1 so that the center of the bonding region Aa and the center of the chuck 100 coincide with each other based on the second eccentricity amount.

Next, in a state where the chuck 100 is arranged at the second position P2, the height of the laser beam emitted from the laser head 110 is adjusted (irradiation height adjustment) (step B8 in FIG. 12). At the second position P2, the lens 111 of the laser head 110 is arranged at a position where the laser beam can be applied to the boundary between the peripheral portion We and the central portion Wc of the processing wafer W.

Here, as will be described later, in step B9, the laser head 110 irradiates the inside of the processed wafer W with laser light while rotating the chuck 100 to form an annular peripheral modification layer. Further, in step B9, the irradiation position (irradiation height) of the laser beam is measured, and the height of the laser beam is adjusted (followed) in real time. Therefore, the height at the irradiation start position of the laser beam is important. Therefore, the laser beam irradiation height adjustment in step B8 is performed at the laser beam irradiation start position in step B9.

Further, the height of the processed wafer W held by the chuck 100 may not be uniform in the wafer surface due to various factors. Then, the heights of the peripheral portion and the central portion of the processed wafer W may be different. For example, if the height of the laser beam is adjusted at the center of the processed wafer W, it may not be adjusted appropriately at the peripheral portion. Therefore, from this point of view, it is preferable that the laser beam irradiation height adjustment in step B8 is performed at the laser beam irradiation start position in step B9.

Further, the sensor 113 used to measure the irradiation position of the laser beam in step B9 has a limited range that can be followed, and this range is, for example, ± in the vertical direction from the back surface Wb of the processing wafer W to be measured. It is 0.2 mm. Therefore, in order to keep the irradiation position of the laser beam in step B9 within the range that can be followed by the sensor 113, it is necessary to adjust the irradiation height in step B8.

In step B8, first, the sensor 114 and the camera 115 are moved to the laser beam irradiation start position in step B9. Then, while moving the laser head 110 up and down, the height of the back surface Wb of the processing wafer W at the irradiation start position of the laser beam is measured by the sensor 114, and the back surface Wb is searched. The height of the back surface Wb measured by the sensor 114 is output to the control device 90. The control device 90 searches (identifies) the position of the back surface Wb based on the height of the back surface Wb.

In step B8, the laser head 110 is then moved horizontally to the laser beam irradiation position in step B9. Subsequently, the back surface Wb is imaged by the camera 115. The image of the back surface Wb captured by the camera 115 is output to the control device 90. The control device 90 calculates the height of the back surface Wb based on the image of the back surface Wb, and further calculates the irradiation position of the laser beam emitted to the inside of the processing wafer W based on the height of the back surface Wb. Then, after the laser head 110 is lowered and arranged at the irradiation height of the laser beam, the calculated position is set at the origin position of the irradiation position of the laser beam with respect to the sensor 113 (zero point adjustment). As described above, in step B8, after the sensor 114 performs a rough search for the back surface Wb, the camera 115 precisely grasps the back surface Wb and adjusts the zero point.

Further, in step B8, the zero point is adjusted by using the sensor 114 and the camera 115 while raising or lowering the laser head 110. Here, as in the case of the focus adjustment shown in FIG. 14 described above, when the height of the back surface Wb is measured by the sensor 114 in a state where the laser head 110 is stopped ascending and descending and then stopped at a desired height. Zero point adjustment takes time. On the other hand, in the present embodiment, the measurement is performed by the sensor 114 while moving the laser head 110 up and down. That is, the laser head 110 does not stop moving up and down when the measurement is performed by the sensor 114. Therefore, the time for zero point adjustment can be shortened. Similarly, when the back surface Wb is imaged by the camera 115 in a state where the laser head 110 is stopped at a desired height after being stopped, the zero point adjustment takes time. On the other hand, the time for adjusting the zero point can be shortened by taking an image of the back surface Wb with the camera 115 while moving the laser head 110 up and down.

Next, the sensor 113 is moved to the laser beam irradiation start position. After that, as shown in FIGS. 17 and 18, laser light L1 (peripheral laser light L1) is irradiated from the laser head 110, and the peripheral modification layer M1 is formed at the boundary between the peripheral portion We and the central portion Wc of the processed wafer W. It is formed (step B9 in FIG. 12, step A1 in FIG. 10). A plurality of peripheral modification layers M1 are formed at different heights. Further, the peripheral modification layer M1 is formed radially inside the outer end portion of the bonding region Aa.

The peripheral modification layer M1 formed by the laser beam L1 extends in the thickness direction and has a vertically long aspect ratio. The lower end of the peripheral modification layer M1 of the lowermost layer is located above the target surface (dotted line in FIG. 17) of the thinned processed wafer W. That is, the distance H1 between the lower end of the peripheral modification layer M1 and the surface Wa of the processed wafer W is larger than the target thickness H2 of the processed wafer W after thinning. In such a case, the peripheral modification layer M1 does not remain on the processed wafer W after thinning. Inside the processed wafer W, cracks C1 propagate from a plurality of peripheral modification layers M1 and reach the back surface Wb and the front surface Wa.

In step B9, the chuck 100 is rotated by the rotating mechanism 103 and the moving mechanism 104 so that the center of the joining region Aa and the center of the chuck 100 coincide with the position of the chuck 100 determined by the control device 90. The chuck 100 is moved in the Y-axis direction. At this time, the rotation of the chuck 100 and the movement in the Y-axis direction are synchronized.

Then, while rotating and moving the chuck 100 (processed wafer W) in this way, the laser beam L1 is irradiated from the laser head 110 to the inside of the processed wafer W. That is, the peripheral modification layer M1 is formed while correcting the second eccentricity calculated in step B7. Then, the peripheral modification layer M1 is formed in an annular shape concentrically with the bonding region Aa. Therefore, in the peripheral edge removing device 61 after that, 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 eccentricity amount includes the X-axis component, the chuck 100 is rotated while moving the chuck 100 in the Y-axis direction to correct the X-axis component. On the other hand, when the second eccentricity amount does not include the X-axis component, it is sufficient to move the chuck 100 in the Y-axis direction without rotating it.

At the second position P2, the microcamera 122 is arranged on the Y-axis positive direction side and the lens 111 of the laser head 110 is arranged on the Y-axis negative direction side with respect to the processed wafer W held by the chuck 100. To. In such a case, in step B9, the peripheral modification layer M1 is formed by the laser head 110, and the peripheral modification layer M1 is imaged by the micro camera 122. The captured image is output to the control device 90, and the control device 90 inspects whether the peripheral modification layer M1 is formed at an appropriate position. By performing the formation and inspection of the peripheral modification layer M1 in parallel in this way, the work efficiency can be improved. Further, as a result of the inspection, when the peripheral modification layer M1 deviates from a desired position, the movement of the chuck 100 can be finely adjusted.

While the peripheral modification layer M1 is formed by irradiating the inside of the processed wafer W with the laser beam L1, the height of the back surface Wb of the processed wafer W is measured by the sensor 113, and the laser beam L1 is further measured by the control device 90. The irradiation position of is calculated. Then, the calculated irradiation position of the laser beam L1 is controlled so as to match the origin position set in step B8. Specifically, the lens 111 is moved up and down by the piezo actuator 112 based on the calculated irradiation position of the laser beam L1. In this way, in step B9, the height of the laser beam L1 is adjusted and followed in real time.

Here, the sensor 113 is provided coaxially with the laser beam L1 emitted from the lens 111. The irradiation radius (radius of the peripheral modification layer) of the laser beam L1 may differ depending on the processing recipe of step B9. In such a case, if the sensor 113 is provided on a different axis from the laser beam L1, the sensor 113 measures the height of the back surface Wb of the processing wafer W at a position different from the position where the laser beam L1 is irradiated. There is a possibility that the height will deviate from the actual height. Therefore, in the present embodiment, the sensor 113 is provided coaxially with the laser beam L1.

In step B9, one peripheral modification layer M1 is formed by irradiating the inside of the processed wafer W with the laser beam L1 for one round as described above. Then, when the plurality of peripheral modification layers M1 are formed at different heights as in the present embodiment, the irradiation position (irradiation height) of the laser beam L1 is changed. Hereinafter, a method for forming a plurality of peripherally modified layers M1 in the present embodiment will be described.

FIG. 19 is an explanatory diagram schematically showing a method of forming a plurality of peripheral modification layers M1, the vertical axis showing the rotation speed, and the horizontal axis showing the time. Further, L1 in FIG. 19 indicates irradiation of the laser beam L1, and D indicates a change in the processing conditions (processing recipe) when forming the peripheral modification layer M1. The processing condition change D is to move the lens 111 up and down to change the irradiation position of the laser beam L1, and the conditions of the laser beam L1, for example, the output (power), frequency, shape (laser pattern), and number of branches of the laser beam L1. Including changing etc. In FIG. 19, (a) shows a comparative example, and (b) shows an example of the present embodiment.

As shown in FIG. 19A, in the comparative example, after accelerating the rotation of the chuck 100, the laser beam L1 is irradiated for one round while maintaining the constant speed to provide one peripheral modification layer M1. Form. Then, after decelerating the rotation of the chuck 100, the processing condition change D is performed with the rotation stopped. That is, the processing condition change D is performed every time one peripheral modification layer M1 is formed. Then, every time the processing condition change D is performed, the rotation of the chuck 100 is repeatedly accelerated and decelerated. Therefore, it takes time.

On the other hand, as shown in FIG. 19B, in the present embodiment, the processing condition change D of the peripheral modification layer M1 is performed while rotating the chuck 100. That is, the rotation of the chuck 100 is not stopped when the processing condition change D is performed. Therefore, it is not necessary to accelerate and decelerate the rotation of the chuck 100 of the comparative example, and the time can be saved. Therefore, the time for forming the plurality of peripheral modification layers M1 can be shortened. In the example of FIG. 19, the time that can be shortened is t2. Further, by shortening the time for forming the plurality of peripheral modification layers M1 in this way, it is possible to increase the number of peripheral modification layers M1 formed.

When the irradiation of the laser beam L1 and the processing condition change D of the peripheral modification layer M1 are continuously performed as shown in FIG. 19B, one peripheral modification layer M1 is continuously performed as shown in FIG. 20. The irradiation start position and the irradiation end position of the laser beam L1 are shifted in the circumferential direction when the laser beam L1 is formed.

On the other hand, as shown in FIG. 21, when forming the peripheral modification layer M1 of one layer, the irradiation start position and the irradiation end position of the laser beam L1 may be the same. Then, after the processing condition change D of the peripheral modification layer M1 is performed, the laser light L1 is not irradiated until the lens 111 is positioned above the irradiation start position of the laser light L1. Even in such a case, when the processing condition change D is performed, the rotation of the chuck 100 is not stopped, and the time for forming the plurality of peripheral modification layers M1 can be shortened.

In the example shown in FIG. 19, a case where the treatment conditions are changed for each peripheral modification layer M1 when forming a plurality of peripheral modification layers M1 has been described, but one peripheral modification layer M1 is used. The conditions of the laser beam L1 may be changed during the formation, that is, while the laser beam L1 makes one round. For example, in the processed wafer W, the condition of the laser beam L1 may be changed according to the crystal orientation of silicon. FIG. 22 is an explanatory diagram showing an example in which the conditions of the laser beam L1 are changed in one round. In the example shown in FIG. 22, the processed wafer W is divided into four, the diagonal processed wafers W1 and W1 are irradiated with the laser beam L1 under one condition, and the processed wafers W2 and W2 are irradiated with the laser beam L1 under the other conditions. To do.

When the processing shown in FIG. 22 is performed, in the comparative example, the processed wafers W1 and W1 are irradiated with the laser beam L1 in the first round in a state where the chuck 100 is rotated, and the processed wafers W2 and W2 are subjected to the laser light L1. Irradiation of the laser beam L1 is stopped. After that, the condition of the laser beam L1 is changed while the rotation of the chuck 100 is once stopped. Then, with the chuck 100 rotated again, the processed wafers W2 and W2 are irradiated with the laser beam L1 on the second lap, and the processed wafers W1 and W1 are stopped from being irradiated with the laser beam L1. In such a case, when the condition of the laser beam L1 is changed, the rotation of the chuck 100 is accelerated and decelerated, which takes time.

On the other hand, in the present embodiment, the condition of the laser beam L1 is changed while rotating the chuck 100. That is, when the condition of the laser beam L1 is changed, the rotation of the chuck 100 is not stopped. Therefore, it is not necessary to accelerate and decelerate the rotation of the chuck 100 of the comparative example, and the time can be saved. Therefore, the time for forming the peripheral modification layer M1 can be shortened.

Here, as shown in FIG. 23, a notch portion Wn is formed at the outer edge portion of the processed wafer W. For example, when the formation position of the peripheral modification layer M1 overlaps with the notch portion Wn as shown in FIG. 23A, the notch portion Wn is irradiated with the laser beam L1. Then, at the end of the notch portion Wn, the cross section irradiated with the laser beam L1 becomes rough. Further, as described above, in step B9, when irradiating the laser beam L1 while rotating the chuck 100, the irradiation position (irradiation height) of the laser beam L1 is adjusted (followed) in real time. At this point, when the notch portion Wn is irradiated with the laser beam L1, the irradiation position of the laser beam L1 changes. Then, it takes time to adjust the irradiation position of the laser beam L1 in real time at a place other than the notch portion Wn.

Therefore, in the present embodiment, in step B9, as shown in FIG. 23 (b), the notch portion Wn is controlled so as not to be irradiated with the laser beam L1. Since the position of the notch portion Wn on the processed wafer W is known in advance, the irradiation of the laser beam L1 may be stopped when the lens 111 of the laser head 110 is arranged above the notch portion Wn. In such a case, since the laser beam L1 is not applied to the notch portion Wn, the cross section of the end portion of the notch portion Wn is not roughened. Further, the notch portion Wn stops the real-time adjustment of the irradiation position of the laser beam L1. Then, in the irradiation of the laser beam L1 in one round, the irradiation position of the laser beam L1 does not fluctuate significantly, and real-time adjustment other than the notch portion Wn becomes easy.

When the peripheral modification layer M1 is formed as described above, the peripheral modification layer is then irradiated with laser light L2 (division laser light L2) from the laser head 110 as shown in FIGS. 24 and 25. The split reforming layer M2 is formed on the radial outer side of M1 (step B10 in FIG. 12, step A2 in FIG. 10).

The split modified layer M2 also extends in the thickness direction like the peripheral modified layer M1 and has a vertically long aspect ratio. The crack C2 propagates from the split modified layer M2 and reaches the back surface Wb and the front surface Wa.

Further, by forming a plurality of the split reforming layers M2 and the cracks C2 at a pitch of several μm in the radial direction, as shown in FIG. 25, the split reforming layer M1 extends outward in the radial direction from the peripheral reforming layer M1. Layer M2 is formed. In the illustrated example, the divided and modified layers M2 of the line extending in the radial direction are formed at eight positions, but the number of the divided and modified layers M2 is arbitrary. At least, if the split modification layer M2 is formed at two positions, the peripheral portion We can be removed. In such a case, when the peripheral edge portion We is removed in the edge trim, the peripheral edge portion We is divided into a plurality of parts by the divided modified layer M2 while being separated from the annular peripheral edge modified layer M1 as a base point. Then, the peripheral portion We to be removed is fragmented and can be removed more easily.

Here, in the comparative example, as shown in FIG. 26, the chuck 100 may be moved in the Y-axis direction to form the split modified layer M2. That is, the chuck 100 is moved from the state where the chuck 100 is located on the Y-axis positive direction side of the lens 111 as shown in FIG. 26A to the chuck 100 in the Y-axis negative direction as shown in FIG. 26B. Then, when the processed wafer W passes below the lens 111, one end of the peripheral edge We is irradiated with the laser beam L2 to form the split reforming layer M21. After that, as shown in FIG. 26C, the chuck 100 is further moved in the negative direction of the Y-axis to form the split reforming layer M22 at the other end of the peripheral edge We. In this way, the split reforming layers M21 and M22 are formed on the opposite peripheral edges We. In such a case, the moving distance D1 of the chuck 100 becomes long. Specifically, the moving distance D1 requires, for example, one processing wafer W, a distance for accelerating the chuck 100, and a distance for decelerating.

On the other hand, in step B10 of the present embodiment, as shown in FIG. 27, the split reforming layer M2 is formed only at one end of the peripheral edge We, and the chuck 100 is further rotated to move the chuck 100. To shorten. That is, the chuck 100 is moved from the state where the chuck 100 is located on the Y-axis positive direction side of the lens 111 as shown in FIG. 27 (a) to the Y-axis negative direction as shown in FIG. 27 (b). Then, when the processed wafer W passes below the lens 111, one end (position in one circumferential direction) of the peripheral edge We is irradiated with the laser beam L2 to form the split reforming layer M21. Next, the chuck 100 is rotated 180 degrees as shown in FIG. 27 (c). After that, as shown in FIG. 27 (d), the chuck 100 is moved in the positive direction of the Y axis to form the split reforming layer M22 at the other end (other circumferential position) of the peripheral edge We. In such a case, the moving distance D2 of the chuck 100 becomes short. Specifically, the moving distance D2 only needs to include, for example, the forming width of the split reforming layer M2, the distance for accelerating and the distance for decelerating the chuck 100.

As described above, in the present embodiment, when the split reforming layer M2 is formed in step B10, the moving distance of the chuck 100 can be shortened to reduce the occupied area (footprint) of the reforming device 60, which saves energy. It can be made into a space.

In the present embodiment, the chuck 100 is moved in the Y-axis direction when the split reforming layer M2 is formed, but the laser head 110 may be moved in the Y-axis direction.

Next, as shown in FIGS. 28 and 29, the laser head 110 irradiates the laser beam L3 (inner surface laser beam L3) to form the internal surface modification layer M3 along the surface direction (FIG. 12). Step B11, step A3 in FIG. 10). The black arrow shown in FIG. 29 indicates the rotation direction of the chuck 100, and the same applies to the following description.

The lower end of the internal surface modification layer M3 is located slightly above the target surface (dotted line in FIG. 28) of the thinned processed wafer W. That is, the distance H3 between the lower end of the internal surface modification layer M3 and the surface Wa of the processed wafer W is slightly larger than the target thickness H2 of the processed wafer W after thinning. Inside the processed wafer W, cracks C3 grow in the plane direction from the internal surface modification layer M3.

In step B11, the chuck 100 (processed wafer W) is rotated, and the laser head 110 is moved from the outer peripheral portion to the central portion of the processed wafer W in the Y-axis direction from the laser head 110 to the inside of the processed wafer W. The laser beam L3 is irradiated. Then, the internal surface modification layer M3 is spirally formed from the outside to the inside in the surface of the processed wafer W.

In the present embodiment, the laser head 110 is moved in the Y-axis direction when the internal surface modification layer M3 is formed, but the chuck 100 may be moved in the Y-axis direction. Further, although the chuck 100 was rotated in forming the internal surface modification layer M3, the laser head 110 may be moved to rotate the laser head 110 relative to the chuck 100.

Next, as shown in FIG. 13 (d), the chuck 100 is moved to the first position P1 (step B12 in FIG. 12). After that, at the first position P1, the polymerized wafer T is carried out by the wafer transfer device 70 (step B13 in FIG. 12).

The above is a series of processes performed by the reformer 60. Hereinafter, returning to FIGS. 10 and 11, the wafer processing performed by the wafer processing system 1 will be described.

The polymerized wafer T carried out from the reformer 60 is then 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. 11D, the peripheral edge portion We of the processed wafer W is removed from the peripheral edge modifying layer M1 as a base point (step A4 in FIG. 10). In step A4, as shown in FIG. 8, the wedge roller 141 is inserted from the outer end portion of the processing wafer W and the support wafer S into the interface between the processing wafer W and the support wafer S. Then, the peripheral edge portion We is pushed up by the inserted wedge roller 141, and is separated from the processing wafer W with the peripheral edge modification layer M1 as a base point and removed. At this time, the peripheral portion We is fragmented and separated from the divided modified layer M2 as a base point. The removed peripheral edge We is collected by a collection unit (not shown).

Next, the polymerized wafer T is transferred to the processing device 80 by the wafer transfer device 70. In the processing apparatus 80, first, the polymerization wafer T is delivered from the transport arm 71 to the chuck 83 at the delivery position A0. At this time, as shown in FIG. 11E, the back surface Wb side of the processed wafer W (hereinafter referred to as the back surface wafer Wb1) is separated from the internal surface modification layer M3 as a base point (step A5 in FIG. 10).

In step A5, the suction plate 170 of the transport arm 71 sucks and holds the processed wafer W, and the chuck 83 sucks and holds the support wafer S. Then, the suction plate 170 is rotated to trim the back surface wafer Wb1 with the internal surface modification layer M3 as a boundary. Then, in a state where the suction plate 170 sucks and holds the back surface wafer Wb1, the suction plate 170 is raised to separate the back surface wafer Wb1 from the processed wafer W. At this time, by measuring the pressure at which the back surface wafer Wb1 is sucked by the pressure sensor 183, the presence or absence of the back surface wafer Wb1 can be detected, and it can be confirmed whether or not the back surface wafer Wb1 is separated from the processed wafer W. The separated back surface wafer Wb1 is collected outside the wafer processing system 1.

Subsequently, the chuck 83 is moved to the processing position A1. Then, as shown in FIG. 11 (f), the back surface Wb of the processed wafer W held by the chuck 83 is ground by the grinding unit 84, and the internal surface modification layer M3 and the peripheral edge modification layer M1 remaining on the back surface Wb are removed. Remove (step A6 in FIG. 10). In step A6, the processing wafer W and the grinding wheel are rotated in a state where the grinding wheel is in contact with the back surface Wb to grind the back surface Wb. After that, the back surface Wb of the processing wafer W may be cleaned with the cleaning liquid using a cleaning liquid nozzle (not shown).

Next, the polymerized 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 (step A7 in FIG. 10). 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 polymerized 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. 5). Grinding marks may be formed on the back surface Wb ground by the processing device 80 described above. In this step A8, grinding marks can be removed by wet etching, and the back surface Wb can be smoothed.

After that, the polymerized wafer T that has been subjected to all the processing is transported 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, by optimizing the positions of the components and the processing contents in the reformer 60, the occupied area of the reformer 60 can be reduced and the space can be saved. Along with this, it is also possible to improve the throughput of wafer processing.

More specifically, in the reformer 60, all the processing can be performed by arranging the chuck 100 at two positions, the first position P1 and the second position. That is, at the first position P1, power check and calibration in step B1, loading and unloading of the polymerized wafer T in steps B2 and B12, and macro alignment in steps B3 and B4 are performed. At the second position P2, micro-alignment in steps B6 and B7, adjustment of the irradiation height of the laser beam in step B8, formation of the peripheral modification layer M1 in step B9, formation of the split modification layer M2 in step B10, and step B11. The inner surface modification layer M3 is formed in the above. Since the chuck 100 may be moved between the first position P1 and the second position P2 in this way, the moving distance is shortened, and the cost of controlling the movement of the chuck 100 can be reduced.

Further, when the chuck 100 is arranged at the first position P1, the power meter 107 is arranged below the lens 111 of the laser head 110. For example, when the power meter 107 is located away from the first position P1, it is necessary to move the chuck 100 from the first position P1 for power check, but in the present embodiment, such a chuck 100 No need to move. Therefore, the occupied area of the reformer 60 can be reduced to save space. Further, in step B1, since the power check and the calibration can be performed while the chuck 100 is on standby, the time for the reforming process can be shortened and the throughput for the wafer process can be improved.

Further, when forming the split reforming layer M2 in step B10, after forming the split reforming layer M21 at one end of the peripheral edge portion We, the chuck 100 is rotated to split and modify the other end portion of the peripheral edge portion We. Layer M22 is formed. Therefore, the moving distance of the chuck 100 can be shortened, and the occupied area of the reformer 60 can be reduced to save space.

In the above embodiment, the peripheral portion We is removed by using the peripheral edge removing portion 140 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 held and removed, or the peripheral edge portion We may be removed by applying a physical impact or ultrasonic waves to the peripheral edge portion We.

Further, in the above embodiment, the back surface wafer Wb1 is separated from the processed wafer W when the polymerized wafer T is transferred from the transfer arm 71 of the wafer transfer device 70 to the chuck 83 of the processing device 80. The method is not limited to this. For example, a separation device (not shown) may be provided in the same device as the peripheral edge removing device 61, or a separation device (not shown) may be provided separately.

Further, in the above embodiment, the thinning of the processed wafer W is performed by separating the back surface wafer Wb1, but the thinning method is not limited to this. For example, the back surface Wb of the processed wafer W may be ground, or the back surface Wb may be etched.

Further, in the above embodiment, the case where the processed body is the polymerized wafer T has been described, but the present invention is not limited to this. The treated body may be something other than a substrate, for example, and the above embodiment can be applied when a modified layer is formed by irradiating the inside of the treated body with laser light.

The embodiments disclosed this time should be considered to be 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.

1 Wafer processing system 60 Remodeling device 90 Control device 100 Chuck 107 Power meter 110 Laser head M1 Peripheral remodeling layer P1 First position P2 Second position S Support wafer T Polymerized wafer W Processing wafer Wc Central part We Peripheral part

Claims

A device that processes a processing body
A holding unit that holds the processed body and
A modified portion that irradiates a laser beam to form a modified layer inside the processed body held by the holding portion, and a modified portion.
A measuring unit that measures the output of the laser beam,
A moving portion for moving the holding portion between a first position for loading and unloading the processed body with respect to the holding portion and a second position for forming the modified layer by the modified portion.
It has a holding unit, a modifying unit, a measuring unit, and a control unit that controls the moving unit.
The control unit controls the holding unit, the measuring unit, and the moving unit so that the measuring unit measures the output of the laser beam when the holding unit stands by at the first position. apparatus.
The measuring unit is provided on the holding unit.
The processing apparatus according to claim 1, wherein the measuring unit is arranged below the modified unit at the first position.
The processed body is a polymerized substrate in which a first substrate and a second substrate are bonded to each other.
The holding portion holds the polymerized substrate from the second substrate side.
The modified portion irradiates the inside of the first substrate with the laser beam along the boundary between the peripheral portion and the central portion to be removed to form the peripheral modified layer which is the modified layer. The processing apparatus according to claim 1 or 2.
When the holding portion is arranged at the first position, the first imaging unit that images the outer end portion of the first substrate and the first imaging unit.
When the holding portion is arranged at the second position, a second image is taken of the boundary between the bonded region where the first substrate and the second substrate are bonded and the unbonded region outside the bonded region. The processing apparatus according to claim 3, further comprising an imaging unit of the above.
It has a rotating part that rotates the holding part,
At the second position, the modified portion is divided and modified by irradiating the inside of the first substrate held by the holding portion with laser light from the peripheral modification layer toward the outside in the radial direction. Form a layer,
The control unit is formed by forming the split reforming layer at the one circumferential position in a state where the reforming portion is arranged above the one circumferential position in the peripheral portion, and then the rotating portion. The holding portion is rotated so that the modified portion is arranged above the other circumferential position on the peripheral portion and the divided modified layer is formed at the other circumferential position. The processing apparatus according to claim 3 or 4, which controls the reforming unit, the moving unit, and the rotating unit.
It is a method of processing a processing body,
Holding the processed body in the holding part and
To form a modified layer by irradiating a laser beam from the modified portion to the inside of the processed body held by the holding portion.
Measuring the output of the laser beam with the measuring unit
Moving the holding portion between a first position for loading and unloading the processed body with respect to the holding portion and a second position for forming the modified layer by the modified portion. Have and
A processing method in which the output of the laser beam is measured by the measuring unit when the holding unit stands by at the first position.
The measuring unit is provided on the holding unit.
The processing method according to claim 6, wherein the measuring unit is arranged below the modified unit at the first position.
The processed body is a polymerized substrate in which a first substrate and a second substrate are bonded to each other.
The holding portion holds the polymerized substrate from the second substrate side.
The modified portion irradiates the inside of the first substrate with the laser beam along the boundary between the peripheral portion and the central portion to be removed to form the peripheral modified layer which is the modified layer. The processing method according to claim 6 or 7.
When the holding portion is arranged at the first position, the outer end portion of the first substrate is imaged by the first imaging unit.
When the holding portion is arranged at the second position, a second imaging is performed on the boundary between the bonded region where the first substrate and the second substrate are bonded and the unbonded region outside the bonded region. The processing method according to claim 8, wherein the image is taken by a unit.
At the second position, a split reforming layer is formed by irradiating the inside of the first substrate held by the holding portion with laser light from the peripheral modification layer toward the outside in the radial direction.
In a state where the modified portion is arranged above one circumferential position on the peripheral portion, the divided modified layer is formed at the one circumferential position, and then the holding portion is rotated to modify the modified portion. The processing method according to claim 8 or 9, wherein the divided and modified layer is formed at the other circumferential position in a state where the portion is arranged above the other circumferential position on the peripheral portion.