TW202040673A - Processing device and processing method - Google Patents

Abstract

An object of the invention is to reduce the time taken for processing during formation of a reformed layer inside a processing target body by irradiation of a laser light. A processing device of the invention comprises a reforming section which forms a reformed layer inside the processing target body held by a holding section, a measurement section which measures the output of the laser light, a moving section which moves the holding section between a first position at which the processing target body is transported to and from the holding section and a second position at which the reformed layer is formed by the reforming section, and a control section which controls the holding section, the reforming section, the measurement section, and the moving section. The control section controls the holding section, the measurement section, and the moving section such that the output of the laser light is measured by the measurement section when the holding section is waiting at the first position.

Description

Processing device and processing method

The content disclosed in the present invention relates to a processing device and a processing method.

In Patent Document 1, a method for manufacturing a wafer from a hexagonal single crystal ingot is disclosed. In this manufacturing method, the condensing point of a laser beam with a wavelength that is transparent to the hexagonal single crystal ingot is positioned at a depth equivalent to the thickness of the manufactured wafer from the surface of the ingot. The condensing point and the hexagonal single crystal ingot are relatively moved, and the laser beam is irradiated on the surface of the ingot to form a modified layer parallel to the surface and cracks developed from the modified layer, forming a separation starting point. After that, the wafer is peeled from the hexagonal single crystal ingot. [Literature Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 2016-146448

[Problems to be solved by the present invention]

The technology disclosed in the present invention shortens the processing time when the laser light is irradiated to the inside of the processed body to form a modified layer. [Technical means to solve the problem]

One aspect disclosed in the present invention is an apparatus for processing a processed body, which includes: a holding portion for holding the processed body; a modified portion for irradiating laser light to the inside of the processed body held on the holding portion to form The modified layer; the measuring part measures the output of the laser light; the moving part makes the holding part move in and out of the first position of the processed body to the holding part, and the modified part is formed by the modified part Moving between the second positions of the layer; and a control part, which controls the holding part, the modified part, the measuring part, and the moving part; the control part, which controls the holding part, the measuring part and the moving part, for When the holding part is waiting at the first position, the output of the laser light is measured by the measuring part. [Effects of the invention]

According to the disclosure of the present invention, when laser light is irradiated to the inside of the object to be processed to form a modified layer, the processing time can be shortened.

In the manufacturing process of semiconductor devices, thinning is performed on a wafer on which a plurality of electronic circuits and other components are formed. There are various methods for thinning wafers, such as: grinding the backside of the wafer; or irradiating the inside of the wafer with laser light to form a modified layer, and then separating the wafer based on the modified layer, etc. .

In the method of manufacturing a wafer disclosed in Patent Document 1, at the point of peeling the wafer from the hexagonal single crystal ingot, the same technique as the thinning of the wafer is used. Here, when irradiating the inside of the wafer with laser light, it is necessary to confirm whether the output (power) of the laser light is appropriate (power confirmation). In addition, this power confirmation should be performed on each wafer of the processing object. However, in Patent Document 1, the implementation of power verification is not disclosed, let alone the reduction of the processing time of power verification at all. Therefore, there is still room for improvement in the conventional method.

The technology disclosed in the present invention shortens the processing time when using laser light to form the modified layer and is implemented efficiently. Hereinafter, the wafer processing system provided with the reforming device as the processing device and the wafer processing method as the processing method of the present embodiment for efficiently performing wafer processing will be described with reference to the drawings. In addition, in this specification and the drawings, the same reference numerals are given to elements having substantially the same functional configuration, so that repeated descriptions are omitted.

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

The wafer processing system 1, as shown in FIGS. 2 and 3, performs a predetermined process on a superposed wafer T as a superposed substrate, and the superposed wafer T combines the processed wafer W as the first substrate and the second substrate. Support wafer S bonding. Then, the wafer processing system 1 removes the peripheral portion We of the wafer W to be processed, and further thins the wafer W to be processed. Hereinafter, in the wafer W to be processed, the surface bonded to the support wafer S is referred to as the front surface Wa, and the surface opposite to the surface Wa is referred to as the back surface Wb. Similarly, in the support wafer S, the surface bonded to the wafer W to be processed is referred to as the surface Sa, and the surface opposite to the surface Sa is referred to as the back surface Sb.

The wafer W to be processed is, for example, 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. In addition, on the element layer, an oxide film F, for example, an SiO ₂ film (TEOS film) is further formed. In addition, the peripheral edge portion We of the wafer W to be processed is chamfered; the cross-section of the peripheral edge portion We becomes smaller toward the front end. In addition, the peripheral edge part We is a part removed in so-called peripheral edge trimming, and is, for example, a range of 1 mm to 5 mm in the radial direction from the outer end of the wafer W to be processed.

In addition, in FIG. 2, in order to avoid the complexity of the illustration, the illustration of the oxide film F is omitted. In addition, in other drawings used in the following description, the illustration of the oxide film F may similarly be omitted.

The support wafer S is a wafer that supports the processed wafer W, such as a silicon wafer. On the surface Sa of the support wafer S, an oxide film (not shown) is formed. In addition, the support wafer S functions as a protective material for protecting elements on the surface Wa of the wafer W to be processed. In addition, in the case of forming a plurality of elements supporting the surface Sa of the wafer S, like the wafer W to be processed, an element layer (not shown) is formed on the surface Sa.

Here, in the peripheral portion We of the wafer W to be processed, if the wafer W to be processed and the support wafer S are bonded, the peripheral portion We may not be properly removed. Therefore, at the interface between the processed wafer W and the supporting wafer S, a bonding area Aa where the oxide film F is bonded to the surface Sa of the supporting wafer S, and an unbonded area Ab, which is a radially outer area of the bonding area Aa, are formed. In this way, by allowing the unjoined area Ab to exist, the peripheral edge We can be appropriately removed. In addition, the outer end portion of the joining area Aa is located slightly radially outward than the inner end portion of the removed peripheral edge portion We.

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. In the carry-out and inbound station 2, for example, a cassette Ct capable of accommodating a plurality of superimposed wafers T is carried in and out between it and the outside. The processing station 3 is equipped with various processing devices for performing predetermined processing on the superposed wafer T.

In the loading/unloading station 2, a cassette mounting table 10 is installed. In the example shown in the figure, a plurality of cassettes, for example, three cassettes Ct, are arbitrarily placed in a row in the Y-axis direction on the cassette mounting table 10. In addition, the number of cassettes Ct placed on the cassette mounting table 10 is not limited to this embodiment and can be determined arbitrarily.

In the loading/unloading station 2, on the X-axis negative direction side of the cassette mounting table 10, the cassette mounting table 10 is adjacent to the cassette mounting table 10, and the wafer transfer device 20 is installed. The wafer transfer device 20 is configured to be arbitrarily movable on a transfer path 21 extending in the Y-axis direction. In addition, the wafer transport device 20 includes, for example, two transport arms 22 and 22 for holding and transporting the superposed wafer T. Each conveyance arm 22 is configured to be able to move arbitrarily in the horizontal direction, in the vertical direction, around the horizontal axis, and around the vertical axis. In addition, the structure of the conveyance arm 22 is not limited to this embodiment, Any structure can be adopted. The wafer transfer device 20 is configured to transfer the superposed wafer T to the cassette Ct of the cassette mounting table 10 and the transfer device 30 described later.

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

In the processing station 3, for example, three processing blocks G1 to G3 are set. The first processing block G1, the second processing block G2, and the third processing block G3 are arranged side by side in the above order from the positive X-axis side (the side of the carry-out/inbound 2) to the negative direction.

In the first processing block G1, an etching device 40, a cleaning device 41, and a wafer transport device 50 are provided. The etching device 40 and the cleaning device 41 are stacked and arranged. In addition, the number and arrangement of the etching device 40 and the cleaning device 41 are not limited to this form. For example, the etching device 40 and the cleaning device 41 may each extend in the X-axis direction and be placed side by side in a plan view. Furthermore, the etching device 40 and the cleaning device 41 may be laminated separately.

The etching device 40 etches the back surface Wb of the wafer W to be processed polished by the processing device 80 described later. For example, a chemical solution (etching solution) is supplied to the back surface Wb, and the back surface Wb is wet-etched. As the chemical solution, for example, HF, HNO ₃ , H ₃ PO ₄ , TMAH, Choline, KOH, etc. are used.

The cleaning device 41 cleans the back surface Wb of the wafer W to be processed that has been polished by the processing device 80 described later. For example, the brush is brought into contact with the back surface Wb, and the back surface Wb is scrubbed and cleaned. In addition, the back Wb can also be cleaned with pressurized cleaning fluid. In addition, the cleaning device 41 may have a configuration that cleans the back surface Sb of the supporting wafer S and the back surface Wb of the wafer W to be processed together.

The wafer transport device 50 is arranged on the negative side of the Y axis with respect to the etching device 40 and the cleaning device 41, for example. The wafer transport device 50 includes, for example, two transport arms 51 and 51 for holding and transporting the superposed wafer T. Each conveying arm 51 is configured to be able to move arbitrarily in the horizontal direction, in the vertical direction, around the horizontal axis, and around the vertical axis. In addition, the structure of the conveyance arm 51 is not limited to this embodiment, Any structure can be adopted. The wafer transfer device 50 is configured to transfer the superposed wafer T to the transfer device 30, the etching device 40, the cleaning device 41, and the modifying device 60 described later.

In the second processing block G2, a reforming device 60, a peripheral edge removing device 61, and a wafer conveying device 70 are provided. The reforming device 60 and the peripheral edge removing device 61 are stacked and arranged. In addition, the number and arrangement of the reforming device 60 and the peripheral edge removing device 61 are not limited to this form.

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

The peripheral edge removing device 61 uses the peripheral edge modified layer formed by the modifying device 60 as a base point to remove the peripheral edge portion We of the wafer W to be processed. The specific configuration of the peripheral edge removing device 61 will be described later.

The wafer transport device 70 is arranged on the positive side of the Y axis with respect to the reforming device 60 and the peripheral edge removing device 61, for example. The wafer transport device 70 includes, for example, two transport arms 71 and 71 for holding and transporting the superposed wafer T. Each transport arm 71 is supported by a multi-joint arm member 72, and is configured to be able to move arbitrarily in the horizontal direction, in the vertical direction, around the horizontal axis, and around 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 superposed wafer T to the cleaning device 41, the reforming device 60, the peripheral edge removing device 61, and the processing device 80 described later.

The processing device 80 is installed in the third processing block G3. In addition, the number and arrangement of processing devices 80 are not limited to this embodiment, and plural processing devices 80 may be arbitrarily arranged.

The processing device 80 grinds the back surface Wb of the wafer W to be processed. Then, on the back surface Wb on which the inner surface reforming layer is formed, the inner surface reforming layer is removed, and the peripheral edge reforming layer is further removed.

The processing device 80 includes a rotating table 81. The rotating table 81 is configured to be able to arbitrarily rotate around a vertical rotation center line 82 by a rotating mechanism (not shown). On the rotating table 81, two suction cups 83 for sucking and holding the superposed wafer T are provided. The chuck 83 is evenly arranged on the same circumference as the rotating table 81. By rotating the turntable 81, the two suction cups 83 can be moved at the transfer position A0 and the processing position A1. In addition, each of the two suction cups 83 is configured to be rotatable about a vertical axis by a rotating mechanism (not shown).

At the transfer position A0, transfer of the overlapped wafer T is performed. At the processing position A1, a polishing unit 84 is arranged. In the polishing unit 84, the back surface Wb of the wafer W to be processed is polished. The grinding unit 84 has a grinding portion 85, and the grinding portion 85 is provided with a ring-shaped and freely rotatable grinding wheel (not shown). In addition, the polishing part 85 is configured to be movable in the vertical direction along the support 86. Then, with the grinding wheel abutting the back surface Wb of the processed wafer W held by the chuck 83, the chuck 83 and the grinding wheel are rotated separately to grind the back surface Wb.

The above-mentioned 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 includes a program storage unit (not shown). In the program storage section, a program for controlling the processing of the superposed wafer T of the wafer processing system 1 is stored. In addition, the program storage section also contains programs for controlling the operation of the above-mentioned various processing devices, conveying devices and other drive systems to realize the wafer processing system 1 described later. In addition, the above-mentioned program can also be recorded on a computer-readable recording medium H, and installed on the control device 90 from the recording medium H.

Next, the above-mentioned reforming device 60 will be described. FIG. 4 is a plan view showing the outline of the structure of the reforming device 60. FIG. 5 is a side view showing the outline of the configuration of the reforming device 60.

The reforming device 60 includes a suction cup 100 as a holding part, and the suction cup 100 holds the superposed wafer T on the top surface. The chuck 100 sucks and holds the support wafer S in a state where the processed wafer W is on the upper side and the support wafer S is arranged on the lower side. The suction cup 100 is supported by the sliding table 102 via an air bearing 101. On the bottom surface side of the sliding table 102, a rotating mechanism 103 as a rotating part is provided. The rotating mechanism 103 serves as a driving source, such as a built-in motor. The chuck 100 is configured to be arbitrarily rotatable about a vertical axis by the rotation mechanism 103 via an air bearing 101. The sliding 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 part provided on the bottom surface side. In addition, the driving source of the moving mechanism 104 is not particularly limited, and a linear motor is used, for example.

A power meter 107 as a measuring unit is installed on the sliding table 102, and measures the output (power) of the laser light irradiated from the laser head 110 described later. The power meter 107 is installed at the end of the sliding table 102 in the negative direction of the Y axis. As will be described later, in the first position P1, the power meter 107 is arranged under the lens of the laser head 110. The power of the laser light measured by the power meter 107 is output to the control device 90. In the control device 90, the power of the laser light corresponding to the processing recipe is set, and it is confirmed whether the measured power of the laser light is appropriate (power confirmation). This power check is performed, for example, for each wafer W to be processed, that is, the processing target.

Above the suction cup 100, a laser head 110 as a reforming part is provided. The laser head 110 includes a lens 111 and a piezoelectric actuator 112. The lens 111 is disposed on the bottom surface of the laser head 110 and irradiates the processed wafer W held on the chuck 100 with laser light. The piezoelectric actuator 112 moves the lens 111 up and down.

In addition, the laser head 110 is provided with a sensor 113 for measuring the position of the laser light irradiated from the lens 111. The sensor 113 is provided coaxially with the laser light irradiated from the lens 111, for example, an AF sensor, and measures the height of the back surface Wb of the wafer W to be processed. 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 light irradiated to the inside of the wafer W to be processed based on the height of the back surface Wb.

Furthermore, the laser head 110 is further provided with a sensor 114 and a camera 115, which are used to adjust the irradiation position (focus) of the laser light irradiated from the lens 111. The sensor 114 is arranged off-axis from the laser light irradiated from the lens 111, and is, for example, an AF sensor; it measures the height of the back surface Wb of the processed wafer W and detects the back surface Wb. In addition, the sensor 114 uses an AF sensor that can measure a wider range than the aforementioned sensor 113. In addition, the camera 115 is provided coaxially with the laser light irradiated from the lens 111 and photographs the back surface Wb of the wafer W to be processed. The height of the back Wb measured by the sensor 114 and the image of the back Wb captured by the camera 115 are output to the control device 90 respectively. As described later, the control device 90 calculates the irradiation position of the laser light irradiated to the inside of the wafer W to be processed based on the height and the image of the back surface Wb.

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

Then, the laser head 110 oscillates from a laser oscillator (not shown) with high-frequency pulse-shaped laser light with a wavelength that is transmissive to the wafer W to be processed. The predetermined location inside is spotlighted. Thereby, the part condensed by the laser light is modified in the inside of the processed wafer W to form a peripheral modified layer, a segmented modified layer, and an inner surface modified layer.

The laser head 110 is supported by the supporting member 116. The laser head 110 is configured to be along a rail 117 extending in a vertical direction, and can be raised and lowered arbitrarily by a lifting mechanism 118. In addition, the laser head 110 is configured to be arbitrarily movable in the Y-axis direction by the moving mechanism 119. In addition, the lifting mechanism 118 and the moving mechanism 119 are supported by the supporting column 120 respectively.

Above the suction cup 100, on the positive side of the Y-axis of the laser head 110, a macro camera 121 as a first imaging unit and a super macro camera 122 as a second imaging unit are provided. For example, the macro camera 121 and the super macro camera 122 are integrated, and the macro camera 121 is arranged on the positive side of the Y axis of the super macro camera 122. The macro camera 121 and the super macro camera 122 are configured to be arbitrarily raised and lowered by the lifting mechanism 123, and further configured to be freely movable in the Y-axis direction by the moving mechanism 124.

The macro camera 121 images the outer end of the processed wafer W (superimposed wafer T). The macro camera 121 includes, for example, a coaxial lens, irradiates visible light, such as red light, and further receives reflected light from the object. In addition, for example, the shooting magnification of the macro camera 121 is 2 times.

The super macro camera 122 photographs the periphery of the processed wafer W, and photographs the boundary between the bonding area Aa and the unbonding area Ab. The super macro camera 122 includes, for example, a coaxial lens, irradiates infrared light (IR light), and further receives reflected light from the object. In addition, for example, the shooting magnification of the super macro camera 122 is 10 times, the field of view is about 1/5 relative to the macro camera 121, and the pixel size is about 1/5 relative to the macro camera 121.

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

The peripheral edge removing device 61 includes a suction cup 130 for holding the superposed wafer T on the top surface. The chuck 130 holds the support wafer S in a state where the processed wafer W is on the upper side and the support wafer S is arranged on the lower side. In addition, the suction cup 130 is configured to be rotatable about a vertical axis by the 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 wafer W to be processed is provided. The peripheral edge removal part 140 gives an impact to the peripheral edge part We, and removes this peripheral edge part We. The peripheral edge removal part 140 includes a wedge roller 141 and a support roller 142.

The wedge roller 141 has a wedge shape with a pointed tip in side view. The wedge roller 141 is inserted from the outer end of the processed wafer W and the support wafer S to the interface between the processed wafer W and the support wafer S. Then, the peripheral edge portion We is pushed up by the inserted wedge roller 141 to separate and remove it from the wafer W to be processed.

The supporting roller 142 passes through the center of the wedge roller 141 to support the wedge roller 141. The support roller 142 is configured to be freely movable in the horizontal direction by a moving mechanism (not shown), and the wedge roller 141 is also moved by the movement of the support roller 142. In addition, the support roller 142 is configured to be freely rotatable about a vertical axis, and the wedge roller 141 is also rotated by the rotation of the support roller 142. In addition, in the present embodiment, the support roller 142 uses a so-called free roller that is rotated by the rotation of the suction pad 130 as described later. However, the support roller 142 may also be actively rotated by a rotating mechanism (not shown).

In addition, in this embodiment, although the wedge roller 141 is used as the insertion member, the insertion member is not limited to this form. For example, if the insertion member has a shape whose width decreases toward the radially outer side in a side view, a knife-shaped insertion member with a sharp tip may also be used.

Above and below the chuck 130, nozzles 150 and 151 for supplying cleaning liquid to the wafer W to be processed are respectively provided. For the cleaning fluid, for example, pure water is used. When the peripheral edge portion We is impacted by the peripheral edge removal portion 140 to remove the peripheral edge portion We, dust (particles) is generated along with the removal. Therefore, in this embodiment, by supplying the cleaning liquid from the nozzles 150 and 151, the scattering of such dust is suppressed.

The upper nozzle 150 is arranged above the chuck 130 and supplies the cleaning liquid from above the processed wafer W to the back surface Wb. With the cleaning liquid from the upper nozzle 150, it is possible to suppress the scattering of dust that occurs when the peripheral portion We is removed, and further suppress the scattering of dust to the wafer W to be processed. Specifically, the cleaning liquid causes dust to flow to the outer peripheral side of the wafer W to be processed. In addition, the lower nozzle 151 is arranged below the chuck 130 and supplies the cleaning liquid to the wafer W to be processed from the supporting wafer S side. With the cleaning liquid from the lower nozzle 151, it is possible to more reliably suppress dust scattering. In addition, by the cleaning liquid from the lower nozzle 151, it is possible to prevent dust or scraps of the peripheral portion We from flowing back to the support wafer S side.

In addition, the number and arrangement of the nozzles 150 and 151 are not limited to this embodiment. For example, the nozzles 150 and 151 may be provided in plural respectively. In addition, the lower nozzle 151 may be omitted.

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

A detection part 160 is provided above the suction cup 130 to confirm whether the peripheral part We has been removed from the wafer W to be processed. The detection part 160 detects the presence or absence of the peripheral part We in the processed wafer W which is held by the suction cup 130 and the peripheral part We has been removed. The detecting unit 160 uses, for example, a sensor. The sensor, for example, a linear laser displacement meter, measures the thickness of the superimposed wafer T by irradiating the laser on the periphery of the superimposed wafer T (wafer W to be processed), and detects the thickness of the superimposed wafer T. With or without. In addition, the detection method of the presence or absence of the peripheral portion We performed by the detection unit 160 is not limited to this form. For example, the detection unit 160 can also use an in-line camera to photograph the overlapped wafer T (the wafer W to be processed), thereby detecting the presence or absence of the peripheral portion We.

In addition, a recovery part (not shown) is provided below the suction cup 130 to recover the peripheral edge We removed by the peripheral edge removal part 140.

Next, the transfer arm 71 of the above-mentioned wafer transfer device 70 will be described. FIG. 9 is a longitudinal sectional view showing the outline of the structure of the transport arm 71.

The transport arm 71 has a larger diameter than the superposed wafer T and includes a disc-shaped suction plate 170. A holding part 180 is provided on the bottom surface of the suction plate 170, and the holding part 180 holds the central part Wc of the wafer W to be processed.

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

On the top surface of the suction plate 170, a rotating mechanism 190 is provided for rotating the suction plate 170 around a vertical axis. The rotating mechanism 190 is supported by the supporting member 191. In addition, the supporting member 191 (rotating mechanism 190) is supported by the arm member 72.

Next, the wafer processing performed by the wafer processing system 1 configured as described above will be described. Figure 10 is a flowchart showing the main steps of wafer processing. Fig. 11 is an explanatory diagram of the main steps of wafer processing. In addition, in this embodiment, in a bonding device (not shown) outside the wafer processing system 1, the processed wafer W and the support wafer S are bonded to form a superposed wafer T in advance.

First, a cassette Ct containing a plurality of stacked wafers T shown in FIG. 11(a) is placed on the cassette mounting table 10 of the carry-in/out station 2.

Next, the superposed wafer T in the cassette Ct is taken out by the wafer transfer device 20 and transferred to the transfer device 30. Then, the superposed wafer T of the conveying device 30 is taken out by the wafer conveying device 50 and conveyed to the reforming device 60. In the reforming device 60, as shown in FIG. 11(b), a peripheral reforming layer M1 and a splitting reforming layer M2 are sequentially formed inside the processed wafer W (steps A1 and A2 of FIG. 10), as shown in FIG. As shown in 11(c), the inner surface reforming layer M3 is formed (step A3 in FIG. 10). The peripheral edge modified layer M1 becomes the base point when the peripheral edge portion We is removed in the peripheral edge trimming. The division of the modified layer M2 serves as a base point for small pieces of the removed peripheral portion We. The inner surface reforming layer M3 serves as a base point for thinning the wafer W to be processed.

FIG. 12 is a flowchart showing the main steps of the reforming process of the reforming device 60. Figure 13 is an explanatory diagram of the main steps of the reforming process. In this embodiment, as shown in FIG. 13, the chuck 100 is arrange|positioned at the 1st position P1 and the 2nd position P2, and each process is performed.

The reforming device 60 moves the chuck 100 (sliding table 102) to the first position P1 as shown in FIG. 13(a) before carrying in the superposed wafer T, and makes it stand by. During the standby of the chuck 100, the power meter 107 is arranged under the lens 111 of the laser head 110. The power meter 107 measures the output (power) of the laser light irradiated from the laser head 110. The power of the laser light measured by the power meter 107 is output to the control device 90, and the power check is performed in the control device 90. In addition, during the standby of the suction cup 100, the correction (calibration) of the optical system of the laser head 110 is also performed (step B1 in FIG. 12).

Here, for example, when the power meter 107 is located away from the first position P1, in order to check the power, it is necessary to move the chuck 100 from the first position P1 and the device becomes larger. In contrast to this, in the present embodiment, in the first position P1, the power meter 107 is arranged below the laser head 110, so the power check can be performed without moving the chuck 100. As a result, the dedicated area (bottom area) of the reforming device 60 can be reduced, and space can be saved. In addition, power verification and calibration can be performed during the standby of the chuck 100, so the time for the modification process can be shortened, and the throughput of wafer processing can be increased. In addition, power verification and calibration can also be performed during the loading of the superposed wafer T in step B2 described later.

Next, as shown in FIG. 13(b), in the state where the chuck 100 is arranged at the first position, the superposed wafer T is carried in from the wafer transfer device 50 (step B2 in FIG. 12). The transferred superposed wafer T is held on the suction cup 100.

Next, in a state where the suction cup 100 is arranged at the first position P1, the macro camera 121 is used to perform macro adjustment. In the first position P1, the macro camera 121 is arranged at a position that can image the outer end of the wafer W to be processed. Then, after the macro adjustment, the focus adjustment of the macro camera 121 is performed (step B3 in FIG. 12), the outer end of the processed wafer W is photographed (step B4 in FIG. 12).

First, in step B3, the focus adjustment of the macro camera 121 is performed on a plurality of points in the height direction of the wafer W to be processed. At this time, the suction cup 100 is not rotated. Then, the macro camera 121 is raised or lowered by the lifting mechanism 123, and the focus adjustment of the macro camera 121 is performed on a plurality of points in the height direction of the processed wafer W.

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

As shown in FIG. 14(a), in the comparative example, after raising and lowering the macro camera 121, the focus adjustment Q1 to Q4 are performed while the macro camera 121 is stopped at a predetermined height. That is, whenever the macro camera 121 is raised and lowered, acceleration and deceleration are repeated. Then, adjust Q1 to Q4 for each focus, and determine whether the focus value is appropriate. Therefore, it takes time.

On the other hand, as shown in FIG. 14(b), in this embodiment, the macro camera 121 is raised and lowered and the focus adjustments Q1 to Q4 are performed. That is, when the focus adjustment is performed, the macro camera 121 is not stopped. Therefore, the acceleration and deceleration of the comparative example are not required, and time can be saved, and further, the appropriateness of the focus value of the focus adjustment Q1 to Q4 can be judged as a whole. Therefore, the time for focus adjustment can be shortened. In addition, in the example of FIG. 14, the shortened time is t1.

Next, in step B4, the outer end of the wafer W to be processed is photographed at plural points in the circumferential direction of the wafer W to be processed. At this time, the macro camera 121 is not lifted and moved, but is fixed. Then, the chuck 100 is rotated, and the outer end R1 of the processed wafer W is photographed at a plurality of points in the circumferential direction of the processed wafer W as shown in FIG. 15 (dotted line in FIG. 15).

In the imaging of the outer end of the wafer W to be processed, similarly to the focus adjustment shown in FIG. 14 described above, in the comparative example, the chuck 100 is rotated and then the imaging is performed while stopping at a predetermined position. In contrast to this, in this embodiment, the chuck 100 is rotated to perform imaging of the outer end of the wafer W to be processed. In other words, when shooting is performed, the rotation of the suction cup 100 is not stopped. Therefore, the shooting time can be shortened. In addition, if the shooting time is shortened in this way, the number of shootings can also be increased. As a result, the macro adjustment can be appropriately implemented.

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

The control device 90 calculates the first eccentricity between the center Cc of the chuck 100 and the center Cw of the wafer W to be processed from the image of the macro camera 121. Furthermore, the control device 90 calculates the movement amount of the suction cup 100 based on the first eccentricity amount to correct the Y-axis component of the first eccentricity amount. The suction cup 100 moves in the Y-axis direction according to the calculated movement amount, so that the suction cup 100 moves to the super-fine pitch adjustment position. The super-macro alignment position is that the super-macro camera 122 can photograph the position of the periphery of the wafer W to be processed. Here, as described above, the field of view of the super macro camera 122 relative to the macro camera 121 is about 1/5, so if the Y-axis component of the first eccentricity is not corrected, there is a peripheral edge of the processed wafer W This is a situation where the viewing angle of the super macro camera 122 is not entered, and the super macro camera 122 cannot be used for shooting. Therefore, the correction of the Y-axis component based on the first eccentric amount can also be said to be for moving the suction cup 100 to the ultra-fine pitch alignment position.

In addition, in the macro adjustment using the macro camera 121, the light amount adjustment is also performed before the focus adjustment. The light quantity adjustment can be performed for each overlapped wafer T, can also be performed for each batch, or can be performed for each processing condition (processing recipe). The light quantity adjustment can be performed on one point or multiple points of the processed wafer W, but in this case, the rotation of the chuck 100 is stopped and the light quantity adjustment is performed. In addition, while the rotation of the suction cup 100 is stopped, the amount of light is changed a plurality of times to perform shooting.

In addition, as mentioned above, the macro adjustment is performed to move the suction cup 100 to the super macro adjustment position, but this macro adjustment can be omitted. That is, if the adjustment is not performed in the two stages of macro and super macro, but only in the super macro stage, the macro adjustment is omitted.

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

Next, with the suction cup 100 arranged at the second position P2, the super macro camera 122 is used to perform super macro adjustment. At the second position P2, the super macro camera 122 is arranged at a position capable of photographing the boundary between the bonded area Aa and the unbonded area Ab of the wafer W to be processed. Then, after the super macro adjustment and the focus adjustment of the super macro camera 122 are performed (step B6 in FIG. 12), the boundary between the joint area Aa and the unjoined area Ab is photographed (step B7 in FIG. 12).

First, in step B6, in the height direction of the processed wafer W, the focus adjustment of the super macro camera 122 is performed on a plurality of points. The focus adjustment of the super macro camera 122 is carried out by lifting the super macro camera 122 through the lifting mechanism 123. Therefore, the time for focus adjustment can be shortened. In addition, the focus adjustment of the super macro camera 122 is the same as the focus adjustment of the macro camera 121 in step B3, so the description is omitted.

Next, in step B7, the boundary between the bonded area Aa and the unbonded area Ab of the processed wafer W is photographed at plural points in the circumferential direction of the processed wafer W. At this time, the macro camera 121 is not lifted and moved, but is fixed. Then, the chuck 100 is rotated, and the boundary R2 between the bonded area Aa and the unbonded area Ab is photographed at a plurality of points in the circumferential direction of the wafer W to be processed as shown in FIG. 16 (dotted line in FIG. 16).

In the imaging of the boundary between the bonded area Aa and the unbonded area Ab, similarly to the imaging of the outer end of the processed wafer W in step B3, in the comparative example, after rotating the chuck 100, it stops at a predetermined position The shooting is carried out in the state. On the other hand, in the present embodiment, the chuck 100 is rotated to perform imaging of the boundary between the bonded area Aa and the unbonded area Ab. In other words, when shooting is performed, the rotation of the suction cup 100 is not stopped. Therefore, the shooting time can be shortened. In addition, if the shooting time is shortened in this way, the number of shootings can also be increased. As a result, the super-macro adjustment can be appropriately performed.

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

The control device 90 calculates the second eccentricity between the center Cc of the suction cup 100 and the center Ca of the joining area Aa from the image of the super macro camera 122. Furthermore, the control device 90 determines the position of the suction cup 100 relative to the peripheral modified layer M1 in such a manner that the center of the joining area Aa is consistent with the center of the suction cup 100 according to the second eccentricity amount.

Next, in a state where the suction cup 100 is arranged at the second position P2, the height adjustment (irradiation height adjustment) of the laser light irradiated from the laser head 110 is performed (step B8 in FIG. 12). In the second position P2, the lens 111 of the laser head 110 is arranged at a position where the laser light can irradiate the boundary between the peripheral portion We and the central portion Wc of the wafer W to be processed.

Here, as described later, in step B9, the chuck 100 is rotated, and laser light is irradiated from the laser head 110 to the inside of the processed wafer W to form a ring-shaped peripheral reforming layer. In addition, in step B9, the irradiation position (irradiation height) of the laser light is measured, and the height of the laser light is adjusted (tracked) in real time. Therefore, the height of the starting position of the laser light irradiation becomes important. Therefore, the irradiation height adjustment of the laser light in step B8 is performed at the start position of the laser light irradiation in step B9.

In addition, the height of the processed wafer W held on the chuck 100 may be uneven in the wafer surface due to various factors. In this way, the height of the peripheral part and the center part 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, the peripheral part may not be adjusted appropriately. Therefore, from this point of view, the adjustment of the irradiation height of the laser light in step B8 is also suitable to be performed at the start position of the laser light irradiation in step B9.

Furthermore, the tracking range of the sensor 113 used for measuring the irradiation position of the laser light in step B9 is limited. This range is, for example, from the measuring object, namely the back surface Wb of the processed wafer W, to the vertical direction ±0.2mm. Therefore, in order to converge the irradiation position of the laser light in step B9 within the trackable range of the sensor 113, the irradiation height adjustment of step B8 must also be performed.

In step B8, first, the sensor 114 and the camera 115 are moved to the start position of laser light irradiation in step B9. Then, the laser head 110 is raised and lowered, and the sensor 114 measures the height of the back surface Wb of the processed wafer W at the start position of the laser light irradiation, and detects the back surface Wb. The height of the back Wb measured by the sensor 114 is output to the control device 90. The control device 90 detects (designates) the position of the back Wb based on the height of the back Wb.

In step B8, next, the laser head 110 is moved horizontally to the irradiation position of the laser light in step B9. Then, with the camera 115, the back Wb is photographed. The image of the back 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 light irradiated to the inside of the wafer W to be processed 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 light, the calculated position is set to the sensor 113 as the origin position of the irradiation position of the laser light (zero point adjustment). In this way, in step B8, after rough detection of the back surface Wb is performed by the sensor 114, the back surface Wb is carefully grasped by the camera 115 to perform zero point adjustment.

In addition, in step B8, the laser head 110 is raised or lowered, and the sensor 114 and the camera 115 are used to perform zero point adjustment. Here, similar to the focus adjustment shown in FIG. 14 above, when the lifting of the laser head 110 is stopped, and the height of the back surface Wb is measured by the sensor 114 in the state of stopping at a predetermined height, the zero point adjustment costs time. In contrast, in this embodiment, the laser head 110 is raised and lowered, and the measurement by the sensor 114 is performed. That is, when the measurement by the sensor 114 is performed, the elevation of the laser head 110 is not stopped. Therefore, the time for zero point adjustment can be shortened. Similarly, the shooting of the back side Wb by the camera 115 is performed after stopping the lifting of the laser head 110 and stopping at a predetermined height, and the zero point adjustment takes time. On the other hand, by raising and lowering the laser head 110 and performing the shooting of the back Wb by the camera 115, the time for zero point adjustment can be shortened.

Next, the sensor 113 is moved to the start position of the laser light irradiation. Thereafter, as shown in FIGS. 17 and 18, laser light L1 (laser light L1 for the peripheral edge) is irradiated from the laser head 110 to form a peripheral edge modified layer on the boundary between the peripheral edge portion We and the central portion Wc of the processed wafer W M1 (Step B9 in Figure 12, Step A1 in Figure 10). The peripheral modified layer M1 is formed in plural at different heights. In addition, the peripheral modified layer M1 is formed on the radially inner side of the outer end of the joining area Aa.

The peripheral modified layer M1 formed by the laser light L1 extends in the thickness direction and has a longitudinal aspect ratio. The lower end of the lowermost peripheral modified layer M1 is located above the target surface (dotted line in FIG. 17) of the thinned wafer W to be processed. That is, the distance H1 between the lower end of the peripheral modified layer M1 and the surface Wa of the processed wafer W is larger than the target thickness H2 of the processed wafer W after thinning. In this case, the processed wafer W after thinning does not leave the peripheral modified layer M1. In addition, in the inside of the processed wafer W, the crack C1 develops from the plurality of peripheral modified layers M1 to reach the back surface Wb and the surface Wa.

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

Then, the chuck 100 (the wafer W to be processed) is rotated and moved in this way, and the laser light L1 is irradiated from the laser head 110 to the inside of the wafer W to be processed. That is, the second amount of eccentricity calculated in step B7 is corrected, and the peripheral edge modified layer M1 is formed. In this way, the peripheral modified layer M1 is formed into a ring shape concentrically with the junction area Aa. Therefore, afterwards, in the peripheral edge removing device 61, the peripheral edge portion We can be appropriately removed using the peripheral edge modified layer M1 as a base point.

In addition, in this example, when the second eccentricity has an X-axis component, the suction cup 100 is moved in the Y-axis direction and the suction cup 100 is rotated to correct the X-axis component. On the other hand, when the second eccentric amount does not have an X-axis component, the suction pad 100 may only be moved in the Y-axis direction without rotating it.

In addition, at the second position P2, with respect to the processed wafer W held by the chuck 100, the super macro camera 122 is arranged on the positive side of the Y axis, and the lens 111 of the laser head 110 is arranged on the negative side of the Y axis. In this case, in step B9, the peripheral modified layer M1 is formed by the laser head 110, and the peripheral modified layer M1 is photographed by the super macro camera 122 at the same time. The captured image is output to the control device 90, and the control device 90 checks whether the peripheral edge modified layer M1 is formed in an appropriate position. In this way, by performing the formation and inspection of the peripheral modified layer M1 in parallel, work efficiency can be improved. In addition, as a result of the inspection, when the peripheral modified layer M1 deviates from a predetermined position, the movement of the suction cup 100 can be finely adjusted.

In this way, between the laser light L1 being irradiated to the inside of the processed wafer W to form the peripheral modified layer M1, the sensor 113 measures the height of the back surface Wb of the processed wafer W, and the control device 90 Calculate the irradiation position of the laser light L1. Then, it is controlled to make the calculated irradiation position of the laser light L1 coincide with the origin position set in step B8. Specifically, according to the calculated irradiation position of the laser light L1, the lens 111 is raised and lowered by the piezoelectric actuator 112. In this way, in step B9, the height of the tracking laser light L1 is adjusted in real time.

Here, the sensor 113 is provided coaxially with the laser light L1 irradiated from the lens 111. According to the processing formula of step B9, the irradiation radius of the laser light L1 (radius of the peripheral modified layer) may be different. In this case, if the sensor 113 is arranged on a different axis from the laser light L1, the sensor 113 becomes the back surface Wb of the processed wafer W that measures a position different from the position irradiated by the laser light L1 It is possible to deviate from the actual height. Therefore, in this embodiment, the sensor 113 is provided coaxially with the laser light L1.

In step B9, a circle of laser light L1 is irradiated to the inside of the wafer W to be processed as described above to form a peripheral modified layer M1. Then, when forming a plurality of peripheral modified layers M1 at different heights as in the present embodiment, the irradiation position (irradiation height) of the laser light L1 is changed. Hereinafter, the method of forming the plurality of peripheral edge modified layers M1 of this embodiment will be described.

FIG. 19 is an explanatory diagram illustrating a method of forming a plurality of peripheral edge modified layers M1, the vertical axis represents the rotation speed, and the horizontal axis represents time. In addition, L1 in FIG. 19 represents the irradiation of the laser light L1, and D represents the change of the processing conditions (processing recipe) when forming the peripheral modified layer M1. Processing condition change D includes: raising and lowering the lens 111 to change the irradiation position of the laser light L1; and changing the conditions of the laser light L1, such as the output (power), frequency, shape (laser pattern), number of branches of the laser light L1, etc. . In addition, Fig. 19 (a) shows a comparative example, and (b) shows an example of this embodiment.

As shown in FIG. 19(a), in the comparative example, after accelerating the rotation of the chuck 100, the laser light L1 is irradiated once at a constant speed to form a peripheral modified layer M1. After that, after decelerating the rotation of the chuck 100, the process condition change D is performed while the rotation is stopped. That is, every time a peripheral modified layer M1 is formed, the process condition change D is performed. Whenever the processing condition change D is performed, the acceleration and deceleration of the rotation of the suction cup 100 are repeated. Therefore, it takes time.

On the other hand, as shown in FIG. 19(b), in this embodiment, the chuck 100 is rotated, and the process condition change D of the peripheral modified layer M1 is performed. That is, when the process condition change D is executed, the rotation of the chuck 100 is not stopped. Therefore, the acceleration and deceleration of the rotation of the suction cup 100 of the comparative example are not required, and time can be saved. Therefore, it is possible to shorten the time for forming a plurality of peripheral modified layers M1. In addition, in the example of FIG. 19, the time that can be shortened is t2. In addition, if the time for forming a plurality of peripheral edge modified layers M1 is shortened in this way, the number of formed peripheral edge modified layers M1 can also be increased.

In addition, when the laser light L1 is continuously irradiated as shown in FIG. 19(b) and the processing condition of the peripheral modified layer M1 is changed D, as shown in FIG. 20, when one layer of the peripheral modified layer M1 is formed The irradiation start position and the irradiation end position of the laser light L1 are respectively offset in the circumferential direction.

On the other hand, as shown in FIG. 21, the irradiation start position and the irradiation end position of the laser light L1 when forming one peripheral edge modified layer M1 may be the same. Then, after the process condition change D of the peripheral modified 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. In this case, the rotation of the chuck 100 is not stopped when the process condition change D is performed, and the time for forming the plurality of peripheral modified layers M1 can be shortened.

In addition, in the example shown in FIG. 19, when forming a plurality of peripheral edge modified layers M1, the case where the processing conditions are changed for each peripheral edge modified layer M1 will be described. However, there is also a case where one layer of peripheral edge modified layer M1 is formed. Time, that is, the condition of changing the conditions of the laser light L1 while the laser light L1 makes one revolution. For example, in the wafer W to be processed, the conditions of the laser light L1 may be changed in accordance with the crystal orientation of silicon. FIG. 22 is an explanatory diagram showing an example in which the conditions of the laser light L1 are changed during one revolution. In the example shown in FIG. 22, the processed wafer W is divided into four, and the diagonally processed wafers W1 and W1 are irradiated with laser light L1 under one condition, and the processed wafers W2 and W2 are irradiated with laser light under another condition. Shoot light L1.

In the case of performing the processing shown in FIG. 22, in the comparative example, with the chuck 100 rotating, the laser beam L1 is irradiated to the processed wafers W1 and W1 in the first circle, and the processed wafers W2 and W2 are stopped. Irradiation of laser light L1. After that, in a state where the rotation of the suction cup 100 is stopped first, the conditions of the laser light L1 are changed. Then, while the chuck 100 is rotated again, the laser light L1 is irradiated to the processed wafers W2 and W2 in the second circle, and the laser light L1 is irradiated to the processed wafers W1 and W1. In this case, since the acceleration and deceleration of the rotation of the chuck 100 are performed when the condition of the laser light L1 is changed, it takes time.

In contrast, in this embodiment, the chuck 100 is rotated and the conditions of the laser light L1 are changed. That is, when the condition of the laser light L1 is changed, the rotation of the suction cup 100 is not stopped. Therefore, the acceleration and deceleration of the rotation of the suction cup 100 of the comparative example are not required, and time can be saved. Therefore, the time for forming the peripheral modified layer M1 can be shortened.

Here, as shown in FIG. 23, a notch portion Wn is formed on the outer edge of the wafer W to be processed. For example, as shown in FIG. 23(a), when the formation position of the peripheral modified layer M1 overlaps the notch portion Wn, the laser light L1 is irradiated to the notch portion Wn. As a result, at the end of the notch portion Wn, the cross-section irradiated by the laser light L1 is roughened. In addition, in step B9 as described above, when the chuck 100 is rotated to irradiate the laser light L1, the irradiation position (irradiation height) of the laser light L1 is adjusted (tracked) in real time. At this point, if the laser light L1 is irradiated to the notch portion Wn, the irradiation position of the laser light L1 changes. In this way, it takes time to adjust the irradiation position of the laser light L1 immediately outside of the notch Wn.

Therefore, in this embodiment, in step B9, as shown in FIG. 23(b), it is controlled so that the laser light L1 does not irradiate the notch portion Wn. Since the position of the notch portion Wn of the wafer W to be processed is grasped in advance, when the lens 111 of the laser head 110 is arranged above the notch portion Wn, the irradiation of the laser light L1 may be stopped. In this case, the laser light L1 is not irradiated to the notch portion Wn, so the end section of the notch portion Wn is not roughened. In addition, in the notch portion Wn, the instant adjustment of the irradiation position of the laser light L1 is stopped. In this way, during the irradiation of the laser light L1 in one circle, the irradiation position of the laser light L1 does not change significantly, and the instant adjustment outside the notch portion Wn becomes simple.

If the peripheral modified layer M1 is formed as described above, then, as shown in FIGS. 24 and 25, laser light L2 (laser light L2 for division) is irradiated from the laser head 110, and the peripheral modified layer M1 is formed radially outside The modified layer M2 is divided (step B10 in FIG. 12, step A2 in FIG. 10).

The divided modified layer M2 also extends in the thickness direction similarly to the peripheral modified layer M1, and has a longitudinal aspect ratio. In addition, the crack C2 develops from the divided modified layer M2 and reaches the back surface Wb and the surface Wa.

In addition, by forming a plurality of split modified layers M2 and cracks C2 at a distance of several μm in the radial direction, as shown in FIG. 25, a split line extending from the peripheral modified layer M1 toward the radially outer side is formed Modified layer M2. In addition, in the example shown in the figure, the divided modified layers M2 extending in the radial direction are formed at 8 locations, but the number of divided modified layers M2 is arbitrary. If the divided modified layer M2 is formed in at least two places, the peripheral edge We can be removed. In this case, when the peripheral portion We is removed during peripheral trimming, the peripheral portion We is separated with the annular peripheral modified layer M1 as a base point, and is divided into a plurality of pieces by dividing the modified layer M2. In this way, the removed peripheral portion We is made into small pieces, and it can be removed more easily.

Here, in the comparative example, as shown in FIG. 26, there is a case where the chuck 100 is moved in the Y-axis direction to form the divided modified layer M2. That is, as shown in FIG. 26(a), from the state where the suction cup 100 is located on the positive side of the Y axis of the lens 111, as shown in FIG. 26(b), the suction cup 100 is moved in the negative direction of the Y axis. Then, when the wafer W to be processed passes under the lens 111, the laser light L2 is irradiated to one end of the peripheral portion We to form the divided modified layer M21. After that, as shown in FIG. 26(c), the chuck 100 is further moved in the negative direction of the Y-axis to form a divided modified layer M22 at the other end of the peripheral portion We. In this way, the divided modified layers M21 and M22 are formed on the peripheral edge portion We in the opposite direction. In this case, the movement distance D1 of the suction cup 100 becomes longer. Specifically, the moving distance D1 includes, for example, one piece of the wafer W to be processed, the distance for acceleration and deceleration from the chuck 100.

In contrast, in step B10 of the present embodiment, as shown in FIG. 27, the divided modified layer M2 is formed only at one end of the peripheral portion We to further rotate the suction cup 100, thereby reducing the moving distance of the suction cup 100. That is, as shown in FIG. 27(a), from the state where the suction cup 100 is located on the positive side of the Y axis of the lens 111, the suction cup 100 is moved in the negative direction of the Y axis as shown in FIG. 27(b). Then, when the wafer W to be processed passes under the lens 111, laser light L2 is irradiated to one end (circumferential position) of the peripheral portion We to form a divided modified layer M21. Next, as shown in FIG. 27(c), the suction cup 100 is rotated 180 degrees. Thereafter, as shown in FIG. 27(d), the suction pad 100 is moved in the positive direction of the Y axis, and the divided modified layer M22 is formed at the other end portion (another circumferential position) of the peripheral edge portion We. In this case, the movement distance D2 of the suction cup 100 becomes shorter. Specifically, the moving distance D2 may only have the formation width of the divided modified layer M2, the distance used for acceleration and the distance used for deceleration with the suction cup 100, for example.

In this way, in the present embodiment, when the divided modified layer M2 is formed in step B10, the moving distance of the suction cup 100 is shortened, and the occupied area (bottom area) of the modifying device 60 can be reduced, thereby saving space.

In addition, in the present embodiment, when the divided modified layer M2 is formed, the suction cup 100 is moved in the Y-axis direction, but the laser head 110 may be moved in the Y-axis direction.

Next, as shown in FIGS. 28 and 29, laser light L3 (laser light L3 for the inner surface) is irradiated from the laser head 110 to form an inner surface reforming layer M3 along the surface direction (step B11 in FIG. 12, step B11 in FIG. 10) Step A3). In addition, the black arrow shown in FIG. 29 indicates the rotation direction of the suction cup 100, which is the same in the following description.

The lower end of the inner surface reforming layer M3 is located slightly above the target surface (dotted line in FIG. 28) of the thinned wafer W to be processed. That is, the distance H3 between the lower end of the inner surface reforming 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. In addition, in the inside of the processed wafer W, the crack C3 develops toward the surface from the inner surface reforming layer M3.

In step B11, the chuck 100 (wafer W to be processed) is rotated, and the laser head 110 is moved in the Y-axis direction from the outer periphery of the wafer W to be processed toward the center portion, and the laser head 110 is directed to the wafer to be processed. The inside of circle W irradiates laser light L3. In this way, the inner surface reforming layer M3 is formed spirally from the outside to the inside in the surface of the wafer W to be processed.

In addition, in this embodiment, when forming the inner surface reforming layer M3, the laser head 110 is moved in the Y-axis direction, but the suction cup 100 may be moved in the Y-axis direction. In addition, when the inner surface reforming layer M3 is formed, the chuck 100 is rotated, but the laser head 110 may be moved so that the laser head 110 rotates relative to the chuck 100.

Next, as shown in FIG. 13(d), the sucker 100 is moved to the first position P1 (step B12 in FIG. 12). Thereafter, in the first position P1, the superposed wafer T is carried out by the wafer transport device 70 (step B13 in FIG. 12).

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

The superposed wafer T carried out from the reforming device 60 is then transported to the peripheral edge removing device 61 by the wafer transporting device 70. In the peripheral edge removing device 61, as shown in FIG. 11(d), the peripheral edge portion We of the processed wafer W is removed based on the peripheral edge modified layer M1 (step A4 in FIG. 10). In step A4, as shown in FIG. 8, the wedge roller 141 is inserted from the outer end of the processed wafer W and the support wafer S to the interface between the processed wafer W and the support wafer S. Then, the peripheral edge portion We is pushed up by the inserted wedge roller 141, and the peripheral edge modified layer M1 is used as a base point to be separated and removed from the processed wafer W. At this time, using the divided modified layer M2 as a base point, the peripheral portion We is divided into small pieces and separated. In addition, the removed peripheral edge part We is recovered to a recovery part (not shown).

Next, the superposed wafer T is transferred to the processing device 80 by the wafer transfer device 70. In the processing device 80, first, the superposed wafer T is transferred from the transfer arm 71 to the chuck 83 at the transfer position A0. At this time, as shown in FIG. 11(e), the back surface Wb side of the processed wafer W (hereinafter referred to as the back surface wafer Wb1) is separated with the inner surface reforming layer M3 as a base point (Step A5 in FIG. 10).

In step A5, the wafer W to be processed is sucked and held by the suction plate 170 of the transport arm 71, and the supporting wafer S is sucked and held by the suction cup 83. Then, the suction plate 170 is rotated to detach the back wafer Wb1 with the inner surface reforming layer M3 as the boundary. Thereafter, in a state where the suction plate 170 adsorbs and holds the back wafer Wb1, the suction plate 170 is raised to separate the back wafer Wb1 from the wafer W to be processed. At this time, by measuring the suction pressure of the back wafer Wb1 with the pressure sensor 183, the presence or absence of the back wafer Wb1 can be detected, and it can be confirmed whether the back wafer Wb1 has been separated from the wafer W to be processed. In addition, the separated back wafer Wb1 is recovered to the outside of the wafer processing system 1.

Then, the suction cup 83 is moved to the processing position A1. After that, by the polishing unit 84, as shown in FIG. 11(f), the back surface Wb of the processed wafer W held on the chuck 83 is polished, and the inner surface modifying layer M3 and the peripheral edge remaining on the back surface Wb are modified. The quality layer M1 is removed (step A6 in FIG. 10). In step A6, in a state where the grinding wheel is in contact with the back surface Wb, the wafer W to be processed and the grinding wheel are rotated separately to polish the back surface Wb. In addition, after that, a cleaning liquid nozzle (not shown) may be used to clean the back surface Wb of the wafer W to be processed with the cleaning liquid.

Next, the superposed wafer T is transferred to the cleaning device 41 by the wafer transfer device 70. The cleaning device 41 scrubs and cleans the polished surface of the processed wafer W, that is, the back surface Wb (Step A7 in FIG. 10). In addition, the cleaning device 41 can also clean the back surface Sb of the supporting wafer S and the back surface Wb of the wafer W to be processed together.

Next, the superposed wafer T is transferred to the etching device 40 by the wafer transfer device 50. The etching device 40 wet-etches the back surface Wb of the wafer W to be processed by the chemical solution (step A8 in FIG. 5). On the back surface Wb polished by the above-mentioned processing device 80, polishing marks may be formed. In this step A8, the polishing marks can be removed by wet etching, and the back surface Wb can be smoothed.

Thereafter, the superposed wafer T that has undergone all the processing is transported by the wafer transport device 50 to the transport device 30, and further transported by the wafer transport device 20 to the cassette of the cassette mounting table 10 Ct. In this way, a series of wafer processing by the wafer processing system 1 is ended.

According to the above-mentioned embodiment, by optimizing the positions of the components of the reforming device 60 and the processing content, the area occupied by the reforming device 60 can be reduced and space is saved. In addition, along with this, the throughput of wafer processing can also be increased.

In more detail, in the reforming device 60, by disposing the suction cup 100 in two positions, the first position P1 and the second position, all the processing can be performed. That is, at the first position P1, the power verification and calibration of step B1, the loading and unloading of the superposed wafer T of steps B2 and B12, and the fine pitch adjustment of steps B3 and B4 are performed. At the second position P2, perform the ultra-fine pitch alignment of steps B6 and B7, the irradiation height adjustment of the laser light in step B8, the formation of the peripheral modified layer M1 in step B9, the formation of the divided modified layer M2 in step B10, And the formation of the inner surface reforming layer M3 in step B11. In this way, it is sufficient to move the suction cup 100 between the first position P1 and the second position P2, so the movement distance thereof is shortened, and the cost of controlling the movement of the suction cup 100 can be reduced.

In addition, when the chuck 100 is arranged at the first position P1, the power meter 107 is arranged under the lens 111 of the laser head 110. For example, when the power meter 107 is located at a position away from the first position P1, it is necessary to move the chuck 100 from the first position P1 in order to confirm the power, but this embodiment does not require such movement of the chuck 100. Therefore, the area occupied by the reforming device 60 can be reduced to save space. In addition, in step B1, power verification and calibration can be performed during the standby of the chuck 100, so the time for the modification process can be shortened, and the throughput of wafer processing can also be increased.

In addition, when forming the divided modified layer M2 in step B10, after the divided modified layer M21 is formed at one end of the peripheral portion We, the chuck 100 is rotated to form the divided modified layer M22 at the other end of the peripheral portion We. Therefore, the moving distance of the suction cup 100 can be shortened, and the occupied area of the reforming device 60 can be reduced to save space.

In addition, in the above embodiment, the removal of the peripheral edge portion We is performed in the peripheral edge removing device 61 using the peripheral edge removing portion 140, but the removal method is not limited to this form. For example, the peripheral portion We may be held and removed, or the peripheral portion We may be removed by giving a physical impact, ultrasonic waves, or the like.

In addition, in the above embodiment, the separation of the backside wafer Wb1 from the processed wafer W is performed when the superposed wafer T is transferred from the transfer arm 71 of the wafer transfer device 70 to the suction cup 83 of the processing device 80, but the separation The method is not limited to this form. For example, the separation device (not shown) and the peripheral edge removal device 61 may be installed in the same device, or the separation device (not shown) may be installed separately.

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

In addition, in the above-mentioned embodiment, the case where the processed system overlaps the wafer T is described, but it is not limited to this form. The object to be processed may be, for example, something other than the substrate, and when laser light is irradiated to the inside of the object to form a modified layer, the above-mentioned embodiment can be applied.

It should be understood that all the points of the embodiments disclosed this time are only examples, and do not limit the present invention. The above-mentioned embodiments may be omitted, replaced, and changed in various forms without departing from the scope of the appended invention patent application and the spirit thereof.

1: Wafer processing system 2: move out and inbound 3: Processing station 10: Wafer cassette placement table 20: Wafer handling device 21: Transport road 22: Handling arm 30: Conveyor 40: Etching device 41: Cleaning device 50: Wafer handling device 51: Handling arm 60: Modification device 61: Perimeter removal device 70: Wafer handling device 71: Handling arm 72: arm member 80: Processing device 81: Rotating table 82: Rotation centerline 83: Suction Cup 84: Grinding unit 85: Grinding Department 86: Pillar 90: control device 100: Suction cup 101: Air bearing 102: Sliding table 103: Rotating mechanism 104: mobile organization 105: Orbit 106: Abutment 107: Power Meter 110: Laser head 111: lens 112: Piezo Actuator 113: Sensor 114: Sensor 115: Camera 116: support member 117: Orbit 118: Lifting mechanism 119: Mobile Organization 120: Support column 121: Macro camera 122: Super Macro Camera 123: Lifting mechanism 124: Mobile Organization 130: Suction Cup 131: Rotating Mechanism 140: Peripheral removal part 141: wedge roller 142: Support scroll wheel 150,151: nozzle 160: Detection Department 170: Adsorption board 180: holding part 181: Suction tube 182: Suction Mechanism 183: Pressure Sensor 190: Rotating Mechanism 191: support member A0: transfer position A1: Processing position Aa: junction area Ab: unjoined area C1, C2, C3: crack Ca, Cc, Cw: Center Ct: Wafer cassette D: Change of processing conditions D1, D2: moving distance F: Oxide film G1~G3: processing block H: recording medium H1, H3: distance H2: target thickness L1, L2, L3: laser light M1: peripheral modified layer M2, M21, M22: split modified layer M3: internal surface modification layer P1: 1st position P2: 2nd position Q1~Q4: Focus adjustment R1: Outer end R2: border S: Support wafer Sa: surface Sb: back T: Coincident wafer W, W1, W2: Wafer being processed Wa: surface Wb: back Wb1: backside wafer Wc: Central We: Peripheral Wn: Notch

FIG. 1 is a plan view showing the outline of the configuration of the wafer processing system of this embodiment. Fig. 2 is a side view showing the outline of the structure of the superposed wafer. Fig. 3 is a side view showing the outline of the structure of a part of the superposed wafer. Fig. 4 is a plan view showing the outline of the configuration of the reforming device. Fig. 5 is a side view showing the outline of the configuration of the reforming device. Fig. 6 is a plan view showing the outline of the configuration of the peripheral edge removing device. Fig. 7 is a side view showing the outline of the configuration of the peripheral edge removing device. Fig. 8 is an explanatory diagram showing the outline of the configuration of the peripheral edge removing device. Fig. 9 is a longitudinal sectional view showing the outline of the structure of the transport arm. FIG. 10 is a flowchart showing the main steps of wafer processing in this embodiment. 11(a) to (f) are explanatory diagrams of the main steps of wafer processing in this embodiment. Figure 12 is a flowchart showing the main steps of the modification process. Figure 13 (a) ~ (d) are explanatory diagrams of the main steps of the reforming process. Fig. 14(a) and (b) are explanatory diagrams showing the timing of performing focus adjustment relative to the elevation of the super macro camera. Fig. 15 is an explanatory diagram showing how the macro camera photographs the outer end of the processed wafer. FIG. 16 is an explanatory diagram showing how the super macro camera photographs the boundary between the bonded area and the unbonded area of the processed wafer. Fig. 17 is an explanatory diagram showing how a peripheral modified layer is formed on a processed wafer. Fig. 18 is an explanatory diagram showing a state in which a peripheral modified layer is formed on a wafer to be processed. Fig. 19 (a) and (b) are explanatory diagrams schematically showing a method of forming a plurality of peripheral modified layers. Fig. 20 is an explanatory diagram showing how a plurality of peripheral modified layers are formed. Fig. 21 is an explanatory diagram showing how a plurality of peripheral modified layers are formed. Fig. 22 is an explanatory view showing how a peripheral modified layer is formed. Fig. 23 (a) and (b) are explanatory diagrams showing the periphery of the notch portion when a peripheral modified layer is formed on the wafer to be processed. FIG. 24 is an explanatory diagram showing how a divided modified layer is formed on a processed wafer. FIG. 25 is an explanatory diagram showing a state where a divided modified layer is formed on the wafer to be processed. Fig. 26 (a) to (c) are explanatory diagrams showing how the divided modified layer is formed in the comparative example. Figures 27 (a) to (d) are explanatory diagrams showing how divided modified layers are formed in this embodiment. Fig. 28 is an explanatory diagram showing how an internal surface reforming layer is formed on a processed wafer. Fig. 29 is an explanatory diagram showing how an internal surface reforming layer is formed on a processed wafer.

100: Suction cup

102: Sliding table

107: Power Meter

110: Laser head

111: lens

121: Macro camera

122: Super Macro Camera

P1: 1st position

P2: 2nd position

W: Wafer being processed

Claims (10)

A processing device used to process the processed object, including: The holding part holds the processed body; The modified part irradiates laser light to the inside of the processed body held in the holding part to form a modified layer; The measuring part measures the output of the laser light; A moving part for moving the holding part between a first position where the object to be processed is carried in and out of the holding part and a second position where the modified layer is formed by the modified part; and A control part, controlling the holding part, the modifying part, the measuring part and the moving part; The control part controls the holding part, the measuring part, and the moving part so that the measuring part measures the output of the laser light when the holding part stands by at the first position. Such as the processing device in item 1 of the request, in which, The measuring part is arranged on the holding part; In the first position, the measuring part is arranged below the modified part. Such as the processing device of claim 1 or 2, in which, The object to be processed is a superimposed substrate formed by joining a first substrate and a second substrate; The holding portion holds the superposed substrate from the second substrate side; The modified part irradiates the laser light along the boundary between the peripheral part and the central part of the work to be removed inside the first substrate to form the modified layer, that is, the peripheral modified layer. Such as the processing device of item 3 of the request, in which, It also contains: A first imaging part, when the holding part is arranged at the first position, imaging the outer end of the first substrate; and The second imaging part, when the holding part is arranged at the second position, photographs the boundary between the bonding area where the first substrate and the second substrate are bonded, and the unbonded area outside the bonding area. Such as the processing device of item 3 or 4 of the request, in which, It further includes a rotating part for rotating the holding part; The modified portion, at the second position, irradiates laser light from the peripheral modified layer to the radially outer side of the first substrate held in the holding portion to form a divided modified layer; The control portion controls the holding portion, the modified portion, the moving portion, and the rotating portion so that the modified portion is arranged above the circumferential position of the peripheral portion to form the After the modified layer is divided, the holding portion is rotated by the rotating portion, and the divided modified layer is formed at the other circumferential position in the state where the modified portion is arranged above another circumferential position of the peripheral portion . A processing method used to process the processed object, including the following steps: Holding the processed body by the holding part; Irradiating laser light from the modified part to the inside of the processed body held in the holding part to form a modified layer; Measuring the output of the laser light by the measuring part; and Moving the holding part between a first position where the object to be processed is carried in and out of the holding part and a second position where the modified layer is formed by the modified part; When the holding part is waiting at the first position, the output of the laser light is measured by the measuring part. Such as the processing method of item 6 of the request, in which, The measuring part is arranged on the holding part; In the first position, the measuring part is arranged below the modified part. Such as the processing method of item 6 or 7 of the request, in which, The object to be processed is a superimposed substrate formed by joining a first substrate and a second substrate; The holding portion holds the superposed substrate from the second substrate side; The modified part irradiates the laser light along the boundary between the peripheral part and the central part of the work to be removed inside the first substrate to form the modified layer, that is, the peripheral modified layer. Such as the processing method of item 8 of the request, where: When disposing the holding part at the first position, the outer end of the first substrate is photographed by the first imaging part; When the holding part is arranged at the second position, the second imaging part is used to image the boundary between the bonding area where the first substrate and the second substrate are bonded, and the unbonded area outside the bonding area. Such as the substrate processing method of claim 8 or 9, in which, At the second position, to the inside of the first substrate held in the holding portion, irradiate laser light from the peripheral modified layer toward the radially outer side to form a divided modified layer; In the state where the modified portion is arranged above the circumferential position of the peripheral portion, after the divided modified layer is formed at the circumferential position, the holding portion is rotated, and the modified portion is arranged on the peripheral portion In a state above the other circumferential position, the divided modified layer is formed at the other circumferential position.

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