CN117729985A

CN117729985A - Substrate processing apparatus and substrate processing method

Info

Publication number: CN117729985A
Application number: CN202280053192.5A
Authority: CN
Inventors: 川口义广; 山胁阳平; 中野征二
Original assignee: Tokyo Electron Ltd
Current assignee: Tokyo Electron Ltd
Priority date: 2021-08-06
Filing date: 2022-07-26
Publication date: 2024-03-19
Also published as: JPWO2023013469A1; TW202314811A; WO2023013469A1; KR20240035619A

Abstract

A substrate processing apparatus that irradiates a substrate with a laser beam to process the substrate, the substrate processing apparatus comprising: a substrate holding unit that holds the substrate; a laser irradiation section that irradiates the laser beam to the substrate held by the substrate holding section; and a dust collection unit that collects dust, wherein the dust collection unit has: an upper dust collection unit disposed above the substrate holding unit; and a lower dust collection part moving below the upper dust collection part with respect to the upper dust collection part. The substrate processing method includes: moving the substrate holding portion and the lower dust collecting portion to a lower side of the upper dust collecting portion; and irradiating the laser beam from the laser irradiation part to the substrate, and sucking an atmosphere gas between the upper dust collection part and the substrate and the lower dust collection part by the upper dust collection part to collect dust.

Description

Substrate processing apparatus and substrate processing method

Technical Field

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

Background

Patent document 1 discloses a laser processing apparatus. The laser processing device is provided with: a laser beam irradiation unit provided with a condenser for performing laser processing on a workpiece; and a dust discharge unit that collects and discharges dust generated by the irradiation of the laser beam.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2007-069249

Disclosure of Invention

Problems to be solved by the invention

The present disclosure relates to a technique for appropriately collecting dust generated when a substrate is irradiated with a laser beam to process the substrate.

Solution for solving the problem

One aspect of the present disclosure is a substrate processing apparatus that irradiates a substrate with a laser beam to process the substrate, the substrate processing apparatus including: a substrate holding unit that holds the substrate; a laser irradiation section that irradiates the laser beam to the substrate held by the substrate holding section; and a dust collection unit that collects dust, wherein the dust collection unit has: an upper dust collection unit disposed above the substrate holding unit; and a lower dust collection part moving below the upper dust collection part with respect to the upper dust collection part.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present disclosure, dust generated when a substrate is processed by irradiating a laser beam thereto can be appropriately collected.

Drawings

Fig. 1 is a side view showing an example of a superimposed wafer processed by a wafer processing system.

Fig. 2 is a plan view schematically showing an outline of the structure of the wafer processing system.

Fig. 3 is an explanatory diagram showing main steps of wafer processing.

Fig. 4 is a flowchart showing main steps of wafer processing.

Fig. 5 is an explanatory diagram showing a state of a peripheral edge modified layer formed inside the first wafer.

Fig. 6 is a plan view schematically showing the structure of the film processing apparatus.

Fig. 7 is a side view showing an outline of the structure of the film processing apparatus.

Fig. 8 is a side view showing an outline of the structure of the film processing apparatus.

Fig. 9 is a schematic perspective cross-sectional view showing the configuration of a part of the laser irradiation section and a part of the upper dust collection section.

Fig. 10 is a perspective view schematically showing the structure of the upper dust collecting part.

Fig. 11 is a perspective cross-sectional view schematically showing the structure of the upper dust collecting part.

Fig. 12 is a schematic plan view showing a configuration of a part of the upper dust collecting part.

Fig. 13 is a schematic perspective cross-sectional view showing a configuration of a part of the upper dust collection unit.

Fig. 14 is an explanatory diagram showing the flow of the atmosphere gas in the upper dust collection portion.

Fig. 15 is an explanatory view showing the flow of the atmosphere gas in the upper dust collecting part.

Fig. 16 is a side view schematically showing the structure of the lower dust collecting part.

Fig. 17 is a schematic plan view showing the structure of the lower dust collecting unit.

Fig. 18 is an explanatory view showing a case where the lower dust collecting part is not provided as a comparative example.

Fig. 19 is a perspective view schematically showing the structure of the lower dust collecting unit.

Fig. 20 is an explanatory diagram showing main steps of the film treatment.

Fig. 21 is a flowchart showing the main steps of the film treatment.

Detailed Description

In recent years, in a manufacturing process of a semiconductor device, a process is performed for a stacked wafer formed by bonding semiconductor substrates (hereinafter, referred to as "wafers") having a plurality of devices such as electronic circuits formed on the surfaces thereof. For example, thinning a first wafer forming a bonded wafer and transferring a device formed on the first wafer to a second wafer forming the bonded wafer are performed.

In general, the peripheral edge portion of the wafer is subjected to chamfering, but when the thinning process and the transfer process are performed on the superimposed wafer as described above, the peripheral edge portion of the thinned first wafer and the transferred superimposed wafer may have a sharp shape (so-called knife edge shape). Then, a notch is generated in the peripheral edge portion of the wafer, and the wafer may be damaged. Therefore, the peripheral edge of the first wafer before processing is removed, that is, so-called edge trimming is performed.

Here, on the surface of the second wafer after edge trimming, specifically, on the peripheral edge portion of the second wafer exposed by removing the first wafer, unnecessary surface films and particles remain. The surface film and particles may be peeled off, dropped, or scattered during the transfer of the superimposed wafers, during the process, and may cause contamination of the inside of the wafer processing system, the inside of the cassette, and other superimposed wafers. Therefore, after the edge trimming, a process of removing the surface film at the peripheral edge portion of the second wafer is performed.

Various methods are conceivable for removing the surface film at the peripheral edge portion, and the removal can be performed by, for example, irradiating the surface film with a laser beam. In the case of using a laser beam as described above, minute dust is generated by laser processing (ablation processing). When dust adheres to the condensing lens of the laser beam, the processing quality is degraded. In addition, when dust adheres to the wafer surface, the production yield of the product wafers decreases. Further, when dust adheres to the wafer processing apparatus, the operation rate is lowered.

Accordingly, conventionally, for example, a laser processing apparatus (wafer processing apparatus) disclosed in patent document 1 is provided with a dust discharge unit that collects and discharges dust generated during laser processing. The dust discharge unit includes a cover member having an opening in a lower wall for sucking dust and passing the laser beam emitted from the condenser. The wafer is irradiated with a laser beam while being moved from one end to the other end of the wafer.

When the end (one end or the other end) of the wafer is irradiated with laser light, a condenser and a cover member are disposed directly above the end. In this case, the opening of the cover member is covered with the wafer at a position radially inward of the end of the wafer in plan view, but is exposed at a position radially outward of the end. Accordingly, there is a risk that the suction amount of dust varies over the entire circumference of the opening, and dust cannot be collected stably. Accordingly, there is room for improvement in conventional substrate processing.

The technology related to the present disclosure suitably collects dust generated when a substrate is irradiated with a laser beam to process the substrate. Next, a wafer processing system including a film processing apparatus as a substrate processing apparatus according to the present embodiment and a wafer processing method as a substrate 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 denoted by the same reference numerals, and redundant description thereof is omitted.

In the wafer processing system 1 according to the present embodiment, a stacked wafer T, which is a substrate obtained by bonding a first wafer W1 and a second wafer W2 as shown in fig. 1, is processed. In the wafer processing system 1, the peripheral edge We of the first wafer W1 is removed. Hereinafter, the surface of the first wafer W1 on the side bonded to the second wafer W2 is referred to as a front surface W1a, and the surface opposite to the front surface W1a is referred to as a rear surface W1b. Similarly, the surface of the second wafer W2 on the side bonded to the first wafer W1 is referred to as a front surface W2a, and the surface opposite to the front surface W2a is referred to as a rear surface W2b. The region of the first wafer W1 radially inward of the peripheral edge We to be removed is referred to as a center Wc.

The first wafer W1 is, for example, a semiconductor wafer such as a silicon substrate, and a device layer D1 including a plurality of devices is formed on the surface W1 a. Further, a bonding film F1 is formed on the device layer D1, and bonded to the second wafer W2 via the bonding film F1. Examples of the bonding film F1 include an oxide film (SiO 2 film, TEOS film), siC film, siCN film, and an adhesive. The peripheral edge portion We of the first wafer W1 is chamfered, and the thickness of the cross section of the peripheral edge portion We decreases toward the front end. The peripheral edge We is a portion removed by edge trimming described later, and is, for example, in the range of 0.5mm to 5mm in the radial direction from the outer end of the first wafer W1. A laser beam absorbing layer (not shown) that can absorb the laser beam irradiated into the overlapping wafer T when the peripheral edge We is removed may be formed at the interface between the first wafer W1 and the device layer D1. The bonding film F1 formed on the device layer D1 may be used as a laser light absorbing layer.

The second wafer W2 has, for example, the same structure as the first wafer W1, and the device layer D2 and the bonding film F2 are formed on the surface W2a of the second wafer W2, and the peripheral edge portion of the second wafer W2 is chamfered. The second wafer W2 need not be a device wafer on which the device layer D2 is formed, but may be a support wafer for supporting the first wafer W1, for example. In this case, the second wafer W2 functions as a protector for protecting the device layer D1 of the first wafer W1.

In the present embodiment, the device layer D1 formed on the first wafer W1, the device layer D2 formed on the second wafer W2, and the bonding films F1 and F2 are sometimes referred to as "surface films", respectively. In other words, a plurality of surface films are formed in the first wafer W1 and the second wafer W2 according to the present embodiment in a stacked manner.

As shown in fig. 2, the wafer processing system 1 has a structure in which a carry-in/out block G1, a carry-in block G2, and a processing block G3 are integrally connected. The carry-in/carry-out block G1, the carry-in block G2, and the process block G3 are arranged in the order described from the X-axis negative direction side.

The carry-in/out block G1 carries in and out a cassette C capable of accommodating a plurality of wafers T stacked therein, for example, between the outside. The cassette loading and unloading block G1 is provided with a cassette mounting table 10. In the illustrated example, a plurality of, for example, four cartridges C are freely placed in a row in the Y-axis direction on the cartridge mounting table 10. The number of cassettes C placed on the cassette placement stage 10 is not limited to this embodiment, and can be arbitrarily determined.

In the transfer block G2, a wafer transfer device 20 is provided adjacent to the cassette stage 10 on the X-axis forward direction side of the cassette stage 10. The wafer transfer device 20 is configured to be movable on a transfer path 21 extending in the Y-axis direction. The wafer transfer device 20 includes, for example, two transfer arms 22 and 22 for holding and transferring the recombined wafer T. Each of the conveyance arms 22 is configured to be movable in the horizontal direction and the vertical direction, and to be movable about the horizontal axis and the vertical axis. The structure of the transport arm 22 is not limited to the present embodiment, and any structure can be adopted. The wafer transfer device 20 is configured to be capable of transferring the stacked wafer T to the cassette C of the cassette mounting stage 10 and a transfer device 30 described later.

In the transfer block G2, a transfer device 30 for transferring the bonded wafer T is provided adjacent to the wafer transfer device 20 on the X-axis forward direction side of the wafer transfer device 20.

The processing block G3 includes a wafer carrier 40, a cleaning device 50, a peripheral edge removing device 60, an interface modifying device 70, an internal modifying device 80, a film processing device 90 as a substrate processing device, and an inspection device 100.

The wafer transfer device 40 is configured to be movable on a transfer path 41 extending in the X-axis direction. The wafer transfer device 40 includes, for example, two transfer arms 42 and 42 for holding and transferring the recombined wafer T. Each of the conveyance arms 42 is configured to be movable in the horizontal direction and the vertical direction, and to be movable about the horizontal axis and the vertical axis. The structure of the transport arm 42 is not limited to the present embodiment, and any structure can be adopted. The wafer transfer device 40 may be configured to transfer the superimposed wafer T to the transfer device 30, the cleaning device 50, the peripheral edge removing device 60, the interface modifying device 70, the internal modifying device 80, and the film processing device 90.

The cleaning device 50 cleans the wafer T. The edge removing apparatus 60 performs edge trimming processing, which is removing the edge We of the first wafer W1. The interface modifying device 70 irradiates a laser beam (an interface laser beam, for example, a CO2 laser beam) onto the interface between the first wafer W1 and the second wafer W2 to form an unbonded area Ae described later. The internal reforming device 80 irradiates the inside of the first wafer W1 with a laser beam (an internal laser beam, for example, YAG laser beam) to form a peripheral reforming layer M1 which becomes a base point of peeling of the peripheral portion We and a divided reforming layer M2 which becomes a base point of chipping of the peripheral portion We. The film processing apparatus 90 irradiates a laser beam (a film processing laser beam, for example, a CO2 laser beam or an IR laser beam) on a surface film (a residual film) exposed at the peripheral edge portion of the second wafer W2 by the edge trimming processing. Further, the detailed structure of the film processing apparatus 90 will be described later. The inspection apparatus 100 inspects the peripheral edge of the first wafer W1 after the non-bonded region Ae is formed or the peripheral edge of the second wafer W2 after the film processing is performed.

The above wafer processing system 1 is provided with a control device 110. The control device 110 is a computer including a CPU, a memory, and the like, and includes a program storage unit (not shown). The program storage unit stores a program for controlling the processing of the reconstituted wafer T in the wafer processing system 1. The program may be recorded on a computer-readable storage medium H, and installed from the storage medium H to the control device 110. The storage medium H may be a transitory storage medium or a non-transitory storage medium.

Next, wafer processing performed using the wafer processing system 1 configured as described above will be described. In the present embodiment, the first wafer W1 and the second wafer W2 are bonded to each other in a bonding apparatus (not shown) outside the wafer processing system 1, so that the bonded wafer T is formed in advance.

First, a cassette C containing a plurality of wafers T is placed on the cassette stage 10 of the carry-in/out block G1. Next, the stacked wafers T in the cassette C are taken out by the wafer carrier 20. After the stacked wafer T taken out from the cassette C is transferred to the wafer transfer device 40 via the transfer device 30, the stacked wafer T is transferred to the interface modifying device 70. In the interface modifying apparatus 70, as shown in fig. 3 a, the unbonded area Ae is formed by irradiating a laser beam (e.g., CO2 laser light having a wavelength of 8.9 μm to 11 μm) onto the interface between the first wafer W1 and the device layer D1 (more specifically, the laser absorption layer formed on the interface) while rotating the bonded wafer T (first wafer W1) (step S1 in fig. 4).

The interface between the first wafer W1 and the device layer D1 in the unbonded area Ae is modified or peeled off, and the bonding strength between the first wafer W1 and the second wafer W2 is reduced or eliminated. Thus, an annular unbonded area Ae and a bonded area Ac radially inward of the unbonded area Ae for bonding the first wafer W1 and the second wafer W2 are formed at the interface between the first wafer W1 and the device layer D1. In the edge trimming described later, the peripheral edge We of the first wafer W1 to be removed is removed, and thus the non-bonded region Ae is present, whereby the peripheral edge We can be removed appropriately.

Next, the stacked wafer T having the unbonded area Ae formed therein is transported to the internal reforming device 80 by the wafer transport device 40. As shown in fig. 3 (b) and fig. 5, in the internal reforming device 80, a peripheral reforming layer M1 and a divided reforming layer M2 are formed inside the first wafer W1 (step S2 of fig. 4). The edge modification layer M1 serves as a base point when the edge We is removed in edge trimming, which will be described later. The segmentation modification layer M2 serves as a base point for the fragmentation of the removed peripheral edge portion We. In the drawings used in the following description, the division modification layer M2 may be omitted to avoid complicating the drawings.

As shown in fig. 3 (b), the crack C1 extends from the peripheral edge modified layer M1 formed inside the first wafer W1 in the thickness direction of the first wafer W1. The lower end of the crack C1 reaches, for example, the surface W1a of the first wafer W1 or the unbonded area Ae.

Next, the wafer T, on which the peripheral edge modification layer M1 and the division modification layer M2 are formed inside the first wafer W1, is transferred to the peripheral edge removing device 60 by the wafer transfer device 40. As shown in fig. 3 c, the edge trimming process is performed in the edge removing device 60, which removes the edge We of the first wafer W1 (step S3 in fig. 4). At this time, the peripheral edge We is peeled off from the central portion Wc of the first wafer W1 with the peripheral edge modified layer M1 and the crack C1 as the base points, and is peeled off from the device layer D1 (the second wafer W2) with the non-bonded region Ae as the base points. In this case, the removed peripheral edge We is fragmented with the segmentation modification layer M2 and the crack C2 as the base points.

In removing the peripheral edge We, a plate having a wedge shape may be inserted into an interface between the first wafer W1 and the second wafer W2 forming the bonded wafer T, for example. When edge trimming is performed, the edge portion We is appropriately peeled off with the edge modification layer M1 and the crack C1 as the base points by applying an impact to the edge portion We of the first wafer W1.

Next, the superimposed wafer T from which the peripheral edge We of the first wafer W1 is removed is conveyed to the film processing apparatus 90 by the wafer conveyance apparatus 40. As shown in fig. 3 d, the film processing apparatus 90 performs a process of removing a surface film at the peripheral edge portion of the second wafer W2 from which the peripheral edge portion We has been removed (hereinafter, sometimes referred to as "film processing") (step S4 in fig. 4).

An unnecessary surface film and particles remain on the surface of the second wafer W2 from which the peripheral edge We is removed, specifically, on the peripheral edge of the second wafer W2 exposed by removing the first wafer W1. The surface film and the particles may be peeled off, dropped, or scattered during the transfer or process of the superimposed wafer T, and may cause contamination of the inside of the wafer processing system 1, the inside of the cassette C, or other superimposed wafers T.

Therefore, in step S4, the surface film at the peripheral edge portion of the second wafer W2 is removed in order to suppress scattering of the surface film and particles after the peripheral edge portion We is removed. That is, for example, a laser beam (e.g., CO2 laser) is irradiated to the surface film to remove the surface film.

In this case, particles remaining on the surface of the surface film removed by the irradiation of the laser beam are also removed together with the surface film, and therefore, the surface film, the particles are prevented from being peeled off, dropped, or scattered.

Next, the superimposed wafer T from which the surface film at the peripheral edge portion of the second wafer W2 is removed is conveyed to the cleaning apparatus 50 by the wafer conveyance apparatus 40. In the cleaning apparatus 50, the rear surface W1b and the exposed portion of the first wafer W1 after the film treatment with the peripheral edge We removed are cleaned (step S5 of fig. 4). In the cleaning apparatus 50, the rear surface W2b of the second wafer W2 may be cleaned together with the rear surface W1b of the first wafer W1.

Thereafter, the wafer carrier 20 carries the recombined wafer T subjected to all the wafer processes to the cassette C of the cassette mounting stage 10 via the carrier 30. In this way, the series of wafer processes in the wafer processing system 1 ends.

Next, the detailed configuration of the film processing apparatus 90 described above will be described.

As shown in fig. 6 to 8, the film processing apparatus 90 includes a holding tray (chuck) 200 as a substrate holding portion, and the holding tray 200 holds the bonded wafer T on the upper surface. The holding tray 200 holds the back surface W2b of the second wafer W2 by suction in a state where the first wafer W1 is on the upper side and the second wafer W2 is arranged on the lower side. The holding disk 200 is supported by a slide table 202 via an air bearing 201. A rotating portion 203 is provided on the lower surface side of the slide table 202. The rotating unit 203 includes a motor as a driving source. The holding plate 200 is configured to be rotatable about a vertical axis by the air bearing 201 via the rotating portion 203. The slide table 202 is configured to be movable on a guide rail 206 provided to extend in the Y-axis direction on a base 205 by a moving portion 204 provided on the lower surface side thereof. The driving source of the moving unit 204 is not particularly limited, but a linear motor is used, for example.

A macro camera 210 is provided above the holding tray 200. For example, macro camera 210 is supported by support column 211. The macro camera 210 photographs the outer end of the second wafer W2. The macro camera 210 includes, for example, a coaxial lens, irradiates infrared light (IR light), and receives reflected light from an object. Further, for example, the magnification of the macro camera 210 is doubled. The image captured by the macro camera 210 is output to the control device 110. In the control device 110, the amount of eccentricity of the center of the holding disk 200 and the center of the second wafer W2 is calculated from the image captured by the macro camera 210.

A laser irradiation unit 220 for irradiating a laser beam onto the wafer T held on the holding disk 200 is provided above the holding disk 200 and on the negative Y-axis direction side of the macro camera 210. The laser irradiation unit 220 is connected to a laser head (not shown) having a laser oscillator (not shown) for oscillating a laser beam, and the like. The laser irradiation section 220 is supported by a support member 221. The laser irradiation section 220 is configured to be vertically movable along a guide rail 222 extending in the vertical direction by a lifting section 223. The laser irradiation unit 220 is configured to be movable in the Y-axis direction along a guide rail 224 extending in the Y-axis direction on the support column 211 by a moving unit 225.

The laser irradiation section 220 irradiates a laser beam to the surface film at the peripheral edge portion of the second wafer W2 to remove the surface film. The laser irradiation section 220 has a condensing lens 231 and a nozzle 232.

As shown in fig. 9, the condensing lens 231 condenses the laser beam oscillated from the laser oscillator of the laser head and irradiates the surface film of the peripheral edge portion of the second wafer W2 with the condensed laser beam.

The nozzle 232 is disposed below the condensing lens 231. The nozzle 232 is a hollow cylindrical member, and irradiates the surface film of the peripheral edge portion of the second wafer W2 with the laser beam from the condenser lens 231 after passing through it.

A first air supply portion 233 for supplying a gas such as dry air into the nozzle 232 is provided at an upper portion of the nozzle 232. The first air supply portion 233 communicates with an air supply path 232a formed inside the sidewall of the nozzle 232. The gas supplied from the first gas supply portion 233 and the gas supply path 232a flows downward through the nozzle 232 and is injected onto the surface film of the peripheral edge portion of the second wafer W2. By this gas, dust generated during laser processing can be suppressed from adhering to the condenser lens 231.

As shown in fig. 6 to 8, the film processing apparatus 90 includes a dust collection unit 240 for collecting dust. The dust collection unit 240 collects minute dust generated when the laser beam is irradiated from the laser irradiation unit 220 to the surface film at the peripheral edge portion of the second wafer W2 at the time of the film processing (at the time of laser processing) at step S4. The dust collection part 240 has an upper dust collection part 241 and a lower dust collection part 242.

The upper dust collection portion 241 is provided above the holding tray 200 and directly below the laser irradiation portion 220. As shown in fig. 10 and 11, the upper dust collecting part 241 has a sleeve 250 and an exhaust duct 260. The sleeve 250 is disposed on an upper surface of the exhaust duct 260.

As shown in fig. 9 and 11, the sleeve 250 has a substantially truncated cone shape in which the diameter becomes smaller as going from the upper side to the lower side. A housing portion 251 for housing a part of the nozzle 232 of the laser irradiation portion 220 is formed in the upper surface center portion of the sleeve 250. The nozzle 232 is capable of being lifted up and down with respect to the housing portion 251 to enter and exit with respect to the housing portion 251. For example, a power meter (not shown) for confirming the output of the laser beam is provided in the laser head, but the output of the laser beam cannot be measured while the dust collection unit 240 is exhausting. In this case, therefore, the nozzle 232 is withdrawn from the housing 251. On the other hand, the nozzle 232 is accommodated in the accommodating portion 251 during laser processing.

The nozzle 232 is movable in the Y-axis direction in the housing 251. The lower end of the nozzle 232 is rotatable about the upper end. The nozzle 232 is not in contact with the housing 251 in a state of being housed in the housing 251.

As described above, since the nozzle 232 is movable in the Y-axis direction and is movable during laser processing, the housing 251 may have a long hole shape having a long axis in the Y-axis direction as shown in fig. 12. A long hole 252 is formed in the lower surface of the housing portion 251, and the long hole 252 is used to pass the laser beam emitted from the nozzle 232, and the long hole 252 may have a long axis in the Y-axis direction. In the film treatment, the distance of movement of the nozzle 232 is, for example, 2mm to 5mm, as will be described later. Therefore, the length of the long hole 252 in the Y-axis direction is preferably 5mm or more.

As shown in fig. 9 and 11, a second air supply portion 253 for supplying a gas such as dry air to an air suction flow path 262 described later is provided on the upper surface of the sleeve 250 on the X-axis positive direction side of the housing portion 251. The second air supply portion 253 communicates with an air supply path 250a formed so as to pass through from the upper surface to the lower surface of the sleeve 250. The air supply path 250a is connected to a discharge portion 250b formed on the lower surface of the sleeve 250. The gas supplied from the discharge portion 250b flows out to the intake passage 262 through the second gas supply portion 253 and the gas supply path 250 a. The fumes generated during laser processing are blown away by the gas. The gas from the second gas supply portion 253 guides the atmosphere gas in the gas suction flow path 262 to a gas discharge flow path 263 described later. At this time, the smoke is also guided to the exhaust passage 263.

As will be described later, in the laser processing, a laser beam is irradiated onto the superimposed wafer T while rotating the superimposed wafer T. The gas from the second gas supply portion 253, the gas supply path 250a, and the discharge portion 250b is preferably supplied in the rotation direction of the superimposed wafer T. In this case, the atmosphere gas in the intake passage 262 can be more reliably guided to the exhaust passage 263.

The exhaust duct 260 is provided extending in the X-axis direction. As shown in fig. 11 and 13, an opening 261 is formed at a lower surface 260a of the exhaust duct 260 and below the sleeve 250, and the opening 261 is for passing the laser beam irradiated from the nozzle 232. The lower surface 260a has a substantially circular shape in plan view. An intake passage 262 and an exhaust passage 263 are formed in the exhaust duct 260.

The intake passage 262 is a passage formed between the sleeve 250 and the opening 261. The suction flow path 262 sucks the atmosphere gas held between the bonded wafer T of the holding tray 200 and the exhaust duct 260 from the opening 261.

The exhaust flow path 263 communicates with the intake flow path 262 and extends in the tangential direction of the superposed wafer T, that is, in the X-axis direction. The exhaust passage 263 communicates with an exhaust pipe 264 provided at the X-axis negative direction side end portion of the exhaust pipe 260. The exhaust pipe 264 is connected to an exhaust device (not shown) that sucks in the internal atmosphere of the exhaust pipe 260.

As shown in fig. 9 and 11, a third air supply portion 265 for supplying air such as dry air is provided inside the exhaust duct 260 on the X-axis positive direction side of the housing portion 251. The third air supply portion 265 communicates with an air supply path 260b formed to pass through from a side wall of the exhaust duct 260 to the lower surface. The air supply path 260b is connected to a discharge portion 260c formed on the lower surface 260a of the exhaust duct 260. A plurality of ejection portions 260c are provided on the lower surface 260a of the exhaust duct 260 around the opening 261. The plurality of ejection portions 260c are provided at equal intervals on the concentric circle of the opening 261, that is, the radial distances between the respective ejection portions 260c and the lower surface 260a are equal. Thus, the atmosphere gas between the exhaust duct 260 and the superposed wafer T is uniformly sucked through the opening 261.

The gas supplied from the third gas supply portion 265, the gas supply path 260b, and the discharge portion 260c is discharged downward around the opening 261 to form a so-called air curtain. In this case, outflow of dust generated during laser processing to the outside of the air curtain is suppressed. Further, since the diameter of the opening 261 is larger than the gap outside the air curtain, the air from the third air supply portion 265, the air supply path 260b, and the discharge portion 260c flows into the air intake channel 262 through the opening 261. In this case, too, the dust flows into the intake passage 262 through the opening 261, and therefore, the dust can be reliably collected in the exhaust duct 260. The number of the air supply paths 260b at the lower surface 260a of the air discharge duct 260 is not limited, but in the case of a large number, the effect as an air curtain becomes high.

As shown in fig. 12, a fourth air supply portion 266 for supplying a gas such as dry air is provided on the side surface of the exhaust duct 260 and on the Y-axis positive direction side of the housing portion 251. The fourth air supply portion 266 communicates with an air supply path 260d formed so as to extend from a side wall of the exhaust duct 260 to the air intake flow path 262. The air supply path 260d is connected to a discharge portion 260e formed on the inner surface of the exhaust duct 260. The air supply path 260d and the discharge portion 260e are formed, for example, so as to face the positive X-axis direction of the air intake channel 262. The gas supplied from the fourth gas supply portion 266, the gas supply path 260d, and the discharge portion 260e flows into the gas suction flow path 262, and a vortex is formed in the gas suction flow path 262. The positions of the air supply path 260d and the discharge portion 260e are not limited to this embodiment as long as they are positions at which a vortex can be formed in the air intake flow path 262.

As shown in fig. 14 and 15, during laser processing, the atmosphere gas between the exhaust duct 260 and the superimposed wafer T is sucked into the exhaust duct 260 through the opening 261, flows through the intake passage 262 and the exhaust passage 263, and is discharged from the exhaust pipe 264. The dust generated during the laser processing is also collected by the air flow. At this time, the gas from the second gas supply portion 253 blows off the fumes generated during the laser processing, and guides the fumes to the exhaust flow path 263. In addition, the outflow of dust to the outside is suppressed by the gas from the third gas supply portion 265. Then, a vortex is formed in the air intake passage 262 by the gas from the fourth air supply portion 266, so that the atmosphere gas and dust are smoothly guided to the air exhaust passage 263.

As shown in fig. 6 and 8, the lower dust collection portion 242 has a dust collection plate 270 and a supporting member 271. The dust collection plate 270 is disposed in proximity to the outer circumference of the holding tray 200. The clearance between the dust collection plate 270 and the outer periphery of the holding plate 200 is, for example, 0.5mm or less. The smaller the gap, the more the outflow of dust from the outside can be suppressed.

As shown in fig. 16, the height of the upper surface of the dust collection plate 270 is desirably the same as the height of the upper surface (the back surface W1b of the first wafer W1) of the bonded wafer T held by the holding tray 200. The lower surface of the dust collection plate 270 is supported by a support member 271. The support member 271 is fixed to the slide table 202. That is, the lower dust collection portion 242 is integrally provided with the holding tray 200, and the lower dust collection portion 242 also moves in the Y-axis direction along with the movement of the holding tray 200.

In fig. 17, the dust collecting plate 270 has a substantially rectangular shape in plan view, and an end 270a on the side of the holding plate 200 is bent along the outer periphery of the holding plate 200. However, since the holding tray 200 rotates, the dust collecting plate 270 is not in contact with the holding tray 200. The Y-axis direction length a of the dust collection plate 270 is greater than the diameter D of the opening 261 of the exhaust duct 260. The X-axis direction length B of the dust collecting plate 270 is larger than the radius D/2 of the opening 261. Also, the dust collecting plate 270 is provided with: when disposed below the exhaust duct 260 of the upper dust collection portion 241, the exhaust duct overlaps the opening 261 in a plan view. In addition, in the case where the holding plate 200 is not rotated unlike the present embodiment, the dust collecting plate 270 may be in contact with the holding plate 200.

Here, as shown in fig. 18, when the laser beam is irradiated to the peripheral edge portion of the second wafer W2 during the laser processing, the holding disk 200 covers a position radially inward of the end portion of the holding disk 200 (the superimposed wafer T) in the top view, but is exposed to the outside of the end portion in the radial direction. Accordingly, the suction amount of the dust may vary over the entire circumference of the opening 26, and the dust may not be stably collected.

In this regard, as shown in fig. 19, the dust collecting plate 270 is provided as: when disposed below the exhaust duct 260, the exhaust duct overlaps the opening 261 in a plan view. In this case, the suction amount of the dust is uniform over the entire circumference of the opening 261, and the dust can be stably collected.

Next, a film process performed by the film processing apparatus 90 configured as described above will be described.

First, as shown in fig. 20 (a), the holding tray 200 is arranged at the standby position P1. At this time, the nozzle 232 is accommodated in the accommodating portion 251 of the sleeve 250. Then, the recombined wafer T is carried into the film processing apparatus 90 and held on the holding tray 200 (step T1 of fig. 21).

Next, the holding tray 200 is moved to the macro alignment position. The macro alignment position is a position where the macro camera 210 can capture the outer end of the second wafer W2. Next, an image of the outer end portion of the second wafer W2 in the circumferential direction of 360 degrees is captured by the macro camera 210. The captured image is output from the macro camera 210 to the control device 110.

In the control device 110, the amount of eccentricity of the center of the holding disk 200 and the center of the second wafer W2 is calculated from the image of the macro camera 210. Further, the control device 110 calculates the amount of movement of the holding disk 200 based on the amount of eccentricity to correct the Y-axis component of the amount of eccentricity. Then, the position of the holding tray 200 is decided so that the center of the second wafer W2m coincides with the center of the holding tray 200 (step T2 of u 22).

Next, as shown in fig. 20 b, the holding tray 200 is moved to the process position P2 (step T3 of fig. 21). The processing position P2 is a position where an end portion of the peripheral edge portion of the second wafer W2 in the Y-axis positive direction is arranged directly below the nozzle 232 of the laser irradiation portion 220. At this time, the dust collecting plate 270 is disposed so as to overlap with the opening 261 of the exhaust duct 260 in a plan view.

Next, while the holding disk 200 is rotated, the nozzle 232 is moved to the X-axis negative direction side, and a laser beam is irradiated from the nozzle 232 onto the surface film at the peripheral edge portion of the second wafer W2. Then, the laser beam is spirally irradiated to the surface film. The movement distance of the nozzle 232 is 2mm to 5mm, and the peripheral edge portion of the second wafer W2 to be processed is in the range of 2mm to 5mm from the outer end. That is, the processing width of the laser beam is adjusted by moving the nozzle 232. Then, the surface film is removed (step T4 of fig. 21).

Dust is generated during the laser processing in step T4. The dust is collected by the upper dust collection part 241. Specifically, as described above, the atmosphere gas between the exhaust duct 260 and the superimposed wafer T is sucked into the exhaust duct 260 through the opening 261, flows through the suction flow path 262 and the exhaust flow path 263, and is discharged from the exhaust pipe 264. Thus, dust generated in laser processing is also collected by the air flow.

Next, when the surface film at the peripheral edge portion of the second wafer W2 is removed, the holding tray 200 is moved to the standby position P1. Then, the recombined wafer T is carried out from the film processing apparatus 90 (step T5 of fig. 21). By doing so, the series of film processes in the film processing apparatus 90 ends.

According to the above embodiment, the dust collecting part 240 has the upper dust collecting part 241 and the lower dust collecting part 242, and the dust collecting plate 270 of the lower dust collecting part 242 is provided as: when disposed below the exhaust duct 260 of the upper dust collection portion 241, the exhaust duct overlaps the opening 261 in a plan view. Therefore, the suction amount of dust becomes uniform over the entire circumference of the opening 261, and dust can be stably collected. In addition, the diameter of the opening 261 can be made large, and dust can be collected over a wide range. Accordingly, dust generated during laser processing can be properly and efficiently collected by the dust collection unit 240.

In the above embodiment, the technique of the present disclosure was applied in removing the surface film at the peripheral edge portion of the second wafer W2, but the technique can be used for other applications as well. For example, the technique according to the present disclosure can also be applied in a case where a laser beam is irradiated to the entire surface of a wafer. For example, when the entire surface of the first wafer W1 is peeled off from the second wafer W2 and the device layer D1 formed on the front surface W1a side of the first wafer W1 is transferred to the second wafer W2, that is, when so-called laser lift-off (laser lift off) is performed, a laser beam is irradiated onto the entire surface of the interface between the first wafer W1 and the second wafer W2. Even in these cases, the same effects as those of the above-described embodiments can be obtained when the laser beam is irradiated to the peripheral edge portion.

The embodiments disclosed herein are to be considered in all respects as illustrative and not restrictive. The above-described embodiments may be omitted, substituted or altered in various ways without departing from the scope of the appended claims and their gist.

Description of the reference numerals

90: a membrane treatment device; 200: a holding plate; 220: a laser irradiation section; 240: a dust collection part; 241: an upper dust collection part; 242: a lower dust collection part; t: the wafer is recombined; w1: a first wafer; w2: and a second wafer.

Claims

1. A substrate processing apparatus that irradiates a substrate with a laser beam to process the substrate, the substrate processing apparatus comprising:

a substrate holding unit that holds the substrate;

a laser irradiation section that irradiates the laser beam to the substrate held by the substrate holding section; and

a dust collection part for collecting dust,

wherein the dust collection unit has:

an upper dust collection unit disposed above the substrate holding unit; and

a lower dust collection part moving relative to the upper dust collection part below the upper dust collection part.

2. The substrate processing apparatus according to claim 1, wherein,

the lower dust collection portion is disposed so as to be close to an outer periphery of the substrate holding portion.

3. The substrate processing apparatus according to claim 2, wherein,

the lower dust collection portion is integrally provided with the substrate holding portion.

4. The substrate processing apparatus according to any one of claims 1 to 3, wherein,

the height of the upper surface of the lower dust collection part is the same as the height of the upper surface of the substrate held by the substrate holding part.

5. The substrate processing apparatus according to any one of claims 1 to 4, wherein,

an opening portion for passing the laser beam irradiated from the laser irradiation portion is formed on a lower surface of the upper dust collection portion,

the lower dust collection part is provided with: when disposed below the upper dust collection portion, the dust collection portion overlaps the opening portion in a plan view.

6. The substrate processing apparatus according to any one of claims 1 to 5, wherein,

the upper dust collection part has:

an exhaust duct; and

a sleeve provided on an upper surface of the exhaust duct, the sleeve having a receiving portion for receiving at least a part of the laser irradiation portion,

an opening portion for passing the laser beam irradiated from the laser irradiation portion is formed on a lower surface of the exhaust duct,

an intake passage for sucking the atmosphere gas between the substrate and the opening and an exhaust passage for exhausting the atmosphere gas are formed in the exhaust duct, and the exhaust passage communicates with the intake passage.

7. The substrate processing apparatus according to claim 6, wherein,

the exhaust flow path is formed along a tangential direction of the substrate.

8. The substrate processing apparatus according to claim 6 or 7, wherein,

the gas supply device further includes a discharge portion provided in the sleeve and configured to supply gas to the suction flow path.

9. The substrate processing apparatus according to any one of claims 6 to 8, wherein,

the gas discharge device further includes a discharge portion that supplies gas downward around the opening.

10. The substrate processing apparatus according to any one of claims 6 to 9, wherein,

the exhaust pipe is provided with an exhaust port, and the exhaust port is provided with an exhaust port for exhausting the exhaust gas.

11. The substrate processing apparatus according to any one of claims 1 to 10, wherein,

the laser irradiation unit irradiates the laser beam to the peripheral edge portion of the substrate.

12. A substrate processing method for processing a substrate by irradiating the substrate with a laser beam using a substrate processing apparatus,

the substrate processing apparatus includes:

a substrate holding unit that holds the substrate;

a dust collection part for collecting dust,

wherein the dust collection unit has:

an upper dust collection unit disposed above the substrate holding unit; and

a lower dust collection part moving relative to the upper dust collection part under the upper dust collection part,

the substrate processing method includes:

moving the substrate holding portion and the lower dust collecting portion to a lower side of the upper dust collecting portion; and

the laser beam is irradiated from the laser irradiation portion to the substrate, and the upper dust collection portion sucks an atmosphere gas between the upper dust collection portion and the substrate and the lower dust collection portion to collect dust.