Substrate processing device and substrate processing method

Abstract

The purpose of this invention is to properly collect the dust generated when processing a substrate by irradiating it with laser light. The present invention relates to a substrate processing apparatus for processing a substrate by irradiating a substrate with laser light, and includes: a substrate holding portion for holding the substrate, a laser irradiation portion for irradiating the substrate held in the substrate holding portion with laser light, and a dust collection portion for collecting dust, the dust collection portion including an upper dust collection portion disposed above the substrate holding portion, and a lower dust collection portion that moves below the upper dust collection portion.

Description

[Technical Field]

[0001] This invention relates to a substrate processing apparatus and a substrate processing method. [Previous Technology]

[0002] Patent Document 1 discloses a laser processing apparatus. The laser processing apparatus includes: a laser light irradiation means, a light collector for laser processing a workpiece, and a dust removal means for collecting and discharging dust generated by laser light irradiation. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2007-069249 [Summary of the Invention]

[0004] [The problem the invention aims to solve]

[0005] According to the technology of the present invention, when processing a substrate by irradiating it with laser light, the generated dust is appropriately collected. [Means for Solving the Problem]

[0006] One aspect of the present invention is a substrate processing apparatus for processing a substrate by irradiating it with laser light, comprising: a substrate holding portion for holding the substrate, a laser irradiation portion for irradiating the substrate held in the substrate holding portion with the laser light, and a dust collection portion for collecting dust, the dust collection portion having an upper dust collection portion disposed above the substrate holding portion, and a lower dust collection portion movable below the upper dust collection portion. [Effects of the Invention]

[0007] Through the present invention, dust generated during the treatment of a substrate by irradiating it with laser light can be properly collected.

Implementation Method

[0009] In recent years, during the manufacturing process of semiconductor devices, overlapping wafers (hereinafter referred to as "wafers") formed by bonding together semiconductor substrates on which multiple electronic circuits and other components are formed on their surfaces are processed. For example, the first wafer forming the overlapping wafer is thinned, or the components formed on the first wafer are transferred to the second wafer forming the overlapping wafer.

[0010] Typically, the periphery of a wafer is chamfered. However, during thinning or transfer processing of overlapping wafers as described above, the periphery of the thinned first wafer or the transferred overlapping wafer may develop a sharp shape (i.e., a blade-like shape). In this case, there is a concern that the wafer may break at its periphery and be damaged. Therefore, the periphery of the first wafer before processing is removed, i.e., edge cutting is performed.

[0011] Here, the surface of the second wafer after edge cutting, specifically the peripheral portion of the second wafer exposed after removing the first wafer, retains unwanted surface film and particles. These surface film and particles may peel off, fall off, or scatter during the handling or processing of the overlapping wafers, thus contaminating the interior of the wafer processing system, the cassette, and other overlapping wafers. Therefore, after edge cutting, the surface film on the peripheral portion of the second wafer is removed.

[0012] Various methods can be considered for removing the surface film on the periphery, such as irradiating the surface film with laser light to remove it. However, using laser light in this way generates fine dust during laser processing (etching). If this dust adheres to the laser light focusing lens, it will reduce the processing quality. Furthermore, if the dust adheres to the wafer surface, it will reduce the production yield of the finished wafer. Moreover, if the dust adheres to the wafer processing equipment, it will reduce the uptime.

[0013] Therefore, conventional laser processing apparatus (wafer processing apparatus) disclosed, for example, in Patent Document 1, includes a dust discharge means for collecting and discharging dust generated during laser processing. The dust discharge means has a covering member on its lower wall, which includes an opening for allowing laser light irradiated from a light collector to pass through and for attracting dust. Furthermore, while moving the wafer, laser light is irradiated onto the wafer from one end to the other.

[0014] When a laser is irradiated onto the end (one end or the other end) of a wafer, a light collector and a cover member are disposed directly above that end. In this case, in the opening of the cover member, the radially inner side of the wafer end is covered by the wafer when viewed from above, but the radially outer side of the end is exposed. Thus, there is a concern that the amount of dust attracted may vary throughout the circumference of the opening, making it difficult to collect dust stably. Therefore, conventional substrate processing still has room for improvement.

[0015] According to the technology of the present invention, when processing a substrate by irradiating it with laser light, the generated dust is appropriately collected. Hereinafter, a wafer processing system having 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. Furthermore, in this specification and drawings, elements having substantially the same functional configuration are marked with the same symbols to omit repeated descriptions.

[0016] In the wafer processing system 1 described later according to this embodiment, the substrate, i.e., the superimposed wafer T, formed by bonding the first wafer W1 and the second wafer W2 is processed as shown in FIG1. ​​Furthermore, in the wafer processing system 1, the peripheral portion We of the first wafer W1 is removed. Hereinafter, in the first wafer W1, the surface bonded to the second wafer W2 is referred to as surface W1a, and the surface opposite to surface W1a is referred to as back surface W1b. Similarly, in the second wafer W2, the surface bonded to the first wafer W1 is referred to as surface W2a, and the surface opposite to surface W2a is referred to as back surface W2b. Also, in the first wafer W1, the region further radially inward than the peripheral portion We to be removed is referred to as the central portion Wc.

[0017] The first wafer W1 is, for example, a semiconductor wafer such as a silicon substrate, and a device layer D1 containing a plurality of devices is formed on its surface W1a. Furthermore, a bonding film F1 is formed on the device layer D1, and the wafer W2 is bonded to the second wafer via this bonding film F1. Examples of the bonding film F1 include oxide films (SiO2 films, TEOS films), SiC films, SiCN films, or adhesives. The peripheral portion We of the first wafer W1 is chamfered, and the thickness of the peripheral portion We decreases towards its leading edge in cross-section. The peripheral portion We is the portion removed during the edge cutting described later, for example, a range of 0.5 mm to 5 mm radially from the outer end of the first wafer W1. Also, a laser absorption layer (not shown) may be formed at the interface between the first wafer W1 and the device layer D1 to absorb laser light irradiated inside the overlapping wafer T when the peripheral portion We is removed. Alternatively, the bonding film F1 formed on the element layer D1 can be used as a laser absorption layer.

[0018] The second wafer W2 has, for example, the same configuration as the first wafer W1, and a device layer D2 and a bonding film F2 are formed on its surface W2a, with its periphery chamfered. Furthermore, the second wafer W2 does not need to be a device wafer with the device layer D2 formed; for example, it can be a support wafer supporting the first wafer W1. In this case, the second wafer W2 functions as a protective material for the device layer D1 of the first wafer W1.

[0019] Furthermore, in this embodiment, the element layers D1 and D2 and the bonding films F1 and F2 formed on the first wafer W1 and the second wafer W2 are referred to as "surface films". In other words, a plurality of surface films are deposited on the first wafer W1 and the second wafer W2 according to this embodiment.

[0020] As shown in Figure 2, the wafer processing system 1 has a configuration that connects the outgoing and incoming transport block G1, the transport block G2, and the processing block G3 into one unit. The outgoing and incoming transport block G1, the transport block G2, and the processing block G3 are arranged sequentially from the negative X-axis direction.

[0021] The move-out / move-in block G1, for example, moves in and out of cassettes C capable of accommodating multiple overlapping wafers T between itself and the outside. A cassette mounting stage 10 is provided in the move-out / move-in block G1. In the illustrated example, multiple (e.g., 4) cassettes C are freely arranged in a row along the Y-axis on the cassette mounting stage 10. Furthermore, the number of cassettes C mounted on the cassette mounting stage 10 is not limited to this embodiment and can be arbitrarily determined.

[0022] In the transport block G2, a wafer transport device 20 is provided adjacent to the cassette stage 10 on the positive X-axis side. The wafer transport device 20 can move freely on the transport path 21 extending in the Y-axis direction. Furthermore, the wafer transport device 20 has, for example, two transport arms 22 for holding and transporting overlapping wafers T. Each transport arm 22 can move freely in the horizontal direction, the vertical direction, or around the horizontal and vertical axes. Moreover, the configuration of the transport arms 22 is not limited to this embodiment and can be any configuration. Furthermore, the wafer transport device 20 can transport the overlapping wafers T to the cassette C of the cassette stage 10 and the transfer device 30 described later.

[0023] In the transport block G2, on the positive X-axis direction side of the wafer transport device 20, a transport device 30 for transporting overlapping wafers T is provided adjacent to the wafer transport device 20.

[0024] The processing block G3 includes a wafer handling device 40, a cleaning device 50, a peripheral removal device 60, an interface modification device 70, an internal modification device 80, a film processing device 90 as a substrate processing device, and an inspection device 100.

[0025] The wafer transport device 40 can move freely on the transport path 41 extending in the X-axis direction. Furthermore, the wafer transport device 40 has, for example, two transport arms 42 for holding and transporting overlapping wafers T. Each transport arm 42 can move freely in the horizontal direction, the vertical direction, or around the horizontal and vertical axes. Moreover, the configuration of the transport arms 42 is not limited to this embodiment and can be any configuration. Furthermore, the wafer transport device 40 can transport overlapping wafers T to the transfer device 30, the cleaning device 50, the peripheral removal device 60, the interface modification device 70, the internal modification device 80, and the film treatment device 90.

[0026] The cleaning apparatus 50 cleans the overlapping wafer T. The peripheral removal apparatus 60 removes the peripheral portion We of the first wafer W1, i.e., performs edge cutting. The interface modification apparatus 70 irradiates the interface between the first wafer W1 and the second wafer W2 with laser light (interface laser light, such as CO2 laser), forming the unbonded region Ae described later. The internal modification apparatus 80 irradiates the interior of the first wafer W1 with laser light (internal laser light, such as YAG laser), forming a peripheral modification layer M1 as the peeling base point of the peripheral portion We, and a segmentation modification layer M2 as the base point for the miniaturization of the peripheral portion We. The film treatment apparatus 90 irradiates the surface film (residual film) exposed at the peripheral portion of the second wafer W2 due to the edge cutting process with laser light (film treatment laser light, such as CO2 laser or IR laser). The detailed configuration of the film treatment apparatus 90 will be described later. The inspection device 100 inspects the periphery of the first wafer W1 after the formation of the unbonded region Ae, or the periphery of the second wafer W2 after film treatment.

[0027] The wafer processing system 1 described above includes a control device 110. The control device 110 is, for example, a computer equipped with a CPU and memory, and has a program storage unit (not shown). The program storage unit stores a program for controlling the processing of the overlapping wafer T in the wafer processing system 1. Furthermore, the program may be stored on a computer-readable recording medium H and installed from the recording medium H onto the control device 110. Also, the recording medium H may be temporary or non-temporary.

[0028] Next, the wafer processing performed using the wafer processing system 1 configured as described above will be described. In this embodiment, the first wafer W1 and the second wafer W2 are bonded in a bonding device (not shown) outside the wafer processing system 1 to pre-form an overlapping wafer T.

[0029] First, a cassette C containing multiple overlapping wafers T is placed on the cassette stage 10 of the transfer-out / transfer-in block G1. Next, the overlapping wafers T in the cassette C are removed by the wafer transport device 20. The overlapping wafers T removed from the cassette C are transferred to the wafer transport device 40 via the transfer device 30 and then transported to the interface modification device 70. In the interface modification device 70, as shown in FIG3(a), while the overlapping wafers T (first wafer W1) are rotated, laser light (e.g., a CO2 laser with a wavelength of 8.9μm to 11μm) is irradiated onto the interface between the first wafer W1 and the device layer D1 (more specifically, the aforementioned laser absorption layer formed on the interface) to form an unbonded region Ae (step S1 in FIG4).

[0030] In the unbonded region Ae, the interface between the first wafer W1 and the device layer D1 is modified or peeled off, thereby reducing or eliminating the bonding strength between the first wafer W1 and the second wafer W2. This forms an annular unbonded region Ae at the interface between the first wafer W1 and the device layer D1, and a bonding region Ac formed by bonding the first wafer W1 and the second wafer W2 within the radial direction of the unbonded region Ae. During the edge cutting described later, the peripheral portion We of the first wafer W1 is removed. By maintaining the unbonded region Ae in this way, the removal of the peripheral portion We can be appropriately performed.

[0031] The overlapping wafer T with the unbonded region Ae is then transported by the wafer transport device 40 to the internal refining device 80. In the internal refining device 80, as shown in Figures 3(b) and 5, a peripheral refining layer M1 and a segmentation refining layer M2 are formed inside the first wafer W1 (step S2 in Figure 4). The peripheral refining layer M1 serves as the base point for removing the peripheral portion We during the edge cutting process described later. The segmentation refining layer M2 serves as the base point for miniaturizing the removed peripheral portion We. Furthermore, in the following description, the illustration of the segmentation refining layer M2 may be omitted to avoid overly complex diagrams.

[0032] Furthermore, the crack C1 extends from the peripheral modified layer M1 formed inside the first wafer W1 in the thickness direction of the first wafer W1, as shown in FIG3(b). The bottom end of the crack C1 reaches, for example, the surface W1a or the unbonded area Ae of the first wafer W1.

[0033] An overlapping wafer T, in which a peripheral modification layer M1 and a dividing modification layer M2 are formed inside the first wafer W1, is then transported by the wafer transport device 40 to the peripheral removal device 60. In the peripheral removal device 60, as shown in FIG3(c), the peripheral portion We of the first wafer W1 is removed, that is, edge cutting is performed (step S3 in FIG4). At this time, the peripheral portion We is peeled off from the central portion Wc of the first wafer W1 with the peripheral modification layer M1 and the crack C1 as the base point, and at the same time, it is peeled off from the element layer D1 (the second wafer W2) with the unbonded area Ae as the base point. At the same time, the removed peripheral portion We is further reduced in size with the dividing modification layer M2 and the crack C2 as the base points.

[0034] Alternatively, when removing the peripheral portion We, a wedge-shaped tool may be inserted at the interface between the first wafer W1 and the second wafer W2 forming the overlapping wafer T. During edge cutting, by applying an impact to the peripheral portion We of the first wafer W1, the peripheral portion We is appropriately peeled off with the peripheral modified layer M1 and the crack C1 as the reference points.

[0035] The overlapping wafer T, after the peripheral portion We of the first wafer W1 has been removed, is then transported by the wafer transport device 40 to the film processing device 90. In the film processing device 90, as shown in FIG3(d), a process is performed to remove the surface film from the peripheral portion of the second wafer W2 after the peripheral portion We has been removed (hereinafter also referred to as "film processing"). (Step S4 in FIG4).

[0036] The surface of the second wafer W2 after removing the peripheral portion We, specifically, on the peripheral portion of the second wafer W2 exposed after removing the first wafer W1, there are unwanted surface films and particles remaining. These surface films and particles may peel off, fall off, or scatter during the handling or processing of the overlapping wafer T, thus becoming a cause of contamination of the interior of the wafer processing system 1, the interior of the cassette C, and other overlapping wafers T.

[0037] Here, in step S4, the surface film on the periphery of the second wafer W2 is removed to suppress the scattering of the surface film and particles after the removal of the periphery We. That is, for example, the surface film is removed by irradiating the surface film with laser light (e.g., CO2 laser).

[0038] In this case, while removing the surface film by irradiating with laser light, the particles remaining on the surface of the surface film are also removed, thus inhibiting the peeling, falling or scattering of the surface film and particles.

[0039] The overlapping wafer T, after the surface film on the periphery of the second wafer W2 has been removed, is then transported by the wafer transport device 40 to the cleaning device 50. In the cleaning device 50, the periphery We is removed, and the back surface W1b and exposed portion of the first wafer W1 after film treatment are cleaned (step S5 in FIG4). Furthermore, in the cleaning device 50, the back surface W2b of the second wafer W2 can be cleaned simultaneously with the back surface W1b of the first wafer W1.

[0040] Then, the superimposed wafer T, after all wafer processing has been performed, is transported by the wafer transport device 20 to the cassette C of the cassette stage 1 via the transfer device 30. Thus, the series of wafer processing in the wafer processing system 1 is completed.

[0041] Next, the detailed configuration of the membrane processing apparatus 90 described above will be explained.

[0042] As shown in Figures 6 to 8, the film processing apparatus 90 includes a suction cup 200 that holds an overlapping wafer T on its top surface as a substrate holding portion. With the first wafer W1 positioned on the upper side and the second wafer W2 positioned on the lower side, the suction cup 200 adheres to and holds the back surface W2b of the second wafer W2. The suction cup 200 is supported by a slide 202 via an air bearing 201. A rotating portion 203 is provided on the bottom surface of the slide 202. The rotating portion 203 may have a built-in motor as a drive source. The suction cup 200 can rotate about a vertical axis via the air bearing 201 through the rotating portion 203. The slide 202 can move freely on a track 206 extending in the Y-axis direction on a base 205 via a moving portion 204 provided on its bottom surface. Furthermore, the drive source of the moving portion 204 is not particularly limited; for example, a linear motor can be used.

[0043] A miniature camera 210 is provided above the suction cup 200. For example, the miniature camera 210 is supported by a support column 211. The miniature camera 210 photographs the outer end of the second wafer W2. The miniature camera 210, for example, has a coaxial lens and emits infrared light (IR light), and also receives reflected light from the object. For example, the magnification of the miniature camera 210 is 2x. The image captured by the miniature camera 210 is output to the control device 110. In the control device 110, the eccentricity between the center of the suction cup 200 and the center of the second wafer W2 is calculated from the image captured by the miniature camera 210.

[0044] Above the suction cup 200 and on the negative Y-axis side of the miniature camera 210, a laser irradiation unit 220 is provided to irradiate laser light onto the overlapping wafer T held on the suction cup 200. The laser irradiation unit 220 is connected to a laser head (not shown) with a built-in laser oscillator (not shown) for irradiating laser light. The laser irradiation unit 220 is supported by a support member 221. The laser irradiation unit 220 can be freely raised and lowered along a track 222 extending in the vertical direction via a lifting part 223. Furthermore, the laser irradiation unit 220 can be freely moved in the Y-axis direction within the support column 211 along a track 224 extending in the Y-axis direction via a moving part 225.

[0045] The laser irradiation unit 220 irradiates the surface film on the periphery of the second wafer W2 with laser light, thereby removing the surface film. The laser irradiation unit 220 has a light-collecting lens 231 and a nozzle 232.

[0046] As shown in Figure 9, the light-collecting lens 231 collects the laser light emitted from the laser oscillator of the laser head and irradiates the surface film of the periphery of the second wafer W2.

[0047] The nozzle 232 is located below the light-collecting lens 231. The nozzle 232 is a hollow cylindrical component that allows laser light from the light-collecting lens 231 to pass through and irradiate the surface film on the periphery of the second wafer W2.

[0048] At the top of the nozzle 232, a first gas supply section 233 is provided for supplying dry air or other gases into the nozzle 232. The first gas supply section 233 communicates with a gas supply passage 232a formed inside the side wall of the nozzle 232. The gas supplied from the first gas supply section 233 and the gas supply passage 232a flows downward through the nozzle 232 and is ejected onto the surface film at the periphery of the second wafer W2. Through this gas, dust generated during laser processing can be prevented from adhering to the light-collecting lens 231.

[0049] As shown in Figures 6 to 8, the film processing apparatus 90 includes a dust collection section 240 for collecting dust. During the film processing (laser processing) in step S4 described above, that is, when laser light is irradiated from the laser irradiation section 220 onto the surface film of the peripheral portion of the second wafer W2, the dust collection section 240 collects the generated fine dust particles. The dust collection section 240 includes an upper dust collection section 241 and a lower dust collection section 242.

[0050] The upper dust collection part 241 is located above the suction cup 200 and directly below the laser irradiation part 220. As shown in Figures 10 and 11, the upper dust collection part 241 has a sleeve 250 and an exhaust pipe 260. The sleeve 250 is located on the top surface of the exhaust pipe 260.

[0051] As shown in Figures 9 and 11, the sleeve 250 has a slightly truncated cone shape with a diameter decreasing from top to bottom. A receiving portion 251 is formed at the center of the top surface of the sleeve 250, which houses a portion of the nozzle 232 of the laser irradiation section 220. The nozzle 232 can move up and down relative to the receiving portion 251, entering or exiting the receiving portion 251. For example, a power meter (not shown) is provided on the laser head to confirm the output of the laser light, but the output of the laser light cannot be measured when the dust collection section 240 is vented. Therefore, in this case, the nozzle 232 is withdrawn from the receiving portion 251. On the other hand, the nozzle 232 is housed in the receiving portion 251 during laser processing.

[0052] Furthermore, the nozzle 232 can move in the Y-axis direction within the receiving portion 251. Moreover, the nozzle 232 can rotate its bottom end using its top end as a base point. Also, the nozzle 232 does not contact the receiving portion 251 when it is received within the receiving portion 251.

[0053] As described above, the nozzle 232 can move in the Y-axis direction and can move during laser processing. Therefore, as shown in FIG12, the receiving portion 251 can also have an elongated hole shape with a long axis in the Y-axis direction. Furthermore, an elongated hole 252 is formed on the bottom surface of the receiving portion 251 to allow laser light irradiated from the nozzle 232 to pass through. This elongated hole 252 can also have a long axis in the Y-axis direction. Moreover, during film processing, the moving distance of the nozzle 232 is, for example, 2 mm to 5 mm, as described later. Therefore, the Y-axis length of the elongated hole 252 is preferably 5 mm or more.

[0054] As shown in Figures 9 and 11, a second air supply section 253 is provided on the top surface of the sleeve 250 in the positive X-axis direction of the receiving portion 251, supplying dry air or other gases to the suction flow path 262 described later. The second air supply section 253 is connected to an air supply path 250a formed through the sleeve 250 from the top to the bottom surface. The air supply path 250a is also connected to a discharge portion 250b formed on the bottom surface of the sleeve 250. Gas supplied from the discharge portion 250b via the second air supply section 253 and the air supply path 250a flows out into the suction flow path 262. This gas disperses the fumes generated during laser processing. Furthermore, the gas from the second air supply section 253 guides the ambient gas in the suction flow path 262 to the exhaust flow path 263 described later. At this time, the aforementioned fumes are also guided to the exhaust flow path 263.

[0055] Furthermore, as described later, during laser processing, the overlapping wafer T is rotated while being irradiated with laser light. The gas from the second gas supply unit 253, the gas supply path 250a, and the exhaust unit 250b is preferably supplied in the direction of rotation of the overlapping wafer T. In this case, the ambient gas in the intake path 262 can be more reliably guided to the exhaust path 263.

[0056] The exhaust duct 260 extends in the X-axis direction. As shown in Figures 11 and 13, an opening 261 is formed in the bottom surface 260a of the exhaust duct 260, below the sleeve 250, to allow laser light irradiated from the nozzle 232 to pass through. The bottom surface 260a has a slightly rounded shape when viewed from above. An intake flow path 262 and an exhaust flow path 263 are formed inside the exhaust duct 260.

[0057] The suction flow path 262 is a flow path formed between the sleeve 250 and the opening 261. The suction flow path 262 draws ambient gas from the opening 261 between the overlapping wafer T held in place by the suction cup 200 and the exhaust pipe 260.

[0058] The exhaust flow path 263 is connected to the intake flow path 262 and extends in the tangential direction of the overlapping wafer T, i.e., in the negative X-axis direction. The exhaust flow path 263 is connected to the exhaust pipe 264 located at the negative X-axis end of the exhaust pipe 260. The exhaust pipe 264 is connected to an exhaust device (not shown) that draws in ambient gas from the interior of the exhaust pipe 260.

[0059] As shown in Figures 9 and 11, a third gas supply section 265 for supplying dry air or other gases is provided inside the exhaust duct 260 on the positive X-axis side of the receiving portion 251. The third gas supply section 265 is connected to a gas supply path 260b formed from the side wall of the exhaust duct 260 to the bottom surface. Furthermore, the gas supply path 260b is connected to a spray section 260c formed on the bottom surface 260a of the exhaust duct 260. A plurality of spray sections 260c are provided around the opening 261 on the bottom surface 260a of the exhaust duct 260. The plurality of spray sections 260c are equally spaced on concentric circles of the opening 261, that is, the radial distance between each spray section 260c and the bottom surface 260a is equal. Thus, the ambient gas between the exhaust duct 260 and the superimposed wafer T is uniformly drawn in through the opening 261.

[0060] The gas supplied from the third air supply unit 265, air supply passage 260b, and spray unit 260c is sprayed downwards around the opening 261, forming an air curtain. In this case, the dust generated during laser processing is prevented from flowing out of the air curtain. Furthermore, the diameter of the opening 261 is larger than the gap outside the air curtain, so the gas from the third air supply unit 265, air supply passage 260b, and spray unit 260c flows into the suction flow passage 262 through the opening 261. In this case, the dust also flows into the suction flow passage 262 through the opening 261, and the dust can be reliably collected in the exhaust pipe 260. Also, the number of air supply passages 260b in the bottom surface 260a of the exhaust pipe 260 is not limited, but the more there are, the better the effect of the air curtain.

[0061] As shown in FIG12, a fourth air supply section 266 for supplying dry air or other gases is provided on the side of the exhaust pipe 260 in the positive Y-axis direction of the receiving portion 251. The fourth air supply section 266 is connected to an air supply passage 260d formed through the side wall of the exhaust pipe 260 into the intake flow passage 262. Furthermore, the air supply passage 260d is connected to a spray portion 260e formed on the inner side of the exhaust pipe 260. The air supply passage 260d and the spray portion 260e are formed, for example, in the positive X-axis direction into the intake flow passage 262. The gas supplied from the fourth air supply section 266, the air supply passage 260d, and the spray portion 260e flows into the intake flow passage 262, and a swirling flow is formed in the intake flow passage 262. Furthermore, the positions of the air supply passage 260d and the spray portion 260e are not limited to this embodiment, as long as they are positions where a swirling flow can be formed in the intake flow passage 262.

[0062] As shown in Figures 14 and 15, during laser processing, the ambient gas between the exhaust pipe 260 and the superimposed wafer T is drawn into the interior of the exhaust pipe 260 through the opening 261, then flows through the suction flow path 262 and the exhaust flow path 263, and is discharged from the exhaust pipe 264. Furthermore, along with this airflow, dust generated during laser processing is also collected. At this time, gas from the second gas supply unit 253 disperses the smoke generated during laser processing and guides it to the exhaust flow path 263. Additionally, gas from the third gas supply unit 265 suppresses dust from flowing outwards. Furthermore, gas from the fourth gas supply unit 266 forms a swirling flow in the suction flow path 262, smoothly guiding the ambient gas and dust to the exhaust flow path 263.

[0063] As shown in Figures 6 and 8, the lower dust collection section 242 includes a dust collection disc 270 and a support member 271. The dust collection disc 270 is disposed near the outer periphery of the suction cup 200. The gap between the dust collection disc 270 and the outer periphery of the suction cup 200 is, for example, 0.5 mm or less. The narrower this gap, the better it can suppress dust from flowing outward.

[0064] As shown in Figure 16, the height of the top surface of the dust collection tray 270 is preferably the same as the height of the top surface of the overlapping wafer T (the back surface W1b of the first wafer W1) held by the suction cup 200. Furthermore, the dust collection tray 270 is supported on its bottom surface by a support member 271. The support member 271 is fixed to the slide table 202. That is, the lower dust collection part 242 is integrated with the suction cup 200, and as the suction cup 200 moves, the lower dust collection part 242 also moves in the Y-axis direction.

[0065] In Figure 17, the dust collection tray 270 has a slightly rectangular shape when viewed from above, and the end 270a on the suction cup 200 side is curved along the outer periphery of the suction cup 200. However, the suction cup 200 rotates, so the dust collection tray 270 does not contact the suction cup 200. The Y-axis length A of the dust collection tray 270 is greater than the diameter D of the opening 261 of the exhaust pipe 260. Also, the X-axis length B of the dust collection tray 270 is greater than the radius D / 2 of the opening 261. Furthermore, the dust collection tray 270 is configured such that when it is positioned below the exhaust pipe 260 of the upper dust collection section 241, it overlaps with the opening 261 when viewed from above. Also, unlike this embodiment, the dust collection tray 270 can contact the suction cup 200 even when the suction cup 200 is not rotating.

[0066] Here, as shown in FIG18, during laser processing, when laser light is irradiated onto the periphery of the second wafer W2, in the opening 261, the radially inner side of the end of the suction cup 200 (overlapping wafer T) is covered by the suction cup 200 in a top view, but the radially outer side of that end is exposed. Thus, there is a concern that the amount of dust attracted may deviate throughout the entire circumference of the opening 261, making it impossible to stably collect dust.

[0067] Regarding this point, as shown in Figure 19, the dust collection tray 270 is configured such that when positioned below the exhaust duct 260, it overlaps with the opening 261 in a top view. In this case, the amount of dust attracted around the entire circumference of the opening 261 is uniform, and dust can be collected stably.

[0068] Next, the membrane treatment performed by the membrane treatment apparatus 90 configured as described above will be explained.

[0069] First, as shown in FIG20(a), the suction cup 200 is positioned in the standby position P1. At this time, the nozzle 232 is received in the receiving portion 251 of the sleeve 250. Then, the overlapping wafer T is moved into the film processing apparatus 90 and held in the suction cup 200 (step T1 in FIG21).

[0070] Next, the suction cup 200 is moved to the macro-adjustment position. The macro-adjustment position allows the miniature camera 210 to capture images of the outer edge of the second wafer W2. Then, the miniature camera 210 captures images of the outer edge of the second wafer W2 in a 360-degree circumferential direction. The captured images are output from the miniature camera 210 to the control device 110.

[0071] In the control device 110, the eccentricity between the center of the suction cup 200 and the center of the second wafer W2 is calculated from the image of the miniature camera 210. Furthermore, the control device 110 calculates the movement of the suction cup 200 based on the eccentricity to correct the Y-axis component of the eccentricity. Then, the position of the suction cup 200 is determined in a way that makes the center of the second wafer W2 coincide with the center of the suction cup 200 (step T2 in FIG. 21).

[0072] Next, as shown in FIG20(b), the suction cup 200 is moved to the processing position P2 (step T3 in FIG21). The processing position P2 is such that the end of the peripheral portion of the second wafer W2 in the positive Y-axis direction is positioned directly below the nozzle 232 of the laser irradiation section 220. At this time, the dust collection tray 270 is arranged to overlap with the opening 261 of the exhaust pipe 260 when viewed from above.

[0073] Next, while the chuck 200 is rotated, the nozzle 232 is moved towards the negative Y-axis direction, and laser light is irradiated onto the surface film at the periphery of the second wafer W2 through the nozzle 232. Thus, the laser light irradiates the surface film in a spiral pattern. The moving distance of the nozzle 232 is 2mm to 5mm, and the periphery of the second wafer W2 being processed is within a range of 2mm to 5mm from the outer edge. That is, the processing width of the laser light is adjusted by moving the nozzle 232. Then, the surface film is removed (step T4 in FIG. 21).

[0074] Dust is generated during the laser processing in step T4. This dust is collected by the upper dust collection unit 241. Specifically, as described above, the ambient gas between the exhaust duct 260 and the superimposed wafer T is drawn into the exhaust duct 260 through the opening 261, then flows through the suction flow path 262 and the exhaust flow path 263, and is discharged from the exhaust pipe 264. Furthermore, the dust generated during the laser processing is also collected along with this airflow.

[0075] After removing the surface film from the periphery of the second wafer W2, the chuck 200 is then moved to the standby position P1. The overlapping wafer T is then removed from the film processing apparatus 90 (step T5 in FIG. 21). This completes a series of film processing steps in the film processing apparatus 90.

[0076] In the above embodiment, the dust collection unit 240 has an upper dust collection unit 241 and a lower dust collection unit 242. When the dust collection disc 270 of the lower dust collection unit 242 is disposed below the exhaust pipe 260 of the upper dust collection unit 241, it overlaps with the opening 261 when viewed from above. Therefore, the amount of dust attracted around the entire circumference of the opening 261 is uniform, and dust can be collected stably. Furthermore, the diameter of the opening 261 can be increased to collect dust over a wider area. Thus, the dust generated during laser processing can be collected appropriately and efficiently through the dust collection unit 240.

[0077] In the above embodiments, the technology of the present invention is applied to removing the surface film at the periphery of the second wafer W2, but this technology can also be used for other purposes. For example, the technology according to the present invention can also be applied when irradiating the entire surface of the wafer with laser light. For example, when the entire surface of the first wafer W1 is peeled off from the second wafer W2, and the element layer D1 formed on the surface W1a side of the first wafer W1 is transferred to the second wafer W2, that is, when laser peeling is performed, laser light is irradiated onto the entire surface of the interface between the first wafer W1 and the second wafer W2. In this case, the same effect as in the above embodiments can be obtained when irradiating the periphery with laser light.

[0078] It should be understood that all embodiments of the present invention are illustrative and not intended to limit. The above embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended patent applications. [Simplified Explanation of the Diagram]

[0008] Figure 1 is a side view showing an example of an overlapping wafer processed in a wafer processing system. Figure 2 is a schematic top view showing the general structure of a wafer processing system. Figures 3(a) to (d) are schematic diagrams showing the main steps of wafer processing. Figure 4 is a flowchart showing the main steps of wafer processing. Figure 5 is a schematic diagram showing the state of the peripheral modification layer formed inside the first wafer. Figure 6 is a schematic top view showing the general structure of a film processing apparatus. Figure 7 is a schematic side view showing the general structure of a film processing apparatus. Figure 8 is a schematic side view showing the general structure of a film processing apparatus. Figure 9 is a schematic cross-sectional perspective view showing the general structure of a portion of the laser irradiation section and the upper dust collection section. Figure 10 is a schematic perspective view showing the general structure of the upper dust collection section. Figure 11 is a schematic cross-sectional perspective view showing the general structure of the upper dust collection section. Figure 12 is a schematic top view showing the general structure of a portion of the upper dust collection section. Figure 13 is a schematic cross-sectional perspective view showing the structure of a portion of the upper dust collection section. Figure 14 is a schematic diagram showing the flow of ambient gas in the upper dust collection section. Figure 15 is a schematic diagram showing the flow of ambient gas in the upper dust collection section. Figure 16 is a schematic side view showing the structure of the lower dust collection section. Figure 17 is a schematic top view showing the structure of the lower dust collection section. Figure 18 is a schematic diagram showing a case where the lower dust collection section is not provided as a comparative example. Figure 19 is a schematic perspective view showing the structure of the lower dust collection section. Figures 20(a) and (b) are schematic diagrams showing the main steps of membrane treatment. Figure 21 is a flowchart showing the main steps of membrane treatment.

Claims

1. A substrate processing apparatus for processing a substrate by irradiating it with laser light, comprising: a substrate holding portion for holding the substrate; a laser irradiation portion for irradiating the substrate held in the substrate holding portion with laser light; and a dust collection portion for collecting dust; the dust collection portion comprising: an upper dust collection portion disposed above the substrate holding portion; and a lower dust collection portion movable below the upper dust collection portion; the height of the top surface of the lower dust collection portion being the same as the height of the top surface of the substrate held in the substrate holding portion.

2. The substrate processing apparatus as described in claim 1, wherein, The lower dust collection section is located near the outer periphery of the substrate holding section.

3. The substrate processing apparatus as described in claim 2, wherein, The lower dust collection part and the substrate holding part are integrated.

4. The substrate processing apparatus as described in any one of claims 1 to 3, wherein, An opening is formed on the bottom surface of the upper dust collection section to allow the laser light irradiated from the laser irradiation section to pass through; the lower dust collection section is configured to overlap with the opening when it is disposed below the upper dust collection section in a top view.

5. The substrate processing apparatus as described in any one of claims 1 to 3, wherein, The upper dust collection section includes: an exhaust duct; and a sleeve disposed on the top surface of the exhaust duct, forming a receiving portion for accommodating at least a portion of the laser irradiation section; an opening formed on the bottom surface of the exhaust duct for allowing the laser light irradiated from the laser irradiation section to pass through; and inside the exhaust duct, an intake flow path is formed for drawing ambient gas between itself and the substrate from the opening; and an exhaust flow path connected to the intake flow path for discharging the ambient gas.

6. The substrate processing apparatus as described in claim 5, wherein, The exhaust flow path is formed in the tangential direction of the substrate.

7. The substrate processing apparatus as described in claim 5 further includes: an ejector unit disposed on the sleeve and supplying gas to the suction flow path.

8. The substrate processing apparatus as claimed in claim 5 further includes: a spray section that supplies gas downward around the opening.

9. The substrate processing apparatus as claimed in claim 5 further includes: an ejector unit disposed in the exhaust duct and supplying gas along the sidewall of the intake flow path.

10. The substrate processing apparatus as described in any one of claims 1 to 3, wherein, The laser irradiation section irradiates the periphery of the substrate with laser light.

11. A substrate processing method, wherein the substrate is processed by irradiating a substrate with laser light using a substrate processing apparatus; the substrate processing apparatus includes: a substrate holding portion for holding the substrate; a laser irradiation portion for irradiating the substrate held in the substrate holding portion with laser light; and a dust collection portion for collecting dust; the dust collection portion includes: an upper dust collection portion disposed above the substrate holding portion; and a lower dust collection portion movable below the upper dust collection portion; the height of the top surface of the lower dust collection portion is the same as the height of the top surface of the substrate held in the substrate holding portion; the substrate processing method includes the following steps: moving the substrate holding portion and the lower dust collection portion to below the upper dust collection portion; and, while irradiating the substrate with laser light from the laser irradiation portion, attracting ambient gas between the upper dust collection portion, the substrate, and the lower dust collection portion through the upper dust collection portion, and collecting dust.

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