JP2023180066A - Substrate processing device and position adjustment method - Google Patents

Abstract

To adjust a position, so as to irradiate the desired position of a substrate with laser light.SOLUTION: A substrate processing device for processing the substrate includes a substrate holding part which holds the substrate, a laser irradiation part which irradiates the substrate held by the substrate holding part with the laser light, a camera which images the substrate, a rotation mechanism which rotates the substrate holding part, a movement mechanism which moves the substrate holding part and the laser irradiation part relatively and horizontally, and a control part. The control part executes control for irradiating the substrate with the laser light, to form an annular processing part on the substrate, control for imaging the processing part by the camera, control for calculating the processing center of the imaged processing part, and control for moving the substrate holding part and the laser irradiation part relatively and horizontally to a position where the processing center aligns with the rotation center of the substrate holding part at least in the movement direction of the movement mechanism.SELECTED DRAWING: Figure 9

Description

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

Patent Document 1 discloses that in a semiconductor substrate on which a peeled oxide film and a semiconductor element are formed, the semiconductor element is transferred to a transfer destination substrate. The method described in Patent Document 1 includes a step of locally heating the peeled oxide film by irradiating light from the back surface of the semiconductor substrate, and a step of heating the peeled oxide film locally and/or at the interface between the peeled oxide film and the semiconductor substrate. and transferring the semiconductor element to a transfer destination substrate.

Japanese Patent Application Publication No. 2007-220749

The technology according to the present disclosure performs position adjustment so that a desired position on a substrate is irradiated with laser light.

One aspect of the present disclosure is a substrate processing apparatus that processes a substrate, including a substrate holding section that holds a substrate, a laser irradiation section that irradiates the substrate held by the substrate holding section with a laser beam, and a substrate processing apparatus that processes a substrate. a camera that takes an image of the substrate holder, a rotation mechanism that rotates the substrate holder, a movement mechanism that relatively moves the substrate holder and the laser irradiation unit in a horizontal direction, and a control unit, the control unit , control to irradiate the substrate with the laser light to form an annular processed portion on the substrate, control to image the processed portion with the camera, and control to calculate the processing center of the imaged processed portion. and control to relatively move the substrate holding part and the laser irradiation part in a horizontal direction to a position where the processing center and the rotation center of the substrate holding part coincide at least in the moving direction of the moving mechanism; Execute.

According to the present disclosure, the position can be adjusted so that a desired position on the substrate is irradiated with laser light.

FIG. 1 is a side view schematically showing the configuration of a polymerized wafer processed in a wafer processing system. FIG. 1 is a plan view schematically showing the configuration of a wafer processing system. FIG. 2 is a side view schematically showing the configuration of a laser irradiation device. FIG. 2 is a plan view schematically showing the configuration of a laser irradiation device. FIG. 2 is an explanatory diagram showing how the separation device operates. FIG. 2 is an explanatory diagram showing how a laser absorption layer is irradiated with laser light. FIG. 2 is an explanatory diagram showing how a laser absorption layer is irradiated with laser light. FIG. 3 is an explanatory diagram showing how a processed portion is formed in a laser absorption layer. FIG. 6 is an explanatory diagram showing how the first adjustment of the machining center and the chuck rotation center is performed. FIG. 6 is an explanatory diagram showing how the second adjustment of the machining center and the chuck rotation center is performed. FIG. 6 is an explanatory diagram showing how the second adjustment of the machining center and the chuck rotation center is performed. FIG. 6 is an explanatory diagram showing how the second adjustment of the machining center and the chuck rotation center is performed.

In the manufacturing process of semiconductor devices, in a polymerized wafer in which two semiconductor substrates (hereinafter referred to as "wafers") are bonded, a device layer formed on the surface of the second wafer is transferred to the first wafer. is being carried out. This device layer transfer is performed using, for example, laser lift-off. That is, the bonding strength between the first wafer and the second wafer is reduced by irradiating the inside of the polymerized wafer held by the chuck with laser light from the laser irradiation unit, and then the second wafer is bonded to the first wafer. The device layer is transferred to the first wafer by peeling from the wafer.

In laser lift-off, while rotating the polymerized wafer, the laser beam is irradiated in a pulsed manner while moving the laser beam from the outside in the radial direction to the inside. At this time, in order to uniformly separate the first wafer and the second wafer within the wafer surface, it is preferable to keep the laser beam irradiation interval, that is, the pulse interval, constant. However, if the pulse interval is kept constant, the rotation speed of the polymerized wafer increases as the laser beam moves from the outside to the inside in the radial direction. Then, when the rotational speed of the superposed wafer reaches its upper limit, as the laser beam irradiation position moves radially inward, the laser beam irradiation interval becomes smaller, and the laser beams may overlap in the central region. Furthermore, if the rotational speed of the overlapping wafers increases in the central region, there is a risk that the first wafer may peel off. Therefore, the laser beam is irradiated while rotating the overlapping wafer in the outer peripheral area, and the laser beam is scanned in the central area while the rotation of the overlapping wafer is stopped.

Here, for example, if the processing center (center of the processing position) of the polymerized wafer and the chuck rotation center are misaligned, the laser beam will not be irradiated at an appropriate position in the outer peripheral area, and the laser beam will not be irradiated at an appropriate position in the outer peripheral area. There is a risk of being irradiated. Furthermore, if the machining center and the chuck rotation center are misaligned, the central area may not be scanned and an unprocessed area may occur at the boundary between the outer peripheral area and the central area.

The technology according to the present disclosure performs position adjustment so that a desired position on a substrate is irradiated with laser light. Hereinafter, a wafer processing system including a laser irradiation device as a substrate processing apparatus and a wafer processing method as a substrate processing method according to the present embodiment will be described with reference to the drawings. Note that in this specification and the drawings, elements having substantially the same functional configuration are designated by the same reference numerals and redundant explanation will be omitted.

In a wafer processing system 1 according to the present embodiment, which will be described later, as shown in FIG. 1, a superposed wafer T as a substrate in which a first wafer W1 and a second wafer W2 are bonded is processed. Hereinafter, in the first wafer W1, the surface to be joined to the second wafer W2 will be referred to as the front surface W1a, and the surface opposite to the front surface W1a will be referred to as the back surface W1b. Similarly, in the second wafer W2, the surface to be 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 back surface W2b.

The first wafer W1 is, for example, a semiconductor wafer such as a silicon substrate. In one embodiment, the first wafer W1 has a substantially disk shape. On the front surface W1a of the first wafer W1, a device layer D1 and a surface film F1 are laminated in this order from the front surface W1a side. Device layer D1 includes multiple devices. Examples of the surface film F1 include an oxide film (THOX film, SiO ₂ film, TEOS film), SiC film, SiCN film, adhesive, and the like.

The second wafer W2 is, for example, a semiconductor wafer such as a silicon substrate. In one embodiment, the second wafer W2 has a substantially disk shape. On the front surface W2a of the second wafer W2, a laser absorption layer P, a device layer D2, and a surface film F2 are laminated in this order from the front surface W2a side. The laser absorption layer P absorbs laser light irradiated from the laser irradiation section 110 as described later. For example, an oxide film (SiO ₂ film) is used for the laser absorption layer P, but it is not particularly limited as long as it absorbs laser light. The device layer D2 and the surface film F2 are similar to the device layer D1 and the surface film F1 of the first wafer W1, respectively. Then, the surface film F1 of the first wafer W1 and the surface film F2 of the second wafer W2 are bonded. In addition, the position of the laser absorption layer P is not limited to the said embodiment, For example, it may be formed between the device layer D2 and the surface film F2.

As shown in FIG. 2, the wafer processing system 1 has a configuration in which a loading/unloading block 10, a transport block 20, and a processing block 30 are integrally connected. The loading/unloading block 10 and the processing block 30 are provided around the transport block 20. Specifically, the carry-in/out block 10 is arranged on the Y-axis negative direction side of the conveyance block 20. A laser irradiation device 31 (described later) and a separation device 32 (described later) of the processing block 30 are arranged on the X-axis negative direction side of the transport block 20, and a first cleaning device 33 (described later) and a second cleaning device 34 (described later) are located on the transport block 20. 20 in the positive direction of the X-axis.

For example, cassettes Ct, Cw1, and Cw2 each capable of accommodating a plurality of stacked wafers T, a plurality of first wafers W1, and a plurality of second wafers W2 are carried in and out of the carry-in/out block 10, respectively. The loading/unloading block 10 is provided with a cassette mounting table 11 . In the illustrated example, a plurality of cassettes, for example, three cassettes Ct, Cw1, and Cw2, can be placed on the cassette mounting table 11 in a line in the X-axis direction. Note that the number of cassettes Ct, Cw1, and Cw2 placed on the cassette mounting table 11 is not limited to this embodiment, and can be arbitrarily determined.

The transport block 20 is provided with a wafer transport device 22 configured to be movable on a transport path 21 extending in the X-axis direction. The wafer transport device 22 has, for example, two transport arms 23, 23 that hold and transport the stacked wafer T, the first wafer W1, or the second wafer W2. Each transport arm 23 is configured to be movable in the horizontal direction, vertical direction, around the horizontal axis, and around the vertical axis. Note that the configuration of the transport arm 23 is not limited to this embodiment, and may have any configuration. Then, the wafer transport device 22 transfers the polymerized wafers T, It is configured to be able to transport the first wafer W1 and the second wafer W2.

The processing block 30 includes a laser irradiation device 31, a separation device 32, a first cleaning device 33, and a second cleaning device 34. In one example, the laser irradiation device 31 and the separation device 32 are stacked and arranged on the X-axis negative direction side of the transport block 20. Further, the first cleaning device 33 and the second cleaning device 34 are stacked and arranged on the X-axis positive direction side of the transport block 20. Note that the number and arrangement of the laser irradiation device 31, the separation device 32, the first cleaning device 33, and the second cleaning device 34 are not limited to these.

The laser irradiation device 31 irradiates the inside of the polymerized wafer T, more specifically, the laser absorption layer P of the second wafer W2, with a laser beam to increase the bonding strength at the interface between the second wafer W2 and the laser absorption layer P. lower. The interface (in this embodiment, the interface between the second wafer W2 and the laser absorption layer P) where the bonding strength is reduced inside the polymerized wafer T may be referred to as a "separation surface" in the technology of the present disclosure. Note that the laser irradiation device 31 functions as a wafer processing device that performs laser processing on the stacked wafers T, and also functions as a position adjustment device that adjusts the processing position of the stacked wafers T.

As shown in FIGS. 3 and 4, a delivery position A1 and a processing position A2 are set inside the laser irradiation device 31. The delivery position A1 is a position where the overlapping wafer T can be delivered from the transport arm 23 to the chuck 100 described below, and is also a position where the overlapping wafer T can be processed by the laser beam formed on the overlapping wafer T (laser absorption layer P) by the later-described camera 120. This is the position where the part can be imaged. The processing position A2 is a position where the polymerized wafer T (laser absorption layer P) can be irradiated with laser light from a laser irradiation unit 110, which will be described later.

The laser irradiation device 31 has a chuck 100 as a substrate holder that holds the superposed wafer T on its upper surface. The chuck 100 has a holding surface for the stacked wafer T on its upper surface, and holds the entire back surface W1b of the first wafer W1 by suction or a part of the radially inner side of the back surface W1b. The chuck 100 is, for example, an electrostatic chuck (ESC) or a vacuum chuck. The chuck 100 is provided with a lifting pin (not shown) for supporting the stacked wafer T from below and lifting it up and down. The elevating pin is inserted into a through hole (not shown) formed through the chuck 100 and is configured to be movable up and down.

The chuck 100 is supported by a slider table 102 via an air bearing 101. A rotation mechanism 103 is provided on the lower surface side of the slider table 102. The rotation mechanism 103 has a built-in motor as a drive source, for example. The chuck 100 is configured to be rotatable around the θ axis (vertical axis) by a rotation mechanism 103 via an air bearing 101. The slider table 102 is movable between the above-mentioned delivery position A1 and processing position A2 by a moving mechanism 104 provided on the lower surface side of the slider table 102 along a rail 106 provided on the base 105 and extending in the Y-axis direction. It is configured. Note that the driving source for the moving mechanism 104 is not particularly limited, but a linear motor may be used, for example. Furthermore, a moving mechanism 107 that moves the chuck 100 in the X-axis direction may be provided. Although the configuration of the moving mechanism 107 is arbitrary, it may be provided, for example, on the air bearing 101 and move the chuck 100 mechanically using a screw or the like.

A laser irradiation unit 110 is provided above the chuck 100 at the processing position A2. The laser irradiation unit 110 includes a laser head 111, an optical system 112, and a lens 113. The laser irradiation unit 110 can scan a laser beam. In the following description, scanning the laser beam L means moving the laser beam L irradiated from the lens 113 of the laser irradiation unit 110 with respect to the laser absorption layer P.

The laser head 111 includes a laser oscillator (not shown) that oscillates laser light in a pulsed manner. This laser light is a so-called pulsed laser. Further, in this embodiment, the laser beam is a CO ₂ laser beam, and the wavelength of the CO ₂ laser beam is, for example, 8.9 μm to 11 μm. Note that the laser head 111 may include equipment other than the laser oscillator, such as an amplifier.

The optical system 112 includes an optical element (not shown) that controls the intensity and position of the laser beam, an attenuator (not shown) that attenuates the laser beam and adjusts the output, and a laser scanning section (not shown) that scans the laser beam. (not shown). For example, a rotary wedge scanner or a galvano scanner is used as the laser scanning unit. Further, the optical system 112 may be configured to be able to control branching of laser light.

The lens 113 irradiates the polymerized wafer T held by the chuck 100 with laser light. The laser light emitted from the laser irradiation section 110 passes through the second wafer W2 and is irradiated onto the laser absorption layer P. The lens 113 may be configured to be movable in the horizontal direction by a moving mechanism (not shown), or may be configured to be vertically movable by a lifting mechanism (not shown).

Further, a camera 120 is provided above the chuck 100 at the delivery position A1. The camera 120 includes one or more cameras selected from macro cameras, micro cameras, and the like. Note that the camera 120 may be configured to be movable in the horizontal direction by a moving mechanism (not shown), or may be configured to be vertically movable by a lifting mechanism (not shown).

The camera 120 images the processed portion of the polymerized wafer T held by the chuck 100 that is irradiated with the laser beam. The camera 120 includes, for example, a coaxial lens, emits infrared light (IR), and receives reflected light from an object. Image data captured by the camera 120 is output to a control device 40, which will be described later.

Note that, as described later, the wafer processing system 1 includes a control device 40, and the control device 40 also functions as a control section that is provided in the laser irradiation device 31 and controls the laser irradiation device 31.

The separation device 32 separates the second wafer W2 from the first wafer W1 based on the interface between the second wafer W2 and the laser absorption layer P, which serves as a separation surface and whose bonding strength has been reduced by the laser irradiation device 31. .

In one example, as shown in FIG. 5, the separation device 32 includes a suction chuck 200 that suction-holds the back surface W1b of the first wafer W1 from below, and a suction pad 210 that suction-holds the back surface W2b of the second wafer W2 from above. and has. Then, in the separation device 32, as shown in FIG. 5, the suction chuck 200 suction-holds the first wafer W1, and the suction pad 210 suction-holds the second wafer W2, and the suction pad 210 is raised. , the second wafer W2 is peeled off from the laser absorption layer P.

Note that the configuration of the separation device 32 is not limited to this, and can take any configuration as long as it can separate the second wafer W2 from the first wafer W1.

The first cleaning device 33 cleans the front surface W1a side of the first wafer W1 separated by peeling in the separation device 32. For example, a brush is brought into contact with the laser absorption layer P on the front surface W1a side of the first wafer W1 to clean the laser absorption layer P. Note that a pressurized cleaning liquid may be used to clean the first wafer W1. Further, the first cleaning device 33 may be configured to clean the front surface W1a side of the first wafer W1 as well as the back surface W1b.

The second cleaning device 34 cleans the front surface W2a side of the second wafer W2 separated by peeling in the separation device 32. For example, a brush is brought into contact with the front surface W2a of the second wafer W2 to clean the front surface W2a. Note that a pressurized cleaning liquid may be used to clean the second wafer W2. Further, the second cleaning device 34 may have a configuration that cleans the front surface W2a side of the second wafer W2 as well as the back surface W2b.

Note that in this embodiment, as described above, the first cleaning device 33 for cleaning the first wafer W1 and the second cleaning device 34 for cleaning the second wafer W2 are arranged independently. The cleaning of the first wafer W1 and the cleaning of the second wafer W2 may be performed using the same cleaning apparatus. In this case, the first wafer W1 and the second wafer W2 may be cleaned simultaneously or independently.

Further, in this embodiment, the second wafer W2 is separated from the first wafer W1 using the separation device 32, but such separation may be performed inside the laser irradiation device 31. For example, a transfer pad (not shown) that can be raised and lowered is provided at the delivery position A1 of the laser irradiation device 31. Then, while the chuck 100 suction-holds the first wafer W1, the transport pad suction-holds the second wafer W2, and further raises the transport pad to move the first wafer W1 to the second wafer W2. Peel off.

As shown in FIG. 2, the above wafer processing system 1 is provided with a control device 40 as a control section. The control device 40 is, for example, a computer, and has a program storage section (not shown). The program storage unit stores a program for controlling the processing of the stacked wafers T in the wafer processing system 1. The program storage unit also stores programs for controlling the operations of drive systems such as the various processing devices and transport devices described above to realize wafer processing in the wafer processing system 1, which will be described later. Note that the above program may be one that has been recorded on a computer-readable storage medium H, and may have been installed in the control device 40 from the storage medium H. Further, the storage medium H may be temporary or non-temporary.

Next, wafer processing performed using the wafer processing system 1 configured as above will be described. Note that 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 form a superposed wafer T in advance.

First, a cassette Ct containing a plurality of stacked wafers T is placed on the cassette mounting table 11 of the loading/unloading block 10 .

Next, the superposed wafer T in the cassette Ct is taken out by the wafer transport device 22 and transported to the laser irradiation device 31. In the laser irradiation device 31, the stacked wafer T is transferred from the transfer arm 23 to the chuck 100 disposed at the transfer position A1, and is held by the chuck 100 by suction. Subsequently, the moving mechanism 104 moves the chuck 100 to the processing position A2.

Next, as shown in FIG. 6, laser light L (CO ₂ laser light) is irradiated from the laser irradiation unit 110 to the laser absorption layer P, more specifically, to the interface between the laser absorption layer P and the second wafer W2 in a pulsed manner. do. At this time, the laser light L passes through the second wafer W2 from the back surface W2b side of the second wafer W2, and is absorbed in the laser absorption layer P. This laser light L reduces the bonding strength between the laser absorption layer P and the second wafer W2. In the embodiment, "the bonding strength is reduced" refers to a state in which the bonding strength is reduced at least compared to before irradiation with the laser beam L, and the term "bonding strength reduced" refers to a state in which the bonding strength is reduced at least compared to before irradiation with the laser light L, and the modification of the laser absorption layer P or the laser absorption layer This includes peeling off P and the second wafer W2.

Here, in this embodiment, while rotating the overlapping wafer T, the laser beam L is irradiated in a pulsed manner while moving the laser beam L from the outside in the radial direction to the inside. At this time, in order to uniformly peel off the second wafer W2 and the laser absorption layer P within the wafer plane, if the interval at which the laser beam L is irradiated is made constant, the laser beam L moves from the outside in the radial direction to the inside. Accordingly, the rotation speed of the polymerized wafer T increases. In such a case, the laser beams L may overlap in the central region of the laser absorption layer P, and if the rotation speed of the polymerized wafer T increases in the central region, the second wafer W2 will peel off during the process during rotation. There is also a risk.

Therefore, as shown in FIG. 7, the laser beam L is irradiated in the outer peripheral region R1 while rotating the overlapping wafer T, and the laser beam L is scanned in the central region R2 while the rotation of the overlapping wafer T is stopped.

The central region R2 of the chuck 100 on which the laser beam L is scanned is a circular region having a desired diameter with respect to the chuck rotation center as a holding center in the chuck 100, and is a circular region R2 that is scanned by the laser beam L. It is set in advance. The radial length of the central region R2 is, for example, the radial position where the relative rotational speed of the chuck 100 with respect to the lens 113 of the laser irradiation unit 110 reaches its upper limit, in other words, it is the limit position where the laser beams L do not overlap. . The diameter length of the central region R2 is, for example, about 10 mm. Further, an outer circumferential region R1 in which the chuck 100 is rotated during irradiation with the laser beam L is set to a region radially outer than the central region R2.

When irradiating the laser absorption layer P with the laser light L, first, the outer peripheral region R1 is imaged with the camera 120. Image data captured by camera 120 is output to control device 40 . The control device 40 determines the irradiation start position of the laser beam L in the outer peripheral region R1 based on the image data.

Next, in the outer circumferential region R1, the chuck 100 (polymerized wafer T) is rotated by the rotating mechanism 103, and the chuck 100 is moved in the Y negative axis direction by the moving mechanism 104, while the laser beam L is irradiated in a pulsed manner. At this time, the laser beam L is fixed without scanning. Then, in the outer circumferential region R1, the laser light L is irradiated in a spiral shape from the outside in the radial direction toward the inside.

Next, the rotation of the chuck 100 is stopped in the central region R2. Then, the laser beam L is irradiated from the laser irradiation unit 110 in a pulsed manner. Further, the laser beam L is scanned in the central region R2. At this time, scanning irradiation of the laser beam L in the X-axis direction and movement of the chuck 100 (polymerized wafer T) in the Y-axis direction are alternately repeated. Alternatively, scanning irradiation of the laser beam L in the X-axis direction and movement of the chuck 100 in the Y-axis negative direction may be synchronized.

As shown in FIG. 8, a spiral processed portion (dashed line in FIG. 8) is formed in the outer peripheral region R1, and a circular processed portion (filled portion in FIG. 8) is formed in the central region R2. Ru. Note that in order to improve the throughput of wafer processing, the laser beam L may be branched by the optical system 112 described above, and multiple points on the laser absorption layer P may be irradiated with the laser beam L at the same time.

When the outer peripheral region R1 and the central region R2 are irradiated with the laser beam L and the bonding strength is reduced over the entire surface of the second wafer W2 and the laser absorption layer P, the chuck 100 (polymerized wafer T) is then moved by the moving mechanism 104. is moved to the delivery position A1.

Next, the stacked wafers T on the chuck 100 are transferred to the transfer arm 23 of the wafer transfer device 22 and transferred to the separation device 32. In the separation device 32, as shown in FIG. 5(a), a suction chuck 200 suction-holds the back surface W1b of the first wafer W1, and a suction pad 210 suction-holds the back surface W2b of the second wafer W2. Thereafter, as shown in FIG. 5(b), with the suction pad 210 holding the second wafer W2 by suction, the suction pad 210 is raised to separate the second wafer W2 from the laser absorption layer P. . At this time, since the bonding strength at the interface between the laser absorption layer P and the second wafer W2 is reduced by the irradiation with the laser beam L as described above, the bonding strength is reduced from the laser absorption layer P to the second wafer W2 without applying a large load. The wafer W2 can be separated.

The separated second wafer W2 is transferred from the suction pad 210 to the transfer arm 23 of the wafer transfer device 22, and then transferred to the second cleaning device 34. At this time, the second wafer W2 carried out from the separation device 32 is turned over, for example, by the operation of a reversing device (not shown) or the suction pad 210, so that the surface W2a, which is the peeling surface, faces upward. After being brought into this state, it may be transported to the second cleaning device 34.

In the second cleaning device 34, the surface W2a, which is the peeling surface, is cleaned. Note that the first cleaning device 33 may clean the back surface W2b as well as the front surface W2a. Further, separate cleaning sections may be provided to clean the front surface W2a and the back surface W2b, respectively. Thereafter, the second wafer W2 that has been cleaned by the second cleaning device 34 is transferred to the cassette Cw2 of the cassette mounting table 11 by the wafer transfer device 22.

On the other hand, the first wafer W1 held by the suction chuck 200 is transferred to the transfer arm 23 and transferred to the first cleaning device 33. In the first cleaning device 33, the surface W1a side which is the peeling surface, specifically, the surface of the laser absorption layer P is cleaned. Note that in the first cleaning device 33, the back surface W1b of the first wafer W1 may be cleaned together with the front surface of the laser absorption layer P. Furthermore, separate cleaning sections may be provided to clean the front surface of the laser absorption layer P and the back surface W1b of the first wafer W1, respectively. Thereafter, the first wafer W1 that has been cleaned by the first cleaning device 33 is transferred to the cassette Cw1 of the cassette mounting table 11 by the wafer transfer device 22.

In this way, a series of wafer processing in the wafer processing system 1 is completed.

Here, when irradiating the outer peripheral region R1 with the laser beam L in the laser irradiation device 31, the processing center of the spiral processing portion (broken line in FIG. 8) shown in FIG. 8 and the chuck rotation center (rotation (center), the laser beam L may be irradiated to a location where the first wafer W1 does not exist.

Furthermore, when irradiating the central region R2 with the laser beam L, if the processing center of the circular processing portion shown in FIG. The central region R2 is not scanned. In this case, there may be an unprocessed area that is not irradiated with the laser beam L at the boundary between the outer peripheral area R1 and the central area R2.

Therefore, before performing the above-described series of wafer processing on the polymerized wafer T to be manufactured, for example, when starting up the laser irradiation device 31, the processing center and the chuck rotation center are adjusted to match. For such adjustment of the processing center and the chuck rotation center, a dummy wafer Wd or a superposed wafer T may be used as the substrate. Hereinafter, a case where a dummy wafer Wd is used will be described as an example.

There are two adjustment methods for adjusting the processing center and the chuck rotation center.

The first adjustment method will be explained. First, the chuck 100 holding the dummy wafer Wd by suction is placed at the processing position A2. Subsequently, while the chuck 100 is rotated by the rotating mechanism 103, the outer peripheral region R1 of the dummy wafer Wd is irradiated with laser light L in an annular pulse shape. At this time, the laser beam L is fixed without scanning. Then, as shown in FIG. 9, a circular ring-shaped outer circumferential processing portion Q1 (broken line in FIG. 9) is formed on the dummy wafer Wd.

Next, the chuck 100 is moved to the delivery position A1. Subsequently, while rotating the chuck 100, the camera 120 is used to take an image of the outer circumference processed portion Q1. Image data captured by camera 120 is output to control device 40 .

The control device 40 calculates the position of the outer circumference processing center Cq1, which is the center of the outer circumference processing portion Q1, based on the image data.

Further, the control device 40 moves the chuck 100 in the horizontal direction so that the outer circumferential processing center Cq1 and the chuck rotation center Cc of the chuck 100 coincide. Specifically, the distance L1 between the outer circumferential processing center Cq1 and the chuck rotation center Cc is calculated, and the moving distance of the chuck 100 in the horizontal direction (Y-axis direction and X-axis direction) is calculated based on this distance L1. Movement of the chuck 100 in the Y-axis direction is performed by a movement mechanism 104. Although the method of moving the chuck 100 in the X-axis direction is arbitrary, it may be moved mechanically using the moving mechanism 107, for example. Further, if the moving mechanism 104 is configured to be able to move the chuck 100 also in the X-axis direction, the moving mechanism 104 may move the chuck 100 in the X-axis direction. Alternatively, the lens 113 of the laser irradiation unit 110 may be moved in the X-axis direction.

In this way, the outer periphery processing center Cq1 and the chuck rotation center Cc coincide, and the annular outer periphery processing portion Q1 can be formed concentrically with the chuck 100 (solid line in FIG. 9). As a result, the relative positional relationship between the irradiation position of the laser beam L from the laser irradiation unit 110 and the position of the chuck 100 can be adjusted.

The second adjustment method will be explained. First, the chuck 100 holding the dummy wafer Wd by suction is placed at the processing position A2. Subsequently, the central region R2 of the dummy wafer Wd is scanned with the laser light L while the rotation of the chuck 100 is stopped, and the laser light L is irradiated in an annular pulse shape. Then, as shown in FIG. 10, a circular ring-shaped central processing portion Q2 (broken line in FIG. 10) is formed on the dummy wafer Wd.

Next, the chuck 100 is moved to the delivery position A1. Subsequently, while rotating the chuck 100, the camera 120 is used to take an image of the central processing portion Q2. Image data captured by camera 120 is output to control device 40 .

The control device 40 calculates the position of the central processing center Cq2, which is the center of the central processing portion Q2, based on the image data.

Further, the control device 40 moves the chuck 100 in the horizontal direction so that the central processing center Cq2 and the chuck rotation center Cc of the chuck 100 coincide. Specifically, the distance L2 between the central processing center Cq2 and the chuck rotation center Cc is calculated, and the moving distance of the chuck 100 in the horizontal direction (Y-axis direction and X-axis direction) is calculated based on this distance L2. Movement of the chuck 100 in the Y-axis direction is performed by a movement mechanism 104. Although the method of moving the chuck 100 in the X-axis direction is arbitrary, it may be moved mechanically using a screw or the like, for example. Further, if the moving mechanism 104 is configured to be able to move the chuck 100 also in the X-axis direction, the moving mechanism 104 may move the chuck 100 in the X-axis direction.

In this way, the central machining center Cq2 and the chuck rotation center Cc coincide, and the annular central machining portion Q2 can be formed concentrically with the chuck 100 (solid line in FIG. 10). As a result, the relative positional relationship between the irradiation position of the laser beam L from the laser irradiation unit 110 and the position of the chuck 100 can be adjusted. Particularly, when the optical system 112 includes a rotary wedge scanner or the like as in this embodiment, adjustment can be performed in consideration of the center of operation of the optical system 112.

Either the first adjustment or the second adjustment described above may be performed to adjust the machining center and the chuck rotation center, or both may be performed to adjust the machining center and the chuck rotation center. . For example, after performing a first adjustment to adjust the positions of the outer machining center Cq1 and the chuck rotation center Cc, a second adjustment is performed to adjust the central machining center Cq2 and the chuck rotation center Cc. Adjustments may be made. In this case, the relative positional relationship between the laser irradiation unit 110 and the chuck 100 can be corrected more precisely.

According to this embodiment, the position can be adjusted so that the processing center and the chuck rotation center coincide. Therefore, formation of an unprocessed area can be suppressed, and defective peeling between the first wafer W1 and the second wafer W2 can be suppressed. Moreover, it is possible to prevent the laser beam L in the outer peripheral region R1 from overlapping with the laser beam L in the central region R2, thereby suppressing damage to the device.

Note that the first adjustment and the second adjustment are performed with the camera 120 properly adjusted in position. That is, the position of the camera 120 is set in advance so that the imaging center of the camera 120, the processing center by the laser beam L from the laser irradiation unit 110, and the chuck rotation center of the chuck 100 are located coaxially in the Y-axis direction. It has been adjusted.

In the above embodiment, when adjusting the processing center and the chuck rotation center, the chuck 100 was moved in the horizontal direction, but the lens 113 of the laser irradiation unit 110 may be moved in the horizontal direction, or the chuck 100 and the lens 113 may be moved in the horizontal direction. Both may be moved horizontally. By relatively moving the chuck 100 and the lens 113 in the horizontal direction, the processing center and the chuck rotation center can be adjusted.

In the above embodiment, when adjusting the machining center and the chuck rotation center, at least either the annular outer peripheral machining part Q1 or the annular central machining part Q2 is formed, but the shape of the machining parts Q1 and Q2 is circular. Not limited to circular shapes. For example, rectangular annular machining portions Q1 and Q2 may be formed, the positions of machining centers Cq1 and Cq2 of the rectangular annular shapes may be calculated, and the machining centers and the chuck rotation center may be adjusted. In such a case, the optical system 112 of the laser irradiation unit 110 may include a galvano scanner.

In the above embodiment, the annular central processing portion Q2 is formed in the second adjustment of the processing center and the chuck rotation center, but the central processing portion Q2 may be formed so as to fill the entire processing area. In such a case, the optical system 112 of the laser irradiation unit 110 may include a galvano scanner.

As shown in FIG. 11, the laser beam L is irradiated to fill the entire circular processing area to form a circular central processing area Q2. For example, a galvano scanner is used to irradiate linear laser beams L of different lengths in steps and repeats to form a circular central processing portion Q2. Then, the chuck 100 is moved in the horizontal direction so that the central processing center Cq2 of the circular central processing portion Q2 and the chuck rotation center Cc coincide with each other.

Further, as shown in FIG. 12, the laser beam L is irradiated to fill the entire rectangular processing area, thereby forming a rectangular central processing area Q2. For example, a galvano scanner is used to irradiate a straight laser beam L of the same length in steps and repeats to form a rectangular central processing portion Q2. Then, the chuck 100 is moved in the horizontal direction so that the central machining center Cq2 of the rectangular central machining portion Q2 and the chuck rotation center Cc coincide with each other.

In the above embodiment, the outer circumferential region R1 is irradiated with the laser light L in a spiral manner as shown in FIG. 8, but the laser light L may be irradiated concentrically over the entire surface of the outer circumferential region R1.

In the above embodiment, the position adjustment method in laser processing of the present disclosure is applied when performing laser lift-off to separate the second wafer W2 from the laser absorption layer P, but the wafer processing to which it is applied is not limited to this. .

In the manufacturing process of semiconductor devices, a modified layer is formed by irradiating the inside of a silicon substrate of a wafer with multiple devices such as electronic circuits formed on the surface along the surface direction, and the modified layer is Wafers are thinned by separating them based on their layers. A YAG laser beam is used for this laser beam. Even when forming a modified layer in this way, the position adjustment method in laser processing of the present disclosure can be applied. Furthermore, the position adjustment method in laser processing of the present disclosure can also be applied to techniques for modifying the surface of a wafer and flattening the surface of the wafer.

Furthermore, when thinning a wafer, so-called edge trim is performed to remove the peripheral edge of the wafer. In edge trim, the peripheral edge is modified by irradiating it with a laser beam, thereby making it easier to remove the peripheral edge. Even when modifying this peripheral portion, the position adjustment method in laser processing of the present disclosure can be applied.

The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The embodiments described above may be omitted, replaced, or modified in various forms without departing from the scope and spirit of the appended claims.

31 Laser irradiation device 40 Control device 100 Chuck 104 Movement mechanism 110 Laser irradiation unit 120 Camera L Laser light T Polymerized wafer Wd Dummy wafer

Claims (13)

A substrate processing apparatus that processes a substrate,
a substrate holding part that holds the substrate;
a laser irradiation unit that irradiates the substrate held by the substrate holding unit with laser light;
a camera that images the board;
a rotation mechanism that rotates the substrate holder;
a moving mechanism that relatively moves the substrate holding section and the laser irradiation section in a horizontal direction;
comprising a control unit;
The control unit includes:
controlling the substrate to be irradiated with the laser beam to form an annular processed portion on the substrate;
controlling to image the processed part with the camera;
Control for calculating a processing center of the imaged processing portion;
controlling to relatively move the substrate holding part and the laser irradiation part in a horizontal direction to a position where the processing center and the rotation center of the substrate holding part coincide at least in the moving direction of the moving mechanism; substrate processing equipment. The control unit includes:
controlling to irradiate the laser beam in an annular manner in an outer peripheral area of the substrate to form an annular outer peripheral processed portion;
Control to image the outer circumference processed portion with the camera;
Control for calculating an outer circumference processing center of the imaged outer circumference processing portion;
2. Control for relatively moving the substrate holding section and the laser irradiation section in a horizontal direction to a position where the outer peripheral processing center and the rotation center coincide at least in the moving direction of the moving mechanism. 1. The substrate processing apparatus according to 1. The control unit includes:
Controlling a central region of the substrate to scan the laser beam while the rotation of the substrate is stopped to irradiate the substrate with the laser beam in an annular manner to form an annular central processing portion;
Control to image the central processing portion with the camera;
Control for calculating a center processing center of the imaged center processing portion;
2. Control for relatively moving the substrate holding section and the laser irradiation section in a horizontal direction to a position where the central processing center and the rotation center coincide at least in the moving direction of the moving mechanism. 3. The substrate processing apparatus according to 1 or 2. The substrate processing apparatus according to claim 1, wherein the control unit executes control to calculate a distance between the processing center and the rotation center, and calculate a relative movement distance between the substrate holding unit and the laser irradiation unit. . The control unit controls the substrate holding unit and the laser irradiation unit to move relatively in a horizontal direction to a position where the processing center and the rotation center coincide in a direction orthogonal to the moving direction of the moving mechanism. , The substrate processing apparatus according to claim 1. A substrate processing apparatus that processes a substrate,
a substrate holding part that holds the substrate;
a laser irradiation unit that irradiates the substrate held by the substrate holding unit with laser light;
a camera that images the board;
a rotation mechanism that rotates the substrate holder;
a moving mechanism that relatively moves the substrate holding section and the laser irradiation section in a horizontal direction;
comprising a control unit;
The control unit includes:
controlling to irradiate the processing area of the substrate with the laser light to form a processing part in the processing area of the substrate;
controlling to image the processed part with the camera;
Control for calculating a processing center of the imaged processing portion;
controlling to relatively move the substrate holding part and the laser irradiation part in a horizontal direction to a position where the processing center and the rotation center of the substrate holding part coincide at least in the moving direction of the moving mechanism; substrate processing equipment. The control unit includes:
Controlling a central region of the substrate to scan the laser beam while the rotation of the substrate is stopped to irradiate the processing area of the substrate with the laser beam to form a central processing portion;
Control to image the central processing portion with the camera;
Control for calculating a center processing center of the imaged center processing portion;
2. Control for relatively moving the substrate holding section and the laser irradiation section in a horizontal direction to a position where the central processing center and the rotation center coincide at least in the moving direction of the moving mechanism. 6. The substrate processing apparatus according to 6. A position adjustment method for adjusting a processing position of a substrate, the method comprising:
holding the substrate with the substrate holding section;
irradiating the substrate held by the substrate holding unit with laser light from a laser irradiation unit to form an annular processed portion on the substrate;
Imaging the processed part;
Calculating a processing center of the imaged processing portion;
A position adjustment method comprising: moving the substrate holding part and the laser irradiation part relatively in a horizontal direction to a position where the processing center and the rotation center of the substrate holding part coincide. irradiating the laser beam in an annular manner in an outer peripheral region of the substrate to form an annular outer peripheral processed portion;
Imaging the outer circumference processed portion;
Calculating the outer circumference processing center of the imaged outer circumference processing portion;
9. The position adjustment method according to claim 8, comprising moving the substrate holding section and the laser irradiation section relatively in a horizontal direction to a position where the outer peripheral processing center and the rotation center coincide. scanning the laser beam in a central region of the substrate while the rotation of the substrate is stopped to irradiate the substrate with the laser beam in an annular manner to form an annular central processing portion;
Imaging the central processing portion;
Calculating a center processing center of the imaged center processing portion;
10. The position adjustment method according to claim 8, comprising relatively moving the substrate holding section and the laser irradiation section in a horizontal direction to a position where the central processing center and the rotation center coincide. 9. The position adjustment method according to claim 8, comprising calculating a distance between the processing center and the rotation center, and calculating a relative moving distance between the substrate holding section and the laser irradiation section. A position adjustment method for adjusting a processing position of a substrate, the method comprising:
holding the substrate with the substrate holding section;
irradiating a processing area of the substrate held by the substrate holding unit with a laser beam from a laser irradiation unit to form a processed part in the processing area of the substrate;
Imaging the processed part;
Calculating a processing center of the imaged processing portion;
A position adjustment method comprising: moving the substrate holding part and the laser irradiation part relatively in a horizontal direction to a position where the processing center and the rotation center of the substrate holding part coincide. scanning the laser beam in a central region of the substrate while the rotation of the substrate is stopped to irradiate the processing area of the substrate with the laser beam to form a central processing portion;
Imaging the central processing portion;
Calculating a center processing center of the imaged center processing portion;
13. The position adjustment method according to claim 12, comprising moving the substrate holding section and the laser irradiation section relatively in a horizontal direction to a position where the central processing center and the rotation center coincide.

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