Laser irradiation apparatus, laser irradiation method, and method for manufacturing compound semiconductor device

Abstract

A laser irradiation apparatus (1) according to an embodiment of the present invention is a laser irradiation apparatus configured to be capable of performing laser irradiation to form a back electrode of a semiconductor device formed on a wafer formed of a compound semiconductor, the laser irradiation apparatus (1) comprising: an excimer laser light source configured to be capable of generating laser light; an optical system (20) configured to be able to irradiate the wafer with the laser light in a linear shape; and a storage unit (100) configured to be capable of holding the wafer.

Description

Technical Field

[0001] This disclosure relates to a laser irradiation apparatus, a laser irradiation method, and a method for manufacturing compound semiconductor devices. Background Technology

[0002] Patent Document 1 discloses an excimer laser annealing apparatus using an excimer laser. In Patent Document 1, a transport unit transports the substrate while the substrate is suspended by a levitation unit. The transported substrate is then irradiated with a line laser. Furthermore, the laser irradiation apparatus includes a line sensor disposed on the substrate. The line sensor captures an image of the transported substrate.

[0003] References

[0004] Patent documents

[0005] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2018-64048 Summary of the Invention

[0006] Technical issues

[0007] In the aforementioned apparatus, it is desirable to irradiate with laser light appropriately.

[0008] Other problems in the related art and the novel features of the present invention will become apparent from the description in the specification and the accompanying drawings.

[0009] Solution to the problem

[0010] According to one embodiment, the laser irradiation apparatus is configured to perform laser irradiation to form a back electrode of a semiconductor device formed on a wafer made of compound semiconductor, the laser irradiation apparatus comprising: an excimer laser source configured to generate laser light; an optical system configured to irradiate the wafer in a linear shape with the laser light; and a stage unit configured to hold the wafer.

[0011] According to one embodiment, the laser irradiation apparatus is configured to perform laser irradiation to form a back electrode of a semiconductor device formed on a wafer made of compound semiconductor. The laser irradiation apparatus includes: a laser source configured to generate laser light; a first unit configured to hold a first wafer; a second unit configured to hold a second wafer; and a control unit configured to control the first unit and the second unit to irradiate the second wafer with the laser during loading or unloading of the first wafer onto or from the first unit, and to irradiate the first wafer with the laser during loading or unloading of the first wafer onto or from the second unit.

[0012] According to one embodiment, the laser irradiation method is used to perform laser irradiation to form a back electrode of a semiconductor device formed on a wafer made of compound semiconductor, the laser irradiation method comprising: (A1) holding the wafer using a stage unit; (A2) generating laser light using an excimer laser source; (A3) irradiating the wafer with the laser in a linear shape; and (A4) driving the stage unit to change the irradiation position of the linearly shaped laser relative to the wafer.

[0013] According to one embodiment, the laser irradiation method is used to perform laser irradiation to form a back electrode of a semiconductor device formed on a wafer made of compound semiconductor, the laser irradiation method comprising: (B1) generating a laser; (B2) irradiating a first wafer on a first stage with the laser; (B3) driving the first stage such that the laser scans the first wafer; (B4) loading a second wafer into or unloading a second wafer from the second stage during the scanning of the first wafer; (B5) driving the second stage such that the laser scans the second wafer; and (B6) loading the first wafer into or unloading the first wafer from the first stage during the scanning of the second wafer.

[0014] According to one embodiment, a method for manufacturing a compound semiconductor device is as follows: a method for manufacturing a compound semiconductor device by laser irradiation to form a back electrode of a semiconductor device formed on a wafer formed of a compound semiconductor, the method comprising: (sa1) holding the wafer using a stage unit; (sa2) generating the laser using an excimer laser source; (sa3) irradiating the wafer with the laser in a linear shape; and (sa4) controlling the stage unit to change the irradiation position of the linearly shaped laser relative to the wafer.

[0015] According to one embodiment, a method for manufacturing a compound semiconductor device includes a method for laser irradiation to form a back electrode of a semiconductor device formed on a wafer made of compound semiconductor. The method includes: (sb1) generating a laser; (sb2) irradiating a first wafer on a first stage with the laser; (sb3) driving the first stage such that the laser scans the first wafer; and (sb4) loading a second wafer into or unloading a second wafer from the second stage during the scanning of the first wafer. The method further includes: (sb5) driving the second stage such that the laser scans the second wafer; and (sb6) loading the first wafer into or unloading the first wafer from the first stage during the scanning of the second wafer.

[0016] Beneficial effects of the invention

[0017] According to one embodiment, a laser irradiation apparatus, a laser irradiation method, and a method for manufacturing compound semiconductor devices can be provided, which are capable of properly irradiating a substrate with a laser. Attached Figure Description

[0018] Figure 1 This is a schematic cross-sectional side view of the laser irradiation device;

[0019] Figure 2 It is a schematic top view showing the internal structure of the laser irradiation device;

[0020] Figure 3 This is a schematic top view of the laser irradiation device;

[0021] Figure 4 This is a schematic diagram illustrating an example of scanning a laser via a drive stage;

[0022] Figure 5 This is a top view showing the structure of the light-shielding plate;

[0023] Figure 6 This is a diagram illustrating the operation of the console unit;

[0024] Figure 7 This is a diagram illustrating the operation of the console unit;

[0025] Figure 8 This is a diagram showing the structure of a dust collector;

[0026] Figure 9 This is a diagram showing the construction of the distribution ring;

[0027] Figure 10This is a cross-sectional view showing a method for manufacturing a semiconductor device according to this embodiment; and

[0028] Figure 11 This is a cross-sectional view showing a method for manufacturing a semiconductor device according to this embodiment. Detailed Implementation

[0029] The laser irradiation apparatus according to this embodiment is, for example, an excimer laser annealing apparatus (ELA apparatus) using an excimer laser. The ELA apparatus irradiates a substrate with a laser to form a back electrode of a compound semiconductor. The substrate is a wafer formed of a compound semiconductor. For example, a nickel film formed on a semiconductor wafer such as SiC is irradiated with a laser. As a result, the nickel is converted into silicide, thereby forming an ohmic contact layer. Then, a metal electrode is formed on the ohmic contact layer of nickel silicide to form the back electrode. Hereinafter, the laser irradiation apparatus, laser irradiation method, and manufacturing method according to this embodiment will be described with reference to the accompanying drawings.

[0030] The accompanying drawings below appropriately illustrate the XYZ three-dimensional orthogonal coordinate system for clarity. The Z-direction is the vertical direction, perpendicular to the principal surface of the substrate. The XY plane is a plane parallel to the principal surface of the substrate. The Z-direction is perpendicular to the vertical direction. Furthermore, in the top view, the Y-direction is parallel to the length direction of the line beam, and the X-direction is perpendicular to it.

[0031] (Overall structure)

[0032] Reference Figure 1 The structure of the laser irradiation device according to this embodiment will be described. Figure 1 This is a schematic cross-sectional side view showing the structure of the laser irradiation device 1. Figure 2 This is a top view showing the internal structure of the laser irradiation device 1. Figure 3 This is a top view showing the structure of the laser irradiation device.

[0033] The laser irradiation device 1 includes a laser source 10, an optical system 20, a slit 30, a beam absorber 40, a window unit 50, a dust collector 60, a display unit 70, 71, a chamber 80, and a control device 90. The chamber 80 houses a stage unit 100, etc. The stage unit 100 includes two stages 110 and 120 to hold two corresponding substrates W.

[0034] Stages 110 and 120 hold the substrate W. Each of these stages 110 and 120 is an xyz stage for driving the substrate W. Therefore, as stages 110 and 120 move, the laser irradiation position relative to the substrate W is scanned. The detailed construction and operation of the stage unit 100 will be described later.

[0035] Laser source 10 is an excimer laser source that generates laser L1. Here, laser L1 is pulsed light with a center wavelength of 308 nm and a repetition frequency of 300 Hz. Laser L1 is incident on optical system 20.

[0036] The optical system 20 includes a variable attenuator 21, a beam shaping unit 22, and a projection lens 23. The variable attenuator 21 serves as a pulse adjustment unit for adjusting the intensity of the laser L1 pulse. For example, the variable attenuator 21 adjusts the pulse intensity by attenuating the laser. Alternatively, a pulse stretcher that extends the pulse length can be used to adjust the pulse waveform. The control device 90, described later, is capable of adjusting the pulse waveform and laser power of the laser L1.

[0037] Laser L1 from variable attenuator 21 is incident on beam shaping unit 22. Beam shaping unit 22 shapes the cross-sectional profile of laser L1 on a plane perpendicular to the optical axis. Beam shaping unit 22 includes a homogenizer for homogenizing laser L1 and a focusing lens for converging laser L1. Figure 3 As shown, laser L1 forms a linear irradiation region 15 on the substrate W. The irradiation region 15 has a linear shape with the Y direction set as the longitudinal direction and the X direction set as the transverse direction. That is, the beam shaping unit 22 shapes laser L1 into a line beam along the Y direction. In addition, the beam shaping unit 22 shapes the contour of laser L1 into a flat-top distribution, for example. The laser L1 shaped by the beam shaping unit 22 is incident on the projection lens 23.

[0038] The projection lens 23 includes multiple lenses for projecting the laser L1 onto the substrate W. The projection lens 23 focuses the laser L1 onto the substrate. On the substrate W, the laser L1 forms a linear irradiation area. The irradiation area 15 has the Y direction set as the longitudinal direction and the X direction set as the transverse direction. For example, the line length in the Y direction is 40 mm, and the beam width in the X direction is 0.5 mm. Furthermore, the laser L1 exhibits a flat-top distribution. Of course, the beam size is not limited to the above values. For example, the line length in the Y direction can be 10 mm or longer.

[0039] The slit 30 is positioned directly below the optical system 20. A laser L1 from the projection lens 23 is incident on the slit 30. The slit 30 has an opening along the Y direction. The laser L1, passing through the opening of the slit 30, is then incident on the window unit 50. The slit 30 can be a variable slit to alter the beam size.

[0040] A beam absorber 40 (beam dumper) is positioned diagonally above the slit 30. Laser L1, blocked by the slit 30, is incident on the beam absorber 40. That is, a portion of the laser L1 reflected at the slit 30 is absorbed by the beam absorber 40. Cooling pipes or similar components for circulating cooling water can also be incorporated into the beam absorber 40.

[0041] Laser L1 from slit 30 is incident on window unit 50. Window unit 50 is attached to the top of chamber 80. That is, window unit 50 is located outside chamber 80. Window unit 50 includes a transparent window, a holder for the window, etc. Laser L1 passes through the window of window unit 50 and propagates within chamber 80. Window unit 50 is configured to be replaceable for maintenance purposes. The construction of window unit 50 will be described next.

[0042] A dust collector 60 is positioned directly below the window unit 50. The dust collector 60 is located within the chamber 80. The dust collector 60 collects dust generated by laser irradiation. An air supply pipe 61 and an exhaust pipe 62 are connected to the dust collector 60. The structure of the dust collector 60 will be described next. The laser L1, having passed through the dust collector 60, is incident on the substrate W.

[0043] The substrate W is placed on each of stages 110 and 120. Stages 110 and 120 are, for example, chuck stages for adsorbing the substrate W. For example, adsorption holes for vacuum adsorption of the substrate W are provided on the surface of each of stages 110 and 120. In addition, each of stages 110 and 120 is a three-dimensional drive stage capable of moving along the xyz direction.

[0044] Therefore, stage 110 includes an X-drive mechanism 111X, a Y-drive mechanism 111Y, and a Z-drive mechanism 111Z. Similarly, stage 120 includes an X-drive mechanism 121X, a Y-drive mechanism 121Y, and a Z-drive mechanism 121Z. When stages 110 and 120 drive the substrates W respectively, the laser L1 moves relative to the position of each substrate W. Stages 110 and 120 each move the substrates W along the xy direction, thereby scanning the substrates W with the laser L1. Therefore, the entire surface of the substrates W is irradiated with the laser L1. In addition, the Z-drive mechanisms 111Z and 121Z perform lifting operations for loading and unloading the substrates W. Since the operation and structure of stage 110 are the same as those of stage 120, stage 110 will be mainly described in the following description.

[0045] A power monitor 117 and a beam analyzer 118 are installed on stage 110. The power monitor 117 and the beam analyzer 118 move together with stage 110. A power monitor 127 and a beam analyzer 128 are installed on stage 120. The power monitor 127 and the beam analyzer 128 move together with stage 120.

[0046] Power monitors 117 and 127 are photodetectors used to measure laser power. Slit shields 117a and 127a are provided on the incident side of power monitors 117 and 127. Slit shields 117a and 127a have elongated openings whose length direction corresponds to the Y direction. Power monitor 117 detects laser L1 passing through slit shield 117a. Power monitor 127 detects laser L1 passing through slit shield 127a. This allows for the detection of the pulsed laser power. By using power monitors 117 and 127, dirt on windows can be monitored.

[0047] Beam analyzers 118 and 128 are photodetectors with multiple pixels, each detecting the laser beam profile. Beam analyzers 118 and 128 measure the laser beam size and spatial distribution. In this manner, power monitors 117 and 127, as well as beam analyzers 118 and 128, are positioned in stages 110 and 120. Power monitors 117 and 127, and beam analyzers 118 and 128 detect laser L1 and output detection signals indicating the detection results to control device 90. By using beam analyzers 118 and 128, dirt on the window can be monitored.

[0048] The control device 90 performs feedback control on the laser source 10, the variable attenuator 21, or the beam shaping unit 22 based on the detection results. Therefore, the power and profile of the laser L1 can be adjusted to be suitable for the irradiation process. For example, when the laser intensity decreases, the laser source 10 and the variable attenuator 21 are controlled to increase the laser intensity. Thus, laser irradiation can be performed at an appropriate intensity. Furthermore, the displays 70 and 71 can also display the detection results of the beam profile and laser power.

[0049] (Taiwanese driver)

[0050] Reference Figure 4 The scanning of laser L1 by driving stage 110 and 120 is explained. Figure 4 This is an XY plan view illustrating an example of a scanning laser L1. As described above, laser L1 forms a linear irradiation area with its length direction corresponding to the Y direction. The line length in the Y direction is 40 mm, and the beam width in the X direction is 0.5 mm. Furthermore, when in... Figure 4 When the substrate W is circular, oriented planes or notches can also be formed on it.

[0051] In this example, stage 110 moves in a zigzag pattern along the XY direction, thereby irradiating the entire surface of substrate W with laser L1. That is, stage 110 moves along the X direction while irradiating substrate W with a linear laser L1 whose length direction corresponds to the Y direction. As laser L1 is scanned from one end of substrate W to the other end, a strip-shaped region (e.g., region 15a) extending along the X direction is irradiated with laser L1. Then, stage 110 moves along the Y direction, shifting the irradiated region 15 in substrate W along the Y direction. Stage 110 repeats the movement in the X and Y directions, thereby irradiating the entire surface of substrate W with laser.

[0052] With a laser L1 illuminating a position 15-1 along the Y direction, stage 110 moves substrate W along the -X direction. A scan of one row ends when laser L1 scans from one end of substrate W to the other. After the first row scan is completed, the strip region 15a becomes the illuminating area. In the Y direction, almost half of the strip region 15a extends beyond substrate W.

[0053] Next, stage 110 moves along the +Y direction at the other end of substrate W. In this example, stage 110 moves along the +Y direction by half the length of the line. Thus, in the Y direction, substrate W is irradiated with laser L1 at an irradiation position 15-2. While irradiating position 15-2 with laser L1, stage 110 moves substrate W along the +X direction. After laser L1 scans from one end of substrate W to the other end, the scan of one row ends. After the scan of the second row ends, the strip region 15b becomes the irradiated region.

[0054] At the other end of the substrate W, stage 110 moves along the +Y direction. In this example, stage 110 moves along the +Y direction by half the length of the line. Thus, in the Y direction, the substrate W is irradiated with laser L1 at an irradiation position 15-3. After stage 110 moves the substrate W along the -X direction while irradiating an irradiation position 15-2 with laser L1, the strip region 15c becomes the irradiated region. In this manner, stage 110 repeatedly moves in both the X and Y directions.

[0055] Then, in the Y direction, the substrate W is irradiated with laser L1 at irradiation positions 15-11. While irradiating positions 15-11 with laser L1, stage 110 moves the substrate W along the +X direction. After laser L1 scans from one end of the substrate W to the other, the last row of scanning ends. After the last row of scanning ends, the strip region 15k becomes the irradiated area. In the Y direction, almost half of the strip region 15k extends beyond the substrate W. In this example, the substrate W is an 8-inch wafer with a line length of 40 mm. Therefore, stage 110 scans 11 rows.

[0056] Here, in the Y direction, stage 110 moves with adjacent irradiation positions overlapping. Specifically, in the Y direction, stage 110 moves with an overlap of almost half the line length. Furthermore, since laser L1 is a pulsed laser, stage 110 also moves with the pulsed laser overlapping in the X direction. Specifically, the moving speed of stage 110 in the X direction is determined by the repetition frequency and linewidth of the pulsed laser. In this example, the moving speed of stage 110 is set such that approximately 80% of the irradiated area overlaps in two consecutive pulses in the X direction. Of course, the laser linelength, linewidth, scanning speed, and overlap amount are not limited to the values ​​mentioned above.

[0057] like Figure 1 As shown, stage 110 includes an X-drive mechanism 111X and a Y-drive mechanism 111Y. Stage 120 includes an X-drive mechanism 121X and a Y-drive mechanism 121Y. The X-drive mechanisms 111X and 121X reciprocate the substrate W in the X direction by scanning the substrate W with laser L1. The Y-drive mechanisms 111Y and 121Y move the substrate W in the linear direction of laser L1. Then, laser L1 scans the substrate W such that the irradiated areas partially overlap in adjacent scan lines. Thus, the substrate W can be uniformly irradiated with laser L1.

[0058] (visor)

[0059] Additionally, light-shielding plates 116 and 126 are respectively provided in stages 110 and 120. A substrate W is disposed below light-shielding plates 116 and 126. Light-shielding plates 116 and 126 each cover the periphery of the substrate W. Light-shielding plate 116 is attached to stage 110 via mounting member 115. Light-shielding plate 126 is attached to stage 120 via mounting member 125.

[0060] Light shields 116 and 126 are made of a material that absorbs or reflects laser L1. Each of light shields 116 and 126 is formed of a multilayer metal reflective film or similar material, such that each of them reflects UV light with a wavelength of 308 nm. Mounting members 115 and 125 are made of ceramic or similar material. Mounting members 115 and 125 are frames used to fix light shields 116 and 126.

[0061] like Figure 4 As shown, since laser L1 is a line beam, the area extending beyond the substrate W is also irradiated by laser L1. A light-shielding plate 116 is disposed on the upper side of the substrate W, covering the periphery and outer side of the substrate W. By providing the light-shielding plate 116, the upper surface of the stage 110 can be prevented from being irradiated by laser L1. Therefore, damage to the stage 110 can be prevented.

[0062] Figure 5This is a top view showing the structure of the light-shielding plate 116. The light-shielding plate 116 includes an opening 116a for allowing the laser L1 to pass through. Therefore, the laser L1 passes through the opening 116a and is irradiated onto the substrate W. The opening 116a is a circle slightly smaller than the outer diameter of the substrate W. Therefore, the periphery of the substrate W is covered by the light-shielding plate 116.

[0063] In addition, such as Figure 1 As shown, cameras 119 and 129 for alignment are disposed above stages 110 and 120. For example, cameras 119 and 129 are positioned directly above stages 110 and 120 at the loading position of the substrate W. Cameras 119 and 129 are attached to chamber 80, for example. Figure 5 As shown, the field of view 119a of the camera 119 includes the edge portion of the substrate W. Furthermore, the field of view 119a includes the boundary between the light-shielding plate 116 and the opening 116a. The camera 119 photographs the substrate W and the light-shielding plate 116 during substrate W loading, thereby enabling the detection of the position of the substrate W relative to the light-shielding plate 116. Therefore, misalignment (misalignment) during substrate W loading can be prevented.

[0064] The light-shielding plate 116 is preferably made of a material that transmits visible light. That is, the light-shielding plate 116 is made of a material that has high reflectivity for the laser wavelength of laser L1 and high transmittance for visible light. Therefore, the camera 119 can capture images of the substrate W beyond the edge of the light-shielding plate 116. The camera 119 is fixed to the chamber 80 in the mounting position of the substrate W, positioned above the light-shielding plate 116.

[0065] The camera 119 outputs the captured image to the control device 90. The control device 90 is capable of measuring the relative positional relationship between the light-shielding plate 116 and the substrate W. For example, the control device 90 controls the loading position of the substrate W based on the image captured by the camera 119. This allows a substrate loading robot or the like to load the substrate W into the appropriate position on the stage 110.

[0066] In this manner, cameras 119 and 129 detect the relative position of the substrate W with respect to the light-shielding plate 116, respectively. Stages 110 and 120 align the substrate W based on the detection results from camera 119. For example, the loading position can also be adjusted using X-drive mechanisms 111X and 121X and Y-drive mechanisms 111Y and 121Y. Alternatively, stages 110 and 120 may include alignment mechanisms for fine-tuning, in addition to the X-drive mechanisms 111X and 121X and the Y-drive mechanisms 111Y and 121Y. Displays 70 and 71 can display the results captured by the cameras.

[0067] (Unit 100)

[0068] Furthermore, in this embodiment, to efficiently irradiate the substrate W with a laser, the stage unit 100 includes two stages 110 and 120. The substrate W is irradiated with laser L1 in one stage 110, while another substrate W is loaded and unloaded in another stage. Therefore, the waiting time for loading and unloading substrate W can be reduced. Thus, the takt time can be reduced, thereby increasing productivity.

[0069] refer to Figure 6 and Figure 7 The operation of 110 and 120 to Taiwan will be explained in detail. Figure 6 and Figure 7 This diagram illustrates the operation of the dual-station setup. Note that... Figure 6 and Figure 7 This is a schematic top view of platforms 110 and 120, with components appropriately simplified. For example, window unit 50, etc., are omitted. Furthermore, in Figure 6 and Figure 7 In this context, substrates W placed on stage 110 are referred to as substrates W1 and W3, and substrates W placed on stage 120 are referred to as substrates W2 and W4.

[0070] Note that substrate W1 is the substrate first irradiated with laser by stage 110, and W3 is the substrate irradiated with laser by stage 110 after substrate W1. Substrate W2 is the substrate first irradiated with laser by stage 120, and W3 is the substrate irradiated with laser by stage 120 after substrate W2. Laser irradiation is performed in the order of substrates W1, W2, W3, and W4.

[0071] The substrate W1 is loaded onto stage 110 (step 1). For example, the Z-drive mechanism 111Z of stage 110 raises and lowers the mounting surface of stage 110, thereby enabling the substrate W1 to be received from the substrate loading robot. In this example, stages 110 and 120 are in the substrate loading / unloading positions. Although this example is described assuming that the loading and unloading positions are the same, they can also be different. The loading / unloading positions are offset from the irradiation area 15 in the Y direction. Specifically, the loading / unloading position of stage 110 is located on the -Y side of the irradiation area 15. The loading / unloading position of stage 120 is located on the +Y side of the irradiation area 15. In addition, the robot arm or the like moves the substrate W1 from the outside of the chamber 80 along the +X direction, thereby loading the substrate W1 onto stage 110. At this time, camera 119 can capture images of the edges of the substrate W1 for alignment.

[0072] After substrate W1 is loaded onto stage 110, stage 110 is driven along the +Y direction, thereby moving substrate W1 to the irradiation area 15 of laser L1 (step 2). Additionally, in this process, substrate W2 is loaded onto stage 120. That is, the movement of stage 110 and the loading of substrate W2 are performed in parallel. In this manner, substrate W2 is loaded onto stage 120 while stage 110 is moving.

[0073] Then, stage 110 is driven in the XY direction, thereby irradiating substrate W1 with laser L1 (step 3). Thus, a portion of substrate W1 becomes the irradiated area 150. As described above, stage 110 moves substrate W1 in a zigzag pattern. Alternatively, stage 110 can scan substrate W1 using a raster scan or the like. At this time, stage 120 waits at the loading / unloading position. Then, after the scanning by stage 110 is completed, substantially the entire surface of substrate W1 is irradiated with laser L1. Therefore, substantially the entire surface of substrate W1 becomes the irradiated area 150 (step 4). Additionally, as described above, camera 129 for alignment can capture images of the edges of substrate W2 for alignment.

[0074] After the laser irradiation treatment on the substrate W1 is completed, stage 110 moves along the -Y direction. Stage 110 retracts to the loading / unloading position to unload the substrate W1 (step 5). At this time, stage 120 moves along the -Y direction. Therefore, stage 120 moves to the irradiation area 15 of laser L1. In this way, the unloading of substrate W1 and the movement of stage 120 are performed simultaneously.

[0075] Then, stage 120 is driven in the XY direction, thereby irradiating substrate W2 with laser L1 (step 6). Thus, a portion of substrate W2 becomes the irradiated area 150. As described above, stage 120 moves substrate W2 in a zigzag pattern. Alternatively, stage 120 can scan substrate W2 using a raster scan or the like. At this time, stage 110 is in the loading / unloading position and performs the loading operation for the next substrate W3. After the scanning by stage 120 is completed, substantially the entire surface of substrate W2 is irradiated with laser L1 (step 7). Therefore, substantially the entire surface of substrate W2 becomes the irradiated area 150. Additionally, camera 119 can capture images of the edges of substrate W3 for alignment.

[0076] After the laser irradiation process on the substrate W2 is completed, the stage 120 moves along the +Y direction. That is, the stage 120 retracts (retraces) to the loading / unloading position and unloads the substrate W2 (step 8). At this time, the stage 110 moves along the +Y direction. Therefore, the stage 110 moves to the irradiation area 15 of the laser L1. In this way, the unloading of the substrate W2 and the movement of the stage 110 are performed simultaneously.

[0077] Then, stage 110 is driven in the XY direction, thereby irradiating substrate W3 with laser L1 (step 9). Thus, a portion of substrate W3 becomes the irradiated area 150. Similar to the above description, stage 110 moves substrate W1 in a zigzag pattern. At this time, the next substrate W4 is loaded onto stage 120 at the loading / unloading position. Thus, the loading of substrate W4 and the movement of stage 110 are performed simultaneously.

[0078] In this way, the control device 90 controls the console unit 100 to cause the stages 110 and 120 to alternately perform laser irradiation processing. When one of the stages 110 and 120 is performing a loading / unloading operation, the other of the stages 110 and 120 moves. For example, during the loading of substrate W3 onto stage 110 or the unloading of substrate W1 from stage 110, stage 120 is driven to irradiate substrate W2 with a laser. Conversely, during the loading of substrate W4 onto stage 120 or the unloading of substrate W2 from stage 120, stage 110 is driven to irradiate substrate W3 with laser L1. This reduces standby time and, consequently, increases productivity.

[0079] (The guide's cover)

[0080] Stages 110 and 120 are xyz driven stages. Therefore, stages 110 and 120 slide in the x and y directions, allowing the substrate W to move. Dust generated during the sliding of stages 110 and 120 can affect the laser irradiation process. When laser irradiation is performed with dust adhering to the substrate W or the windows of the window unit, a portion of the laser light is absorbed or reflected by the dust. In this case, alloying (silicide formation) may not occur properly. To address this problem, in this embodiment, a cover is provided in the guiding mechanism to reduce dust.

[0081] For example, such as Figure 1 As shown, the Y-drive mechanisms 111Y and 121Y include a guide mechanism 132. The guide mechanism 132 is, for example, a guide rail and is arranged along the Y direction. The guide mechanism 132 guides the movement of the stages 110 and 120 in the Y direction. The movable parts of the Y-drive mechanisms 111Y and 121Y move along the guide mechanism 132. The guide mechanism 132 is covered by a cover 130. The cover 130 has, for example, an expandable bellows structure.

[0082] For example, one end of the cover 130 is attached to one end of the guide mechanism 132, and the other end is attached to the movable part. Therefore, the cover 130 extends and retracts according to the movement of the movable part. This prevents dust generated by the sliding of the movable parts of the guide mechanism 132 and the Y drive mechanisms 111Y and 121Y from floating in the chamber 80. Therefore, it prevents dust from adhering to the surface of the substrate W.

[0083] Similarly, the X-drive mechanisms 111X and 121X include a guide mechanism 133. The guide mechanism 133 guides the movement of the stages 110 and 120 in the X direction. The guide mechanism 133 is covered by a cover 135. The guide mechanism 133 is, for example, a guide rail, and is arranged along the X direction. The cover 135 has, for example, an expandable bellows structure.

[0084] For example, one end of the cover 135 is attached to the guide mechanism 132, and the other end of the cover 135 is attached to the movable part. Therefore, the cover 130 extends and retracts according to the drive of the X drive mechanisms 111X and 121X. Therefore, it is possible to prevent dust generated by the sliding of the movable parts of the guide mechanism 133 and the X drive mechanisms 111X and 121X from floating in the chamber 80. Therefore, it is possible to prevent dust from adhering to the surface of the substrate W.

[0085] As described above, the laser irradiation device 1 includes covers 130 and 135. Since covers 130 and 135 cover the guide mechanisms 132 and 133, dust can be prevented from scattering, thereby enabling stable laser irradiation processing.

[0086] (Window Unit 50)

[0087] Window unit 50 is designed to be replaceable for maintenance purposes. If the window of window unit 50 becomes dirty, the entire window unit 50 can be replaced with another window unit. Figure 3 As shown, the window unit 50 is positioned directly below the slit 30 and the optical system 20. Since there is insufficient space directly below the optical system 20, replacement operations are difficult. Therefore, in this embodiment, the window unit 50 is configured to be movable to a replacement position.

[0088] Specifically, window unit 50 is attached to replacement track 51. Replacement track 51 is a mechanism for replacing window unit 50 with another window unit. Replacement track 51 is a guide mechanism arranged along the Y direction. Replacement track 51 extends along the Y direction and is attached to the upper surface of chamber 80. Window unit 50 moves along replacement track 51 in the Y direction.

[0089] The window unit 50 is moved to the replacement position (position of window unit 50a). This moves the window unit 50 from a position directly below the optical system 20 and the slit 30. Therefore, the window unit 50 can be easily replaced. During laser irradiation, the window unit 50 is pushed into the chamber 80 by a cylinder or the like. During maintenance, the pressure applied by the cylinder is released.

[0090] As described above, the window unit 50 moves in the Y direction along the replacement track 51. Therefore, the window unit 50 can retract from a position directly below the optical system 20. Since sufficient operating space is ensured for replacement, operators can perform replacement operations efficiently. This reduces maintenance time and, consequently, increases productivity.

[0091] (Dust collector)

[0092] When dust accumulates in chamber 80, it can affect the laser irradiation process. For example, as a result of laser irradiation, a metallic material such as a nickel film disposed on the substrate W may evaporate and turn into dust. When dust adheres to the window, it can affect the laser irradiation process. To solve this problem, in this embodiment, as... Figure 2 As shown, the dust collector 60 is positioned near the irradiation area 15. Figure 1 As shown, the dust collector 60 is positioned directly below the window unit 50. That is, the dust collector 60 is positioned directly above the irradiation area 15. The dust collector 60 collects dust, such as metal, generated from the substrate W due to laser irradiation.

[0093] like Figure 1 and Figure 2 As shown, air supply pipe 61 and exhaust pipe 62 are connected to dust collector 60. Air supply pipe 61 and exhaust pipe 62 are pipes extending to the outside of chamber 80. Air supply pipe 61 is connected to a gas cylinder or the like located outside chamber 80. Gas from the gas cylinder or the like is then supplied to dust collector 60 via air supply pipe 61. Exhaust pipe 62 is connected to an exhaust pump or the like located outside chamber 80. Gas inside dust collector 60 is then discharged to the outside of chamber 80 via exhaust pipe 62.

[0094] Reference Figure 8 The structure of the dust collector 60 is described in detail. Figure 8 The front view, top view, and cross-sectional view of the dust collector 60 are shown. Additionally, in Figure 8 In the cross-sectional and front views, the window unit 50 is also shown together with the dust collector 60. The window unit 50 is disposed on the dust collector 60.

[0095] The dust collector 60 includes a housing 601 and a conductive ring 607. The housing 601 is hollow. A cylindrical space 610 is formed inside the housing 601. The laser L1 passes through the space 610 and is incident on the substrate W. A discharge port 602 and a supply port 603 are formed on the inner peripheral side of the housing 601. The discharge port 602 and the supply port 603 penetrate the housing 601 with the discharge port 602 and the supply port 603 facing the space 610.

[0096] Window unit 50 includes a retainer 501 and a window 502. Window 502 is a transparent disk formed of resin or glass. Laser L1 passes through window 502. Retainer 501 holds window 502. Space 610 is arranged directly below window 502. Laser L1 is irradiated onto substrate W by passing through window 502 disposed above substrate W.

[0097] Additionally, connectors 604 and 605 are connected to the outer peripheral side of housing 601. Discharge port 602 is connected to connector 604. Figure 1 The exhaust pipe 62 shown is connected to the connector 604. The exhaust pipe 62 is capable of discharging air from the space 610 to the outside through the exhaust port 602. Thus, the exhaust port 602 is configured to discharge dust generated by laser irradiation.

[0098] Supply port 603 is connected to connector 605. Figure 1 The air supply pipe 61 shown is connected to the connector 605. The air supply pipe 61 can supply gas to the space 610 from the supply port 603. Specifically, a cleaning gas, such as air or nitrogen, is injected into the space 610 from the supply port 603. The supply port 603 can supply gas toward the substrate W.

[0099] Furthermore, the exhaust port 602 and the supply port 603 are disposed above the substrate W. The supply port 603 is disposed above the exhaust port 602. Gas ejected from the supply port 603 flows downward and is discharged from the exhaust port 602. Therefore, the gas flows downward in the space 610, thereby preventing evaporated metal material from adhering to the window. That is, due to the downward flow generated by the supply port 603, the evaporated metal material flows downward and is discharged from the exhaust port 602. Therefore, it is possible to prevent metal dust from adhering to the window 502, etc.

[0100] Additionally, a conductive ring 607 is disposed on the lower surface of the housing 601. The conductive ring 607 is a plate disposed opposite to the substrate W. The conductive ring 607 is fixed to the housing 601 by bolts or the like. An opening 607a for allowing the laser L1 to pass through is disposed at the center of the conductive ring 607. The opening 607a is a slit opening having a longitudinal direction. The laser L1 passes through the opening 607a and is irradiated onto the substrate W.

[0101] Furthermore, to limit the electrical conductivity between the substrate W and the dust collector 60, the conductive ring 607 includes a plurality of trapping openings 607b. That is, the electrical conductivity can be adjusted by changing the number, size, and shape of the trapping openings 607b. For example, a plurality of conductive rings 607 with different numbers, sizes, and shapes of trapping openings 607b can be prepared in advance. The conductive rings 607 are then attached to the housing 601 to achieve the desired electrical conductivity. This allows for control of the gas flow on the upper side of the substrate W.

[0102] In addition, such as Figure 8 As shown in the cross-sectional view, a distribution ring 510 is provided below window 502. (Refer to...) Figure 9 The construction of the distribution ring 510 is described in detail.

[0103] Figure 9 These are top and front views of the distribution ring 510. The distribution ring 510 is formed in a circular shape with a hollow portion 510b. The hollow portion 510b is located directly above the space 610. A plurality of gas ejection holes 510a are provided in the distribution ring 510. The gas ejection holes 510a are formed on the inner circumferential side of the distribution ring 510. Alternatively, the gas ejection holes 510a may be provided on the upper surface side (window side) of the distribution ring 510. The gas ejection holes 510a are aligned circumferentially. The plurality of gas ejection holes 510a are connected together inside the distribution ring 510.

[0104] The distribution ring 510 is also connected to the air supply pipe 61. Therefore, gas is injected from the gas ejection port 510a. The gas injected from the gas ejection port 510a passes through the hollow portion 510b and flows through the space 610.

[0105] The gas injected by the distribution ring 510 forms a downward flow (airflow) in the space 610. Therefore, it can prevent evaporated metal from adhering to the window 502.

[0106] Note that the laser irradiation device may not include all of the above-mentioned components. That is, some of the components of the laser irradiation device 1 may be omitted. For example, a laser irradiation device according to one aspect of this embodiment includes: an excimer laser source configured to generate laser light; an optical system configured to irradiate the wafer in a linear shape with the laser light; and a stage unit configured to hold the wafer.

[0107] The above-mentioned components can also be added to the laser irradiation device.

[0108] Note that the laser irradiation method according to one aspect of this embodiment includes the steps (A1) to (A4).

[0109] (A1) The step of holding the wafer using a stage unit;

[0110] (A2) The steps for generating laser light using an excimer laser source;

[0111] (A3) The step of irradiating the wafer in a linear shape with the laser; and

[0112] (A4) The step of driving the stage unit to change the irradiation position of the laser relative to the wafer with a linear shape.

[0113] The processing of the above-mentioned components can also be added to this laser irradiation method.

[0114] Additionally, according to another aspect of this embodiment, the laser irradiation apparatus includes: a laser source configured to generate laser light; a first unit configured to hold a first wafer; a second unit configured to hold a second wafer; and a control device configured to control the first unit and the second unit to irradiate the second wafer with the laser light during loading or unloading the first wafer onto or from the first unit, and to irradiate the first wafer with the laser light during loading or unloading the first wafer onto or from the second unit.

[0115] The aforementioned components can also be added to the aforementioned laser irradiation device.

[0116] Note that the laser irradiation method according to another aspect of this embodiment includes the steps (B1) to (B6).

[0117] (B1) The steps for generating laser light;

[0118] (B2) The step of irradiating the first wafer on the first stage with the laser;

[0119] (B3) The step of driving the first unit to cause the laser to scan the first wafer;

[0120] (B4) The step of loading the second wafer into or unloading the second wafer from the second stage during the scanning of the first wafer.

[0121] (B5) The step of driving the second unit to enable the laser to scan the second wafer.

[0122] (B6) The step of loading the first wafer into or unloading the first wafer from the first stage during the scanning of the second wafer.

[0123] The processing of the above-mentioned components can also be added to this laser irradiation method.

[0124] The laser irradiation method described above can be applied to methods for manufacturing compound semiconductor devices. The laser irradiation apparatus 1 is used in the process of forming the back electrode of a semiconductor device. For example, the laser irradiation apparatus 1 irradiates a wafer formed of a compound semiconductor with a laser. Thus, the back electrode of the semiconductor device formed on the wafer can be formed.

[0125] Reference Figure 10 and Figure 11 The method for manufacturing compound semiconductor devices is described. Figure 10 It is a cross-sectional view showing the manufacturing process. Figure 10and Figure 11 The structure in the laser irradiation process is illustrated schematically.

[0126] The substrate W includes a metal film 301, a wafer 302, a semiconductor device 303, an adhesive 304, and a glass substrate 305. The wafer 302 is a semiconductor wafer formed from a compound semiconductor such as silicon carbide (SiC). The wafer 302 includes a semiconductor device 303, such as a transistor. The semiconductor device 303 is a SiC power device. A metal film 301 is formed on the back side of the wafer 302. Furthermore, after device formation, the wafer 302 can be thinned by grinding, polishing, or other methods.

[0127] The glass substrate 305 is bonded to the surface side of the wafer 302 via an adhesive 304. The metal film 301 is, for example, a nickel film. Of course, the metal film 301 can also be formed of molybdenum (Mo), titanium (Ti), or tungsten (W) other than nickel (Ni). Furthermore, the metal film 301 can be an alloy film including the aforementioned metallic materials.

[0128] Laser irradiation device 1 irradiates metal film 301 with laser L1. Therefore, metal film 301 is formed into silicide, and an ohmic contact layer 310 is formed (see...). Figure 11 The ohmic contact layer 310 can be thinned by polishing, etching, etc. Then, a metal film 311 is formed on the ohmic contact layer 310, thereby forming the back electrode 312. Since the metal film 301 is a nickel film, the ohmic contact layer 310 is a nickel silicide film. Furthermore, the metal film 311 can be titanium (Ti), aluminum (Al), silver (Ag), gold (Au), etc., and can have a stacked structure.

[0129] In this embodiment, laser L1 is an excimer laser with a wavelength of 308 nm. Therefore, the light absorption rate in nickel is higher than that of a solid-state laser with a wavelength of 532 nm. This allows for efficient annealing of the metal film 301, thereby increasing production output. Furthermore, compared to a solid-state laser with a wavelength of 532 nm, the pulse width can be shorter in an excimer laser. This prevents damage to the semiconductor device 303 and suppresses temperature rise in the adhesive 304. Therefore, laser irradiation can be performed appropriately, thereby improving productivity.

[0130] Note that the present invention is not limited to the above embodiments, and can be appropriately modified without departing from the spirit of the present invention.

[0131] List of reference numerals 1. Laser irradiation device 10. Laser source 15 Irradiation Area 20 Optical System 21 Variable Attenuator 22 beam shaping units 23 Projection Lens 30 slits 40 beam absorber 50 window units 60 dust collector 61 Air supply pipe 62 Exhaust pipe 70 display 71 Display 80 chambers 90 Control device 100 units 110 units 111X X-drive mechanism 111Y Y-drive mechanism 111Z Z drive mechanism 115 Installation Parts 116 visor 117 Power Monitor 117a Slit Light-Blocking Panel 118 Beam Analyzer 119 camera 120 units 121X X-drive mechanism 121Y Y-drive mechanism 121Z Z-drive mechanism 125 mounting parts 126 visor 127 Power Monitor 127a Slit Light-Blocking Panel 128 Beam Analyzer 129 camera 130 masks 132 Guiding Organization 133 Guiding Organization 135 mask 301 metal film 302 wafer 303 Semiconductor Devices 304 adhesive 305 glass substrate 310 Ohm Contact Layer 311 metal film 312 Back Electrode 501 Retainer Window 502 510 Distribution Ring 510a Gas ejection port 510b Hollow section 601 Housing 602 Discharge Port 603 Supply Port 604 connector 605 connector 607 Conductive Ring 610 Space

Claims

1. A laser irradiation apparatus configured to perform laser irradiation to form a back electrode of a semiconductor device formed on a wafer made of compound semiconductor, the laser irradiation apparatus comprising: An excimer laser source, which is configured to generate laser light; An optical system configured to illuminate the wafer in a linear shape with the laser; as well as A unit cell, configured to hold the wafer.

2. The laser irradiation device according to claim 1, wherein, The compound semiconductor is silicon carbide, and The back electrode is formed by irradiating the nickel film formed on the wafer with the laser.

3. The laser irradiation apparatus according to claim 1 or 2 further includes a light shield configured to cover the periphery of the wafer.

4. The laser irradiation device according to claim 3, comprising: A camera configured to detect the relative position of the wafer with respect to the light shield; as well as An alignment mechanism configured to align the wafer based on the results of the detection by the camera.

5. The laser irradiation device according to claim 1 or 2, wherein, The station unit includes: The first unit, configured to hold the first wafer; and The second unit is configured to hold the second wafer; The laser irradiation device drives the stage unit to: During the loading or unloading of the first wafer onto or from the first stage, the second stage is driven to irradiate the second wafer with the laser; and During the loading or unloading of the second wafer onto or from the second stage, the first stage is driven to irradiate the first wafer with the laser.

6. The laser irradiation device according to claim 5, wherein, The first unit and the second unit each include: A first driving mechanism is configured to reciprocate the wafer in a direction perpendicular to the linear direction of the laser, so that the laser scans the wafer; and A second drive mechanism is configured to move the wafer along the line direction; In adjacent scan rows, the laser scans the wafer in such a way that the irradiated areas partially overlap.

7. The laser irradiation device according to claim 6, wherein, The first and second units include: The guiding mechanism is configured to guide the movement of the platform; and The cover is configured to cover the guiding mechanism.

8. The laser irradiation device according to claim 1 or 2, comprising: A chamber configured to accommodate the stage unit; A window unit is attached to the cavity in a manner that it is disposed above the wafer, and the laser is transmitted through the window unit; as well as A window replacement mechanism is disposed on the chamber and guides the movement of the window unit.

9. The laser irradiation device according to claim 8 further includes a dust collector disposed in the chamber and positioned directly below the window unit. in, The dust collector will discharge the dust generated by the laser irradiation.

10. A laser irradiation apparatus configured to perform laser irradiation to form a back electrode of a semiconductor device formed on a wafer made of compound semiconductor, the laser irradiation apparatus comprising: A laser source, which is constructed to generate laser light; The first unit, which is configured to hold the first wafer; The second unit is configured to hold the second wafer; as well as A control unit configured to control the first and second units to irradiate the second wafer with the laser during loading or unloading the first wafer onto or from the first unit, and to irradiate the first wafer with the laser during loading or unloading the first wafer onto or from the second unit.

11. The laser irradiation apparatus according to claim 10, wherein, The first unit and the second unit each include: A first driving mechanism is configured to reciprocate the wafer in a direction perpendicular to the linear direction of the laser, so that the laser scans the wafer. A second drive mechanism is configured to move the wafer along the line direction; In adjacent scan rows, the laser scans the wafer in such a way that the irradiated areas partially overlap.

12. The laser irradiation apparatus according to claim 11, wherein, The first and second units include: The guiding mechanism is configured to guide the movement of the platform; and The cover is configured to cover the guiding mechanism.

13. The laser irradiation apparatus according to claim 11 or 12 further includes a light shield configured to cover the periphery of the wafer.

14. The laser irradiation apparatus according to claim 13, comprising: A camera configured to detect the relative position of the wafer with respect to the light shield when the wafer is loaded; as well as An alignment mechanism configured to align the wafer based on the results of the detection by the camera.

15. A laser irradiation method for performing laser irradiation to form a back electrode of a semiconductor device formed on a wafer formed of a compound semiconductor, the laser irradiation method comprising: (A1) The step of holding the wafer using a stage unit; (A2) The steps for generating laser light using an excimer laser source; (A3) The step of irradiating the wafer in a linear shape with the laser; as well as (A4) The step of driving the stage unit to change the irradiation position of the laser relative to the wafer with a linear shape.

16. The laser irradiation method according to claim 15, wherein, The compound semiconductor is silicon carbide, and The back electrode is formed by irradiating the nickel film formed on the wafer with the laser.

17. The laser irradiation method according to claim 15 or 16, wherein, A light-shielding plate is provided, which is configured to cover the periphery of the wafer.

18. The laser irradiation method according to claim 17, wherein, The relative position of the wafer with respect to the light-shielding plate is detected by a camera; and The wafer is aligned based on the detection results from the camera.

19. The laser irradiation method according to claim 15 or 16, wherein, The station unit includes: The first unit, configured to hold the first wafer; and The second unit is configured to hold the second wafer; The laser irradiation method includes driving the stage unit to: During the loading or unloading of the first wafer onto or from the first stage, the second stage is driven to irradiate the second wafer with the laser; and During the loading of the first wafer onto or unloading it from the second stage, the first stage is driven to irradiate the first wafer with the laser.

20. The laser irradiation method according to claim 19, wherein, The first unit and the second unit each include: A first driving mechanism is configured to reciprocate the wafer in a direction perpendicular to the linear direction of the laser, so that the laser scans the wafer; and A second drive mechanism is configured to move the wafer along the line direction; In adjacent scan rows, the laser scans the wafer in such a way that the irradiated areas partially overlap.

21. The laser irradiation method according to claim 20, wherein, The first and second units include: The guiding mechanism is configured to guide the movement of the platform; and The cover is configured to cover the guiding mechanism.

22. The laser irradiation method according to claim 15 or 16, wherein, The stage unit is housed within the chamber. The laser is transmitted through a window unit, which is attached to the cavity in a manner that positions it above the wafer, and A window replacement mechanism mounted on the chamber guides the movement of the window unit.

23. The laser irradiation method according to claim 22 further includes a dust collector disposed in the chamber directly below the window unit. in, The dust collector will discharge the dust generated by the laser irradiation.

24. A laser irradiation method for performing laser irradiation to form a back electrode of a semiconductor device formed on a wafer formed of a compound semiconductor, the laser irradiation method comprising: (B1) The steps for generating laser light; (B2) The step of irradiating the first wafer on the first stage with the laser; (B3) The step of driving the first unit to cause the laser to scan the first wafer; (B4) The step of loading the second wafer into or unloading the second wafer from the second machine during the scanning of the first wafer; (B5) The step of driving the second unit to cause the laser to scan the second wafer; as well as (B6) The step of loading the first wafer into or unloading the first wafer from the first stage during the scanning of the second wafer.

25. The laser irradiation method according to claim 24, wherein, The first unit and the second unit each include: A first driving mechanism is configured to reciprocate the wafer in a direction perpendicular to the linear direction of the laser, so that the laser scans the wafer; and A second drive mechanism is configured to move the wafer along the line direction; In adjacent scan rows, the laser scans the wafer in such a way that the irradiated areas partially overlap.

26. The laser irradiation method according to claim 25, wherein, The first and second units include: The guiding mechanism is configured to guide the movement of the platform; and The cover is configured to cover the guiding mechanism.

27. The laser irradiation method according to claim 25 or 26, wherein, A light-shielding plate is provided, which is configured to cover the periphery of the wafer.

28. The laser irradiation method according to claim 27, wherein, When the wafer is loaded, a camera is used to detect the relative position of the wafer with respect to the light-shielding plate, and The wafer is aligned based on the detection results from the camera.

29. A method for manufacturing a compound semiconductor device, comprising laser irradiation to form a back electrode of the semiconductor device formed on a wafer formed of a compound semiconductor, the method comprising: (sa1) The step of holding the wafer using a stage unit; (sa2) The step of generating the laser using an excimer laser source; (sa3) The step of irradiating the wafer in a linear shape with the laser; as well as (sa4) The step of controlling the stage unit to change the irradiation position of the laser relative to the wafer with a linear shape.

30. The method for manufacturing a compound semiconductor device according to claim 29, wherein, The compound semiconductor is silicon carbide, and The back electrode is formed by irradiating the nickel film formed on the wafer with the laser.

31. The method for manufacturing a compound semiconductor device according to claim 29 or 30, wherein, A light-shielding plate is provided, which is configured to cover the periphery of the wafer.

32. The method for manufacturing a compound semiconductor device according to claim 31, wherein, The relative position of the wafer with respect to the light-shielding plate is detected by a camera; as well as The wafer is aligned based on the detection results from the camera.

33. The method for manufacturing a compound semiconductor device according to claim 29 or 30, wherein, The station unit includes: The first unit, configured to hold the first wafer; and The second unit is configured to hold the second wafer; The method includes driving the stage unit to: During the loading or unloading of the first wafer onto or from the first stage, the second stage is driven to irradiate the second wafer with the laser; and During the loading of the first wafer onto or unloading it from the second stage, the first stage is driven to irradiate the first wafer with the laser.

34. The method for manufacturing a compound semiconductor device according to claim 33, wherein, The first unit and the second unit each include: A first driving mechanism is configured to reciprocate the wafer in a direction perpendicular to the linear direction of the laser, so that the laser scans the wafer; and A second drive mechanism is configured to move the wafer along the line direction; In adjacent scan rows, the laser scans the wafer in such a way that the irradiated areas partially overlap.

35. The method for manufacturing a compound semiconductor device according to claim 34, wherein, The first and second units include: The guiding mechanism is configured to guide the movement of the platform; and The cover is configured to cover the guiding mechanism.

36. The method for manufacturing a compound semiconductor device according to claim 34, wherein, The stage unit is housed within the chamber. The laser is transmitted through a window unit, which is attached to the cavity in a manner that positions it above the wafer, and A window replacement mechanism mounted on the chamber guides the movement of the window unit.

37. The method for manufacturing a compound semiconductor device according to claim 36, further comprising a dust collector disposed in the chamber directly below the window unit. in, The dust collector will discharge the dust generated by the laser irradiation.

38. A method for manufacturing a compound semiconductor device, comprising laser irradiation to form a back electrode of the semiconductor device formed on a wafer formed of a compound semiconductor, the method comprising: (sb1) The steps for generating laser light; (sb2) The step of irradiating the first wafer on the first stage with the laser; (sb3) The step of driving the first unit to cause the laser to scan the first wafer; (sb4) The step of loading the second wafer into or unloading the second wafer from the second machine during the scanning of the first wafer; (sb5) The step of driving the second unit to cause the laser to scan the second wafer; as well as (sb6) The step of loading the first wafer into or unloading the first wafer from the first stage during the scanning of the second wafer.

39. The method for manufacturing a compound semiconductor device according to claim 38, wherein, The first unit and the second unit each include: A first driving mechanism is configured to reciprocate the wafer in a direction perpendicular to the linear direction of the laser, so that the laser scans the wafer; and A second drive mechanism is configured to move the wafer along the line direction; In adjacent scan rows, the laser scans the wafer in such a way that the irradiated areas partially overlap.

40. The method for manufacturing a compound semiconductor device according to claim 39, wherein, The first and second units include: The guiding mechanism is configured to guide the movement of the platform; and The cover is configured to cover the guiding mechanism.

41. The method for manufacturing a compound semiconductor device according to claim 39 or 40, wherein, A light-shielding plate is provided, which is configured to cover the periphery of the wafer.

42. The method for manufacturing a compound semiconductor device according to claim 41, wherein, When the wafer is loaded, a camera is used to detect the relative position of the wafer with respect to the light-shielding plate, and The wafer is aligned based on the detection results from the camera.

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