Laser annealing apparatus, laser annealing method, and storage medium

Abstract

The invention provides a laser annealing device and the like capable of reducing irradiation unevenness in annealing treatment. A laser annealing apparatus (1) for performing annealing treatment by irradiating an irradiation region (IR) on a semiconductor wafer (3) with a laser pulse (LP), the laser annealing apparatus (1) being provided with: a laser scanning unit (6) for scanning the laser pulse (LP) so that the laser pulse (LP) sequentially irradiates different irradiation positions in the irradiation region (IR); and an irradiation position alignment unit (63) that adjusts irradiation positions during scanning by the laser scanning unit (6) such that different irradiation positions in the irradiation region (IR) are aligned in a first direction and a second direction that intersect each other. The laser scanning unit (6) performs a first scan in which the laser pulse (LP) is scanned in a first direction, and a second scan in which the laser pulse (LP) is scanned in a second direction.

Description

[0001] This application claims the benefit of priority based on Japanese Patent Application No. 2023-176660 filed on October 12, 2023. The entire contents of this Japanese application are incorporated herein by reference. Technical Field

[0002] The present invention relates to a laser annealing device and the like. Background Art

[0003] Patent Document 1 discloses a laser annealing apparatus that performs annealing by sequentially irradiating an irradiation region on a workpiece such as a semiconductor wafer with laser pulses. The laser pulses are two-dimensionally scanned over the entire irradiation region by an appropriate laser scanning mechanism.

[0004] Such two-dimensional scanning of the laser is usually achieved by a combination of a first scan along a first direction and a second scan along a second direction orthogonal to the first direction. For example, in a first scan, the laser is linearly scanned along the first direction between one end and the other end of the irradiation area. And, in a second scan, the laser is scanned along the second direction so that the position of the subsequent first scan is offset.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-67642

[0006] In each first scan, the laser is usually scanned linearly along the first direction from a starting position inscribed in the periphery of the irradiation area (for example, the periphery of the semiconductor wafer itself). At this time, the irradiation position of the laser in each first scan is aligned along the first direction. However, the irradiation positions of the laser in different first scans are not necessarily aligned along the second direction. In this way, when the irradiation positions of the laser are not aligned along the second direction, "irradiation unevenness" in which the consistency or uniformity of the annealing process in the irradiation area is low may result. Summary of the invention

[0007] The present invention has been made in view of such circumstances, and an object of the present invention is to provide a laser annealing apparatus and the like that can reduce irradiation unevenness in an annealing process.

[0008] In order to solve the above-mentioned problems, a laser annealing device according to one embodiment of the present invention irradiates an irradiation area on a processed object with a laser to perform an annealing process, and comprises: a laser scanning unit for scanning the laser so as to sequentially irradiate different irradiation positions in the irradiation area; and an irradiation position alignment unit for adjusting the irradiation positions in the scanning performed by the laser scanning unit so that different irradiation positions in the irradiation area are respectively aligned along a first direction and a second direction intersecting with each other.

[0009] According to this aspect, different irradiation positions in the irradiation region are aligned along the first direction and the second direction, so that irradiation unevenness in the annealing process can be reduced.

[0010] Another embodiment of the present invention is a laser annealing method. The method is a laser annealing method for irradiating an irradiation area on a processed object with a laser to perform an annealing process, and the method performs the following steps: scanning the laser so that it sequentially irradiates different irradiation positions in the irradiation area; and adjusting the irradiation positions during the scanning so that the different irradiation positions in the irradiation area are respectively aligned along a first direction and a second direction that intersect each other.

[0011] Another embodiment of the present invention is a storage medium. The storage medium stores a laser annealing program for irradiating an irradiation area on a processed object with a laser to perform an annealing process, wherein the laser annealing program is executed by a computer to perform the following steps: scanning the laser so that it sequentially irradiates different irradiation positions in the irradiation area; and adjusting the irradiation positions during the scanning so that the different irradiation positions in the irradiation area are respectively aligned along a first direction and a second direction that intersect each other.

[0012] In addition, any combination of the above constituent elements or any form of converting these expressions into methods, apparatuses, systems, recording media, computer programs, etc. are also included in the present invention.

[0013] According to the present invention, irradiation unevenness in annealing can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a diagram schematically showing the structure of a laser annealing apparatus.

[0015] Figure 2 This is a schematic functional block diagram of the laser scanning control unit, etc.

[0016] Figure 3 Examples of the first scanning and the second scanning of the laser pulse by the laser scanning unit are schematically shown.

[0017] Figure 4 An example in which the irradiation positions in different rows of the first scan are aligned along the X direction is schematically shown.

[0018] In the figure: 1-laser annealing device, 2-laser device, 3-semiconductor wafer, 4-stage device, 6-laser scanning unit, 7-measuring device, 15-Galvano scanner, 41-moving platform, 53-personal computer, 54-scanner control unit, 55-stage control unit, 56-laser scanning control unit, 61-irradiation area setting unit, 62-starting position setting unit, 63-irradiation position alignment unit, LP-laser pulse. DETAILED DESCRIPTION

[0019] Hereinafter, the method for implementing the present invention (hereinafter, also referred to as an embodiment) is described in detail with reference to the accompanying drawings. In the following description and / or the accompanying drawings, the same or equivalent constituent elements, parts and processes are marked with the same symbols, and repeated descriptions are omitted. For the convenience of recording, in the accompanying drawings, the scale or shape of each part is appropriately set, and it is not interpreted restrictively unless otherwise specifically stated. The embodiment is an example, and it does not limit the scope of the present invention in any way. All the features or combinations thereof suggested in the embodiment are not necessarily the essence of the present invention. For convenience, the embodiment is disassembled into constituent elements for realizing each function and / or each functional group of the embodiment and suggested. However, a constituent element in the embodiment can be realized by a combination of multiple constituent elements that are actually separate, and multiple constituent elements in the embodiment can also be realized by a constituent element that is actually integrated.

[0020] Figure 1 The structure of a laser annealing device 1 according to an embodiment of the present invention is schematically shown. The laser annealing device 1 is a device that irradiates a semiconductor wafer 3 (mounted on a wafer platform 31 fixed to a stage device 4 described later) as a workpiece with laser light (e.g., laser pulse LP) oscillated by a laser device 2 to perform an annealing process (heating process). The laser annealing device 1 in the illustrated example greatly simplifies the actual device and omits many components not mentioned in the description of this embodiment (e.g., components for measuring laser light or semiconductor wafer 3, components for conveying semiconductor wafer 3, and components for stopping laser irradiation in an emergency).

[0021] Furthermore, the structure shown in the figure is only an example, and the present invention can be applied to laser annealing devices of different arbitrary structures. For example, in the example shown in the figure, the control system is composed of a laser control unit 51, a trigger pulse control unit 52, a personal computer (PC) 53, a scanner control unit 54, and a stage control unit 55, but as long as the laser annealing device 1 and the laser device 2 can reliably perform annealing on the semiconductor wafer 3, a control system of different arbitrary structures can also be set. Furthermore, in the example shown in the figure, an energy adjustment mechanism 11, a transmission optical system 12, a mask 13, an irradiation optical system 14, a Galvano scanner 15, and an fθ lens 16 are set along the path of the laser, but as long as the laser from the laser device 2 can accurately irradiate the semiconductor wafer 3, any other components can also be set between the laser device 2 and the semiconductor wafer 3, and their configuration can also be arbitrary.

[0022] Hereinafter, directions related to the structure and / or function of the laser annealing device 1 are described based on a three-dimensional orthogonal coordinate system having mutually orthogonal XYZ axes as coordinate axes. Hereinafter, for convenience, it is assumed that the X direction and the Y direction are horizontal directions (i.e., the XY plane is a horizontal plane), and the Z direction is a vertical direction. As described later, the semiconductor wafer 3 is driven relative to the laser from the laser device 2 in the XY plane under the control of the scanner control unit 54 and / or the stage control unit 55.

[0023] For example, the semiconductor wafer 3 is integrally driven in the X direction with the moving platform 41 in the stage device 4 driven in the X direction under the control of the stage control unit 55 (the X direction is also indicated as the driving direction at this time), and the laser from the laser device 2 is scanned in the Y direction by the Galvano scanner 15 controlled by the scanner control unit 54 (the Y direction is also indicated as the scanning direction at this time). In addition, the semiconductor wafer 3 is integrally driven in the Z direction with the lifting platform 42 in the stage device 4 driven in the Z direction under the control of the stage control unit 55 (the Z direction is also indicated as the lifting direction at this time). The Z direction is also the incident direction of the laser light incident on the semiconductor wafer 3. In the following, for convenience, the X direction is also indicated as the longitudinal direction, the Y direction is also indicated as the lateral direction, and the Z direction is also indicated as the height direction.

[0024] The laser device 2 is a pulse laser device that oscillates laser pulses LP at a frequency of, for example, about 20 kHz under the control of the laser control unit 51. However, the frequency of the laser pulses LP oscillated by the laser device 2 is arbitrary. The laser device 2 involved in this embodiment can be composed of, for example, a fiber laser device that oscillates laser pulses LP through an optical fiber.

[0025] The laser pulse LP is emitted from the laser device 2, for example, in the X direction. In the laser annealing device 1 that introduces the laser pulse LP into the semiconductor wafer 3 as the irradiation object (processed object), an energy adjustment mechanism 11, a transmission optical system 12, a mask 13, an irradiation optical system 14, a Galvano scanner 15, and an fθ lens 16 are sequentially arranged along the path of the laser pulse LP (schematically indicated by a single-dot chain line).

[0026] The energy adjustment mechanism 11 adjusts the energy or energy density of the laser pulse LP emitted from the laser device 2 to a value suitable for a desired annealing process.

[0027] The transmission optical system 12 is an optical system for transmitting laser pulses LP. The transmission optical system 12 is composed of any optical elements such as lenses, mirrors, prisms, filters, and diffraction gratings, and it can be responsible not only for the transmission of laser pulses LP, but also for the adjustment of the size (diameter) of laser pulses LP, the shaping of laser pulses LP, and the adjustment of the intensity distribution of laser pulses LP. In addition, the adjustment of the size (diameter) of laser pulses LP or the shaping of laser pulses LP can also be performed by a mask 13 having a size (diameter) and / or shape suitable for the desired annealing process. The irradiation optical system 14 is composed of any optical elements such as lenses, mirrors, prisms, filters, and diffraction gratings, and it adjusts the laser pulses LP to a state suitable for irradiating the semiconductor wafer 3 (for example, size (diameter), shape, intensity distribution).

[0028] The Galvano scanner 15 is a laser scanning unit that scans the laser pulse LP adjusted by the irradiation optical system 14 and the like in the Y direction. The Galvano scanner 15 includes: a Galvano mirror 151 as a drivable optical element that reflects the incident laser pulse LP and directs it to a desired scanning position in the Y direction; and a motor (not shown) that drives the Galvano mirror 151 to a desired posture or angle. By adjusting the posture or angle of the Galvano mirror 151 using the motor, the laser pulse LP incident on the Galvano mirror 151 is reflected to a desired position in the Y direction.

[0029] In addition, the laser scanning unit that directs the incident laser pulse LP toward the desired scanning position in the Y direction is not limited to the Galvano scanner 15, and may also be composed of a polygonal mirror scanner with a rotatable and driven polygonal mirror (optical element) or a drivable MEMS (Micro Electro Mechanical Systems) reflector and other optical elements. In addition, the scanning direction of the laser pulse LP based on the laser scanning unit such as the Galvano scanner 15 is not limited to the Y direction, but may be a direction intersecting the Y direction such as the X direction, or may be both the X direction and the Y direction. If the laser scanning unit such as the Galvano scanner 15 can scan the laser pulse LP on the XY plane (i.e., the surface of the semiconductor wafer 3) as in the latter, the stage device 4 (movable platform 41) that drives the semiconductor wafer 3 and the wafer platform 31 along the X direction may not be provided. In this case, the laser scanning unit in both the X direction and the Y direction is composed of the Galvano scanner 15 and the like.

[0030] The fθ lens 16 focuses the laser pulse LP scanned in the Y direction by the Galvano scanner 15 on the semiconductor wafer 3 to be annealed. The laser pulse LP from the fθ lens 16 is incident on the semiconductor wafer 3 in the Z direction. The laser pulse LP focused on the semiconductor wafer 3 by the fθ lens 16 moves in the Y direction on the surface of the semiconductor wafer 3 by scanning in the Y direction by the Galvano scanner 15. The size of the laser pulse LP focused on the semiconductor wafer 3 can be arbitrarily designed, but is preferably between 0.10 mm square and 0.15 mm square, and more preferably between 0.12 mm square and 0.13 mm square. In addition, the scanning speed of the laser pulse LP in the Y direction on the surface of the semiconductor wafer 3 (and / or the driving speed of the semiconductor wafer 3 in the X direction by the stage device 4 (moving platform 41)) can also be arbitrarily designed, but is preferably set between 10 cm / s and 500 cm / s, and more preferably between 100 cm / s and 300 cm / s.

[0031] The moving stage 41 in the stage device 4 is a driving device that drives the semiconductor wafer 3 and the wafer stage 31 relatively in the X direction with respect to the laser pulse LP. The moving stage 41 relatively moves the laser pulse LP on the surface of the semiconductor wafer 3 in the X direction.

[0032] As described above, by combining the scanning of the laser pulse LP in the Y direction by the Galvano scanner 15 as the laser scanning unit in the Y direction and the driving of the semiconductor wafer 3 in the X direction by the moving platform 41 as the laser scanning unit in the X direction, it is possible to scan the laser pulse LP on the XY plane (that is, the surface of the semiconductor wafer 3). In addition, the driving direction of the semiconductor wafer 3 based on the moving platform 41 is not limited to the X direction, but can also be a direction intersecting the X direction such as the Y direction, or can be both the X direction and the Y direction. If the moving platform 41 can drive the semiconductor wafer 3 relative to the laser pulse LP on the XY plane as in the latter, the Galvano scanner 15 that scans the laser pulse LP along the Y direction etc. can be omitted. In this case, the laser scanning units in both the X direction and the Y direction are constituted by the moving platform 41.

[0033] The laser annealing device 1 and the laser device 2 described above are controlled by a control system, and the control system includes a laser control unit 51 , a trigger pulse control unit 52 , a personal computer 53 , a scanner control unit 54 , and a stage control unit 55 .

[0034] The laser control unit 51 controls the laser pulse LP oscillated by the laser device 2 according to various control parameters. Examples of the control parameters include the energy of the laser pulse LP, the energy density of the laser pulse LP, the repetition frequency of the laser pulse LP, the duration of the laser pulse LP (pulse width), the peak intensity of the laser pulse LP, the distribution of the laser pulse LP (for example, intensity distribution), the delay time (time difference) when the laser pulse LP is irradiated to the same position by a plurality of laser devices 2 (not shown), and the overlap ratio (ratio of overlap of irradiation traces) between adjacent rows (or adjacent columns) when the laser pulse LP is reciprocated and scanned.

[0035] The trigger pulse control unit 52 generates a trigger pulse synchronized with the laser pulse LP oscillated by the laser device 2 based on the synchronization signal provided by the laser control unit 51. For example, the frequency of the trigger pulse generated by the trigger pulse control unit 52 is 1 / N (N is an arbitrary natural number) times or N times the repetition frequency or oscillation frequency of the laser pulse LP.

[0036] The scanner control unit 54 controls the Galvano scanner 15 (scanning control) based on the trigger pulse processed by the personal computer 53 as needed. Similarly, the stage control unit 55 controls the moving platform 41 in the stage device 4 (stage control) based on the trigger pulse processed by the personal computer 53 as needed. In this way, based on the trigger pulse synchronized with the laser pulse LP, the scanner control unit 54 can accurately use the Galvano scanner 15 to perform scanning in the Y direction of the laser pulse LP, and the stage control unit 55 can accurately use the moving platform 41 to drive the semiconductor wafer 3 in the X direction. The personal computer 53 can be used for adjustment in the scanner control unit 54 and / or the stage control unit 55 (hereinafter also collectively referred to as the laser scanning control unit 56) described below.

[0037] Figure 2 It is a schematic functional block diagram of the laser scanning control unit 56 and the like involved in this embodiment. The laser scanning control unit 56 includes an irradiation area setting unit 61, a start position setting unit 62, and an irradiation position alignment unit 63. As long as the laser scanning control unit 56 can achieve at least a part of the functions and / or effects described below, part of these functional blocks can be omitted. These functional blocks can be implemented by the computer's central processing unit, memory, input device, output device, supporting equipment connected to the computer and other hardware resources and the collaboration of software executed using these. Regardless of the type of computer or the location of the computer, the above-mentioned functional blocks can be implemented by the hardware resources of a single computer, or by combining the hardware resources distributed in multiple computers.

[0038] The laser scanning control unit 56 controls the first scanning of the laser pulse LP along the Y direction as the first direction and the second scanning of the laser pulse LP along the X direction as the second direction performed by the laser scanning unit 6. Figure 1 In the case where the galvano scanner 15 functions as the first scanning unit that performs the first scanning of the laser pulse LP along the Y direction as in the example, a part of the laser scanning control unit 56 (i.e., the scanner control unit 54) functions as the first scanning control unit that controls the first scanning unit 15, and in the case where the moving platform 41 functions as the second scanning unit that performs the second scanning of the laser pulse LP along the X direction (driving the semiconductor wafer 3 along the X direction), a part of the laser scanning control unit 56 (i.e., the stage control unit 55) functions as the second scanning control unit that controls the second scanning unit 41. The following description is based on this example unless otherwise specified.

[0039] However, as described above, when the Galvano scanner 15 functions as the first scanning unit and the second scanning unit that perform the first scanning and the second scanning of the laser pulse LP along both the Y direction and the X direction, the laser scanning control unit 56 may be constituted by only the scanner control unit 54 that substantially controls the Galvano scanner 15. Similarly, when the moving platform 41 functions as the first scanning unit and the second scanning unit that perform the first scanning and the second scanning of the laser pulse LP along both the Y direction and the X direction, the laser scanning control unit 56 may be constituted by only the stage control unit 55 that substantially controls the moving platform 41.

[0040] The irradiation region setting unit 61 sets one or more irradiation regions IR on the semiconductor wafer 3 as the object to be processed. Here, the irradiation region IR refers to the region on the semiconductor wafer 3 irradiated by the laser pulse LP through a series of or one XY scans (plane scans) performed by the galvano scanner 15 and the moving platform 41. If there are no problems in the performance of the laser device 2 and the laser scanning unit 6, Figure 2 As shown, it is preferred that the irradiation region setting unit 61 sets the entire surface (entire surface) of the semiconductor wafer 3 to be processed as the irradiation region IR. On the other hand, when the entire surface of the semiconductor wafer 3 cannot be covered by a single XY scan, the irradiation region setting unit 61 can divide the processed surface of the semiconductor wafer 3 into a plurality of irradiation regions IR.

[0041] With respect to the irradiation region IR on the semiconductor wafer 3 as described above, the laser scanning unit 6 sequentially irradiates different irradiation positions in the irradiation region IR while scanning the laser pulse LP along the XY direction under the control of the laser scanning control unit 56. As described above, in the example of the present embodiment, the Galvano scanner 15 as the first scanning unit performs the first scanning of the laser pulse LP along the Y direction, and the moving stage 41 as the second scanning unit performs the second scanning of the laser pulse LP along the X direction.

[0042] Figure 3 The figure schematically shows an example of the first scan and the second scan of the laser pulse LP performed by the laser scanning unit 6. The multiple circles in this figure schematically show the area (hereinafter, for convenience, also shown as the irradiation trace) that is subjected to the annealing treatment by the laser pulse LP that is continuously irradiated while sequentially changing the irradiation position in the irradiation area IR set by the irradiation area setting unit 61 (i.e., while scanning). In this example, as shown by the arrows in the up and down directions, the Galvano scanner 15 as the first scanning unit performs the annealing treatment at both ends of the irradiation area IR ( Figure 3 Furthermore, the moving platform 41 as the second scanning unit performs a second scanning in which the laser pulse LP is scanned linearly along the X direction (a second direction intersecting or orthogonal to the Y direction as the first direction) so as to shift the position of the subsequent first scanning.

[0043] In addition, in the example shown in the figure, the unit scanning amount (the distance between two irradiation positions of adjacent or continuous laser pulses LP) in each of the first scan and the second scan is set to the length of a typical irradiation mark, so that the irradiation marks do not overlap but are roughly circumscribed. However, in the present invention, the unit scanning amount (the distance in the Y direction) of the first scan and the unit scanning amount (the distance in the X direction) of the second scan are arbitrary. For example, when the unit scanning amount of the first scan is smaller than the size of the irradiation mark, two irradiation marks adjacent to each other in the Y direction overlap with each other. Similarly, when the unit scanning amount of the second scan is smaller than the size of the irradiation mark, two irradiation marks adjacent to each other in the X direction overlap with each other.

[0044] In the example shown in the figure, the first scan of the laser pulse LP in the Y direction is continuously performed while shifting the position in the X direction by the second scan. Specifically, from the -X side ( Figure 3 left side) towards the +X side ( Figure 3 The second scan is performed multiple times from the -Y side ( Figure 3 The lower side in the middle) towards the +Y side ( Figure 3 The first scan of the upper side of the image. Figure 3The irradiation traces generated by performing three first scans from the first time are shown in FIG. The columns along the Y direction of the irradiation traces generated by each first scan are as follows: Figure 3 The left side of is represented as the 1st column, the 2nd column, and the 3rd column respectively.

[0045] The starting position or the bottom end position of each column in the first scan is set by the starting position setting unit 62. Figure 3 In the example of , the start position setting unit 62 sets the irradiation position inscribed in the periphery of the irradiation region IR among the X positions of each column as the start position of each column when setting the start position S1 of the first scan of the first column, the start position S2 of the first scan of the second column, and the start position S3 of the first scan of the third column. As a result, the irradiation position substantially closest to the periphery of the irradiation region IR is set as the start position or the lower end position in the first scan of each column, so that the utilization efficiency of the annealing process of the irradiation region IR can be improved.

[0046] On the other hand, since the starting position or the lower end position in the first scan of each column is set at a different inscribed position with respect to the periphery of the irradiation region IR in each column, there is a problem that the irradiation traces of each column (the first to third columns) are not aligned along the X direction (the second direction) as shown in the figure. In this way, when the irradiation position of the laser pulse LP is not aligned along the X direction, "irradiation unevenness" in which the consistency or uniformity of the annealing process in the irradiation region IR is low may be caused.

[0047] In this embodiment, in order to reduce the irradiation unevenness in the annealing process, Figure 2 The irradiation position alignment unit 63 in the irradiation area IR is used. The irradiation position alignment unit 63 adjusts the irradiation position in at least one of the first scan and the second scan so that different irradiation positions or irradiation marks in the irradiation area IR are aligned along the first direction (Y direction) and the second direction (X direction). In the example shown in the figure, as described above, since the laser pulse LP is scanned along the Y direction in each first scan performed by the Galvano scanner 15, the irradiation positions or irradiation marks are naturally aligned along the Y direction in each column of the first scan (without relying on the irradiation position alignment unit 63).

[0048] Therefore, in the example shown in the figure, the irradiation position alignment unit 63 adjusts the irradiation positions in the first scan so that the irradiation positions or irradiation traces in different columns (for example, the first to third columns shown in the figure) of the first scan are aligned along the second direction (X direction). For example, the irradiation position alignment unit 63 adjusts each irradiation position in the second scan after the two consecutive first scans separated by the second scan so that it is aligned with each irradiation position in the previous first scan along the second direction. Specifically, the irradiation position alignment unit 63 adjusts each irradiation position in the first scan after the second column of the two consecutive first scans of the first column and the second column so that it is aligned with each irradiation position in the first scan of the previous first column along the second direction. Similarly, the irradiation position alignment unit 63 adjusts each irradiation position in the first scan after the third column of the two consecutive first scans of the second column and the third column so that it is aligned with each irradiation position in the first scan of the previous second column along the second direction.

[0049] As described above, the result of the alignment of the irradiation position by the irradiation position alignment unit 63 is as follows: Figure 4 As shown in FIG. 1 , the irradiation positions or irradiation marks in different columns of the first scan are aligned along the X direction. Therefore, in the entire irradiation region IR, different irradiation positions or irradiation marks are aligned in a grid-like configuration along the first direction (Y direction) and the second direction (X direction). Thus, according to the present embodiment, different irradiation positions in the irradiation region IR are aligned along the first direction (Y direction) and the second direction (X direction), thereby reducing irradiation unevenness during the annealing process.

[0050] In addition, in the first scan (i.e., the first scan of the first row) in the irradiation region IR, the start position setting unit 62 sets the first scan position corresponding to the first row. Figure 3 That is, the start position setting unit 62 sets the irradiation position inscribed in the periphery of the irradiation region IR as the start position S1 of the first scan of the first column. With regard to the start position S1, considering the alignment processing of the irradiation position performed by the irradiation position alignment unit 63, it is preferable that the start position setting unit 62 sets the total number of irradiations (total number of beams) of the laser pulse LP in the irradiation region IR to be maximized.

[0051] Here, Figure 4 The starting position S1 in the figure is the lower left corner of the laser pulse LP or the irradiation trace. Therefore, the actual irradiation starting position of the laser pulse LP is a position offset from the starting position S1 by half the size of the laser pulse LP or the irradiation trace (for example, the radius of the laser pulse LP or the irradiation trace of a circular cross section) in the X direction and the Y direction, respectively (that is, the center position of the laser pulse LP or the irradiation trace).

[0052] like Figure 4As shown, in at least one of the first scans after the second scan in the irradiation region IR, the irradiation position alignment unit 63 sets the irradiation position at the lower end on the start position S1 side to be not inscribed in the periphery of the irradiation region IR. Specifically, in the first scans of the second and third columns, the irradiation position alignment unit 63 sets the irradiation start position at the lower end on the start position S1 side to positions S2 and S3 ( Figure 3 As described above, in the first scan after the second column, the irradiation start position or the end position is not set at a position (S2 or S3) inscribed in the periphery of the irradiation area IR, but is set according to the configuration of the irradiation position or the irradiation trace in the first scan of the previous column, so that the irradiation position or the irradiation trace can be aligned in a grid shape in the entire irradiation area IR.

[0053] The adjustment of the irradiation position by the irradiation position alignment unit 63 as described above may also be performed manually by the personal computer 53 which can be operated by a user such as an administrator of the laser annealing apparatus 1. Specifically, the irradiation position alignment unit 63 adjusts the irradiation position in at least one of the first scan (Y scan) and the second scan (X scan) based on the irradiation position adjustment information provided from the personal computer 53 based on the user's operation.

[0054] When the irradiation position is adjusted manually in this way, a measuring device 7 can be used to measure the arrangement or various characteristics of the irradiation traces in the semiconductor wafer 3 after the annealing process is actually performed by the laser pulse LP based on the irradiation position before adjustment and / or the irradiation position after adjustment. The measurement results measured by such a measuring device 7 are provided to the personal computer 53, and are prompted or displayed to the user through its display or the like. Thus, for example, the user can confirm in almost real time whether the irradiation position set by the user realizes the desired irradiation trace arrangement or characteristics on the semiconductor wafer 3. In the case where the irradiation position does not realize the desired irradiation trace arrangement or characteristics on the semiconductor wafer 3, the user can operate the personal computer 53 to appropriately update the irradiation position.

[0055] In addition, the irradiation position alignment unit 63 may autonomously (or automatically) set the adjustment value of the irradiation position based on the measurement result from the measuring device 7, instead of the manual adjustment performed by the user and the personal computer 53 as described above. Such an irradiation position alignment unit 63 autonomously sets the appropriate irradiation position in a manner that realizes the desired irradiation mark arrangement or characteristics (measured by the measuring device 7) on the semiconductor wafer 3.

[0056] The characteristics of the semiconductor wafer 3 (after annealing) measured by the measuring device 7 are arbitrary, but the surface resistance at each irradiation position of the semiconductor wafer 3 can be exemplified. The irradiation position alignment unit 63 that automatically adjusts the irradiation position can set the most suitable irradiation position in each part of the irradiation region IR while comprehensively referring to these measurement results.

[0057] In addition, the irradiation position alignment unit 63 can autonomously (or automatically) set the adjustment value of the irradiation position based on various setting information or control parameters such as the irradiation area IR set by the irradiation area setting unit 61, the starting position S1 set by the starting position setting unit 62, the unit scanning amount of the laser pulse LP (especially the X direction), the size of the laser pulse LP, the distribution of the laser pulse LP, and the overlap rate of the laser pulse LP, instead of using the measurement results from the measuring device 7.

[0058] The present invention has been described above based on the embodiments. It is obvious to those skilled in the art that various modifications may be made to the combinations of the constituent elements or processes in the exemplified embodiments, and such modifications are also included in the scope of the present invention.

[0059] In the above embodiments, the scanning of the laser pulse LP in the irradiation area IR is achieved by a combination of X scanning and Y scanning as linear scanning (also expressed as raster scanning), but it can also be achieved by any other method. For example, the laser pulse LP can also be scanned in a spiral shape mainly along the circumference of the circular irradiation area IR. In this case, the appropriate irradiation position in each part of the irradiation area IR is also set by the irradiation position alignment unit 63 to achieve a grid-like alignment configuration of the irradiation position or irradiation trace in the entire irradiation area IR.

[0060] In addition, the structure, function, and function of each device or method described in the embodiments may be realized by hardware resources or software resources, or by the cooperation of hardware resources and software resources. As hardware resources, for example, a processor, ROM, RAM, and various integrated circuits may be used. As software resources, for example, programs such as an operating system and an application may be used.

Claims

1. A laser annealing device, which irradiates a laser on an irradiation area on a workpiece to perform an annealing process, wherein the laser annealing device is characterized in that it has: a laser scanning unit configured to scan the laser so as to sequentially irradiate different irradiation positions in the irradiation area; and The irradiation position aligning unit adjusts the irradiation positions during scanning by the laser scanning unit so that the different irradiation positions in the irradiation area are aligned along a first direction and a second direction intersecting each other.

2. The laser annealing device according to claim 1, characterized in that: The laser scanning unit performs a first scan and a second scan, wherein the first scan causes the laser to scan along the first direction, and the second scan causes the laser to scan along the second direction. The irradiation position alignment unit adjusts the irradiation position in at least one of the first scan and the second scan so that the different irradiation positions in the irradiation area are aligned along the first direction and the second direction, respectively.

3. The laser annealing device according to claim 2, characterized in that: In the first scan performed by the laser scanning unit, the laser is scanned linearly along the first direction between the two ends of the irradiation area, and in the second scan, the laser is scanned along the second direction so that the position of the subsequent first scan is shifted. The irradiation position aligning unit adjusts the irradiation positions in the latter of the two first scans that are performed consecutively with the second scan interposed therebetween so as to be aligned with the irradiation positions in the former first scan along the second direction.

4. The laser annealing device according to claim 3, characterized in that: The laser annealing device further includes a starting position setting unit, which sets the irradiation position inscribed in the periphery of the irradiation area as a starting position of the first scanning in the irradiation area. In at least one of the second and subsequent first scans in the irradiation region, the irradiation position aligning unit sets the irradiation position at the end portion located on the start position side so as not to be inscribed in the periphery of the irradiation region.

5. A laser annealing method, which irradiates a laser on an irradiated area on a processed object to perform an annealing process, wherein the laser annealing method is characterized by performing the following steps: Scanning the laser so as to sequentially irradiate different irradiation positions in the irradiation area; and The irradiation positions in the scanning are adjusted so that the different irradiation positions in the irradiation area are aligned along a first direction and a second direction that intersect each other.

6. A storage medium storing a laser annealing program for irradiating an irradiation area on a workpiece with a laser to perform an annealing process, characterized in that: The laser annealing program is executed by a computer to perform the following steps: Scanning the laser so as to sequentially illuminate different irradiation positions in the irradiation area; and The irradiation positions in the scanning are adjusted so that the different irradiation positions in the irradiation area are aligned along a first direction and a second direction that intersect each other.

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