TW202404729A - Laser annealing apparatus, laser annealing method, and laser annealing program - Google Patents

Abstract

This laser annealing apparatus performs: a surface melting step for irradiating a semiconductor wafer with laser pulses LP oscillated by a pulse laser device and melting the surface of the semiconductor wafer by heating the surface thereof to a melting point or higher by means of a plurality of laser pulses (LP); and an activation step for irradiating the semiconductor wafer with the laser pulses (LP) consecutively from the surface melting step, and further heating the lower portion of the surface of the semiconductor wafer to a predetermined activation temperature or higher by means of the plurality of laser pulses (LP) for at least a predetermined time period, so that a dopant added to the lower portion of the surface of the semiconductor wafer is activated. In the activation step, a region up to 10 [mu]m below the surface of the semiconductor wafer is heated to 1,000 DEG C or higher over at least 10 [mu]s.

Description

Laser annealing device, laser annealing method, laser annealing program

The present invention relates to a laser annealing device and the like.

Patent Document 1 discloses a laser annealing technology that irradiates a semiconductor wafer with laser light oscillated by a laser device. In this technology, which aims at forming extremely shallow pn junctions, dopants added just below the surface of the semiconductor wafer are activated by irradiating laser light with an intensity that does not melt the semiconductor wafer. In addition, through the subsequent "low-temperature rapid thermal annealing", the crystal damage of the semiconductor wafer is repaired. [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Publication No. 2003-528462 [Patent Document 2] Japanese Patent Publication No. 2013-258288

[Problem to be solved by the invention]

In laser annealing, unlike Patent Document 1, it is also common to repair damage caused by ion implantation of dopants by melting the surface of the semiconductor wafer. In this way, laser annealing has two different functions: damage repair through melting of the surface of the semiconductor wafer and activation of dopants implanted in the semiconductor wafer. As disclosed in Patent Document 2, in order to effectively achieve surface melting and subsurface activation, a plurality of different types of laser light are required, and usually a plurality of different laser devices need to be prepared.

The present invention was made in view of these circumstances, and its object is to provide a laser that can effectively achieve melting of the surface of a semiconductor wafer and activation of the subsurface of the semiconductor wafer using a single pulse laser device. Annealing device, etc. [Technical means to solve problems]

In order to solve the above problems, a laser annealing device according to one aspect of the present invention performs a surface melting step, irradiating the semiconductor wafer with laser pulses oscillated by the pulse laser device, and using a plurality of laser pulses, the semiconductor wafer is The surface is heated to above the melting point and melted; and an activation step is followed by a surface melting step that continuously irradiates the semiconductor wafer with laser pulses, and further uses a plurality of laser pulses to heat the surface of the semiconductor wafer to Above a predetermined activation temperature, dopants added to the subsurface of the semiconductor wafer are activated.

In this method, through continuous surface melting steps and activation steps, a pulse laser device continuously irradiates the semiconductor wafer with laser pulses, while simultaneously performing surface melting and subsurface activation. Although the surface of the semiconductor wafer melted in the surface melting step will continue to be irradiated with laser pulses intermittently during the activation step, due to heat dissipation from the surface during non-pulse periods when the laser pulse is not irradiated, etc. The surface of the semiconductor wafer is prevented from becoming overheated during the activation step. Furthermore, the surface melting step and the activation step may overlap in time.

Another aspect of the present invention is a laser annealing method. The method includes: a surface melting step, in which the semiconductor wafer is irradiated with laser pulses oscillated by a pulse laser device, and a plurality of laser pulses are used to heat the surface of the semiconductor wafer above the melting point to melt it; and an activation step, Then the surface melting step continues to irradiate the semiconductor wafer with laser pulses, and further uses a plurality of laser pulses to heat the surface of the semiconductor wafer above the predetermined activation temperature within at least a predetermined time, and the activation is added to the semiconductor wafer. Dopants under the round surface.

Furthermore, any combination of the above constituent elements or any form in which the expressions are converted into methods, devices, systems, recording media, computer programs, etc. are also included in the present invention. [Effects of the invention]

According to the present invention, it is possible to effectively achieve melting of the surface of the semiconductor wafer and activation of the subsurface of the semiconductor wafer using a single pulse laser device.

Hereinafter, modes for implementing the present invention (hereinafter also referred to as embodiments) will be described in detail with reference to the drawings. In the description and/or drawings, the same or equivalent components, members, processes, etc. are denoted by the same reference numerals, and repeated descriptions are omitted. The scale and shape of each part shown in the drawings are set for convenience in order to simplify the description, and will not be interpreted restrictively unless otherwise mentioned. The embodiments are examples and do not limit the scope of the present invention in any way. All features described in the embodiments and their combinations are not necessarily limited to the essence of the present invention.

FIG. 1 is a perspective view schematically showing the structure of the laser annealing apparatus 1 according to the embodiment of the present invention. The laser annealing device 1 is a device that irradiates the semiconductor wafer 3 with laser pulses oscillated by the pulse laser device 2 to perform annealing treatment (heating treatment).

The semiconductor wafer 3 fixedly mounted on the wafer stage 31 can be driven in the x-direction as shown in the figure by the stage device 4 described below, integrally with the wafer stage 31 . In addition, the laser pulse (laser light) oscillated by the pulse laser device 2 can be scanned along the y direction orthogonal to the x direction by the galvano scanner 14 described below. The laser pulse (laser light) scanned in the y direction by the galvanometer scanner 14 is reflected by a mirror 16 to be described later, and is incident on the semiconductor wafer 3 along the z direction orthogonal to the x direction and the y direction.

Hereinafter, directions related to the structure and/or operation of the laser annealing apparatus 1 will be described based on a three-dimensional orthogonal coordinate system using the XYZ axes that are orthogonal to each other as coordinate axes. The x direction, which is the driving direction of the semiconductor wafer 3, is parallel to the X-axis direction (X direction), and the y direction, which is the scanning direction of the laser pulse (laser light), is parallel to the Y-axis direction (Y direction). As the laser pulse ( The z-direction (laser light) incident on the semiconductor wafer 3 is parallel to the Z-axis direction (Z-direction). Hereinafter, for the sake of convenience, the x direction and the X direction are also called the longitudinal direction, the y direction and the Y direction are also called the transverse direction, and the z direction and the Z direction are also called the height direction.

The pulse laser device 2 is a laser device that oscillates laser pulses at a frequency of 100 kHz or above. On the basis of fully obtaining the functions or effects described below of the laser annealing device 1 of this embodiment, the frequency of the laser pulse oscillated by the pulse laser device 2 is, for example, between 100 kHz and 10 MHz, preferably 500 kHz. and 5MHz, more preferably between 700kHz and 3MHz. In this embodiment, an example will be described in which the frequency of the laser pulse oscillated by the pulse laser device 2 is 800 kHz.

The pulse laser device 2 of this embodiment is composed of, for example, an optical fiber laser device that oscillates a laser pulse through an optical fiber. FIG. 2 schematically shows the structure of the optical fiber 20 as the main part of the optical fiber laser device and the principle of generation and amplification of the laser pulse LP in the optical fiber 20 . The optical fiber 20 includes a core 201 in the center, a first clad 202 provided around the core 201, and a second clad 203 provided around the first clad 202. The refractive index of the core 201 is higher than the refractive index of the first cladding 202 , and the refractive index of the first cladding 202 is higher than the refractive index of the second cladding 203 . That is, the refractive index of the optical fiber 20 is higher as it is closer to the central portion (core 201 ), and lower as it is closer to the peripheral portion (second cladding 203 ).

Excitation light EL generated by a light-emitting element such as a laser diode is incident from one end of the optical fiber 20 (for example, the left end in FIG. 2 ). This excitation light EL is totally reflected by the boundary surface between the first cladding 202 and the second cladding 203 and propagates inside the core 201 and the first cladding 202 . Each time the excitation light EL passes through the fiber core 201, it excites rare earth elements such as Yb added to the fiber core 201 and generates induced emission light that becomes the source of the laser pulse LP (laser light). The induced emission light generated in the fiber core 201 propagates inside the fiber core 201 while being totally reflected at the boundary surface between the fiber core 201 and the first cladding 202 . As will be described later, total reflection mirrors such as FBG (Fiber Bragg Grating) or reflecting mirrors such as output mirrors are formed at both ends of the fiber core 201, and the induced emission light repeatedly reflected between these reflecting mirrors reciprocates. While being amplified inside the fiber core 201, a laser pulse LP (laser light) is formed. The laser pulse LP is output out of the optical fiber 20 from an output mirror formed at one end of the fiber core 201 (for example, the right end in FIG. 2 ).

FIG. 3 schematically shows the structure of the pulse laser device 2 which is an optical fiber laser device having the optical fiber 20 shown in FIG. 2 . The pulse laser device 2 includes an excitation light supply unit 21, a laser light generation unit 22, and a laser light supply unit 23. The excitation light supply unit 21 includes one or more light-emitting elements 211 such as laser diodes that emit one or more sources of light for the excitation light EL. When a plurality of light-emitting elements 211 are provided, the light of each light is coupled to form the excitation light EL. Coupling part 212. The excitation light supply section 21 supplies the excitation light EL generated based on the light emitted from the light emitting element 211 to the laser light generation section 22 .

The laser light generating unit 22 includes the optical fiber 20 described above, which receives the supply of the excitation light EL from an input end (the left end in FIG. 3 ), and an input mirror 221 and an output mirror 222 formed at both ends thereof. The input mirror 221 and the output mirror 222 are both formed at both ends of the fiber core 201 by FBG, for example. It is preferable that the reflectance of the input mirror 221 provided on the input side (excitation light supply part 21 side) is higher than the reflectance of the output mirror 222 provided on the output side (laser light supply part 23 side). In particular, the input mirror 221 is preferably a total reflection mirror configured to totally reflect the induced emission light inside the fiber core 201 that is the source of the laser pulse LP (laser light) to the output side. The output mirror 222 reflects part of the induced emission light inside the fiber core 201 to the input side, and outputs the remaining part to the laser light supply unit 23 .

The laser light supply unit 23 includes an optical fiber 231 that guides the laser pulse LP (laser light) generated by the laser light generation unit 22 to the output point OP of the pulse laser device 2 . Furthermore, the output point of the laser light generating unit 22 may also be used as the output point OP of the pulse laser device 2, and in this case, there is no need to provide the laser light supply unit 23.

In FIG. 1 , laser pulse LP is emitted from the output point OP of the pulse laser device 2 in the X direction. The laser annealing apparatus 1 for guiding the laser pulse LP to the semiconductor wafer 3 to be irradiated includes a beam expander 11, a mirror 12, a beam shaping optical element 13, a galvanometer scanner 14, an fθ lens 15, and a mirror. 16.

The beam expander 11 adjusts the laser pulse LP (laser light) emitted from the output point OP of the pulse laser device 2 to a predetermined size (diameter). For example, when the cross section of the laser pulse LP (laser light) emitted from the output point OP of the pulse laser device 2 is substantially circular with a diameter D0, the beam expander 11 converts the cross section of the laser pulse LP (laser light). (usually enlarged) into a roughly circular shape with a predetermined diameter D1. The beam expander 11 is composed of a plurality of lenses 111, 112, and 113. Generally, the lens 111 is a convex lens, the lens 112 is a concave lens, and the lens 113 is a convex lens. However, the number or types of lenses and other optical elements constituting the beam expander 11 are arbitrary as long as the desired effect and/or effect of adjusting the size of the laser pulse LP can be obtained. For example, the beam expander 11 may be composed of two or more convex lenses and one or more concave lenses arranged in any order, or may be composed of only three or more convex lenses.

The reflecting mirror 12 reflects the laser pulse LP whose size has been adjusted by the beam expander 11 and changes its traveling direction from the X direction to the Y direction.

The beam shaping optical element 13 shapes the laser pulse LP whose size has been adjusted by the beam expander 11 to adjust its shape and/or intensity distribution. For example, the cross section of the laser pulse LP whose size is adjusted by the beam expander 11 has a substantially circular intensity distribution following a Gaussian distribution or a normal distribution, but is shaped into a substantially rectangular and substantially uniform shape by the beam shaping optical element 13 intensity distribution. This type of beam shaping optical element 13 is composed of, for example, a diffractive optical element (DOE: Diffractive Optical Element).

The galvanometer scanner 14 is a laser pulse scanning unit that scans the laser pulse LP shaped by the beam shaping optical element 13 along the y direction (Y direction). The galvanometer scanner 14 includes a galvanometer mirror 141 that can reflect the laser pulse LP and a motor 142 that drives the galvanometer mirror 141 to rotate around the Z-axis. By adjusting the rotation position or rotation angle around the Z-axis of the galvanometer mirror 141 by the motor 142, the laser pulse LP incident on the galvanometer mirror 141 can be reflected to any y-direction position.

Furthermore, the laser pulse scanning unit that scans the laser pulse LP along the y direction is not limited to the galvanometer scanner 14, and may also be a polygon mirror scanner equipped with a rotatably driven polygon mirror or MEMS (Micro Electro Mechanical Systems). : Micro-electromechanical system), reflective mirror, etc. In addition, the scanning direction of the laser pulse LP caused by the laser pulse scanning unit such as the galvanometer scanner 14 is not limited to the y direction (Y direction), and may be any direction such as the x direction (X direction) crossing the y direction (Y direction). The direction may also be two directions: x direction (X direction) and y direction (Y direction). As in the latter case, when the laser pulse scanning unit such as the galvanometer scanner 14 can scan the laser pulse LP in the xy plane (in the XY plane), that is, in the semiconductor wafer 3 surface, it is not necessary to provide The semiconductor wafer 3 and the stage device 4 of the wafer stage 31 are driven in the direction (X direction).

The fθ lens 15 focuses the laser pulse LP scanned in the y direction (Y direction) by the galvanometer scanner 14 onto the semiconductor wafer 3 to be annealed. The reflecting mirror 16 provided between the fθ lens 15 and the semiconductor wafer 3 reflects the laser pulse LP from the fθ lens 15 in the X direction and irradiates the semiconductor wafer 3 along the Z direction (z direction). The laser pulse LP focused on the semiconductor wafer 3 by the fθ lens 15 and the mirror 16 is scanned in the y direction by the galvanometer scanner 14 and moves along the Y direction within the surface of the semiconductor wafer 3 . The size of the laser pulse LP focused on the semiconductor wafer 3 can be designed arbitrarily, but for example, it is preferably between 0.10 mm square and 0.15 mm square, and further preferably between 0.12 mm square and 0.13 mm square. In addition, the scanning speed of the laser pulse LP on the surface of the semiconductor wafer 3 in the Y direction (and/or the driving speed of the semiconductor wafer 3 in the X direction by the stage device 4) can also be designed arbitrarily, but for example, it is preferably Between 100cm/s and 500cm/s, more preferably between 250cm/s and 350cm/s.

Furthermore, when the stage device 4 drives the semiconductor wafer 3 and the wafer stage 31 along the x direction (X direction), the laser pulse LP moves relatively along the X direction within the surface of the semiconductor wafer 3 . In this way, by combining the y-direction scanning of the laser pulse LP by the galvanometer scanner 14 and the x-direction driving of the semiconductor wafer 3 by the stage device 4, it is possible to scan in the xy plane (in the XY plane), that is, Laser pulse LP is scanned within 3 planes of the semiconductor wafer. Furthermore, the driving direction of the semiconductor wafer 3 by the stage device 4 is not limited to the x direction (X direction), and may be a direction intersecting the x direction (X direction) such as the y direction (Y direction), or may be the x direction. direction (X direction) and y direction (Y direction). When the stage device 4 can relatively drive the semiconductor wafer 3 with respect to the laser pulse LP in the xy plane (in the XY plane) as in the latter case, it is not necessary to provide a scanning laser along the y direction (Y direction), etc. A laser pulse scanning unit such as the galvanometer scanner 14 that emits the pulse LP.

FIG. 4 shows changes over time in the surface temperature of the semiconductor wafer 3 irradiated with various types of laser light. The solid line represents the surface temperature when irradiated with the laser pulse LP of a high frequency (800 kHz in the illustrated example) oscillated by the fiber laser device as the pulse laser device 2 of this embodiment. The dotted line represents the surface temperature when irradiated with the high peak power (usually several hundred kW) and low frequency (usually between 2 kHz and tens of kHz) laser pulses oscillated by conventional pulse oscillation laser devices. The dotted line represents the surface temperature when irradiated with low peak power (usually several kW) and low frequency laser light oscillated by conventional diode laser devices. In addition, the peak power refers to the value obtained by dividing the pulse energy by the pulse width.

The high peak power and low frequency laser pulses oscillated by the conventional pulse oscillation laser device indicated by the dotted line are used for the following purpose: to repair defects caused by ion implantation of dopants by melting the surface of the semiconductor wafer 3 of damage. When the semiconductor wafer 3 is made of common silicon, the surface is melted by heating to above its melting point (1,410°C). In the example shown in the figure, due to the high peak power laser pulse oscillated by the conventional pulse oscillation laser device indicated by the dotted line, the surface temperature of the semiconductor wafer 3 instantly rises to more than 1,500°C. Therefore, silicon with a melting point of 1,410°C is The surface of the formed semiconductor wafer 3 is melted and the damage is repaired. However, the conventional laser pulse has a low frequency, so the surface temperature of the semiconductor wafer 3 drops sharply immediately after the laser pulse is irradiated. Therefore, the inside or subsurface of the semiconductor wafer 3 in which the dopant is implanted is not sufficiently heated, and the dopant is not activated.

Therefore, in order to activate the dopant implanted in the semiconductor wafer 3, low peak power and low frequency laser light oscillated by the conventional diode laser device shown by the dotted line is used. The laser light has a low peak power, so it cannot heat the surface of the semiconductor wafer 3 above the melting point, but it can continue to heat the inside or the surface of the semiconductor wafer 3 to activate the implanted dopant. As described above, a pulse oscillation laser device (dashed line) is usually used for melting the surface of the semiconductor wafer 3 , and a diode laser device (dashed line) is used for activation of the subsurface of the semiconductor wafer 3 . Since different laser devices need to be prepared for annealing for different purposes, the laser annealing device will become larger or more expensive.

In contrast, according to the high-frequency laser pulse LP of this embodiment represented by the solid line, the surface of the semiconductor wafer 3 can be effectively melted by one pulse laser device 2 (fiber laser device, etc.) and activation under the surface of semiconductor wafer 3 . Specifically, the pulse laser device 2 of this embodiment performs a surface melting step (the "surface melting" period shown in the figure), and uses a plurality of laser pulses LP to heat the surface of the semiconductor wafer 3 to above the melting point. melting; and activation step (the "activation" period in the figure), and then the surface melting step continues to irradiate the semiconductor wafer 3 with laser pulses LP, and further, through a plurality of laser pulses LP, the surface of the semiconductor wafer 3 The temperature is raised above a predetermined activation temperature for at least a predetermined period of time to activate the dopant added to the subsurface of the semiconductor wafer 3 .

In the surface melting step, by intermittently irradiating a plurality of laser pulses LP at a high frequency (800 kHz in the illustrated example), the surface temperature of the semiconductor wafer 3 rises above the melting point (1,410° C.). Therefore, the surface of the semiconductor wafer 3 is melted, and damage caused by ion implantation of dopants or the like is repaired. Furthermore, as shown in the figure, each laser pulse LP does not have sufficient power to heat the surface of the semiconductor wafer 3 to above the melting point, but it accumulates heat on the semiconductor wafer 3 by irradiating it at a high frequency. As a result, the surface temperature rises above the melting point. The surface melting step starts when the surface temperature of the semiconductor wafer 3 rises above the melting point, and ends when the surface temperature of the semiconductor wafer 3 drops below the melting point.

As described above, the laser pulse LP is scanned along the Y direction (y direction) on the semiconductor wafer 3 by the galvanometer scanner 14 as the laser pulse scanning unit. However, the laser pulse LP has a width along the Y direction. The time required for the LP to pass a point on the semiconductor wafer 3 is substantially the same as the time of the surface melting step. Strictly speaking, since there is a time from when the laser pulse LP starts to contact a point on the semiconductor wafer 3 until the surface temperature reaches the melting point, and a time when the surface temperature drops below the melting point after the laser pulse LP passes through a point on the semiconductor wafer 3, Therefore there will be a slight time difference.

In the activation step, by continuously irradiating the semiconductor wafer 3 with laser pulse LP following the surface melting step, the temperature inside or below the surface of the semiconductor wafer 3 in which the dopant is implanted is raised to a predetermined activation temperature or above, and the dopant is doped. The impurities are activated. The activation temperature may vary depending on the type of dopant or the material of the semiconductor wafer 3 (silicon, silicon carbide, gallium nitride, etc.), but the most common silicon semiconductor wafer 3 has receptors such as boron (P type dopant) is typically about 1,000°C. In addition, in order to fully activate the dopant added inside or under the surface of the semiconductor wafer 3 , it is necessary to maintain the temperature of the region above the activation temperature for a predetermined period of time. The predetermined time may vary depending on the type or amount of dopant and the material of the semiconductor wafer 3 , but is usually about 10 μs. In this way, in the activation step, the general target is to make the area inside or below the surface of the semiconductor wafer 3 in which the dopant is implanted (usually the area up to 10 μm below the surface of the semiconductor wafer 3) within at least 10 μs. Raise the temperature to above 1000℃.

The activation step starts when the temperature of the activation region under the surface of the semiconductor wafer 3 in which the dopant is implanted rises above the activation temperature, and ends when the temperature of the activation region drops below the activation temperature. . FIG. 4 showing the surface temperature of the semiconductor wafer 3 does not show the temperature of the activation region below the surface, so the start time point and the end time point of the activation step are shown as a reference. Typically, as shown in the figure, the activation step is shorter than the surface melting step. In addition, the start time of the activation step is usually later than the start time of the surface melting step. Furthermore, the end time point of the activation step is substantially the same as the end time point of the surface melting step. However, strictly speaking, the temperature of the activation region within the semiconductor wafer 3 involved in the activation step is less likely to drop than the temperature of the surface of the semiconductor wafer 3 involved in the surface melting step, so it is considered that the end time of the activation step The point (where the activation area is cooled down to less than the activation temperature) will be slightly later than the end of the surface melting step (when the surface is cooled down to less than the melting point).

Furthermore, when the dopant dose added to the activation region is larger than usual or when the activation region is deeper than 10 μm, the activation step may be set to be longer than 10 μs. Specifically, by slowing down the scanning speed of the laser pulse LP in the Y direction (y direction) by the galvanometer scanner 14 as the laser pulse scanning unit, the activation step can be lengthened. Alternatively, the same effect can be obtained by setting the oscillation frequency of the laser pulse LP of the pulse laser device 2 to be higher than 800 kHz. If the activation step is prolonged, the surface melting step will inevitably be prolonged. However, due to heat dissipation from the surface of the semiconductor wafer 3 during the non-pulse period when the intermittent laser pulse LP is not irradiated, the surface of the semiconductor wafer 3 is prevented from being damaged. It becomes an overheated state (in the example in the figure, the surface temperature is controlled below 2,000°C). In this way, according to the present embodiment, the surface melting step can be appropriately performed without depending on the length of the activation step.

According to this embodiment, through continuous surface melting steps and activation steps, one pulse laser device 2 continuously irradiates the semiconductor wafer 3 with laser pulses LP, so that surface melting and subsurface activation can be performed simultaneously.

The present invention has been described above based on the embodiments. Combinations of each component or each process in the illustrated embodiments may have various modifications, and it is obvious to those skilled in the art that such modifications are included in the scope of the present invention.

Furthermore, the configuration, action, and function of each device or each method described in the embodiments can 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 can be used. As software resources, programs such as operating systems and applications can be used, for example. This application claims priority based on Japanese Patent Application No. 2022-114798 filed on July 19, 2022. The entire contents of this Japanese application are incorporated by reference into this specification.

1: Laser annealing device 2: Pulse laser device 3: Semiconductor wafer 4: Carrier device 11: Beam expander 13: Beam shaping optical components 14: Galvanometer Scanner 20: Optical fiber 22: Laser light generation part LP: laser pulse

[Fig. 1] is a perspective view schematically showing the structure of a laser annealing apparatus. [Fig. 2] schematically shows the structure of an optical fiber as a main part of the optical fiber laser device and the principle of generation and amplification of laser pulses in the optical fiber. [Fig. 3] schematically shows the structure of a pulse laser device as a fiber laser device. [Fig. 4] schematically shows changes over time in the surface temperature of a semiconductor wafer irradiated with various types of laser light.

LP: laser pulse

Claims (6)

A laser annealing device performs the following steps: The surface melting step is to irradiate the semiconductor wafer with laser pulses oscillated by the pulse laser device, and through a plurality of the aforementioned laser pulses, the surface of the aforementioned semiconductor wafer is heated to above the melting point and melted; and The activation step is to irradiate the semiconductor wafer with the laser pulse following the surface melting step, and further use a plurality of the laser pulses to raise the temperature under the surface of the semiconductor wafer to a predetermined activation level within at least a predetermined time. Above the temperature, the dopant added under the surface of the semiconductor wafer is activated. The laser annealing device of claim 1, wherein, The pulse laser device oscillates the laser pulse at a frequency of 100 kHz or above. The laser annealing device of claim 1, wherein, The aforementioned pulse laser device is a fiber laser device that oscillates the aforementioned laser pulse through an optical fiber. The laser annealing device of any one of claims 1 to 3, wherein, The aforementioned activation step is to raise the temperature of a region up to 10 μm below the surface of the semiconductor wafer to 1000° C. or higher within at least 10 μs. A laser annealing method, which includes: The surface melting step is to irradiate the semiconductor wafer with laser pulses oscillated by the pulse laser device, and through a plurality of the aforementioned laser pulses, the surface of the aforementioned semiconductor wafer is heated to above the melting point and melted; and The activation step is to irradiate the semiconductor wafer with the laser pulse following the surface melting step, and further use a plurality of the laser pulses to raise the temperature under the surface of the semiconductor wafer to a predetermined activation level within at least a predetermined time. Above the temperature, the dopant added under the surface of the semiconductor wafer is activated. A laser annealing program that causes a computer to perform the following steps: The surface melting step is to irradiate the semiconductor wafer with laser pulses oscillated by the pulse laser device, and through a plurality of the aforementioned laser pulses, the surface of the aforementioned semiconductor wafer is heated to above the melting point and melted; and The activation step is to irradiate the semiconductor wafer with the laser pulse following the surface melting step, and further use a plurality of the laser pulses to raise the temperature under the surface of the semiconductor wafer to a predetermined activation level within at least a predetermined time. Above the temperature, the dopant added under the surface of the semiconductor wafer is activated.

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