JP2008251839A - Laser annealing method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form extremely shallow junction with shallow junction and without a crystal-defect. <P>SOLUTION: Pulse width of a pulse laser beam 6 and moving speed of a semiconductor substrate are controlled so that total irradiation time of the laser beam per unit region in a surface layer part is within a range of 1 μs to 999 μs and the number of irradiating times becomes not more than the prescribed number of times with a condition that the surface layer part in which impurities (ions) are implanted is not melted. The surface layer part is irradiated with the pulse laser beam 6. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a laser annealing method and a laser annealing apparatus, and more particularly to a technique effective for forming an ultra shallow junction of a MOS field effect transistor.

  In a MOS field effect transistor (hereinafter referred to as MOSFET), an impurity diffusion region adjacent to the source / drain region and having a shallow depth from the substrate surface is called an ultra-shallow junction (or extension region). The ultra-shallow junction serves to prevent a gate deterioration phenomenon due to generation of a high electric field when the FET is operated.

  In order to form the ultra-shallow junction of the MOSFET, an impurity implantation step of implanting impurities such as arsenic (As) ions, phosphorus (P) ions, boron (B) ions, etc. into the silicon wafer and electrically activating the impurities At the same time, a heat treatment step for removing crystal defects caused by impurity implantation is required. The latter heat treatment step is usually called activation annealing. In conventional activation annealing, an annealing method using a halogen lamp has been adopted. Note that the “removal of crystal defects” can be rephrased as “restoration of crystallinity”.

  In recent years, with the high integration of semiconductor integrated circuits due to the miniaturization of MOSFETs, the demand for ultra-shallow junctions of MOSFETs has become strict. For this reason, in the annealing method using the halogen lamp described above, the annealing time (heating time) is as long as several seconds, so that there is a problem that impurities diffuse to a deep region.

  In view of such a problem, an annealing method using a xenon flash lamp or a pulse laser has been developed (refer to Patent Document 1 below regarding the latter method). The former can achieve an annealing time of milliseconds, and the latter can achieve nanoseconds. However, in order to put an ultra-fine MOSFET having a technology node of 45 nm or less into practical use, a technology for forming an ultra-shallow junction having a low resistance and a junction depth of less than 20 nm is required. In such an ultra-fine MOSFET, In the annealing time of milliseconds, there is a problem that impurities are diffused to a deep region.

  On the other hand, in the annealing method using a pulse laser, it is difficult to adjust the nanosecond pulse width (laser irradiation time for one pulse), and the laser irradiation time is short. There is a problem that the annealing time necessary for removing the defect cannot be obtained. In addition, in order to obtain an annealing time necessary for removing crystal defects, it is conceivable to irradiate a pulsed laser so that the total irradiation time becomes microseconds. In order to make the total irradiation time on the order of microseconds, the number of irradiation times of about 1000 to 100,000 times is required. When the same position is irradiated with pulsed laser light, the effect of the heating due to the previous irradiation remains because the pulse interval is short, and the initial temperature of the irradiated part rises with each irradiation. If this is done, even if laser light of constant energy is always irradiated, the annealing temperature may rise too much due to the effect of heat storage, and silicon may melt, and a good annealing effect cannot be expected.

Further, in response to the above problems, research on a method of obtaining a microsecond annealing time using a continuous wave laser has been recently conducted. However, this method also has the following problems.
In laser annealing, the laser irradiation position is usually fixed and the laser is scanned by moving the substrate, but the substrate is transported at a very high speed (for example, several m / s) in order to obtain a microsecond annealing time. This is difficult at present.
In Patent Document 2 below, a technique for scanning the laser at high speed by fixing the position of the substrate and moving the irradiation position of the laser at high speed is proposed. However, there is a problem with lens accuracy and scanning optical system. As a result, the laser shape changes when the laser is scanned, so that there is a problem that the annealing process is not performed accurately and uniformly.

JP-A-2005-101196 JP-T-2006-505953

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a laser annealing method and a laser annealing apparatus capable of forming an ultra-shallow junction having a shallow junction depth and no crystal defects.

In order to solve the above problems, the laser annealing method and laser annealing apparatus of the present invention employ the following means.
(1) The present invention is a laser annealing method for irradiating a laser beam onto a surface layer portion where ions as impurities of a semiconductor substrate are implanted, and oscillating a continuous laser beam from a continuous laser oscillator. The laser beam is modulated into a pulse laser beam by a modulator, and the semiconductor substrate is moved so that the pulse laser beam is scanned on the surface of the semiconductor substrate. And controlling the pulse width of the pulse laser beam and the moving speed of the semiconductor substrate so that the total irradiation time of the laser beam is in the range of 1 μsec to 999 μsec and the number of irradiations is not more than a predetermined number, And irradiating with the pulsed laser beam.

(2) Further, the present invention is a laser annealing apparatus for irradiating a laser beam onto a surface layer portion into which ions as impurities of a semiconductor substrate are implanted, and a continuous laser oscillator that oscillates a continuous laser beam; A beam shaper that focuses laser light from the continuous laser oscillator on the surface of the semiconductor substrate, a modulator that modulates the continuous laser light into pulsed laser light, and the pulsed laser light scans the surface of the semiconductor substrate. And a transfer stage for moving the semiconductor substrate, and the total irradiation time of the laser light per unit region of the surface layer portion is within a range of 1 μsec to 999 μsec under the condition that the surface layer portion is not melted. Control the pulse width of the pulse laser beam and the moving speed of the semiconductor substrate so that the number of times of irradiation is equal to or less than the predetermined number of times, and irradiate the surface layer part with the pulse laser beam It is characterized by.

According to the laser annealing method and apparatus of the present invention described above, the total irradiation time of the laser light per unit region of the surface layer portion under the condition that the surface layer portion into which the impurity (ion) is implanted does not melt while moving the semiconductor substrate. The pulse width and the moving speed of the semiconductor substrate are controlled so that the pulse width and the moving speed of the semiconductor substrate are within the range of 1 μsec to 999 μsec, and the surface layer portion is irradiated with the pulse laser light, which is realized by a conventional method using a flash lamp or simply a pulse laser. An annealing time of microseconds that could not be achieved can be realized. Therefore, it is possible to ensure an annealing time sufficient to remove crystal defects generated during impurity implantation without diffusing the impurities to a deep region, so that the junction depth is shallow and there is no crystal defect. A bond can be formed.
Also, the pulse width and the moving speed of the semiconductor substrate are controlled so that the number of irradiations per unit area is less than or equal to the predetermined number of times, and the surface layer part is irradiated with pulsed laser light, thus suppressing the effect of heat storage and increasing the temperature. Overpass can be avoided.
Further, since the laser beam is scanned on the surface of the semiconductor substrate by moving the semiconductor substrate, it has been conventionally used without using a scanning optical system that is required in the technique of Patent Document 2 and is difficult to manufacture. The substrate stage can be applied as it is.

(3) In the laser annealing method and apparatus of the present invention, the modulator uses an acousto-optic element, an electro-optic element or a magneto-optic element, or mechanically switches between passing and blocking of laser light. It is a shutter.

  With the modulators listed above, continuous laser light can be modulated into pulse laser light having a desired pulse width.

(4) Further, the present invention is a laser annealing method for annealing by irradiating a laser beam onto a surface layer portion into which ions as impurities of a semiconductor substrate are implanted, and oscillating a pulse laser beam from a semiconductor laser, The semiconductor substrate is moved so that pulsed laser light is scanned on the surface of the semiconductor substrate, and the total irradiation time of the laser light per unit region of the surface layer part is 1 μs to 999 μs under the condition that the surface layer part is not melted. The surface layer portion is irradiated with the pulsed laser light by controlling the pulse width of the pulsed laser light and the moving speed of the semiconductor substrate so that the number of times of irradiation is within a predetermined range and less than a predetermined number of times. .

(5) Further, the present invention is a laser annealing apparatus for irradiating a laser beam onto a surface layer portion into which ions as impurities of a semiconductor substrate are implanted, the semiconductor laser oscillating a pulse laser beam, A beam shaper for condensing pulse laser light from a semiconductor laser on the surface of the semiconductor substrate; and a transport stage for moving the semiconductor substrate so that the pulse laser light is scanned on the surface of the semiconductor substrate. The pulse of the pulsed laser light so that the total irradiation time of the laser light per unit region of the surface layer portion is in the range of 1 μsec to 999 μsec and the number of irradiation times is a predetermined number or less under the condition that the surface layer portion does not melt The width and the moving speed of the semiconductor substrate are controlled to irradiate the surface layer portion with the pulsed laser light.

According to the laser annealing method and apparatus described above, as in the method (1) and apparatus (2) above, an extremely shallow junction having a shallow junction depth and no crystal defects can be formed. The substrate stage thus obtained can be applied as it is.
In addition, since a semiconductor laser is used as the laser light source, it is not necessary to use a large-scale laser transmitter, the apparatus configuration can be simplified, and the apparatus can be miniaturized.

  According to the present invention, it is possible to obtain an excellent effect that an extremely shallow junction having a shallow junction depth and no crystal defects can be formed.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

[First Embodiment]
FIG. 1 is a diagram showing an overall schematic configuration of a laser annealing apparatus A according to the first embodiment of the present invention.
As shown in FIG. 1, the laser annealing apparatus A is an apparatus for irradiating the surface layer portion of the semiconductor substrate 1 into which impurities are implanted by irradiating laser light 6 and is a continuous laser that oscillates a continuous laser light 3a. An oscillator 3, a beam shaper 5 for condensing laser light from the continuous laser oscillator 3 on the surface of the semiconductor substrate 1, a modulator 4 for modulating the continuous laser light 3 a into pulsed laser light 6, and the surface of the semiconductor substrate 1 A transfer stage 2 for moving the semiconductor substrate 1 so as to be scanned with the pulse laser beam 6 is provided.

The semiconductor substrate 1 is, for example, a silicon wafer, and the impurities are, for example, arsenic (As) ions, phosphorus (P) ions, boron (B) ions, and the like.
The continuous laser oscillator 3 is not particularly limited as long as it can oscillate the continuous laser light 3a. Examples of such a continuous laser oscillator 3 include excimer lasers, solid lasers such as YAG, YLF, and YVO ₄ , semiconductor lasers, and CO ₂ lasers. More specifically, an excimer laser having a wavelength of 248 nm or 308 nm, a YAG laser having a wavelength of 1064 nm, 532 nm or 355 nm, a semiconductor laser (laser diode) having a wavelength of 600 nm to 1000 nm, and a CO ₂ laser having a wavelength of 10.6 μm are exemplified.

  As shown in FIG. 2, in the laser annealing, the laser beam 6 is usually shaped into a linear beam and condensed on the surface of the semiconductor substrate 1. Therefore, the beam shaper 5 is preferably one that can shape the laser light 6 into a linear shape. When the linear beam is considered as an elongated rectangular beam as shown in FIG. 2, the short dimension 9 is, for example, several tens of micrometers to several hundreds of micrometers, and the long dimension 10 is, for example, 50 mm to 100 mm. In the example shown in FIG. 2, the long dimension 10 of the linear beam is shorter than the diameter of the semiconductor substrate 1. The beam shaper 5 capable of shaping laser light into a linear beam as described above is well known in the art and will not be described in detail. However, the beam shaper 5 is constituted by a beam expander, a cylindrical lens, a cylindrical lens array, or the like. preferable.

  The modulator 4 is not particularly limited as long as it can modulate the continuous laser beam 3 into a pulse laser beam 6 having a desired pulse width. However, the modulator 4 uses an acousto-optic element, an electro-optic element or a magneto-optic element, or A high-speed shutter that mechanically switches between passing and blocking the laser beam is preferable. Note that the pulse width means the irradiation time of laser light for one pulse.

The acoustooptic device can be applied to a modulator 5 that converts continuous light incident from the outside into pulsed light using an acoustooptic effect. The acousto-optic effect means that when ultrasonic waves propagate in solids and liquids, the medium has a periodic refractive index for light that is parallel to the direction of sound propagation and has a period of sound wavelength due to the photoelastic effect. A phenomenon in which fluctuation occurs and a part of the light incident on this medium is diffracted.
As the acoustooptic device, LiNbO that transmits ultrasonic waves to an optical crystal such as chalcogenide glass such as As ₁₂ Ge ₃₃ Se ₅₅ and As ₂ Se ₃ , Te glass, PbMoO ₄ , TeO ₂ , Ge, LiNbO ₃ , and GaP. _3. An example is one in which a piezoelectric thin film transducer such as ZnO is attached and a high frequency voltage is applied to generate a high frequency sound wave in the crystal.
If linearly polarized continuous laser light 3a is input to the acoustooptic device and the voltage applied to the transducer of the acoustooptic device is a predetermined pulse, the continuous laser beam that passes through the acoustooptic device is converted into diffracted light when applied, When applied, it can be converted to transmitted light. If only the diffracted light or only transmitted light is put in the optical path, it can be modulated into pulse laser light 6 having a desired pulse width. Here, the linearly polarized continuous laser beam 3a to the acoustooptic device is incident on the ultrasonic wavefront generated in the acoustooptic device so as to satisfy the Bragg reflection condition.

The electro-optic element can be applied to a modulator 4 that converts continuous light incident from the outside into pulsed laser light 6 by utilizing an electro-optic effect. The electro-optic effect is a phenomenon in which birefringence occurs when an electric field is applied to a crystalline material such as LiNbO ₃ , KDP (KH ₂ PO ₄ ), or ADP, and the phase of light passing through the material changes.
When linearly polarized continuous laser light is input to the electro-optic element and a voltage is applied to the electro-optic element, a constant polarization angle can be given to the continuous laser light 3a. Therefore, if the voltage applied to the electro-optic element is a predetermined pulse, the continuous laser beam 3a that passes through the electro-optic element is an ordinary ray whose polarization direction does not change when not applied, and an extraordinary ray whose polarization direction changes when applied. It can be. Then, a deflection filter that allows passage of only the light beam that coincides with the polarization direction of one of the ordinary light beam and the extraordinary light beam is provided on the laser light emission side of the electro-optic element, and only the ordinary light beam or the extraordinary light beam is the optical path. In this case, the pulse laser beam 6 having a desired pulse width can be modulated.

The magneto-optical element can be applied to the modulator 4 that converts the continuous laser light 3 a incident from the outside into the pulsed laser light 6 by using the magneto-optical effect. The magneto-optical effect is a phenomenon in which a difference in refractive index between the magnetic field direction and the vertical direction, that is, birefringence occurs when a magnetic field is applied from a direction perpendicular to the traveling direction of linearly polarized light.
When linearly polarized continuous laser light 3a is input to the magneto-optical element and a magnetic field is applied to the magneto-optical element, a constant polarization angle can be given to the continuous laser light 3a. Therefore, if the magnetic field applied to the magneto-optic element is a predetermined pulse, the continuous laser light 3a that passes through the magneto-optic element can be an ordinary ray when not applied and an extraordinary ray whose polarization direction changes when applied. . Then, a deflection filter is provided on the laser light emitting side of the magneto-optical element to pass only a ray that matches one of the polarization directions of the ordinary ray and the extraordinary ray, and only the ordinary ray or only the extraordinary ray is used in the optical path. If it is inserted, it can be modulated into a pulse laser beam 6 having a desired pulse width. A polarization angle can be expanded by introducing a birefringent crystal after the magneto-optical element.

  The transfer stage 2 has a function of placing the semiconductor substrate 1 on the upper surface and moving it two-dimensionally in a horizontal plane. As shown in FIG. 2, in this embodiment, the transfer stage 2 can move in the X direction that matches the short direction of the linear beam and in the Y direction that matches the long direction of the linear beam. Therefore, by moving the transfer stage 2 in the X direction and the Y direction, the pulse laser beam 6 can be scanned on the surface of the semiconductor substrate 1 placed thereon. More specifically, as shown in FIG. 2, when the long dimension 10 of the linear beam is shorter than the diameter of the semiconductor substrate 1, the semiconductor substrate 1 is irradiated with the laser beam 6 on the surface of the semiconductor substrate 1. Is moved to one side in the X direction, and the semiconductor substrate 1 is moved in the Y direction so that the irradiated portion of the laser beam 6 is shifted to the non-irradiated portion side by the long dimension 10 when irradiated to the end of the semiconductor substrate 1. Then, by moving the semiconductor substrate to the other side in the X direction and repeating such an operation, the entire surface of the semiconductor substrate 1 can be irradiated with the laser beam 6.

The laser annealing apparatus A further includes a control device 14 that controls the modulator 4 and the transport stage 2. The control device 14 is configured so that the total irradiation time of the laser light 6 per unit region of the surface layer portion is within a range of 1 μsec to 999 μsec and the number of irradiation times is equal to or less than a predetermined number of times under the condition that the surface layer portion does not melt. The continuous laser transmitter 3 (specifically, the pulse width of the pulsed laser beam 6) and the transfer stage 2 (specifically, the moving speed of the semiconductor substrate 1) are controlled.
Here, the predetermined number of times can be arbitrarily set, and is preferably within 5 times, for example, in order to suppress the effect of heat storage.

  In addition, it is preferable that the conveyance stage 2 exists in the irradiation chamber 12 from a viewpoint of dust prevention or prevention of the oxide film production | generation on a substrate surface. In that case, the continuous laser oscillator 3, the modulator 4, and the beam shaper 5 are arranged outside the irradiation chamber 12, and the pulsed laser light 6 to the semiconductor substrate 1 on the transfer stage 2 is transmitted above the irradiation chamber 12. Irradiation is performed through an irradiation window 13 included in the. Further, the method of the irradiation chamber 12 is not particularly limited, but a method of filling the chamber with a vacuum or an inert gas atmosphere, and a method of purging the irradiated portion of the laser light 6 by inert gas injection are exemplified.

  According to the above-described embodiment, the total irradiation time of the laser light per unit region of the surface layer portion is 1 μsec to 999 μsec under the condition that the surface layer portion into which the impurity is implanted is not melted while moving the semiconductor substrate 1. By controlling the pulse width of the pulse laser beam 6 and the moving speed of the semiconductor substrate 1 so as to be within the range and irradiating the surface layer portion with the pulse laser beam 6, the conventional method using a flash lamp or simply a pulse laser is used. Microsecond annealing time that could not be realized can be realized. Therefore, it is possible to ensure an annealing time sufficient to remove crystal defects generated during impurity implantation without diffusing the impurities to a deep region, so that the junction depth is shallow and there is no crystal defect. A bond can be formed.

  In addition, the pulse width and the moving speed of the semiconductor substrate 1 are controlled so that the number of times of irradiation per unit region is equal to or less than the predetermined number, and the surface layer portion is irradiated with the pulsed laser light 6, so that the effect of heat storage is suppressed, It is possible to avoid an excessive increase in the temperature of the irradiated part.

  In addition, since the laser beam 6 is scanned on the surface of the semiconductor substrate 1 by moving the semiconductor substrate 1, the conventional technique can be used without using a scanning optical system that is difficult to manufacture, which is required in the technique of Patent Document 2. The transfer stage 2 that has been used can be applied as it is.

[Second Embodiment]
FIG. 3 is a diagram showing an overall schematic configuration of a laser annealing apparatus B according to the second embodiment of the present invention.
As shown in FIG. 3, the laser annealing apparatus B of the second embodiment replaces the continuous laser oscillator 3 and the modulator 4 in the first embodiment with a semiconductor laser (laser diode) 11 that oscillates pulsed laser light 6. It is a form. The pulse width and pulse frequency of the pulsed laser beam 6 oscillated by the semiconductor laser 11 can be arbitrarily adjusted according to the ON / OFF timing of the voltage applied to the semiconductor laser 11. The control of the ON / OFF timing is performed by the control device 14. About another structure, it is the same as that of 1st Embodiment.

  The laser annealing apparatus B configured as described above has a total irradiation time of the laser light per unit region of the surface layer portion within a range of 1 μsec to 999 μsec under the condition that the surface layer portion into which the impurity of the semiconductor substrate 1 is implanted does not melt. By controlling the pulse width of the pulsed laser light 6 and the moving speed of the semiconductor substrate 1 so that the number of times of irradiation is a predetermined number or less, the surface layer part is irradiated with the pulsed laser light 6.

According to the present embodiment, as in the first embodiment, an ultra-shallow junction having a shallow junction depth and no crystal defects can be formed, and the conventionally used transfer stage 2 can be applied as it is. In addition, the effect of heat storage can be suppressed, and an excessive increase in the temperature of the irradiated site can be avoided.
In this embodiment, since the semiconductor laser 11 is used as the laser light source, it is not necessary to use a large-scale laser transmitter, the apparatus configuration can be simplified, and the apparatus can be downsized.

1 is a diagram showing an overall schematic configuration of a laser annealing apparatus A according to a first embodiment of the present invention. It is the figure which showed typically the operation | movement of the pulse laser and the conveyance stage in the laser annealing method and laser annealing apparatus of this invention. It is a figure which shows the whole schematic structure of the laser annealing apparatus B concerning 2nd Embodiment of this invention.

Explanation of symbols

A, B Laser annealing apparatus 1 Semiconductor substrate 2 Transport stage 3 Laser oscillator 3a Continuous laser beam 4 Modulator 5 Beam shaper 6 Pulse laser beam 9 X-axis dimension in the transport direction of the transport stage 10 Y-axis dimension in the transport direction of the transport stage 11 Semiconductor laser (laser diode)
12 Irradiation chamber 13 Irradiation window 14 Control device

Claims (6)

A laser annealing method for annealing by irradiating a surface layer portion into which ions as impurities of a semiconductor substrate are implanted with laser light,
A continuous laser beam is oscillated from a continuous laser oscillator, the continuous laser beam is modulated into a pulsed laser beam by a modulator, the semiconductor substrate is moved so that the pulsed laser beam is scanned on the surface of the semiconductor substrate, and the surface layer The pulse width of the pulse laser beam and the pulse width of the pulsed laser light so that the total irradiation time of the laser light per unit region of the surface layer portion is in the range of 1 μsec to 999 μsec and the number of irradiation times is a predetermined number or less under the condition that the portion does not melt A laser annealing method, wherein the moving speed of a semiconductor substrate is controlled to irradiate the surface layer portion with the pulsed laser light.   2. The laser annealing method according to claim 1, wherein the modulator is an acousto-optic element, an electro-optic element or a magneto-optic element, or a high-speed shutter that mechanically switches between passing and blocking of laser light. A laser annealing method for annealing by irradiating a surface layer portion into which ions as impurities of a semiconductor substrate are implanted with laser light,
Pulsed laser light is oscillated from a semiconductor laser, the semiconductor substrate is moved so that the pulsed laser light is scanned on the surface of the semiconductor substrate, and the laser light per unit region of the surface layer part under the condition that the surface layer part does not melt The pulse width of the pulse laser beam and the moving speed of the semiconductor substrate are controlled so that the total irradiation time of the laser beam is within a range of 1 μsec to 999 μsec and the number of irradiations is a predetermined number or less, and the pulse is applied to the surface layer portion. A laser annealing method characterized by irradiating a laser beam. A laser annealing apparatus that anneals by irradiating a laser beam to a surface layer portion into which ions as impurities of a semiconductor substrate are implanted,
A continuous laser oscillator that oscillates continuous laser light;
A beam shaper that focuses laser light from the continuous laser oscillator on the surface of the semiconductor substrate;
A modulator for modulating the continuous laser light into pulsed laser light;
A transport stage for moving the semiconductor substrate so that the pulsed laser beam is scanned on the surface of the semiconductor substrate,
The pulse width of the pulsed laser light so that the total irradiation time of the laser light per unit region of the surface layer portion is in the range of 1 μsec to 999 μsec and the number of irradiation times is equal to or less than the predetermined number of times under the condition that the surface layer portion does not melt. And a laser annealing apparatus for controlling the moving speed of the semiconductor substrate and irradiating the surface layer portion with the pulsed laser light.   The laser annealing apparatus according to claim 4, wherein the modulator is an acousto-optic element, an electro-optic element or a magneto-optic element, or a high-speed shutter that mechanically switches between passing and blocking of laser light. A laser annealing apparatus that anneals by irradiating a laser beam to a surface layer portion into which ions as impurities of a semiconductor substrate are implanted,
A semiconductor laser that oscillates pulsed laser light;
A beam shaper that focuses the pulsed laser light from the semiconductor laser onto the surface of the semiconductor substrate;
A transport stage for moving the semiconductor substrate so that the pulsed laser beam is scanned on the surface of the semiconductor substrate,
The pulse width of the pulsed laser light so that the total irradiation time of the laser light per unit region of the surface layer portion is in the range of 1 μsec to 999 μsec and the number of irradiation times is equal to or less than the predetermined number of times under the condition that the surface layer portion does not melt. And a laser annealing apparatus for controlling the moving speed of the semiconductor substrate and irradiating the surface layer portion with the pulsed laser light.

Images