TW201351504A - Laser, annealing apparatus and method - Google Patents

Abstract

The present invention is a laser annealing device which anneals an amorphous silicon film (5) by irradiating the amorphous silicon film (5) with laser light. The laser annealing device comprises: a first pulse laser (6) for generating first laser light (L1) with a prescribed pulse width and a prescribed wavelength; a second pulse laser (7) for generating second laser light (L2) with a pulse width and a wavelength that are longer than those of said first laser light (L1); a synthesizing means (8) for synthesizing said first laser light (L1) and said second laser light (L2) into light having the same optical axis; and a control means (3) for controlling the timing for the emission of the first and second laser light (L1, L2) by operating said first and second pulse lasers (6, 7). The control means (3) controls said first pulse laser (6) such that said first laser light (L1) is emitted at a prescribed timing within the pulse width of said second laser light (L2).

Description

Laser annealing device and laser annealing method

The present invention relates to a laser annealing device for irradiating laser light to an amorphous germanium film for annealing treatment, and more particularly to a laser annealing device and a lightning device for improving the utilization efficiency of laser energy and performing annealing treatment with good efficiency. Shot annealing method.

The conventional laser annealing apparatus irradiates each of the intermittently irradiated laser light to an island-shaped plurality of annealed films formed on the main surface of the substrate, thereby performing annealing, so that the plurality of the annealed films become a film having desired characteristics. The annealed film is annealed by repeatedly irradiating the spot laser light to the annealed film several times (for example, refer to Japanese Laid-Open Patent Publication No. Hei 9-45632).

However, in the conventional annealing apparatus, since the irradiated laser light is a single-wavelength ultraviolet laser light, when the irradiation of the laser light causes, for example, the amorphous germanium film is melted, there is a problem that the absorption rate of the ultraviolet laser light is lowered. . Therefore, it cannot be sufficiently melted to the deep portion of the amorphous ruthenium film, and it is not sufficiently polycrystalline.

Further, in the case where it is desired to generate a plurality of spot laser lights from one of the laser light generated by one light source device while annealing the plurality of positions of the annealed film, the laser beam is required to be irradiated due to the reduction of the irradiation energy of the laser light. A large-scale light source device with a larger energy, and an increase in the manufacturing cost of the annealing device.

For the above problem, it is conceivable to anneal the annealed film by a complex shot of laser light, but the annealing process efficiency is lowered, and the production cycle of the annealing process is prolonged.

Accordingly, in view of the foregoing problems, an object of the present invention is to provide a laser annealing apparatus and a laser annealing method which can improve the utilization efficiency of laser energy and can perform annealing treatment with good efficiency. law.

In order to achieve the above object, the laser annealing apparatus of the present invention irradiates laser light onto an amorphous germanium film for annealing treatment, and is characterized in that: a first pulse laser is provided to generate a fixed pulse width and a fixed wavelength. a first laser beam; a second laser beam having a pulse width and a longer wavelength than the first laser beam; and a synthesizing mechanism for synthesizing the first laser beam and the second laser beam a control unit for controlling the timing of the first and second laser beams by the first and second pulse lasers; and the control mechanism controlling the first pulse laser to make the first 1 Laser light is generated at a predetermined timing within the pulse width of the second laser light.

According to the above configuration, the first pulse laser having a fixed pulse width and a fixed wavelength is controlled by the control means, and the second pulse laser is controlled, and the pulse width and the wavelength are generated more than the first laser light. In the second laser light, the first laser light and the second laser light are combined into a same optical axis by a synthesizing mechanism, and the first and second laser light are irradiated onto the amorphous germanium film to be annealed. At this time, the first pulse laser is controlled by the control means so that the first laser light is generated at a predetermined timing within the pulse width of the second laser light.

Preferably, the control mechanism controls the first pulsed laser to adjust the timing of generating the first laser light to within the pulse width of the second laser light.

More preferably, the first pulsed laser generates the first laser light having a wavelength of 355 nm or 532 nm; and the second pulsed laser generates the second laser light having a wavelength of 1064 nm.

Further, in the laser annealing method of the present invention, the first laser light having a fixed pulse width and a fixed wavelength and the second laser light having a pulse width and a longer wavelength than the first laser light are combined into the same optical axis. Irradiating to the amorphous germanium film for annealing treatment, wherein the following steps are performed: a stage of generating the second laser light and irradiating the amorphous germanium film; and a predetermined timing within a pulse width of the second laser light The first laser beam is irradiated with the amorphous germanium film.

Preferably, the wavelength of the first laser light is 355 nm or 532 nm; and the wavelength of the second laser light is 1064 nm.

1‧‧‧Light source device

2‧‧‧Lighting device

3‧‧‧Control agency

4‧‧‧Substrate

5‧‧‧Amorphous film

6‧‧‧1st pulse laser

7‧‧‧2nd pulse laser

8‧‧‧Synthesis agency

9‧‧‧Resonator

10‧‧‧Optical amplifier

11‧‧‧Laser Attenuator

12‧‧‧ Front mirror

13‧‧‧Mirror Department

14‧‧‧ND: YAG rods

15‧‧‧Polarized beam splitter

16‧‧‧λ/4 wave plate

17‧‧‧ Boques components

18‧‧‧Q switch

19A‧‧‧1st Polarizing Beam Splitter

19B‧‧‧2nd polarizing beam splitter

20‧‧‧Bocks components

20A‧‧‧1st Boques component

20B‧‧‧2nd Boques Components

21‧‧‧Control Department

22‧‧‧Polarized beam splitter

23‧‧‧ Beam expander

24‧‧‧Mirror

25‧‧‧1st fly-eye lens

26‧‧‧1st condenser lens

27‧‧‧2nd fly eye lens

28‧‧‧beam scanner

29‧‧‧2nd condenser lens

30‧‧‧1st electro-optic crystal element

31‧‧‧2nd electro-optic crystal element

32‧‧‧λ/2 wave plate

33A‧‧‧electrode

33B‧‧‧electrode

L ₁ ‧‧‧1st laser light

L ₂ ‧‧‧2nd laser light

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a front elevational view showing an embodiment of a laser annealing apparatus of the present invention.

Fig. 2 is a plan view showing a configuration example of a second pulse laser used in the above embodiment.

3 is an explanatory view showing an application voltage of a Pockels cell for controlling a Q switch in the second pulse laser, and generating a long-pulse second laser light, and FIG. 3(a) shows a normal control. The graph, Fig. 3(b) shows a graph when the applied voltage is gradually lowered.

Fig. 4 is a graph showing the laser pulse generated when the applied voltage is applied to cause the gradient of the applied voltage to gradually generate an inflection point in Fig. 3(b).

Fig. 5 is a plan view showing a configuration example of a laser attenuator used in the second pulse laser.

Fig. 6 is a view showing a state in which the energy of a specific time is selectively reduced in one-shot laser light by the above-described laser attenuator, and Fig. 6(a) shows the state before the reduction, and Fig. 6(b) shows Reduced state.

Fig. 7 is an explanatory view showing an example of pulse waveforms of the first and second laser beams used in the above embodiment, wherein Fig. 7(a) shows the first laser light, and Fig. 7(b) shows the second laser beam.

Fig. 8 is a graph showing the relationship between the wavelength of various inorganic materials and the light absorption coefficient.

Fig. 9 is an explanatory view showing the laser energy effective for the annealing treatment in the laser annealing method of the present invention, and Fig. 9(a) shows the pulse width of the first laser light in the second laser light. In the case where the predetermined timing is generated, FIG. 9(b) shows a case where the first and second laser beams are simultaneously generated.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a front elevational view showing an embodiment of a laser annealing apparatus of the present invention. In the laser annealing apparatus, laser light is irradiated onto an amorphous germanium film to perform annealing treatment, and the light source device 1, the illumination device 2, and the control mechanism 3 are provided.

The light source device 1 is configured to generate laser light for annealing the amorphous germanium film 5 formed on the substrate 4, and includes a first pulse laser 6, a second pulse laser 7, and a combining mechanism 8.

Here, the first pulse laser 6 is, for example, a first laser light L ₁ having a pulse width W ₁ of 20 nsec and a wavelength λ ₁ of 355 nm or 532 nm, for example, using a non-linear optical crystal and a fundamental wave having a wavelength of 1064 nm. A conventional YAG laser generated by wavelength conversion. In the following description, the case where the first laser light L ₁ is laser light of λ ₁ = 355 nm is described. Further, the first pulse laser 6 is not limited to the YAG laser, and may be a short-wavelength laser light, for example, an excimer laser or the like. However, the case of the YAG laser will be described here.

The second pulse laser 7 can generate a second laser light L _{2 having} a pulse width and a longer wavelength than the first laser light L ₁ , and generates, for example, laser light having a pulse width W ₂ of 350 nsec and a wavelength λ ₂ of 1064 nm. YAG laser. Further, the second pulse laser 7 is not limited to the YAG laser, and may be a long-wavelength laser light, for example, a CO ₂ laser or the like. However, the case of the YAG laser will be described here.

More specifically, as shown in FIG. 2, the second pulse laser 7 includes a resonator 9, an optical amplifier 10, and a laser attenuator 11, and is oriented upstream from the direction in which the second laser light L ₂ is directed toward the downstream. The above order is configured.

The resonator 9 generates a standing wave by rotating the laser light back and forth between the front mirror portion 12 and the rear mirror portion 13 as a resonator mirror, and is provided with a laser beam excited by a flash lamp (not shown) to generate laser light. For example, the ND:YAG rod 14 of the medium, and the Q disposed as the polarizing element, the λ/4 wave plate 16 and the Boques element 17 disposed behind the ND:YAG rod 14 Switch 18.

In this case, the voltage applied to the Pocks element 17 is gradually lowered by the control unit omitted from the illustration of the individual design to increase the pulse width of the second laser light L ₂ .

In the case of this, a general control method for rapidly reducing the applied voltage to the Poles element 17 as shown in Fig. 3 (a) is applied to the application of the Poles element 17 as shown in Fig. 3 (b). In the case where the voltage is gradually lowered as the control is performed, the pulse width is increased, for example, from 10 ns to 70 ns. That is, in the oscillation in the resonator 9, the output energy returned from the Q switch 18 gradually increases along the time axis and is lower than the normal energy, so the extraction of energy in the ND:YAG rod 14 becomes slow, and the Q is extended. The pulse oscillation time in the switch 18 becomes longer as the pulse width of the output.

Further, at the gradient of the gradually decreasing voltage applied to the Boquex element, as shown in FIG. 4, if the applied voltage is controlled to generate at least one inflection point, the pulse width can be further increased. As a result, by controlling the voltage applied to the Poles element 17, the second laser light L _{2 having} a pulse width W ₂ of 350 nsec can be generated.

Further, an optical amplifier 10 is provided downstream of the resonator 9. The optical amplifier 10 amplifies and outputs the pulse energy of the laser light, and for example, an ND:YAG rod can be used.

Further, downstream of the optical amplifier 10, a laser attenuator 11 is provided. The laser attenuator 11 lowers the energy of the second laser light L ₂ , and as shown in FIG. 5 , the laser attenuator 11 is disposed on the optical path of the second laser light L _{2 to} be a crossed Nichol prism. The first and second polarization beam splitters 19A and 19B as polarizing elements; and between the first and second polarization beam splitters 19A and 19B, linearly polarized light (for example, P-polarized light) that enters the optical axis is 45°. As a general configuration, a polarizing surface that passes through the internal laser light is rotated by a voltage to be applied, and a Pocks element 20 as a photovoltaic element; and a control unit 21 that controls an applied voltage value and an application timing to the Pocks element 20.

In one example of the Poles element 20 used in the present embodiment, the effect of the λ/4 wave plate is obtained by applying a voltage of -3.6 kV at maximum, by using the first and second Poles elements 20A, 20B. In the series arrangement, parallel control is performed at a maximum applied voltage of -3.6 kV, and the effects of the λ/2 wave plate are obtained by combining the first and second Poles elements 20A and 20B. In this case, when the applied voltages of the first and second Poles elements 20A and 20B vary between, for example, 0 kV to -3.6 kV, the light transmittance of the laser attenuator 11 is between 0% and 100%. Variety.

Further, the laser attenuator 11 controls the applied voltage of the Boquez element 20 by time, planarizes the envelope of the laser light of one pulse, and makes the laser energy uniform in the time axis. For example, when the laser attenuator 11 inputs a long-pulse second laser light L ₂ that releases excessive pulse energy in time t _n as shown in FIG. 6( a ), for example, when the pulse energy is to be reduced by 50%, the system is applied toward the time t _n of the first and second Boke Si elements 20A, 20B of the voltage is -1.8kV, the elapsed time t _n is controlled to -3.6kV.

Thereby, the transmittance of the second laser light L ₂ penetrating the laser attenuator 11 during the initial time t _n is reduced to 50%, and after the elapse of time t _n , the transmittance is 100%. Therefore, the laser intensity of the long-pulse second laser light L ₂ shown in Fig. 6(a) is reduced by 50% in the initial time t _n , and the laser intensity after the time t _n is maintained at the original intensity. As a result, as shown in FIG. 6(b), the laser intensity in one pulse is slightly fixed across the entire width.

Further, in Fig. 2, reference numeral 22 is a polarization beam splitter, reference numeral 23 is a beam expander for expanding a laser beam path, and symbol 24 is a mirror.

A synthesizing mechanism 8 is provided at an intersection of the optical path of the first pulsed laser 6 and the optical path of the second pulsed laser 7. The synthesizing mechanism 8 combines the first laser light L ₁ and the second laser light L ₂ into the same optical axis, for example, the first laser light L ₁ that penetrates λ ₁ = 355 nm and reflects the _second λ ₂ = 1064 nm. Beam splitter for laser light L ₂ .

On the downstream side of the light source device 1, an illumination device 2 is provided. The lighting device In the second embodiment, the laser beam is irradiated onto the predetermined annealing region of the amorphous germanium film 5 on the substrate 4, and the first fly-eye lens 25, the first collecting lens 26, and the second fly-eye lens are sequentially provided from the upstream to the downstream of the laser light. 27. A beam scanner 28 and a second condenser lens 29.

The first fly-eye lens 25 has a plurality of convex lenses arranged in the same plane, and has a uniform distribution of the intensity distribution in the cross section of the laser light, and has a function of a beam expander that increases the laser beam.

On the optical axis, the first focus lens 26 is disposed in focus after the front focus is aligned to the first fly-eye lens 25. The first condensing lens 26 is configured to collect the laser light beams that have been emitted after the first fly-eye lens 25 is emitted, and to enter the second fly-eye lens 27 to be described later.

In order to make the intensity distribution in the cross section of the laser light uniform, the second fly-eye lens 27 has a pair of lens arrays in which a plurality of convex lenses are arranged in the same plane so that the corresponding convex lens central axes are aligned. To the configuration.

The beam scanner 28 includes square columnar first and second electro-optical crystal elements 30 and 31 that are deflected in the vertical direction, and laser light is applied between the first and second electro-optical crystal elements 30 and 31. The polarizing surface is rotated by 90° and aligned with the λ/2 wave plate 32 of the crystal axis of the second electro-optical crystal element 31, and the optical axes of the first and second electro-optical crystal elements 30 and 31 are respectively disposed at parallel opposing faces. 1 pair of electrodes 33A, 33B. In this case, the mounting positions of the pair of electrodes 33A of the first electro-optical crystal element 30 and the pair of electrodes 33B of the second electro-optical crystal element 31 are shifted by 90 degrees around the optical axis.

The second condensing lens 29 is provided to align the front focus to the focus position after the optical axis of the second fly-eye lens 27, so as to have a function of causing the laser light irradiated onto the substrate 4 to be parallel rays.

A control mechanism 3 electrically connected to the first pulsed laser 6 and the second pulsed laser 7 of the light source device 1 is provided. The control unit 3 controls the timing of generation of the first and second laser lights L ₁ and L ₂ by the first and second pulse lasers 6 and 7, and controls the first pulse laser 6 in detail. The first laser light L _{1 is} generated at a predetermined timing within the pulse width W ₂ of the second laser light L ₂ .

More specifically, the control means may control the 3 lines 6 of the first laser pulse to produce a first laser beam L ₁ of the timing adjustment to the second laser light L ₂ of the _two pulse wave width W. Thereby, the irradiation energy of the laser light irradiated to the amorphous germanium film 5 can be appropriately adjusted.

Next, the operation of the above-described laser annealing apparatus will be described.

First, a stage (not shown) on which the substrate 4 on which the amorphous germanium film 5 is formed is placed is moved in a two-dimensional direction in a parallel plane of the upper surface thereof, and the substrate 4 is annealed. The regional center coincides with the optical axis of the illumination device 2.

Next, by the control unit (not shown), the gradient of gradually decreasing the applied voltage of the Poles element 17 of the second pulse laser 7 is controlled to be gradually reduced as a predetermined value to generate, for example, a pulse width W ₂ = 350 nsec. a long-pulse second laser light L _{2 having a} wavelength λ ₂ = 1064 nm.

The second laser light L ₂ is increased to a fixed level by the optical amplifier 10 described later, and the applied voltage of the first and second booxons 20A and 20B of the laser attenuator 11 is reduced to a pre-experiment by parallel control. The necessary energy intensity is sufficient in the confirmed annealing treatment. At the same time, as shown in Fig. 7(b), the laser intensity within one pulse is slightly fixed between the full widths. Next, the second laser light L ₂ is reflected by the beam splitter of the combining mechanism 8 and is incident on the illumination device 2 in the subsequent stage.

On the other hand, by the control of the control unit 3, the first pulse laser 6 is driven by the second pulse laser 7 for a fixed time and then driven to generate, for example, a pulse width W ₁ = 20 nsec, and a wavelength λ ₁ = For example, the short-pulse first laser light L ₁ shown in Fig. 7(a) is 355 nm. Next, the first laser light L ₁ is transmitted through the beam splitter of the synthesizing mechanism 8 and combined with the second laser beam L ₂ to be incident on the illumination device 2 .

The first and second laser beams L ₁ and L ₂ synthesized as described above are increased in beam diameter by the illumination device 2, and the intensity distribution is made uniform. Then, the substrate 4 is guided by the beam scanner 28 in the two-dimensional direction of the surface. The bias is used to adjust the illumination position. Thereby, the first and second laser beams L ₁ and L ₂ can be prevented from interfering with each other, and the laser beam having uniform intensity distribution can be irradiated onto the substrate 4. As a result, the amorphous germanium film 5 in the annealed region is melted and recrystallized and phase-changed into polycrystalline germanium.

Here, the annealing treatment by the first and second laser beams L ₁ and L ₂ will be described in more detail.

As shown in FIG. 8, in general, it is known that erbium (Si) has a lower light absorptivity when the wavelength of the laser light is longer. Therefore, in general, in the case of annealing the amorphous germanium film 5, laser light having a high light absorptivity, for example, ultraviolet light having a wavelength of 355 nm or the like is used.

On the other hand, it is also known that the enthalpy of fusion has a low absorption rate of ultraviolet rays. Therefore, in the case where the irradiation energy of the ultraviolet laser light is not sufficiently high, the irradiation by the ultraviolet laser light makes the non- When the surface of the wafer film 5 is melted, the absorption rate of the ultraviolet laser light is lowered and the molten film is not sufficiently melted to the deep portion of the amorphous germanium film 5. Therefore, the amorphous germanium film 5 is also not sufficiently polycrystalline to the deep portion.

On the other hand, as shown in FIG. 8, since the long-wavelength laser light of, for example, 1064 nm is hard to be absorbed by the germanium, it is generally not used in the laser annealing process. However, it is also known that long-wavelength laser light is more easily absorbed by the melting enthalpy.

Here, in the present invention, first, the amorphous germanium film 5 is melted by the first laser light L ₁ having a short wavelength, and then the amorphous germanium film 5 is melted by the second laser light L ₂ having a long wavelength. Deep.

Specifically, as shown in FIG. 9( a ), after the second laser light L _{2 is} generated and irradiated onto the amorphous germanium film 5, a fixed timing in the pulse width W ₂ of the second laser light L ₂ is, for example, The first laser light L ₁ is generated at a timing after t=100 nsec elapses from the generation timing (pulse rise timing) of the second laser light L ₂ . In this case, since the amorphous germanium film 5 does not absorb the second laser light L ₂ before the first laser light L _{1 is} irradiated, the amorphous germanium film 5 does not melt. However, by the irradiation light L ₁ of the first laser, so that when the amorphous silicon film 5 is once molten, and thereafter, the amorphous silicon film 5 is absorbed by the second laser beam L ₂ to melt and deeper. In this case, the first and second laser beams L ₁ and L _{2 are} applied to the energy of the annealing process of the amorphous germanium film 5, and the energy of the hatched region is plotted in FIG. 9(a).

Accordingly, even when light L by irradiation of _a laser so that the first molten amorphous silicon film 5 of the first reducing absorption of the laser beam L ₁ ratio, but the absorption wavelength than the first laser light L ₁ is longer the second Ray The amorphous ruthenium film 5 is melted by the light L ₂ to anneal the amorphous ruthenium film 5 to the deep portion. Therefore, compared with the case where only the ultraviolet light of the ultraviolet light is used in the prior art, the utilization efficiency of the laser energy can be further improved to perform the annealing process with better efficiency.

In the present invention, the timing of generating the first laser light L ₁ is appropriately adjusted to be within the pulse width W ₂ of the second laser light L ₂ , and the irradiation energy of the laser light can be adjusted. For example, FIG. 9 (b), in the generating the second laser beam L ₂ generate the first laser beam L while the case _1, the energy applied to the annealing treatment system of FIG. 5 of the amorphous silicon film 9 (b) The energy of the oblique line region is plotted, and the irradiation energy can be increased as compared with FIG. 9(a). Of course, vice versa.

Further, in the above-described embodiment, the case where the annealing region at one position on the amorphous germanium film 5 is annealed is described. However, the present invention is not limited thereto, and may be, for example, the second polymerization of the illumination device 2. The light exit side of the optical lens 29 is disposed with a plurality of annealing regions A microlens array having a plurality of microlenses is arranged to generate a plurality of synthetic laser light from one synthetic laser light while simultaneously annealing a plurality of annealed regions. In this case, since the utilization efficiency of the laser energy is higher than that of the prior art, the pulsed laser power used can be smaller than the conventional technique.

Further, the substrate 4 may be transported at a fixed speed in a direction perpendicular to the direction in which the microlenses are arranged, and may be imaged by an imaging device in advance and a plurality of annealed regions may be detected, and the substrate 4 may be detected after the annealing region is detected. Moving the fixed distance, when the plurality of annealed regions reach directly below the plurality of microlenses of the microlens array, controlling the first and second pulsed lasers 6, 7 to generate the first and second laser light L ₁ , L ₂ . Thereby, the plurality of annealing regions in the vertical direction of the substrate 4 in the direction in which the substrate 4 is transported can be annealed together, and the annealing treatment can be repeated in the substrate transfer direction to anneal the entire surface of the substrate 4.

1‧‧‧Light source device

2‧‧‧Lighting device

3‧‧‧Control agency

4‧‧‧Substrate

5‧‧‧Amorphous film

6‧‧‧1st pulse laser

7‧‧‧2nd pulse laser

8‧‧‧Synthesis agency

25‧‧‧1st fly-eye lens

26‧‧‧1st condenser lens

27‧‧‧2nd fly eye lens

28‧‧‧beam scanner

29‧‧‧2nd condenser lens

30‧‧‧1st electro-optic crystal element

31‧‧‧2nd electro-optic crystal element

32‧‧‧λ/2 wave plate

33A‧‧‧electrode

33B‧‧‧electrode

L ₁ ‧‧‧1st laser light

L ₂ ‧‧‧2nd laser light

Claims (5)

A laser annealing device that irradiates laser light onto an amorphous germanium film for annealing treatment, and is characterized in that: a first pulse laser is provided to generate a first laser light having a fixed pulse width and a fixed wavelength; a 2-pulse laser that generates a second laser light having a pulse width and a wavelength longer than the first laser light; and a synthesizing mechanism that combines the first laser light and the second laser light into a same optical axis; and controls a mechanism for controlling a timing of generating the first and second laser beams by the first and second pulse lasers; wherein the control mechanism controls the first pulse laser such that the first laser light is at the second A predetermined timing within the pulse width of the laser light is generated. A laser annealing apparatus according to claim 1, wherein the control means controls the first pulsed laser to adjust the timing of generating the first laser light to within a pulse width of the second laser light. The laser annealing apparatus of claim 1 or 2, wherein the first pulse laser generates the first laser light having a wavelength of 355 nm or 532 nm; and the second pulse laser generates the first wavelength of 1064 nm 2 laser light. A laser annealing method is characterized in that a first laser beam having a fixed pulse width and a fixed wavelength and a second laser beam having a pulse width and a wavelength longer than the first laser light are combined into a same optical axis and irradiated to an amorphous state. The ruthenium film is subjected to annealing treatment, characterized in that a stage of generating the second laser light and irradiating the amorphous ruthenium film is performed; and the first time is generated at a predetermined timing within a pulse width of the second laser light The stage of laser light and irradiation of the amorphous germanium film. The laser annealing method of claim 4, wherein the first laser light has a wavelength of 355 nm or 532 nm; and the second laser light has a wavelength of 1064 nm.