JP2005116729A - Laser processing apparatus and method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser annealing device capable of keeping the average energy density of laser light with which a workpiece is irradiated constant even when a profile of the laser light is changed. <P>SOLUTION: In the laser annealing device 10 when an irradiation optical system unit 12 irradiates laser light emitted from a laser oscillator unit 11 to an irradiation position of a substrate 17, a Joule meter 13 detects laser light energy, and a profile meter 14 detects the profile of the laser light. On the basis of these detection outputs, calculation means 15 calculates the average energy density of the laser light irradiated to the substrate 17, and control means 16 controls the average energy density of the laser light with which the substrate 17 is irradiated such that it becomes a predetermined constant value in response to an output of the calculation means 15. With the control, the average energy density of the laser light with which the substrate 17 is irradiated is kept unchanged. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a laser processing apparatus and a laser processing method.

Laser light is coherent light and has excellent convergence, and thus is used in various processing fields such as welding, cutting, and surface treatment. One of the processing fields using laser light is laser annealing in which, for example, an amorphous silicon (Si) film formed on a substrate is irradiated with a laser beam and heated to form a polycrystalline Si film. In this laser annealing, laser light is irradiated to an amorphous Si film, and the Si film is converted into a polycrystalline Si film through the process of heating and melting and solidifying Si.

A Si film formed on a substrate made of glass, synthetic quartz or the like is used, for example, in a pixel portion of a liquid crystal panel. The pixel portion of the liquid crystal panel displays an image by switching a thin film transistor formed on the Si film. If the Si film is amorphous, the carrier mobility is low to constitute a transistor active layer, and it is difficult to use it in an integrated circuit that requires high speed and high performance. Is thinned to realize a thin film transistor with high mobility.

In conventional laser annealing, the surface of an amorphous Si film formed on a substrate is scanned while irradiating a laser beam, and the amorphous Si film is heated and melted at the irradiated portion of the laser beam to progress the irradiated portion. Accompanying this, a method of obtaining a polycrystalline Si film by sequentially cooling the melted portion and solidifying the melted Si film with a certain width in the cooling process is used. A polycrystalline Si film having a small number of lattice defects over a wide range can be produced by laser annealing in which a desired range of the amorphous Si film is irradiated with a laser beam.

It is known that the characteristics of a polycrystalline Si film formed by laser annealing are greatly affected by the energy of laser light. Therefore, homogeneous polycrystalline S
In order to form the i film, it is necessary to maintain the energy value of the laser beam on the irradiated surface of the Si film at a desired constant value. As a method often used for keeping the energy value of the laser beam constant, an APC (monitoring the laser beam output from the laser oscillator on the laser oscillator side and feedback-controlling the detected laser beam output is performed. Auto Power Control) is known. Although the energy value of the laser light oscillated from the laser oscillator can be kept constant by this APC, the efficiency of the irradiation optical system changes with time when the laser irradiation is performed for a long time. There is a problem that the energy value of the laser beam on the irradiated surface of the Si film changes with time due to the change.

Conventional techniques for solving such problems include energy detection means for detecting the energy of laser light at a measurement position corresponding to the irradiation position of the laser light, and laser light emitted from the irradiation optical system based on the output of the energy detection means. And a control means for adjusting the energy of the laser beam. The energy of the laser beam at the measurement position is detected at a necessary timing, and the energy of the laser beam emitted from the irradiation optical system is adjusted as needed to irradiate the workpiece. The laser light energy is simply and precisely controlled (see Patent Document 1), and the substrate on which the irradiated film is formed and the stage on which the substrate is mounted are configured to transmit light, and pass through the substrate and the stage. The profile of the irradiated laser beam on the irradiated film is measured by detecting the laser beam detected by the laser beam detection means, and the measurement And controls the laser output from the laser irradiation means based on the profile, there is that equalizes the intensity distribution of the irradiated laser beam on the irradiated film (see Patent Document 2).
Japanese Patent Laid-Open No. 2001-351876 JP 2002-176008 A

However, the cause of the laser beam energy change when laser irradiation is performed for a long period of time is that the laser beam on the surface to be irradiated accompanying the decrease in output due to gas deterioration in the laser oscillator and the change in efficiency of the irradiation optical system. In addition to the change in energy over time, there are fluctuations in the efficiency of the irradiation optical system and changes in the profile of the laser beam as the spread angle of the laser beam emitted from the laser oscillator changes.

For the energy change of the laser beam caused simply by the efficiency change of the irradiation optical system,
By detecting the energy of the laser beam at the measurement position corresponding to the irradiation position of the laser beam as disclosed in the above-mentioned prior art, or by adjusting the attenuator according to the profile measurement result of the laser beam that has passed through the substrate and the stage The total energy of the laser beam on the irradiated surface can be kept constant.

However, if the profile changes as the laser beam spread angle changes, the laser light irradiation area changes, so even if the total energy amount does not change, the total energy per unit area divided by the irradiation area A phenomenon that the average irradiation energy (average energy density) changes occurs, and there is a problem that such a phenomenon cannot be solved by the prior art.

4 and 5 are diagrams showing profiles when the spread angles of the laser beams are different. In FIG. 4, the energy density distribution in the radial direction of the beam when the laser beam spread angle is small is represented by line 1, and the area of the area defined by the broken line 2 represents the total energy amount of the laser beam. The vertical axis reading on line 2 represents the average energy density. In this specification, the energy density distribution in the radial direction of the laser beam is referred to as a profile. In FIG. 5, the energy density distribution (profile) in the radial direction of the beam when the spread angle of the laser beam is large is represented by a line 3, and the area area defined by the broken line 4 represents the total energy amount of the laser beam. The vertical axis reading on line 4 represents the average energy density. Although FIG. 4 and FIG. 5 are different in the laser beam profile, the total energy obtained by integrating the energy density indicated by the profile, that is, the area area defined by line 2 and the area area defined by line 4 are the same. A case where and are equal is illustrated.

When the spread angle of the laser beam increases, the profile spreads in the radial direction of the beam. Therefore, even if the total energy amount is equal, the vertical axis reading of line 2 in FIG. 4 and the vertical axis reading of line 4 in FIG. As is apparent from the different values, the average energy density changes. That is, it is not possible to correct the change in the average energy density due to the profile change only by controlling the total energy amount of the laser light to be constant.

In addition, the attenuator control as disclosed in the prior art is to return the profile in which the light beam divergence angle is increased and the irradiation area is increased to a desired setting profile (reference profile) set in advance for laser processing. However, it is impossible, and precise adjustment by a laser beam shape forming unit such as a homogenizer has to be performed. However, it is very difficult to perform this fully automatically.

The present inventors detect the energy of the laser beam at the measurement position corresponding to the irradiation position of the laser beam, and feed back the detection output to control the operation of the attenuator. Attempts were made to adjust the energy density and the change with time was investigated. FIG.
These are figures which show a time-dependent change of beam size and energy density. In FIG. 6, a line 5 represents a change with time of the beam size, a line 6 represents a change with time of the average energy density, and a line 7 is an optical used as an index for evaluating the crystal state of the Si film after laser annealing. This represents the change in luminance over time. As apparent from FIG. 6, it has been found that it is difficult to maintain the average energy density at a constant value only by the attenuator control based on the total energy of the laser beam.

As described above, the crystallized state of the Si film in laser annealing, that is, the transistor characteristics of the crystal greatly depends on the energy density of the laser beam. Therefore, in the control disclosed in the prior art, the crystal state of the Si film after laser annealing is used. Becomes non-uniform, increases in transistor characteristic variation, and is difficult to apply to an integrated circuit that requires high speed and high performance.

An object of the present invention is to provide a laser processing apparatus and a laser processing method capable of maintaining a constant average energy density of laser light applied to a workpiece even when the profile of the laser light changes. is there.

The present invention is a laser processing apparatus that performs processing by irradiating a workpiece with laser light,
A light source that emits laser light;
An irradiation optical system for irradiating the irradiation position of the workpiece with laser light emitted from a light source;
Energy detecting means for detecting the energy of the laser beam irradiated to the workpiece;
Profile detection means for detecting the profile of the laser light irradiated to the workpiece;
A computing means for computing an average energy density of the laser light irradiated to the workpiece based on detection outputs of the energy detecting means and the profile detecting means;
And a control means for controlling the average energy density of the laser light applied to the workpiece to be a predetermined value in response to the output of the computing means.

According to the present invention, a laser processing apparatus includes: an energy detection unit that detects energy of laser light that is emitted from a light source and is irradiated on a workpiece through an irradiation optical system; a profile detection unit that detects a profile; Means for calculating the average energy density of the laser beam irradiated to the workpiece based on the detection output of the means and the profile detection means, and the average of the laser beam irradiated to the workpiece in response to the output of the calculator Control means for controlling the energy density to be a predetermined value. The laser processing apparatus configured as described above calculates the average energy density of the laser beam at the measurement position at a desired timing, and sets the predetermined average energy density so as to be suitable for laser processing of the workpiece. By performing feedback control so that the deviation from the density becomes zero (0), the average energy density of the laser beam emitted from the irradiation optical system and irradiated onto the workpiece can be adjusted as needed. it can. Therefore, it is possible to easily and precisely control the average energy density of the laser light applied to the workpiece, and to maintain the energy stability of the laser light on the irradiated surface with high accuracy.

In the present invention, the workpiece is a silicon film formed on a substrate.
The processing performed by irradiating the silicon film with laser light controlled so that the average energy density becomes constant by the control means is laser annealing processing.

According to the present invention, the workpiece is a silicon film formed on the substrate, and is applied by irradiating the silicon film with laser light that is controlled by the control means so that the average energy density is constant. Processing is laser annealing processing. Therefore, the laser processing apparatus is a laser annealing apparatus. According to this laser annealing apparatus, the average energy density is precisely controlled with respect to the amorphous Si film formed on the substrate, which is a workpiece, and the energy on the irradiated surface is stable. Since the amorphous Si film can be laser-annealed by irradiating the laser beam maintained with high accuracy, it is possible to form a polycrystalline Si film having a uniform crystal state. Thus, it is possible to provide a polycrystalline Si film that can be suitably used for an integrated circuit that requires high speed and high performance.

Further, the present invention is a laser processing method for performing processing by irradiating a workpiece with laser light emitted from a light source,
Detecting the energy of laser light applied to the workpiece;
Detecting the profile of the laser beam irradiated to the workpiece;
A step of calculating an average energy density of the laser beam irradiated to the workpiece based on the detected energy and profile of the laser beam;
A step of controlling the average energy density of the laser light irradiated to the workpiece based on the calculation result of the average energy density to be a predetermined constant value;
A laser beam controlled so that the average energy density becomes a predetermined value,
And a process for processing by irradiating the workpiece.

According to the present invention, the average energy density of the laser beam at the measurement position is obtained at a desired timing, and based on the obtained average energy density, the average energy density of the laser beam irradiated onto the workpiece is made constant. Provided is a laser processing method that can be controlled easily and precisely and can maintain the energy stability of laser light on an irradiated surface with high accuracy.

According to the present invention, a laser processing apparatus includes an energy detection unit that detects energy of laser light emitted from a light source and irradiated onto a workpiece through an irradiation optical system, a profile detection unit that detects a profile, and an energy detection unit. Means for calculating the average energy density of the laser beam irradiated to the workpiece based on the detection output of the means and the profile detection means, and the average of the laser beam irradiated to the workpiece in response to the output of the calculator Control means for controlling the energy density to be a predetermined value. The laser processing apparatus configured as described above calculates the average energy density of the laser beam at the measurement position at a desired timing, and sets the predetermined average energy density so as to be suitable for laser processing of the workpiece. By performing feedback control such that the deviation from the density is zero, the average energy density of the laser light emitted from the irradiation optical system and irradiated onto the workpiece can be adjusted as needed. Therefore, it is possible to easily and precisely control the average energy density of the laser light applied to the workpiece, and to maintain the energy stability of the laser light on the irradiated surface with high accuracy.

According to the invention, the workpiece is a silicon film formed on the substrate, and is applied by irradiating the silicon film with a laser beam controlled by the control means so that the average energy density is constant. The processing to be performed is laser annealing processing. Therefore, the laser processing apparatus is a laser annealing apparatus. According to this laser annealing apparatus, the average energy density is precisely controlled with respect to the amorphous Si film formed on the substrate, which is a workpiece, and the energy on the irradiated surface is stable. By irradiating laser light that is maintained with high accuracy, amorphous Si
Since the film can be laser-annealed, a polycrystalline Si film having a uniform crystal state can be formed. Thus, it is possible to provide a polycrystalline Si film that can be suitably used for an integrated circuit that requires high speed and high performance.

Further, according to the present invention, the average energy density of the laser beam at the measurement position is obtained at a desired timing, and the average energy density of the laser beam irradiated to the workpiece is made constant based on the obtained average energy density. Thus, there is provided a laser processing method that can be controlled easily and precisely and can maintain the energy stability of the laser beam on the irradiated surface with high accuracy.

FIG. 1 is a block diagram showing a simplified configuration of a laser processing apparatus 10 according to an embodiment of the present invention. In the present embodiment, the laser processing apparatus 10 exemplifies a laser annealing apparatus 10 that forms a polycrystalline Si film by irradiating an amorphous Si film formed on a substrate with laser light to perform laser annealing. .

The laser annealing apparatus 10 generally includes a laser oscillator unit 11, an irradiation optical system unit 12, energy detection means 13 that detects the energy of laser light emitted from the laser oscillator unit 11, and a profile that detects the profile of the laser light. Detection means 14, energy detection means 13, and profile detection means 14
Calculating means 15 for calculating the average energy density of the laser beam based on the detected output of
In response to the output of the calculation means 15, a control means 16 for controlling the average energy density of the laser beam to a predetermined value and a workpiece 17 to be annealed by the laser light in its internal space. And a process chamber 18 for receiving.

The laser oscillator unit 11 is a laser oscillator 2 that is a light source that emits laser light.
1, a beam splitter 22 that separates part of the laser light emitted from the laser oscillator 21, and a power meter that receives the laser light separated by the beam splitter 22 and outputs an electrical signal corresponding to the intensity of the laser light 23.

In the present embodiment, an excimer laser that is a gas laser is used for the laser oscillator 21. The laser oscillator is not limited to the excimer laser,
For example, other gas lasers such as carbon dioxide laser and solid state lasers such as Nd-YAG
A laser or the like may be used. As the beam splitter 22, for example, a prism or the like can be used. The laser oscillator 21 has an APC (not shown).
And is controlled on the oscillator side so that the output intensity of the laser light oscillated from the laser oscillator 21 is constant according to the intensity of the laser light detected and fed back by the power meter 23.

The irradiation optical system unit 12 provided to irradiate the irradiation position of the workpiece 17 with the laser beam emitted from the laser oscillator 21 includes a variable attenuator 24,
An attenuator control unit 25 that controls the operation of the variable attenuator 24 and a beam shaping lens 26 are configured.

The variable attenuator 24 is an optical member that can variably adjust the light transmittance. The laser light from the laser oscillator 21 is incident on the variable attenuator 24, and the laser light whose transmittance is adjusted by passing through the variable attenuator 24 is emitted toward the beam shaping lens 26. Attenuator control unit 25
Is a processing circuit, and the average energy density of the laser light irradiated to the workpiece 17 obtained by the computing means 15 and a predetermined set energy density stored in a memory provided in the attenuator control unit 25. The operation of the variable attenuator 24 is feedback-controlled so that the deviation becomes zero, and the average energy density of the laser light after passing through the variable attenuator 24 is adjusted to be constant. Therefore, the variable attenuator 24 and the attenuator control unit 25 constitute the control means 16 described above. The beam shaping lens 26 is a variable attenuator 2.
A beam of laser light incident after passing through 4 is shaped into a linear shape and irradiated to the irradiation position of the workpiece 17.

A part of the laser light whose beam is shaped into a linear shape by the beam shaping lens 26 is separated by another beam splitter 27. The laser beams separated by the other beam splitter 27 are incident on the energy detection means 13 and the profile detection means 14, respectively.

The energy detection means 13 is a joule meter in the present embodiment. The joule meter 13 detects the total energy amount of light incident on the joule meter 13. The profile detection means 14 is a profile meter in the present embodiment. The profile meter 14 detects the energy density distribution on the irradiation surface of the light incident on the profile meter 14. The irradiated surface of the profile meter 14 is
By setting so as to coincide with a cross section perpendicular to the optical axis of the laser light incident on the profile meter 14, the energy density distribution detected by the profile meter 14 is changed to a profile which is the energy density distribution in the radial direction of the beam. Will be equal.

The arithmetic means 15 is an arithmetic circuit, and calculates the average energy density of the laser light irradiated into the workpiece 17 after being linearly shaped by the beam shaping lens 26 based on the detection outputs of the joule meter 13 and the profile meter 14. The average energy density as the calculation result is given to the control means 16 described above.

The process chamber 18 is a processing container that can accommodate the workpiece 17 in its internal space, and is formed of, for example, stainless steel. Although not shown, the process chamber 18 is provided with a vacuum pump and a gas supply device as an auxiliary device, and is configured so that the internal space can be made into a vacuum atmosphere or an atmosphere filled with a desired gas.

In the present embodiment, the workpiece 17 is a substrate on which an amorphous Si film is formed on glass. The substrate 17 is placed on a stage 28 provided in the process chamber 18 and movable in at least two axial directions. By moving the stage 28, the laser light applied to the amorphous Si film is irradiated in a desired direction. It is configured to be able to scan.

Hereinafter, calculation of the average energy density by the calculation means 15 based on the detection outputs of the joule meter 13 and the profile meter 14 will be described.

Let P be the laser power of the laser light output from the laser oscillator 21. When the beam radius of the laser light detected by the profile meter 14 is wx and the energy density distribution of the beam is a Gaussian beam following a Gaussian distribution, the unit per unit time detected by the profile meter 14 at the radial position x of the beam. The energy density I (x) is given by equation (1).

The average energy density Em per unit time calculated by the calculation means 15 using the energy density I (x) of the beam detected by the profile meter 14 is obtained as shown in Equation (2).

From equation (2), it can be seen that the average energy density Em per unit time becomes constant by keeping the ratio (P / wx) between the laser power P and the beam radius wx constant. Next, the cumulative average energy density Em · Δt when the laser beam is irradiated for the time Δt is obtained by the equation (3) obtained by multiplying the equation (2) by the time Δt.

In the joule meter 13, the total energy E irradiated with the laser light for the time Δt.
Since t is detected and the total energy Et is equal to the amount of energy irradiated with the laser power P for the time Δt, Et = P · Δt is established. Therefore, in the laser annealing apparatus 10, the cumulative average energy density Em · Δt is equal to the joule meter 1.
3 is obtained by dividing the absolute value of the total energy Et detected by 3 by using the beam radius wx detected by the profile meter 14 as shown in the equation (3).

Since Et = P · Δt as described above, the cumulative average energy density Em · Δt can be replaced with 0.47725 (Et / wx) from Equation (3). Further, since the laser beam irradiated to the joule meter 13 and the profile meter 14 is light after passing through the variable attenuator 24 of the irradiation optical system unit 12,
When the transmittance of the variable attenuator 24 is r, the cumulative average energy density Em · Δt is given by 0.47725 · (Et / wx) · r multiplied by the transmittance r. Therefore, the average energy density Em is set to a predetermined energy density suitable for laser annealing, for example, by controlling the transmittance r so that the term constituted by the variable shown in the following formula (4) becomes a constant value. It can be controlled to be equal to Es.

In the present embodiment, the control for making the average energy density Em of the laser beam irradiated to the substrate 17 constant is performed by separating a part of the laser beam by the beam splitter 27 instead of the laser beam itself irradiated to the substrate 17. This is based on the laser beam. However, by using the beam splitter 27 having a constant separation ratio for separating the laser light for monitoring by the joule meter 13 and the profile meter 14 from the laser light emitted from the irradiation optical system unit 12, a part of the separated light is obtained. The control value based on the laser light can be corrected with a coefficient based on the separation ratio to be a control value for the laser light irradiated onto the substrate 17.

The laser annealing method that is an embodiment of the present invention will be briefly described below.
Laser light is oscillated and output from the laser oscillator 21. A part of the laser beam that is oscillated and output is separated by the beam splitter 22 and irradiated to the power meter 23. The output intensity of the laser beam detected by the power meter 23 is the AP of the laser oscillator 21.
Feedback of C is performed, and the output of the laser beam is controlled to be stabilized on the oscillator side.

The laser light emitted from the laser oscillator 21 passes through a variable attenuator 24 whose transmittance r can be variably set, and enters a beam shaping lens 26. The beam shaping lens 26 forms the beam shape of the laser light into a linear shape suitable for annealing. A part of the laser beam formed linearly by the beam shaping lens 26 is separated by the beam splitter 27 while being irradiated onto the substrate 17.

The laser light separated by the beam splitter 27 is incident on the joule meter 13 and the profile meter 14, respectively, and energy and profile are detected. The detection outputs from the joule meter 13 and the profile meter 14 are input to the calculation means 15, and the calculation means 15 irradiates the substrate 17 with the average energy density Em of the laser light based on the detected laser light energy and profile. And the calculation result is output to the attenuator control unit 25 of the control means 16.

The attenuator control unit 25 responds to the calculation result of the average energy density Em so that the deviation between the set energy density Es set in advance so as to be suitable for the annealing of the substrate 17 and the average energy density Em becomes zero. The transmittance r of the variable attenuator 24 is controlled.

FIG. 2 is a diagram for explaining the outline of average energy density control. In FIG.
A line 3 indicated by a thin line is a profile in a state in which the laser beam spread angle increases as the time-dependent change from FIG. 4 to FIG. 5 described above and the laser light spreads in the beam radial direction, and is indicated by a thin broken line. Line 4 is likewise the average energy density Em. The attenuator control unit 25 of the control unit 16 controls the operation so that the transmittance r of the variable attenuator 24 becomes large when the average energy density Em input from the calculation unit 15 is smaller than the set energy density Es, and the laser beam From the line 3 to the line 31, and the average energy density Em is set to the set energy density Es indicated by the line 32.

In this way, the laser beam whose average energy density Em is controlled by the control means 16 to be a predetermined constant value Es is irradiated to the amorphous Si film formed on the surface of the substrate 17, and the stage. By scanning 28, an annealing process is performed in which the amorphous Si film is sequentially melted and solidified to form polycrystalline Si.

FIG. 3 is a graph showing changes over time in beam size and energy density when the apparatus and method of the present invention are used.

The characteristics of the polycrystalline Si film formed by annealing the amorphous Si film are greatly affected by the average energy density Em of the irradiated laser beam. y is used. This optical brightness y
Is experimentally given by equation (5).

In Expression (5), x (t) is a coefficient that relates energy density and optical luminance and includes fluctuations with time, influencing factors of the previous process, and the like, and vt represents variation in optical luminance measurement. Represent. Et, r, and wx are the expressions (1) described above.
The total energy, transmittance, and beam radius used in (4). Formula (5
) Can be calculated by the calculating means 15 described above.

In FIG. 3, a line 33 represents a change in beam size with time, a line 34 represents an average energy density controlled by the control means 16, and a line 35 represents an optical luminance y after annealing. According to the control of the present invention, the average energy density is calculated by the calculation means 15 based on the detection outputs of the joule meter 13 and the profile meter 14, and the transmittance r of the variable attenuator 24 is variably set according to the calculation result. It can be seen that the average energy density of the laser light on the surface to be irradiated of the substrate 17 is held at a constant value very stably even when the time fluctuates over time. Further, since the optical luminance y is also maintained at a substantially constant value, it can be seen that a polycrystalline Si film having a uniform crystal state is formed by annealing.

As described above, in this embodiment, the laser processing apparatus is a laser annealing apparatus. However, the laser processing apparatus is not limited to this, and is, for example, a surface modification apparatus for a liquid crystal or a semiconductor device, a compound synthesis apparatus, or the like. May be.

It is a block diagram which simplifies and shows the structure of the laser processing apparatus 10 which is one Embodiment of this invention. It is a figure explaining the outline of average energy density control. It is a figure which shows the time-dependent change of the beam size at the time of using this invention apparatus and method, and an energy density. It is a figure which shows a profile in case the spreading angle of a laser beam is small. It is a figure which shows a profile in case the spreading angle of a laser beam is large. It is a figure which shows the time-dependent change of beam size and energy density.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Laser annealing apparatus 11 Laser oscillator unit 12 Irradiation optical system unit 13 Joule meter 14 Profile meter 15 Calculation means 16 Control means 17 Substrate 18 Process chamber 21 Laser oscillator 22, 27 Beam splitter 23 Power meter 24 Variable attenuator 25 Attenuator control part 26 Beam Plastic lens 28 stage

Claims (3)

A laser processing apparatus that performs processing by irradiating a workpiece with laser light,
A light source that emits laser light;
An irradiation optical system for irradiating the irradiation position of the workpiece with laser light emitted from a light source;
Energy detecting means for detecting the energy of the laser beam irradiated to the workpiece;
Profile detection means for detecting the profile of the laser light irradiated to the workpiece;
An arithmetic means for calculating an average energy density of laser light irradiated on the workpiece based on detection outputs of the energy detection means and the profile detection means;
And a control means for controlling the average energy density of the laser light applied to the workpiece to a predetermined value in response to the output of the computing means. The workpiece is a silicon film formed on a substrate,
2. The laser processing according to claim 1, wherein the processing performed by irradiating the silicon film with laser light controlled so that an average energy density becomes constant by the control means is laser annealing processing. apparatus. A laser processing method for performing processing by irradiating a workpiece with laser light emitted from a light source,
Detecting the energy of laser light applied to the workpiece;
Detecting the profile of the laser beam irradiated to the workpiece;
A step of calculating an average energy density of the laser beam irradiated to the workpiece based on the detected energy and profile of the laser beam;
In response to the calculation result of the average energy density, the step of controlling the average energy density of the laser light irradiated to the workpiece to a predetermined constant value;
A laser beam controlled so that the average energy density becomes a predetermined value,
And a step of processing by irradiating the workpiece.

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