JP4459581B2 - Laser device, laser irradiation method, and semiconductor device manufacturing method - Google Patents

Description

  The present invention relates to a laser apparatus or a laser irradiation method, and more particularly to a laser apparatus or a laser irradiation method having a mechanism for stabilizing the energy of output laser light. The present invention also relates to a method for manufacturing a semiconductor device including a step of crystallizing a semiconductor film using the laser device or the laser irradiation method.

Lasers are classified into gas lasers and solid-state lasers according to the laser medium, and there are various types. Lasers differ in the wavelength, energy, pulse characteristics, etc. of the obtained laser light depending on the laser medium, and searches for applications according to the properties of the laser light have been conducted. Among various lasers, YAG laser, CO ₂ laser, excimer laser, and the like are used in most industrial laser apparatuses.

  Among them, the excimer laser which is a gas laser is a powerful ultraviolet ray, and its wavelength is as short as 0.193 μm for ArF and 0.351 μm for XeF, and has excellent light collecting properties. Therefore, it is suitable for a field requiring ultra fine processing of μm level as represented by semiconductor manufacturing including mask molding and the like in addition to general part processing.

However, gas lasers typified by excimer lasers and CO ₂ lasers generally tend to fluctuate in the pressure of the gas that is the laser medium in the oscillator, and oscillate by circulating the gas that is the laser medium in the discharge tube. In this case, the gas flow rate is likely to fluctuate. For this reason, the energy of the laser beam output from the oscillator is difficult to be kept stable, and it is difficult to uniformly process the object to be processed.

  Therefore, conventionally, the fluctuation of the pressure of the laser medium in the discharge tube is detected so that the energy of the output laser light is stabilized, and the fluctuation of the pressure is canceled to cancel the fluctuation. A method for suppressing fluctuations in pressure or flow rate has been proposed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 07-038180 (page 2-3, FIG. 3)

  In Patent Document 1, a pressure fluctuation of a gas that is a laser medium is detected by a pressure sensor provided in a gas supply duct, and is input to a feedback control unit as a detection signal. The feedback control unit inverts the phase of the detection signal. Then, the waveform signal is subjected to frequency analysis by fast Fourier transform (FFT) on the detection signal whose phase is inverted in the waveform generator. The waveform signal is amplified and then input to the vibrator. The vibrator generates a pressure fluctuation in the opposite phase with the same amplitude as the pressure fluctuation detected by the pressure sensor according to the inputted waveform signal after amplification, and cancels the fluctuation in the pressure of the laser medium.

However, according to the above method, it is difficult to accurately generate the pressure fluctuation in the opposite phase by the vibrator, and there is a limit in suppressing the pressure fluctuation of the laser medium. Originally, the excimer laser has a smaller fluctuation in the energy of the laser beam to be output than the CO ₂ laser described in Patent Document 1. However, excimer lasers are evaluated for their excellent light-collecting properties and are frequently used for microfabrication. Therefore, higher levels of stability are required than CO ₂ lasers. Therefore, in the case of an excimer laser, it is difficult to achieve stabilization of the energy of the output laser light to a sufficient level in the case of an excimer laser when the method of canceling the pressure fluctuation of the laser medium using the vibrator as in the above method.

  If the output of the laser beam is not stable, it is difficult to uniformly process the workpiece. For example, in crystallization of a semiconductor film using laser light irradiation, it is considered that a difference in crystallinity is caused by a subtle fluctuation in energy of about 10%.

  Therefore, the present inventors sampled a part of the laser beam output from the pulsed excimer laser, and observed the fluctuation of the energy. FIG. 8A shows the value of the sampled laser light energy with respect to time. The oscillation frequency of the excimer laser is 25 Hz.

  FIG. 8B shows data obtained by performing FFT on the data shown in FIG. In FIG. 8B, the horizontal axis represents frequency and the vertical axis represents amplitude. In the data subjected to FFT, a markedly high peak was observed at a frequency of 0.24583 Hz. This frequency corresponds to the frequency of fluctuation of the energy of the laser beam with a fixed period observed in FIG.

  Note that, in FIG. 8A, during the period from the start of measurement to 20 seconds, due to the transient response of the detector of the measuring device, the fluctuation of energy is larger than the others, but regardless of whether the data in this period is cut or not, The data after the FFT is the same.

  Assuming that the semiconductor film is crystallized by scanning the laser beam having the energy fluctuation described above at 0.8 mm / sec, the energy density is highest at an interval of 0.8 / 0.24583≈3.3 mm. It is calculated that the semiconductor film is irradiated with laser light.

  FIG. 9 shows a photograph of a semiconductor film that has been crystallized by being irradiated with laser light from an excimer laser as viewed from above. As the laser light, a pulsed excimer laser was used, and the irradiation was performed at an oscillation frequency of 25 Hz and a scanning speed of 0.8 mm / sec. In the semiconductor film shown in FIG. 9, a plurality of horizontal stripes caused by the difference in crystallinity are visually recognized in the direction perpendicular to the scan direction indicated by the arrow. The interval between the plurality of horizontal stripes is 3.4 mm, which is substantially coincident with the value obtained by the above calculation of 3.3 mm. Therefore, the horizontal stripes are caused by fluctuations in the energy of the laser beam at a fixed period. I can hear that.

  Further, in FIG. 10, a photograph of the semiconductor film after crystallization viewed from the top and a part of the laser beam output from the pulsed excimer laser can be sampled, and the energy value can be expressed in 15 gradations. The figures shown as above are shown side by side. In FIG. 10, the oscillation frequency of the laser light is 30 Hz, the scanning speed is 1.0 mm / sec, and the scanning direction is as indicated by an arrow.

  As can be seen from FIG. 10, the semiconductor film after crystallization has a plurality of horizontal stripes caused by the difference in crystallinity in the direction perpendicular to the scanning direction. In addition, a plurality of horizontal stripes resulting from fluctuations in the periodic energy of the sampled laser light are formed by shading indicating the strength of the energy. These two horizontal stripes have the same interval. Therefore, a plurality of horizontal stripes that are observed in the semiconductor film due to the difference in crystallinity are caused by fluctuations in the energy of the laser light at a constant period. This can also be seen from FIG.

  When a thin film transistor (TFT) is manufactured using a semiconductor film with such a variation in crystallinity, the on-current varies depending on the location of the semiconductor film. In a light emitting device using the TFT as a transistor for controlling a current to the light emitting element, there is a problem that a high luminance region and a low luminance region are visually recognized as stripes.

  FIG. 11 shows a photograph of the upper surface of a semiconductor film after crystallization by laser light and a photograph of the upper surface in a state where all white is displayed on a light emitting device using the semiconductor film. Specifically, in the light-emitting device illustrated in FIG. 11, a pixel including a TFT formed using a crystallized semiconductor film and a light-emitting element in which a current supplied by the TFT is controlled is provided in the pixel portion. A plurality are provided. Note that the light emitting element uses an electroluminescent material capable of obtaining luminescence generated by applying an electric field.

  In FIG. 11, the crystallized semiconductor film 2000 and pixel portions 2001, 2002, and 2003 of the light-emitting device are overlapped at corresponding positions of the semiconductor film. Note that the pixel portions 2001, 2002, and 2003 of the light emitting device have different gradations for display.

  As shown in FIG. 11, horizontal stripes are visually recognized in a part 2001 of the pixel portion, although it is difficult to visually recognize the parts 2002 and 2003 of the pixel portion of the light emitting device. The horizontal stripes coincide with the horizontal stripes of the semiconductor film, and it can be confirmed that the horizontal stripes are displayed on the display of the light emitting device due to the variation in the energy of the laser light.

  In view of the above-described problems, an object of the present invention is to provide a laser device or a laser irradiation method capable of uniformly processing an object to be processed using laser light.

  The present inventors control the scanning speed of the laser beam output from the oscillator to perform the processing on the workpiece more uniformly than the conventional method of suppressing fluctuations in the pressure and flow rate of the medium in the oscillator. I thought I could do it.

  In the present invention, a part of the laser beam outputted from the oscillator is sampled to grasp the fluctuation of the energy of the laser beam. Then, using the obtained energy fluctuation data, the moving speed of the stage is controlled so that the sum of the energy of the laser beam applied to the object to be processed per unit time approaches a constant value.

Specifically, the correction means possessed by the laser device of the present invention is:
(B) Means for sampling a part of the laser light emitted from the oscillator (optical system)
(B) Means (sensor) for generating an electrical signal including, as data, fluctuations in the energy of the laser beam using a part of the laser beam sampled by the optical system
(C) By performing signal processing on the electrical signal, the state of fluctuation of the laser beam energy is grasped, and the speed of movement of the stage in the direction opposite to the scanning direction of the laser beam is determined by the energy of the laser beam. Means to control the stage driver so that it changes at the same phase as the fluctuation of the signal (signal processing unit)
have.

  In addition to the above means, (d) means for placing a workpiece (stage) or (e) means for controlling the position of the stage (stage driver) may be included in the configuration of the present invention.

  The scanning speed of the laser beam can be precisely controlled, and the processing of the object to be processed can be performed more uniformly than the conventional method using the vibrator.

  Further, by using the laser device for crystallization of a semiconductor film, the crystallinity of the semiconductor film can be made more uniform. Note that the method for manufacturing a semiconductor device of the present invention can be used for a method for manufacturing an integrated circuit or a semiconductor display device. In particular, liquid crystal display devices, light-emitting devices including light-emitting elements typified by organic light-emitting elements in each pixel, semiconductor display devices such as DMD (Digital Micromirror Device), PDP (Plasma Display Panel), and FED (Field Emission Display). When used for a semiconductor element such as a transistor provided in the pixel portion, it is possible to suppress the horizontal stripes due to the energy distribution of the laser light irradiated in the pixel portion from being visually recognized.

The present invention can be applied not only to excimer lasers and CO ₂ lasers but also to other gas lasers, and can be applied not only to gas lasers but also to solid-state lasers.

  In the present invention, by controlling the scanning speed of the laser beam, it is possible to perform the processing on the object to be processed more uniformly than the conventional method using the vibrator.

  In the present embodiment, the configuration of the correction means using the means for controlling the scan speed of the laser apparatus of the present invention will be described. FIG. 1 shows a block diagram of the correction means 101 of the present embodiment. A correction unit 101 illustrated in FIG. 1 includes an optical system 102, a sensor 103, a signal processing unit 104, and a stage driver 105.

  The optical path is controlled by the optical system 102 so that a part of the laser light oscillated from the oscillator 100 is sampled and incident on the sensor 103. Other laser beams are incident on an optical system 107 separate from the optical system 102 provided in the correction unit 101. The optical system 107 is used as means for processing the shape of the beam spot of the laser beam on the object to be processed on the stage 106. Hereinafter, in order to distinguish between the two optical systems, the optical system 102 provided in the correcting unit 101 is referred to as a first optical system, and the optical system 107 used as a unit for processing the shape of the laser light beam spot is referred to as the first optical system. This is called a second optical system.

  The sensor 103 converts part of the incident laser light into an electrical signal. As the sensor 103, any photoelectric conversion element may be used as long as the sensor 103 can generate an electric signal having the fluctuation of energy of laser light as data. For example, a photodiode, a phototransistor, a CCD (charge coupled device), or the like can be used.

  FIG. 2 is a graph showing energy fluctuations of sampled laser light. A pulsed excimer laser is used, the horizontal axis indicates time (sec), and the vertical axis indicates the relative ratio (%) of energy at each measurement point to the average value of the energy of all measurements. .

  2A is 10 Hz, FIG. 2B is 20 Hz, FIG. 2C is 30 Hz, FIG. 2D is 40 Hz, and FIG. 2E is 50 Hz.

  In the signal processing unit 104, signal processing of the input electric signal is performed, and the fluctuation of the fixed period is analyzed among the fluctuations of the energy of the laser beam. The signal processing is not limited to the fast Fourier transform, and various signal processing can be used. Among the fluctuations in the energy of the laser beam, the minimum required are the frequency and amplitude of fluctuations in a fixed period. Here, a case where signal processing is performed using fast Fourier transform will be described.

  The fast Fourier transform was performed according to the equation shown in Equation 1 below using the calculation program software IGOR Pro manufactured by WaveMetrics, Inc.

  When frequency analysis is performed by fast Fourier transform, the highest peak frequency and the peak height can be obtained. The frequency corresponds to a constant period fluctuation (constant period fluctuation) among fluctuations in energy of the laser beam. Hereinafter, the frequency is referred to as a fixed frequency. The relative height of the peak corresponds to the amplitude of the periodic fluctuation.

  FIG. 3 shows the data after performing fast Fourier transform on the data shown in FIG. 3A is FIG. 2A, FIG. 3B is FIG. 2B, FIG. 3C is FIG. 2C, and FIG. 3D is FIG. FIG. 3E corresponds to FIG. 2E, respectively. The horizontal axis represents frequency (Hz), and the vertical axis represents amplitude.

  In each of the graphs of FIGS. 3A to 3E, only one highest peak is observed. Specifically, it is 4.78 Hz in FIG. 3A, 4.78 Hz in FIG. 3B, 5.2275 Hz in FIG. 3C, 15.21 Hz in FIG. 3D, and 24 in FIG. The highest peak is observed at .8 Hz. The frequency of the peak corresponds to a fixed frequency.

  Then, an electrical signal including the fixed frequency as information is input to the signal processing unit 104. In the signal processing unit 104, the calculated constant periodic frequency is used, and the speed at which the stage moves in one direction (specifically, the direction opposite to the scanning direction of the laser beam) is constant. The stage driver 105 is controlled to move the stage 106 so as to change at the same frequency and the same phase as the period variation.

  FIG. 4A shows a waveform of the periodic fluctuation of the energy of the laser light calculated from the fast Fourier transform. If the periodic frequency is 1 / T, the periodic fluctuation period is represented by T. A represents the amplitude of the periodic fluctuation of the laser beam. FIG. 4B shows a waveform of the stage speed fluctuation generated from the waveform of the fixed period fluctuation shown in FIG. The waveform of the stage speed fluctuation in one direction has the same period T as the waveform of the fixed period fluctuation, and the phases thereof are the same. B represents the amplitude of the stage speed.

  The amplitude of the speed of the stage 106 determined by the signal processing unit 104 is most desirably set so that the total energy of the laser light irradiated per unit time becomes more constant. The amplitude of the stage speed can be adjusted using the peak intensity of the laser beam obtained by the FFT and the ratio of the laser beam incident on the sensor 103 and the energy of the remaining laser beam incident on the optical system 107. It is.

  Next, how to adjust the phase of the fluctuation of the laser beam and the phase of the stage speed will be described. There are various methods for adjusting the phase. In this embodiment, the phase of the speed of the stage 106 and the phase of the energy of the laser light before correction may be matched with a signal synchronized with the oscillation of the laser light in the oscillator. Specifically, the phase difference from the fluctuation of the laser beam before correction and the signal (reference signal) whose frequency is known in advance and the constant frequency of the laser beam before correction are calculated, The phase can be adjusted.

  In FIG. 5A, when the phase difference between the phase of the fluctuation of the laser beam and the phase of the stage speed is ideal, the waveform of the laser beam before correction is a broken line, and the waveform of the laser beam after correction is a solid line It shows with. However, FIG. 5A shows a waveform that does not include fluctuations that occur below the oscillation frequency in order to make it easier to understand the waveform of the periodic fluctuations. In FIG. 5A, the waveform of the laser beam before correction and the waveform of the laser beam after correction have the same phase. Therefore, it is considered that the phase of the speed fluctuation is set to exactly match the phase of the fixed period fluctuation of the laser light before correction. Then, the stability of the energy of the corrected laser beam can be further improved by adjusting the velocity amplitude so that the corrected amplitude A ′ of the laser beam becomes smaller.

  Next, in FIG. 5B, the waveform of the laser beam before correction when the speed phases do not match is indicated by a broken line, and the waveform of the laser beam after correction is indicated by a solid line. However, similarly to FIG. 5 (A), FIG. 5 (B) also shows a waveform that does not include fluctuations occurring below the oscillation frequency in order to make the periodic fluctuation waveform easy to understand. In FIG. 5B, the waveform of the laser beam before correction and the waveform of the laser beam after correction do not have the same phase. Therefore, it is predicted that the phase of the speed fluctuation does not match the phase of the fixed period fluctuation of the laser light before correction. In this case, the signal processor corrects the velocity phase separately, thereby suppressing the fixed period fluctuation of the corrected laser beam.

  As shown in FIG. 12A, when the width Wb of the beam spot 1101 is longer than the width Ws of the workpiece 1102 in the direction perpendicular to the scanning direction indicated by the arrow, the laser beam in the scanning direction A single scan can be done. As shown in FIG. 12B, when the width Wb of the beam spot 1101 is shorter than the width Ws of the workpiece 1102 in the direction perpendicular to the scanning direction indicated by the arrow, the laser beam in the scanning direction Scan multiple times. In either case, the stage speed in each scan is controlled so as to fluctuate in the same phase as the constant period fluctuation of the laser beam.

  With the above-described configuration, the total energy of the laser light emitted from the second optical system to the object to be processed placed on the stage 106 per unit time can be made close to a constant value. Therefore, it is possible to more uniformly process the object to be processed.

  The correction means stores information on the frequency and amplitude of the speed fluctuation of the stage 106 determined by the signal processing unit in a memory or the like, and adjusts the frequency and amplitude of the speed fluctuation of the stage 106 again next time. You may make it save time and effort.

  The laser beam scanning method includes an irradiation system moving type that fixes the object to be processed and moves the irradiation position of the laser light, and an object movement type that moves the object to be processed while fixing the irradiation position of the laser light. And a combination of the above two methods.

  The correction means described above is used for a workpiece moving type laser apparatus, but the present invention is not limited to this. The present invention can also be used for an irradiation system moving laser device or a laser device combining a workpiece moving type and an irradiation system moving type.

  In the case of an irradiation system moving type laser device, the moving speed of the irradiation position is controlled so as to change in the same phase with respect to fluctuations in the energy of the laser beam. That is, regardless of which method is used, in the present invention, the relative movement speed of the beam spot with respect to the object to be processed is controlled so as to change in the same phase with respect to the fluctuation of the laser beam energy. Just do it.

  Moreover, even if the fluctuation of energy has no periodicity, it is possible to control the relative speed of the laser beam spot with respect to the object to be processed at a response speed that allows the monitored result to be immediately fed back to the laser beam. , The fluctuation can be suppressed.

  The periodic fluctuation of the laser beam energy varies depending on the oscillation frequency of the oscillator. In the present embodiment, the relationship between the oscillation frequency of laser light emitted from an excimer laser oscillator and the frequency of periodic fluctuation will be described.

  FIG. 6 shows the relationship between the oscillation frequency (Hz) of the laser light and the highest peak frequency (Hz) obtained by Fourier transform. The horizontal axis represents the oscillation frequency (Hz), and the vertical axis represents the peak position (Hz) after Fourier transform. Each measurement has a different date, but the measurement conditions other than the oscillation frequency are the same.

  The highest peak frequency obtained by the Fourier transform means the frequency of the periodic fluctuation of the energy of the laser beam. The frequency of the periodic fluctuation is repeatedly increased and decreased in stages. Specifically, the frequency of the periodic fluctuation has a minimum value when the oscillation frequency is about 5 Hz, 12 Hz, and 25 Hz, and has a maximum value when the oscillation frequency is about 3 Hz, 10 Hz, and 17 Hz. And after the oscillation frequency exceeds about 25 Hz, it continues to increase.

  As shown in FIG. 6, by searching in advance the relationship between the oscillation frequency of the laser beam to be used and the frequency of the periodic fluctuation, the optimum condition for actually irradiating the workpiece with the laser beam is sought. Can help. For example, by selecting a condition for increasing the frequency of the periodic fluctuation, the interval between the horizontal stripes of the semiconductor film generated by the periodic fluctuation can be shortened to the extent that it cannot be visually recognized. Conversely, by selecting a condition that the frequency of the periodic fluctuation is low, it is possible to increase the interval between the horizontal stripes of the semiconductor film generated by the periodic fluctuation so that the horizontal stripes do not appear in the irradiation region. .

  Based on the data in FIG. 6, the same number of shots (about 13 shots) as the standard laser light irradiation conditions (oscillation frequency 30 Hz, scan speed 1.0 mm / sec) used for crystallization of the semiconductor film are obtained. The distance between the horizontal stripes that is expected to occur at each oscillation frequency when the laser beam is irradiated is calculated so as to be obtained. Specifically, the calculation is performed from the following equation (2).

d (ω): Spacing period of horizontal stripes
ω: oscillation frequency ω ₀ : oscillation frequency under standard irradiation conditions (= 30 Hz)
ν ₀ : substrate scanning speed under standard irradiation conditions (= 1.0 mm / sec)
T (ω): Frequency of periodic fluctuation

  FIG. 13 shows the relationship between the horizontal fringe period and the oscillation frequency calculated from the equation shown in Equation (2). A characteristic peak appeared at the oscillation frequency ω = 25 Hz, and the horizontal stripes at 25 Hz were predicted to be about 3.9 mm apart. At other oscillation frequencies, the intervals were about 60 to about 500 μm. The assumed value of the substrate scanning speed at 25 Hz is 0.833 mm / sec when the number of shots is adjusted to the standard condition (30 Hz, 1.0 mm / sec).

  In this example, an example of the laser device of the present invention described in the embodiment mode will be described.

  FIG. 7 shows the configuration of the laser apparatus of this embodiment. A part of the laser light oscillated from the oscillator 1500 is sampled in the optical system 1502. The sampled laser light is incident on the sensor 1503.

  On the other hand, the remaining laser light other than the sampled laser light is incident on the beam expander 1504. In this embodiment, a shutter 1505 for blocking laser light is provided in the optical path between the oscillator 1500 and the beam expander 1504, but it is not always necessary to provide it.

  The beam expander 1504 can suppress the spread of the incident laser light and can adjust the size of the beam spot.

  The laser light emitted from the beam expander 1504 is condensed by the beam homogenizer 1506 so that the shape of the beam spot is rectangular, elliptical, or linear. The condensed laser light is reflected by the mirror 1507 and enters the lens 1508. The incident laser light is condensed again by the lens 1508 and irradiated to the substrate 1509 on which the semiconductor film is formed. In this embodiment, a cylindrical lens is used as the lens 1508.

  The substrate 1509 is placed on a stage 1511, and the position of the stage 1511 is controlled by three position control means (drivers) 1512 to 1514. Specifically, the stage 1511 can be rotated in the horizontal plane by the φ direction position control means 1512. Further, the stage 1511 can be moved in the X direction in the horizontal plane by the X direction position control means 1513. Further, the stage 1511 can be moved in the Y direction in the horizontal plane by the Y direction position control means 1514. The operation of each position control means is controlled by a stage driver 1515 included in the central processing unit 1510.

  By controlling the operation of the above-described three position control means, the position of the substrate 1509 irradiated with the laser light can be controlled.

  On the other hand, the sensor 1503 converts the sampled laser light into an electrical signal and inputs the electrical signal to a signal processing unit 1516 included in the central processing unit 1510. The electrical signal has the state of fluctuation of the laser beam energy as data. Then, the data is analyzed by the signal processing in the signal processing unit 1516, and the fluctuation state of the energy of the laser light is grasped.

  A reference signal synchronized with the transmission of the laser beam is input from the oscillator 1500 to the signal processing unit 1516. The signal processing unit 1516 uses the grasped fluctuation state, the reference signal, the ratio of the energy of the sampled laser light among the laser light oscillated from the oscillator, and the like at a speed having the same phase as the fluctuation state. Control is performed using a stage driver 1515 so as to move the stage 1511.

  Specifically, if the operation of the above-described three position control means is controlled so that the relative movement speed of the beam spot with respect to the substrate 1509 changes in the same phase as the fluctuation of the energy of the laser beam. good.

  The correction unit 1501 of the present invention includes an optical system 1502, a sensor 1503, and a signal processing unit 1516. Further, a stage driver 1515 may be included.

  Further, as in this embodiment, a monitor 1517 using a light receiving element such as a CCD may be provided so that the position of the substrate can be accurately grasped.

  This embodiment can be implemented in combination with the first embodiment.

The block diagram which shows the structure of a correction | amendment means. The graph which shows the measured value of the energy for every oscillation frequency. The graph which shows the data after FFT of the measured value of the energy for every oscillation frequency. The figure which shows the fixed period fluctuation | variation of energy, and the fluctuation | variation of the moving speed of a stage. The figure which shows the fluctuation | variation of the speed of movement of a stage. The graph which shows the relationship between an oscillation frequency and the peak position of the frequency after a Fourier transform. The figure which shows the structure of the laser apparatus of this invention. The laser beam energy value with respect to time and the data after FFT. A top view of a crystallized semiconductor film irradiated with excimer laser light. The photograph which looked at the semiconductor film after crystallizing from the upper surface, and the figure which showed the value of the energy of a laser beam with light and shade. The photograph which looked at the semiconductor film after crystallization from the upper surface, and the photograph of the pixel part of the light-emitting device formed using this semiconductor film. The figure which shows the relationship between the beam spot of a laser beam, and the width | variety of a to-be-processed object. The figure which shows the relationship between an oscillation frequency and the space | interval of a horizontal stripe when the number of shots is match | combined with the standard.

Claims (13)

Means for generating an electrical signal including the fluctuation of the energy of the laser beam as data;
Performs signal processing on the electrical signal, and means for controlling to vary the beam spot of the laser beam, the relative speed with respect to the object to be processed, the same phase at and at the same frequency as the fluctuation in the object to be processed A laser device comprising: An optical system for sampling a part of the laser light emitted from the oscillator;
Means for generating an electrical signal including fluctuations in energy of the laser beam as data using the partial laser beam;
Performs signal processing on the electrical signal, and means for controlling to vary the beam spot of the laser beam, the relative speed with respect to the object to be processed, the same phase at and at the same frequency as the fluctuation in the object to be processed A laser device comprising: An optical system for sampling a part of the laser light emitted from the oscillator;
Means for generating an electrical signal including fluctuations in energy of the laser beam as data using the partial laser beam;
The electric signal is subjected to signal processing, and the relative speed of the beam spot of the laser beam on the object to be processed is changed at the same phase and the same frequency as the fluctuation. And a means for controlling the position of the object. An optical system for sampling a part of the laser light emitted from the oscillator;
Means for generating an electrical signal including fluctuations in energy of the laser beam as data using the partial laser beam;
Signal processing is performed on the electrical signal, and the beam spot of the laser beam on the object to be processed is changed at the same phase and at the same frequency as the fluctuation, with respect to the object to be processed. And a means for controlling the position of the laser device. In any one of Claims 1 thru | or 4,
The laser apparatus is characterized in that the signal processing determines a periodic frequency from fluctuations in the energy of the laser light, and performs the periodic frequency based on data. In claim 5,
The periodic frequency is obtained by a fast Fourier transform. Generate an electrical signal that contains the fluctuations in the energy of the laser light as data,
Performs signal processing on the electrical signal, the beam spot of the laser beam in the object to be processed, the relative speed with respect to the object to be treated, to control so as to change in phase a and the same frequency as the fluctuation The laser irradiation method characterized. Sampling a part of the laser light emitted from the oscillator,
Generating an electrical signal including the fluctuation of the energy of the laser beam as data;
By performing signal processing on the electrical signal, the fluctuation of the energy of the laser beam is analyzed, and the relative speed of the beam spot of the laser beam on the workpiece to the workpiece is the same phase as the fluctuation. And a laser irradiation method characterized in that control is performed so as to change at the same frequency. Sampling a part of the laser light emitted from the oscillator,
Generating an electrical signal including the fluctuation of the energy of the laser beam as data;
The electric signal is subjected to signal processing, and the relative speed of the beam spot of the laser beam on the object to be processed is changed at the same phase and the same frequency as the fluctuation. A laser irradiation method characterized by controlling the position of an object. Sampling a part of the laser light emitted from the oscillator,
Generating an electrical signal including the fluctuation of the energy of the laser beam as data;
Signal processing is performed on the electrical signal, and the beam spot of the laser beam on the object to be processed is changed at the same phase and at the same frequency as the fluctuation, with respect to the object to be processed. A laser irradiation method characterized by controlling the position of the laser beam. In any one of Claims 7 to 10,
In the laser irradiation method, the signal processing determines a periodic frequency by fast Fourier transform from fluctuations in energy of the laser light, and applies the periodic frequency based on data. Sampling a part of the laser light emitted from the oscillator,
Using the part of the laser light, an electrical signal including data of energy fluctuation of the laser light is generated,
Signal processing is performed on the electrical signal, and the relative speed of the beam spot of the laser beam in the semiconductor film with respect to the semiconductor film is controlled so as to change at the same phase and the same frequency as the fluctuation,
The method for manufacturing a semiconductor device comprising a benzalkonium be irradiated with the laser beam to the semiconductor film. In claim 12,
By performing signal processing on the electrical signal, the frequency, amplitude, and phase of fluctuations in the energy of the laser light are calculated,
Using the ratio of the energy of the laser light oscillated from the oscillator and the part of the laser light, the calculated frequency, the amplitude, and the phase, the beam spot of the laser light in the semiconductor film in addition to controlling to vary the relative speed with respect to the semiconductor film in the same phase at and at the same frequency as the fluctuation in the total energy of the laser light radiated on the semiconductor film per unit of time is constant the method for manufacturing a semiconductor device comprising a control child so.