JP2007150245A - Light irradiation device, method of regulating light irradiation device, crystallization apparatus, crystallization method, and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light irradiation device which can suppress the impact of the strain of the wave face of a luminous flux resulting from the impairment of the behavior of a laser light source with time, etc., and can form a desired light intensity distribution stably. <P>SOLUTION: The light irradiation device includes the laser light source (1), an illumination optical system (4) including a homogenizer for illuminating an optical modulator (3) in a superposition based on the light from the laser light source, an imaging optical system (8) formed in a predetermined light intensity distribution in a predetermined surface (6) based on the light in which the phase modulation was carried out by the optical modulator, a wave face correction optical element (5) which is arranged between the laser light source and the homogenizer, and rectifies and ejects the wave face of incoming luminous flux, wave face measurement sections (9, 10) which takes out the luminous flux from an optical path between the wave face correction optical element and the homogenizer, and measures the wave face of this luminous flux, and a control section (11) for controlling the wave face correction optical element based on the output of the wave face measurement sections. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light irradiation apparatus, a light irradiation apparatus adjustment method, a crystallization apparatus, a crystallization method, and a device. In particular, the present invention relates to a technique for manufacturing a field effect transistor on a surface layer portion of a non-single crystal thin film substrate, a non-single crystal thin film substrate for manufacturing the field effect transistor, and a liquid crystal display device and information processing incorporating the field effect transistor. The present invention relates to a technique suitable for a manufacturing technique of an electronic device such as a device.

  In a display device such as an active matrix liquid crystal display device or an organic EL display device, in order to drive each pixel individually, a number of thin film transistors (Thin-Film-Transistors: "TFT") is formed. The amorphous silicon (amorphous-silicon: hereinafter referred to as “a-Si”) film in which the source, drain, and channel regions of the TFT are formed has a low forming temperature and is relatively easily formed by a vapor phase method. Therefore, the semiconductor thin film is generally used as a semiconductor thin film used for a TFT.

  However, the amorphous silicon film is inferior in physical properties such as conductivity to a poly-silicon (hereinafter referred to as “p-Si”) film (a-Si mobility is p-Si mobility). There is a disadvantage that it is two orders of magnitude lower than the degree). For this reason, in order to increase the operating speed of the TFT, a technique for forming the source, drain, and channel regions of the TFT in the polycrystalline silicon film, such as an annealing method using an excimer laser (Excimer Laser Annealing; hereinafter referred to as “ELA method”). Is used). This ELA method can be performed in a temperature range in which a general-purpose glass substrate can be used, that is, a temperature range from room temperature to about 500 ° C.

  In the ELA method, for example, an amorphous silicon film is deposited on a substrate to a predetermined thickness (for example, a thickness of about 50 nm), and then a KrF (krypton fluorine) excimer laser beam having a wavelength of 248 nm is deposited on the amorphous silicon film. A laser beam such as XeCl (xenon chlorine) excimer laser beam having a wavelength of 308 nm is shaped into a linear shape, and the substrate is scanned and irradiated to locally melt and recrystallize the amorphous silicon film in the irradiated region. The crystallization method is to change to a polycrystalline silicon film having an average grain size of about 0.1 to 0.2 μm.

  The ELA method can be applied to various other processes by changing the average intensity (fluence) of laser light. For example, if the intensity of the laser beam is set so that only the action of heating is exerted, it can be used for the impurity activation step of the TFT. Further, if the intensity of the laser beam is set to be extremely large, a rapid temperature rise is caused, and therefore, it can be used for removing a film in the TFT. The use of these phenomena is not limited to TFTs, and can be widely applied to semiconductor processes.

  By the way, in the case of a display device such as a liquid crystal display device or an organic EL display device, when a TFT is formed on a polycrystalline silicon film in order to increase the operation speed or performance, the crystal grain boundary of the polycrystalline silicon film becomes the TFT. It will exist in the channel region. In this case, the number of crystal grain boundaries formed in the channel region of each TFT is different. Due to the difference in the number of crystal grain boundaries, variations in characteristics such as threshold voltage and mobility for each TFT are remarkably increased. The variation in the threshold voltage for each TFT causes the operating characteristics of the display device as a whole to deteriorate significantly, and causes image quality and the like to deteriorate.

  For this reason, the number of crystal grain boundaries in the channel region of each TFT is made as uniform as possible, or a crystallized region having a large grain size is formed and each TFT is formed in each crystallized region. It is desired to eliminate the grain boundary from the channel region of each TFT by controlling the position. Conventionally, a technique for generating crystallized silicon with a large grain size by irradiating a semiconductor film with light having a light intensity distribution with an inverse peak pattern generated via a phase shift mask (phase shifter) has been disclosed (non- (See Patent Literature 1, Patent Literature 1 and 2).

Chang-Ho OH et al., "A Novel Phase-Modulated Excimer-Laser Crystallization Method of Silicon Thin Films", Japanese Journal of Applied Physics, Vol. 37 (1998), pp. L492-L495 JP 2000-082669 A JP 2000-306859 A

  According to the research of the present inventor, in order to eliminate the crystal grain boundary from the active layer of the TFT by generating a crystal having a grain size sufficiently larger than the size of the TFT and controlling the formation position, In addition, it is necessary to stably form a desired light intensity distribution. If the light intensity distribution (planar image) of the laser light on the amorphous silicon film as the substrate to be processed is adjusted to an appropriate light intensity distribution, a position-controlled large grain silicon single crystal thin film can be obtained. . By aligning the single crystal thin film and the channel region of the TFT, it is possible to create a high performance TFT having no crystal grain boundary in the active region.

  Furthermore, the light intensity gradient on the surface of the substrate to be processed is an important factor for stable crystallization of the desired particle size, and micro stability and macro uniformity of the light intensity distribution are important. It is. In order to realize the micro stability and the macro uniformity of the light intensity distribution, it is necessary that the characteristics of the laser light source (local light parallelism, coherency, etc.) are stable. However, according to the research of the present inventor, it has been found that these characteristics deteriorate when an excimer laser light source is used for a long time.

  When an excimer laser light source is used for a long period of time, the parallelism and coherency of light in a local region are lowered, and wavefront distortion (disturbance) occurs in the emitted light beam. The distortion of the wavefront of the light beam emitted from the laser light source is caused by image shift at the position of the substrate to be processed (position shift of light intensity distribution on a plane orthogonal to the optical axis), image unevenness (illuminance unevenness), image blur. A phenomenon such as (positional deviation of the light intensity distribution in the optical axis direction) is generated. Regarding the method of grasping the phenomenon such as image shift, unevenness, and blur, since the excimer laser beam is invisible, it is difficult for an operator to monitor with the naked eye.

  Therefore, for example, after scanning the substrate on which amorphous silicon (amorphous silicon) is formed, laser annealing is actually performed, and a process of highlighting crystal grain boundaries by Secco etching or the like is performed, followed by a scanning electron microscope. By observing the crystal structure by, for example, a method for judging the occurrence of a phenomenon such as an image shift, unevenness, or blur, a so-called off-line inspection method can be performed. Since this off-line inspection method is very time consuming and laborious, it is not practical and it is difficult to form a stable crystal structure.

  The present invention has been made in view of the above-described problems, and stably forms a desired light intensity distribution by suppressing the influence of distortion of the wavefront of a light beam caused by deterioration of characteristics of a laser light source over time. An object of the present invention is to provide a light irradiation apparatus that can perform the above-described process.

In order to solve the above problems, in the first embodiment of the present invention, a laser light source;
An illumination optical system including a homogenizer for superimposingly illuminating a light modulation element based on light from the laser light source;
An imaging optical system that forms a predetermined light intensity distribution on a predetermined surface based on the light phase-modulated by the light modulation element;
A wavefront correcting optical element disposed between the laser light source and the homogenizer to correct and emit a wavefront of an incident light beam;
A wavefront measuring unit that takes out a light beam from an optical path between the wavefront correcting optical element and the homogenizer and measures a wavefront of the light beam;
And a control unit that controls the wavefront correcting optical element based on an output of the wavefront measuring unit.

In the second embodiment of the present invention, a laser light source;
An illumination optical system including a homogenizer for superimposingly illuminating a light modulation element based on light from the laser light source;
An imaging optical system that forms a predetermined light intensity distribution on a predetermined surface based on the light phase-modulated by the light modulation element;
A wavefront correcting optical element disposed between the laser light source and the homogenizer to correct and emit a wavefront of an incident light beam;
A movable diaphragm that variably limits the pupil of the illumination optical system;
A beam profiler for measuring the light intensity distribution formed on the predetermined surface;
A control unit for controlling the movable diaphragm and the wavefront correcting optical element,
The control unit provides the light irradiation apparatus that controls the wavefront correction optical element based on information on a light intensity distribution measured according to a change in a pupil of the illumination optical system.

In the third embodiment of the present invention, the light modulation element is superimposedly illuminated by the light from the laser light source by the illumination optical system including the homogenizer, and the light phase-modulated by the light modulation element is applied to the predetermined surface by the imaging optical system. An adjustment method of a light irradiation device that forms an image and forms a predetermined light intensity distribution on the predetermined surface,
A wavefront measuring step for measuring a wavefront of a light beam extracted from the optical path on the light source side of the homogenizer;
And a wavefront correcting step of correcting a wavefront of a light beam incident on the homogenizer based on a measurement result obtained in the wavefront measuring step.

In the fourth aspect of the present invention, the light modulation element is superimposedly illuminated by the light from the laser light source by the illumination optical system including the homogenizer, and the light phase-modulated by the light modulation element is applied to the predetermined surface by the imaging optical system. An adjustment method of a light irradiation device that forms an image and forms a predetermined light intensity distribution on the predetermined surface,
A limiting step of variably limiting the pupil of the illumination optical system;
A distribution measuring step for measuring a light intensity distribution formed on the predetermined surface;
And a wavefront correction step of correcting a wavefront of a light beam incident on the homogenizer based on a measurement result obtained in the distribution measurement step according to a change in a pupil of the illumination optical system. provide.

In the fifth aspect of the present invention, the light modulation element is superimposedly illuminated by the light from the laser light source by the illumination optical system including the homogenizer, and the light phase-modulated by the light modulation element is applied to the predetermined surface by the imaging optical system. An adjustment method of a light irradiation device that forms an image and forms a predetermined light intensity distribution on the predetermined surface,
A coarse accuracy correction step of correcting the wavefront of the light beam incident on the homogenizer with coarse accuracy using the adjustment method of the third embodiment;
There is provided an adjustment method comprising: a fine accuracy correction step of correcting the wavefront of the light beam incident on the homogenizer with a fine accuracy using the adjustment method of the fourth embodiment.

  In a sixth aspect of the present invention, the light irradiation apparatus according to the first or second aspect and a stage for holding a non-single crystal semiconductor film on the predetermined surface, the non-single crystal held on the predetermined surface There is provided a crystallization apparatus characterized in that a crystallized semiconductor film is produced by irradiating a semiconductor film with light having the predetermined light intensity distribution.

  In the seventh embodiment of the present invention, the light irradiation apparatus of the first embodiment or the second embodiment is used to irradiate the non-single crystal semiconductor film held on the predetermined surface with light having the predetermined light intensity distribution. There is provided a crystallization method characterized in that a crystallized semiconductor film is formed.

  In the eighth embodiment of the present invention, the non-single crystal semiconductor film held on the predetermined surface has the predetermined light intensity distribution using the light irradiation apparatus adjusted by the adjustment method of the third to fifth embodiments. There is provided a crystallization method characterized in that a crystallized semiconductor film is produced by irradiation with light.

  According to a ninth aspect of the present invention, there is provided a device manufactured using the crystallization apparatus according to the sixth aspect or the crystallization method according to the seventh or eighth aspect.

  In the light irradiation apparatus of the present invention, a desired light intensity distribution is stably formed on the surface of the substrate to be processed while suppressing the influence of the wavefront distortion of the light beam caused by the deterioration of the characteristics of the laser light source over time. As a result, crystallization with a desired particle size can be performed stably. As a result, for example, a crystal having a grain size sufficiently larger than the size of the TFT can be generated, and the crystal grain boundary can be excluded from the active layer of the TFT by controlling the formation position.

  Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram schematically showing a configuration of a light irradiation apparatus according to the first embodiment of the present invention. Referring to FIG. 1, a light irradiation apparatus according to the first embodiment includes a laser light source 1, an attenuator 2 disposed immediately after the laser light source 1, and a phase shifter (light modulation element) 3 using laser light that has passed through the attenuator 2. An illumination optical system 4 for illuminating, a deformable mirror 5 disposed between the attenuator 2 and the illumination optical system 4, a substrate stage 7 for holding the substrate 6 to be processed, the phase shifter 3 and the substrate 6 to be processed And an imaging optical system 8 provided therebetween.

  The light irradiation apparatus of the first embodiment measures a half mirror (beam splitter) 9 disposed between the deformable mirror 5 and the illumination optical system 4 and the wavefront of the laser light reflected by the half mirror 9. And a control unit 11 that controls the deformable mirror 5 based on the output of the wavefront sensor unit 10. As the laser light source 1, a light source capable of emitting an energy beam for melting the object to be crystallized, for example, an ArF excimer laser light source, a XeF excimer laser light source, a KrF excimer laser light source, a XeCl excimer laser light source, or the like can be used.

  The laser light oscillated from the laser light source 1 is attenuated by the attenuator 2 whose inclination angle with respect to the optical axis is variable, and after the light intensity is adjusted, the illumination optical system 4 is passed through the deformable mirror 5 and the half mirror 9. Is incident on. Operations of the deformable mirror 5 and the half mirror 9 will be described later. As shown in FIG. 2, the laser light incident on the illumination optical system 4 is expanded through a telescope (beam expander) 4a, and then a homogenizer 4b composed of a pair of lens arrays 4ba and 4bb and a field lens 4bc. Is incident on. The light flux that has passed through the homogenizer 4b illuminates the phase shifter 3 in a superimposed manner.

  The homogenizer 4b makes it possible to equalize the incident angle on the phase shifter 3 for the laser light incident on the illumination optical system 4. Thus, the illumination optical system 4 irradiates the phase shifter 3 with laser light having a substantially uniform light intensity distribution. The laser light that has entered the phase shifter 3 and has undergone phase modulation enters the substrate 6 to be processed via the imaging optical system 8. Here, the imaging optical system 8 optically conjugates the phase pattern surface of the phase shifter 3 and the substrate 6 to be processed. In other words, the substrate 6 to be processed is set to a surface optically conjugate with the phase pattern surface of the phase shifter 3 (image surface of the imaging optical system 8).

  The imaging optical system 8 includes a first positive lens group 8a, a second positive lens group 8b, and an aperture stop 8c disposed between these lens groups. The size of the aperture (light transmitting portion) of the aperture stop 8c (and consequently the image-side numerical aperture NA of the imaging optical system 8) is set so as to generate a required light intensity distribution on the semiconductor film of the substrate 6 to be processed. Has been. The imaging optical system 8 may be a refractive optical system, a reflective optical system, or a refractive reflective optical system.

The substrate 6 to be processed is formed by sequentially forming a lower insulating film, a semiconductor thin film, and an upper insulating film on the substrate. That is, the substrate 6 to be processed is formed by sequentially forming a base insulating film, a non-single crystal film such as an amorphous silicon film and a cap film on a transparent substrate such as a glass plate for liquid crystal display by chemical vapor deposition (CVD). It has been done. The cap film is, for example, SiO ₂ or SiO _x . The base insulating film prevents the amorphous silicon film and the glass substrate from coming into direct contact to prevent components such as Na contained in the glass from entering the amorphous silicon film, and the heat of the amorphous silicon film directly In order to prevent heat transfer to the glass substrate, SiN or a multilayer film of SiN and SiO ₂ is used.

  A non-single crystal silicon thin film is a semiconductor film to be crystallized. The cap film is heated by a part of the light beam incident on the non-single-crystal silicon thin film, and stores the heated temperature. This heat storage effect is that when the incidence of the light beam is interrupted, the high temperature part of the irradiated surface of the non-single-crystal silicon thin film is relatively rapidly cooled, but this temperature gradient is relaxed and the large grain size is reduced in the lateral direction. Promotes crystal growth. The substrate 6 to be processed is positioned and held at a predetermined position on the substrate stage 7 by a vacuum chuck or an electrostatic chuck.

  In the light irradiation apparatus shown in FIG. 1, for example, a reverse peak light intensity distribution is formed immediately after passing through the phase shifter 3, and an image of the reverse peak light intensity distribution is formed by the imaging optical system 8. Formed on the surface. As a result, a crystal grows from the crystal nucleus in the lateral direction along the light intensity gradient direction in the light intensity distribution having an inverse peak shape, and a crystallized semiconductor film having a large particle size is generated. However, as described above, the wavefront distortion of the light flux occurs due to the deterioration of the characteristics of the laser light source over time, and a desired light intensity distribution on the surface of the substrate 6 to be processed due to the influence of the wavefront distortion. Cannot be formed stably.

  Specifically, when an ideal plane wave light beam having no distortion (disturbance) in the wavefront is incident on the homogenizer 4b in the illumination optical system 4, the light from each of the plurality of small light sources formed by the homogenizer 4b is also the same. The phase shifter 3 is illuminated with a planar wavefront, and light from each small light source forms a desired light intensity distribution as a clear image on the plane immediately after the phase shifter 3. As a result, the light from each small light source forms a desired light intensity distribution as a sharp composite image on the surface of the substrate 6 to be processed via the imaging optical system 8.

  On the other hand, when a light beam having a wavefront distortion is incident on the homogenizer 4b in the illumination optical system 4, light from at least some of the plurality of small light sources formed by the homogenizer 4b is also a phase light beam having a wavefront distortion. The shifter 3 is illuminated. Therefore, light from a small light source forms a desired light intensity distribution as a clear image on a plane immediately after the phase shifter 3, but light from a small light source is on the plane immediately after the phase shifter 3. A light intensity distribution as a distorted image is formed.

  Here, the “distorted image” refers to an image position shift on a plane orthogonal to the optical axis caused by incident light that is not ideal wavefront aligned light, and the position of the image in the optical axis direction. Displacement, distortion of image shape, etc. Light from each small light source forms a light intensity distribution as a blurred composite image on the surface of the substrate 6 to be processed via the imaging optical system 8. That is, the light intensity distribution formed on the surface of the substrate 6 to be processed is displaced along the surface of the substrate 6 as compared with the desired light intensity distribution, or in the optical axis direction of the imaging optical system 8 ( The position is shifted in the focus direction) or the shape (profile) is distorted, and a desired light intensity distribution cannot be obtained on the surface of the substrate 6 to be processed.

  In order to solve this problem, there is a method of obtaining a desired light intensity distribution by using only the central portion without using the periphery of the laser beam, that is, by using only a light beam having a substantially uniform wavefront. However, with this method, the available light energy is greatly reduced, resulting in an extremely low throughput.

  Further, as shown in FIG. 3, a method of obtaining a desired light intensity distribution by using only a light beam having a substantially uniform wavefront by using a two-stage homogenizer (see FIG. 2), which is normally a one-stage structure. There is also. In the two-stage configuration shown in FIG. 3, after being enlarged through the telescope 4a, the second homogenizer 4b (4ba, 4bb, 4bc) is provided through a first homogenizer 4b (4ba, 4bb, 4bc). The incident surface of the homogenizer 4c is illuminated in a superimposed manner.

  Further, the light flux that has passed through the second homogenizer 4c illuminates the phase shifter 3 in a superimposed manner. By the first homogenizer 4b, the laser beam incident on the illumination optical system 4 is made uniform with respect to the incident angle on the phase shifter 3. Further, the second homogenizer 4c makes it possible to equalize the light intensity at each position in the plane on the phase shifter 3 with respect to the laser light whose incident angle from the first homogenizer 4b is made uniform. However, even in the method of using a two-stage homogenizer, the available light energy is greatly reduced, and the throughput is extremely reduced.

  In addition, since the above-mentioned problem is caused by the deterioration of the characteristics of the laser light source over time, there is a method of replacing the tube (laser gas container) of the laser light source. However, this method is not practical from the viewpoint of cost because the tube of the laser light source is very expensive.

  Therefore, in the first embodiment, a deformable mirror 5 and a half mirror 9 are provided between the laser light source 1 and the illumination optical system 4, and the wavefront of the laser beam taken out from the illumination optical path by the half mirror 9 is a wavefront sensor. A configuration in which the deformable mirror 5 is controlled by the control unit 11 based on the output of the wavefront sensor unit 10 while being measured by the unit 10 is employed. The deformable mirror 5 is a wavefront correcting optical element for correcting wavefront distortion (disturbance). By the way, a deformable mirror (made by Intellite), which is commercially available, uses the electrostatic stress generated between the matrix-shaped high-voltage electrodes provided on the back surface of the mirror made of thin film aluminum to localize the mirror plane. It is an active deformation mirror that controls the wavefront by deforming it.

  Moreover, as the wavefront sensor unit 10, for example, a Shack-Hartmann type wavefront sensor can be used. In this case, the wavefront sensor unit 10 includes, in order from the light incident side, for example, a protective shutter (not shown), a microlens array 10a, and a photodetector (for example, a CCD) 10b having a detection surface at the condensing position. Consists of. For example, a personal computer can be used as the control unit 11 that analyzes the measurement result of the wavefront sensor unit 10 and controls the deformation of the reflecting surface of the deformable mirror 5.

  As shown in FIG. 4A, the microlens array 10a of the wavefront sensor unit 10 includes a large number of microlenses (microlenses) 10aa arranged in a grid pattern. Therefore, the light beam incident on the microlens array 10a is divided into wavefronts by a large number of microlenses 10aa, and the light beam that has passed through each microlens 10aa is condensed on the detection surface 10ba of the CCD 10b. When the wavefront of the light beam incident on the wavefront sensor unit 10 is flat and has no distortion, as shown in FIG. 4B, the CCD 10b corresponds to a large number of microlenses 10aa arranged in a grid pattern. A large number of condensing points are formed in a grid pattern on the detection surface 10ba.

  On the other hand, when the wavefront of the light beam incident on the wavefront sensor unit 10 is distorted, one or more condensing points on the detection surface 10ba of the CCD 10b correspond to the wavefront distortion as shown in FIG. Deviation from a predetermined position. Based on the positional deviation information from the predetermined position of one or a plurality of condensing points on the detection surface 10ba of the CCD 10b, the control unit 11 provides information on the distortion of the wavefront of the light beam incident on the wavefront sensor unit 10, and thus the laser light source. Information on the wavefront distortion of the light beam emitted from 1 is calculated. Then, the control unit 11 calculates the required deformation amount of the deformable mirror 5 necessary for correcting the wavefront distortion based on the wavefront distortion information obtained by calculation, and calculates the reflection surface of the deformable mirror 5. Change the required area by the required amount.

  Hereinafter, the wavefront adjustment method according to the first embodiment will be described with reference to the flowchart of FIG. In the wavefront adjustment method of the first embodiment, first, an allowable range of wavefront distortion (condensation point allowable range of focus on the detection surface 10ba of the CCD 10b) is read into the control unit 11 (S11). Next, the laser light source 1 is turned on to cause the laser beam to oscillate (S12). Thereafter, the wavefront sensor unit 10 measures (collects) wavefront distortion data (S13), and the control unit 11 determines whether or not the measured wavefront distortion amount is within an allowable range (S14). If it is determined in the determination step S14 that the wavefront distortion amount is within the allowable range, the wavefront adjustment method ends.

  On the other hand, when it is determined in the determination step S14 that the wavefront distortion amount exceeds the allowable range, the control unit 11 calculates a required deformation amount of the deformable mirror 5 necessary for correcting the wavefront distortion ( S15). Next, the control unit 11 deforms the required area of the reflecting surface of the deformable mirror 5 by the required amount based on the calculation result of the required deformation amount (S16). In this way, the laser light source 1 is turned on and the laser beam is pulse-oscillated again (S12), the wavefront distortion data is measured (S13), and it is determined whether the measured wavefront distortion amount is within the allowable range (S14). ).

  When it is determined in the second determination step S14 that the wavefront distortion amount is within the allowable range, the wavefront adjustment method ends. On the other hand, when it is determined in the second determination step S14 that the wavefront distortion amount exceeds the allowable range, the calculation step S15, the deformation step S16, the oscillation step S12, the measurement step S13, and the determination step S14 are repeated. Perform proper adjustment (correction) of the wavefront.

  Thus, in the light irradiation apparatus of the first embodiment, the desired light intensity distribution on the surface of the substrate 6 to be processed is suppressed while suppressing the influence of the distortion of the wavefront of the light beam caused by the deterioration of the characteristics of the laser light source 1 over time. Can be stably formed, and as a result, crystallization with a desired particle size can be performed stably. That is, for example, a crystal having a grain size sufficiently larger than the size of the TFT can be generated, and the crystal grain boundary can be excluded from the active layer of the TFT by controlling the formation position. The timing for adjusting the wavefront is preferably immediately before laser annealing.

In the first embodiment, the optical system portion subsequent to the illumination optical system 4 is irrelevant to the wavefront adjustment. For this reason, a light shielding plate for protecting the optical system may be inserted between the half mirror 9 and the illumination optical system 4 during the wavefront adjustment. The half mirror 9 does not have a transmittance of 50% and a reflectance of 50%. For example, a mirror having a transmittance of 99% and a reflectance of 1% can be used. Various modifications are possible for the ratio of transmission and reflection of the half mirror 9, but considering the laser light resistance of the wavefront sensor unit 10, the laser fluence in the CCD 10b is about 10 mJ / cm ² or less. It is preferable to use the half mirror 9 having a transmittance of about 95% and a reflectance of about 5%.

Examples of degradation of the laser light source are shown in FIGS. 17 (a) and 17 (b). FIG. 17B guides the beam from the KrF excimer laser light source after oscillation of 1 × 10 ⁸ shots to the optical system of FIG. 17A having a configuration similar to that of the illumination optical system of FIG. In the optical system of (a), a pair of cylindrical lens arrays (corresponding to the pair of lens arrays 4ba and 4bb in FIG. 2) obtained when printed on the thermal paper 40 arranged in the optical path between 4ba ′ and 4bb ′. Profile (light intensity distribution). FIG. 17B shows that the stronger the degree of black, the higher the laser intensity.

  Since the lens elements constituting the cylindrical lens array 4ba ′ arranged just before the thermal paper 40 are arranged at equal intervals and have the same curvature, all the intervals shown by a in the figure should be equal to 12 mm. However, in the measurement results, these intervals were different from each other. In addition, the light was present in a region (a region indicated by b in the figure) that should not reach after the laser beam is condensed. This is probably because the wavefront of the laser beam is disturbed and there are many obliquely inclined components, so that the region b is generated. As described above, in the laser light source, the distortion of the wavefront becomes remarkable due to deterioration with time.

  FIG. 6 is a diagram schematically showing a configuration of a light irradiation apparatus according to the second embodiment of the present invention. The second embodiment has a configuration similar to that of the first embodiment, except that the half mirror 9 and the wavefront sensor unit 10 are removed, a beam profiler 12 is provided on the substrate stage 7, and illumination optics. The point that the movable diaphragm 4d is provided in the system 4 is different from the first embodiment. Hereinafter, the second embodiment will be described by focusing on the differences from the first embodiment.

  In the second embodiment, the beam profiler 12 and the control unit 11 that analyzes the measurement result of the beam profiler 12 are used in order to control the deformable mirror 5. In order to localize the light source, a movable stop 4d provided in the illumination optical system 4 is used. The beam profiler 12 is provided on a substrate stage 7 that holds the substrate 6 to be processed, and has a measurement surface (observation surface) that can be positioned substantially flush with the surface of the substrate 6. The beam profiler 12 can move independently in the X and Y directions orthogonal to each other on the surface of the substrate 6 and in the Z direction along the optical axis of the imaging optical system 8, and is about 1 to 200 times. The magnification is

  The beam profiler 12 may include a thin film having fluorescence as a sensor for detecting invisible laser light, and may be a system equivalent to a fluorescence microscope that measures changes in the thin film. The beam profiler 12 may be a system that directly measures invisible laser light, such as a UV microscope. Specifically, the beam profiler disclosed in Japanese Patent Application Laid-Open No. 2004-336013 can be used as the beam profiler 12 of the second embodiment.

  In the second embodiment, it is preferable to use a simple phase shifter 3 such as a line and space type phase shifter having a step of 1/2 the wavelength of the light emitted from the laser light source 1. Also, a square-shaped phase shifter may be used to make it easier to see the direction in which the angle is changed by 90 degrees. This is because the reliability and high speed of data processing are improved by using a phase shifter whose theoretical value is easy to understand when measuring the basic characteristics of the laser light source 1. As shown in FIG. 7, the movable diaphragm 4d used for localizing the light source is disposed immediately before the rear lens array 4bc in the illumination optical system 4, and variably limits the pupil of the illumination optical system 4. .

  FIG. 7 shows a lens array in which lenses are arranged vertically and horizontally along an XY plane (a plane orthogonal to the optical axis). However, in the case of a laser beam shape having a large aspect ratio such as an excimer laser. There is also a method of separating a set of cylindrical lens arrays having refractive power only in the X direction and a set of cylindrical lens arrays having refractive power only in the Y direction. The movable diaphragm 4d is configured to be movable along the XY plane so that light can pass through only one arbitrary lens in the rear lens array 4bc, and the size of the opening (light transmission portion) can be adjusted. Has been.

  Hereinafter, the wavefront adjustment method in the second embodiment will be described with reference to the flowchart of FIG. In the wavefront adjusting method of the second embodiment, first, the control unit 11 sets the allowable range of the beam profile (two-dimensional data of the light intensity distribution obtained at the same height position as the surface of the substrate 6 corresponding to the phase shifter 3). Read (S21). Next, the beam profiler 12 is moved to the measurement position (S22), and the opening of the movable diaphragm 4d is set to a position corresponding to one lens in the lens array 4bc (S23). Thereafter, the laser light source 1 is turned on to cause the laser beam to oscillate (S24), and the beam profile (light intensity distribution) is measured using the beam profiler 12 (S25). The measurement result of the beam profiler 12 is supplied to the control unit 11.

  While changing the aperture position according to the XY mapping of the movable aperture 4d (that is, while changing the pupil of the illumination optical system 4), the aperture setting step S23 of the movable aperture 4d, the pulse oscillation step S24 of the laser light source 1, and the beam profile The measurement step S25 is repeated. When the required number of measurement steps S25 are completed, the controller 11 performs a beam profile synthesis calculation based on the measurement result of the beam profiler 12 (S26). That is, the control unit 11 extracts a difference between the beam profiles, and obtains a correlation between the difference and XY mapping of the movable diaphragm 4d (opening position of the movable diaphragm 4d).

  Next, the control unit 11 requires the deformable mirror 5 necessary for correcting the beam profile (and thus correcting the wavefront distortion) based on the correlation between the difference between the beam profiles and the XY mapping of the movable diaphragm 4d. A deformation amount is calculated (S27). Further, the control unit 11 deforms the required area of the reflecting surface of the deformable mirror 5 by a required amount based on the calculation result of step S27 (S28). Next, the movable diaphragm 4d is fully opened (a state optically equivalent to the state without the movable diaphragm 4d) (S29), the laser light source 1 is turned on to oscillate the laser light (S210), and the beam profiler 12 is turned on. The beam profile is measured using (S211).

  The control unit 11 determines whether or not the beam profile obtained in the measurement step S211 is within an allowable range (S212). When it is determined in the determination step S212 that the beam profile is within the allowable range, the wavefront adjustment method ends. On the other hand, if it is determined in the determination step S212 that the beam profile exceeds the allowable range, the process returns from the movement step S22 to the setting step S23 and the operations from the step S23 to the step S212 are repeated, thereby Make an appropriate adjustment (correction). Thus, also in the light irradiation apparatus of the second embodiment, the desired light intensity on the surface of the substrate 6 to be processed can be suppressed while suppressing the influence of the distortion of the wavefront of the light beam caused by the deterioration of the characteristics of the laser light source 1 over time. A distribution can be formed stably, and as a result, crystallization with a desired particle size can be performed stably.

  FIG. 9 is a diagram schematically showing a configuration of a light irradiation apparatus according to the third embodiment of the present invention. The third embodiment has both the characteristic main part configuration of the first embodiment and the characteristic main part configuration of the second embodiment. Hereinafter, the third embodiment will be described by paying attention to differences from the first embodiment and differences from the second embodiment. In the light irradiation apparatus of the third embodiment, the deformable mirror 5 is a wavefront correcting optical element, the wavefront measuring unit 5 is used for coarse wavefront adjustment, and the beam profiler 12 is used for fine wavefront adjustment.

  Hereinafter, the wavefront adjustment method according to the third embodiment will be described with reference to the flowcharts of FIGS. 10 and 11. In the wavefront adjustment method of the third embodiment, the wavefront adjustment method of the first embodiment is applied for coarse-accuracy wavefront adjustment. That is, in the coarse-accuracy wavefront adjustment stage in the wavefront adjustment method of the third embodiment, as shown in FIG. 10, the allowable range of distortion of the wavefront is read into the control unit 11 (S31), the laser light source 1 is turned on and the laser is turned on. The light is pulse-oscillated (S32), and the wavefront sensor unit 10 measures wavefront distortion data (S33), and determines whether the measured wavefront distortion amount is within an allowable range (S34). If it is determined in the determination step S34 that the wavefront distortion amount is within the allowable range, the coarse-accuracy wavefront adjustment step is terminated.

  On the other hand, if it is determined in the determination step S34 that the wavefront distortion amount exceeds the allowable range, the required deformation amount of the deformal mirror 5 necessary for correcting the wavefront distortion is calculated (S35), The required area of the reflecting surface of the mirror 5 is deformed by a required amount (S36), the laser light source 1 is turned on, the laser light is pulsed again (S32), and the distortion data of the wavefront is measured (S33). It is determined whether or not the wavefront distortion amount is within an allowable range (S34). If it is determined in the second determination step S34 that the amount of wavefront distortion is within the allowable range, the coarse-accuracy wavefront adjustment step ends. On the other hand, when it is determined in the second determination step S34 that the wavefront distortion amount exceeds the allowable range, the calculation step S35, the deformation step S36, the oscillation step S32, the measurement step S33, and the determination step S34 are repeated. The appropriate coarse accuracy adjustment (correction) of the wavefront is performed.

  Next, in the wavefront adjustment method of the third embodiment, a wavefront adjustment method similar to that of the second embodiment is applied for fine-precision wavefront adjustment. That is, in the fine wavefront adjustment stage in the wavefront adjustment method of the third embodiment, as shown in FIG. 11, the allowable range of the beam profile is read into the control unit 11 (S31), and the beam profiler 12 is moved to the measurement position. (S32) The aperture of the movable diaphragm 4d is set to the initial position (S33), the laser light source 1 is turned on to oscillate the laser beam (S34), and the beam profile is measured using the beam profiler 12 (S35). .

  The setting step S33, the oscillation step S34, and the measurement step S35 are repeated while changing the opening position according to the XY mapping of the movable diaphragm 4d. When the required number of measurement steps S35 are completed, the beam profile synthesis calculation is performed (S36), the required deformation amount of the deformable mirror 5 is calculated (S37), and the required area of the reflecting surface of the deformable mirror 5 is only the required amount. The movable diaphragm 4d is fully opened (S39), the laser light source 1 is turned on, the laser light is pulse-oscillated (S310), and the beam profile is measured using the beam profiler 12 (S311).

  The control unit 11 determines whether or not the beam profile obtained in the measurement step S311 is within an allowable range (S312). When it is determined in the determination step S312 that the beam profile is within the allowable range, the wavefront adjustment method ends. On the other hand, if it is determined in the determination step S312 that the beam profile exceeds the allowable range but the difference is relatively small, the process returns from the movement step S32 to the setting step S33, and the operations from step S33 to step S312 are performed. By repeating the above, appropriate fine precision adjustment (correction) of the wavefront is performed.

  If it is determined in the determination step S312 that the beam profile exceeds the allowable range and the difference is relatively large, the process returns between the reading step S31 and the oscillation step S32, and the above-described coarse wavefront adjustment and Perform fine wavefront adjustment again. Thus, also in the light irradiation apparatus of the third embodiment, the desired light intensity on the surface of the substrate 6 to be processed can be suppressed while suppressing the influence of the distortion of the wavefront of the light beam caused by the deterioration of the characteristics of the laser light source 1 over time. A distribution can be formed stably, and as a result, crystallization with a desired particle size can be performed stably.

Next, a method for manufacturing an electronic device in a crystallized region using the light irradiation apparatus (crystallization apparatus) of the present embodiment will be described with reference to FIGS. As shown in FIG. 12A, a base film 81 (for example, SiN having a thickness of 50 nm and a SiO ₂ layer having a thickness of 100 nm is laminated on an insulating substrate 80 (for example, alkali glass, quartz glass, plastic, polyimide, etc.). Film) and an amorphous semiconductor film 82 (for example, Si, Ge, SiGe, etc. having a film thickness of about 50 nm to 200 nm) and a cap film 82a (for example, a SiO ₂ film having a film thickness of 30 nm to 300 nm), for example. A substrate 5 to be processed is prepared using a chemical vapor deposition method or a sputtering method. Then, a laser beam 83 (for example, KrF excimer laser beam or XeCl excimer laser beam) is irradiated to a predetermined region on the surface of the amorphous semiconductor film 82 using the light irradiation apparatus according to the present embodiment. .

In this way, as shown in FIG. 12B, a polycrystalline semiconductor film or a single crystallized semiconductor film 84 having a crystal with a large grain size is generated. Next, after the cap film 82a is removed by etching, as shown in FIG. 12C, a polycrystalline semiconductor film or a single crystallized semiconductor film 84 is formed with, for example, a region for forming a thin film transistor using a photolithography technique. An island-shaped semiconductor film 85 is processed, and a SiO ₂ film having a thickness of 20 nm to 100 nm is formed as a gate insulating film 86 on the surface by using a chemical vapor deposition method or a sputtering method. Further, as shown in FIG. 12D, a gate electrode 87 (for example, silicide or MoW) is formed on the gate insulating film, and impurity ions 88 (in the case of an N-channel transistor) using the gate electrode 87 as a mask. Phosphorus and boron in the case of a P-channel transistor are ion-implanted. After that, annealing is performed in a nitrogen atmosphere (for example, 450 ° C. for 1 hour in a furnace) or activation by laser (using laser light 83) to activate the impurities, and the source region 91, A drain region 92 is formed. Next, as shown in FIG. 12E, an interlayer insulating film 89 is formed to form contact holes, and a source electrode 93 and a drain electrode 94 connected to a source 91 and a drain 92 connected by a channel 90 are formed.

  In the above process, the channel 90 is formed in accordance with the position of the large grain crystal of the polycrystalline semiconductor film or the single crystallized semiconductor film 84 generated in the process shown in FIGS. Through the above steps, a thin film transistor (TFT) can be formed in a polycrystalline transistor or a single crystal semiconductor. Polycrystalline transistors or single crystal transistors manufactured in this way can be applied to driving circuits such as liquid crystal display devices (displays) and EL (electroluminescence) displays, and integrated circuits such as memories (SRAM and DRAM) and CPUs. is there.

  Note that in the above description, the present invention is applied to a crystallization apparatus that generates a crystallized semiconductor film by irradiating a non-single-crystal semiconductor film with light having a predetermined light intensity distribution. However, the present invention is not limited to this, and a light irradiation device that generally forms a predetermined light intensity distribution on a predetermined surface via an imaging optical system, such as a laser annealing device, a laser crystallization device, a laser ablation processing device, etc. The present invention can be applied to.

  Specifically, the present invention can also be applied to a laser annealing apparatus using a line beam (linear) optical system that is generally used at present to compensate for wavefront distortion, that is, to adjust the wavefront. . The line beam is obtained by extremely shortening the short side of the rectangular laser beam as compared with the long side, and has a cross-sectional shape of about 0.5 mm × 10 mm to 500 mm, for example. In the line beam laser annealing apparatus, laser irradiation is performed by relatively moving (scanning) the line beam in a direction intersecting the long side direction at an angle of 1 to 90 degrees. The scan pitch is typically about 20 μm / pulse to 30 μm / pulse.

  FIG. 13 is a diagram schematically showing a first example in which the present invention is applied to a line beam laser annealing apparatus. The apparatus shown in FIG. 13 has a configuration similar to that of the first embodiment shown in FIG. 1, except that the image forming optical system 8 is omitted and the substrate 6 is disposed at the position of the phase shifter 3. The difference from the first embodiment is that a cylindrical lens 21 is provided between the substrate 4 and the substrate 6 to be processed. In FIG. 13, elements having the same functions as those in the first embodiment in FIG. 1 are denoted by the same reference numerals as in FIG. 1. Hereinafter, a first example of a line beam laser annealing apparatus will be described by paying attention to differences from the first embodiment.

  In the line beam laser annealing apparatus of FIG. 13, the cylindrical lens 21 provided in the optical path between the illumination optical system 4 and the substrate 6 to be processed has a positive refractive power in a plane parallel to the paper surface of FIG. In addition, there is no refractive power in a plane perpendicular to the paper surface of FIG. Therefore, a line beam extending very long along the direction perpendicular to the paper surface of FIG. 13 due to the action of the cylindrical lens 21, for example, a line beam having a cross-sectional shape of about 0.5 mm × 10 mm to 500 mm is formed on the substrate 6 to be processed. Irradiate the surface. In other words, the refractive power of the cylindrical lens 21 is set so that a line beam having a desired cross-sectional shape is formed on the surface of the substrate 6 to be processed.

  Thus, in the line beam laser annealing apparatus of FIG. 13, the wavefront adjustment function of the deformable mirror 5 can suppress the influence of the distortion of the wavefront of the light beam caused by the deterioration of the characteristics of the laser light source 1 over time, and consequently A line beam having a desired light intensity distribution can be stably formed on the surface of the substrate 6 to be processed. In the case of the line beam laser annealing apparatus of FIG. 13, since the partial divergence difference greatly affects the quality of the line beam, correction of the wavefront by the deformable mirror 5 is extremely effective, and image deviation, unevenness, blur, etc. In addition to suppressing the above phenomenon satisfactorily, there is an effect that the depth of focus (DOF) relating to image formation on the substrate 6 to be processed becomes deep.

  FIG. 14 is a diagram schematically showing a second example in which the present invention is applied to a line beam laser annealing apparatus. The apparatus shown in FIG. 14 has a configuration similar to that of the first embodiment shown in FIG. 1 except that an imaging optical system 8A including a cylindrical lens 22 is arranged instead of the imaging optical system 8. It is different from the form. In FIG. 14, elements having the same functions as those in the first embodiment of FIG. 1 are denoted by the same reference numerals as in FIG. 1. Hereinafter, a second example of the line beam laser annealing apparatus will be described by paying attention to differences from the first embodiment.

  In the line beam laser annealing apparatus of FIG. 14, the cylindrical lens 22 included in the imaging optical system 8A has a positive refractive power in a plane parallel to the paper surface of FIG. 14, and is a surface perpendicular to the paper surface of FIG. No refractive power. Accordingly, a line beam extending very long along the direction perpendicular to the paper surface of FIG. 14 due to the action of the imaging optical system 8A including the cylindrical lens 22, for example, a line beam having a cross-sectional shape of about 0.5 mm × 10 mm to 500 mm. Is irradiated on the surface of the substrate 6 to be processed. In other words, the refractive power of the cylindrical lens 22 in the imaging optical system 8A is set so that a line beam having a desired cross-sectional shape is formed on the surface of the substrate 6 to be processed.

  Thus, in the line beam laser annealing apparatus of FIG. 14 as well, in the same way as the apparatus of FIG. 13, the wavefront adjustment function of the deformable mirror 5 causes the wavefront distortion of the light beam due to the deterioration of the characteristics of the laser light source 1 over time. The influence can be suppressed, and as a result, a line beam having a desired light intensity distribution can be stably formed on the surface of the substrate 6 to be processed. Also in the case of the line beam laser annealing apparatus of FIG. 14, since the difference in partial divergence greatly affects the quality of the line beam, the correction of the wavefront by the deformable mirror 5 is extremely effective, the image shift, In addition to satisfactorily suppressing phenomena such as unevenness and blurring, there is an effect that the depth of focus related to image formation on the substrate 6 to be processed becomes deep.

  In the second embodiment shown in FIG. 6, the pupil of the illumination optical system 4 is variably limited by using a movable stop 4d disposed immediately before the lens array 4bc in the illumination optical system 4 as shown in FIG. is doing. Specifically, the movable diaphragm 4d can move along the XY plane and can adjust the size of the opening (light transmission part) so that light can pass through only one arbitrary lens in the lens array 4bc. It is configured. Since the lens array 4bc is composed of a large number of lenses arranged vertically and horizontally and densely, as shown in FIG. 15A, the light beam incident on each lens of the lens array 4bc is schematically represented by one circle. The light beam incident on the entire lens array 4bc is schematically represented by a large number of circles arranged vertically and horizontally and regularly.

  In the second embodiment, as shown in FIG. 15B, the opening (light transmitting portion) of the movable diaphragm 4d is set so that light passes only through one arbitrary lens in the lens array 4bc. . In FIG. 15B, a black portion is a light shielding portion that blocks light passage, and a white portion in the light shielding portion is an opening portion that allows light passage. In the second embodiment, the beam profile is measured using the beam profiler 12 while changing the aperture position according to the XY mapping of the movable diaphragm 4d. If the measured beam profile is not in a desired state, the aperture position of the movable diaphragm 4d is set. The required area of the reflecting surface of the corresponding deformable mirror 5 is deformed to correct the wavefront distortion.

  However, the deformable mirror 5 as a wavefront correcting optical element is not always universal, and it is conceivable that the wavefront distortion of light passing through one or more lenses in the lens array 4bc cannot be corrected. In this case, when light is applied to the substrate 6 to be processed, one or a plurality of lenses that have not corrected the wavefront distortion are not actively used, that is, the light flux that has not corrected the wavefront distortion can be moved. By blocking with the aperture 4d, the pupil of the illumination optical system 4 can be limited to various shapes to perform modified illumination, and a desired light intensity distribution can be stably formed on the substrate 6 to be processed.

  For example, in the modification of the second embodiment, the pupil of the illumination optical system 4 is limited to a ring shape as shown in FIG. 16A, or the pupil of the illumination optical system 4 is changed as shown in FIG. It is limited to a square ring corresponding to the four sides of the square, the pupil of the illumination optical system 4 is limited to a relatively small circular shape as shown in FIG. 16C, or as shown in FIG. The pupil of the illumination optical system 4 is limited to a relatively small square shape. Further, the pupil of the illumination optical system 4 is limited to a quadrupole shape composed of four circles as shown in FIG. 16E, or the pupil of the illumination optical system 4 is limited to four squares as shown in FIG. Or the pupil of the illumination optical system 4 is limited to a rectangular shape elongated in one direction, as shown in FIG.

  In this modification, the depth of focus and the resolution related to the image formation on the substrate 6 to be processed can be improved. However, since the illuminance on the substrate 6 to be processed decreases due to the loss of light quantity at the movable diaphragm 4d, it is necessary to increase the output (laser power) of the laser light source 1. Further, since the pupil distribution of the incident light on the substrate 6 to be processed is changed by the modified illumination, it is necessary to simulate the imaging characteristics and correct the pattern formed on the substrate 6 to be processed.

It is a figure which shows roughly the structure of the light irradiation apparatus concerning 1st Embodiment of this invention. It is a figure which shows schematically the structure of the illumination optical system of FIG. It is a figure which shows roughly the illumination optical system which made the homogenizer 2 steps | paragraphs structure. It is a figure explaining the structure and effect | action of a wavefront sensor unit. It is a flowchart explaining the process of the wavefront adjustment method in 1st Embodiment. It is a figure which shows schematically the structure of the light irradiation apparatus concerning 2nd Embodiment of this invention. It is a figure which shows a mode that the movable stop for localizing a light source is arrange | positioned in the illumination optical system. It is a flowchart explaining the process of the wavefront adjustment method in 2nd Embodiment. It is a figure which shows schematically the structure of the light irradiation apparatus concerning 3rd Embodiment of this invention. It is a 1st flowchart explaining the process of the wavefront adjustment method in 3rd Embodiment. It is a 2nd flowchart explaining the process of the wavefront adjustment method in 3rd Embodiment. It is process sectional drawing which shows the process of producing an electronic device using the light irradiation apparatus of this embodiment. It is a figure which shows roughly the 1st example which applied this invention to the line beam laser annealing apparatus. It is a figure which shows roughly the 2nd example which applied this invention to the line beam laser annealing apparatus. It is a figure which supplementarily demonstrates operation | movement of 2nd Embodiment, Comprising: (a) represents typically the light beam which injects into a lens array by many circles arranged regularly vertically and horizontally, (b) is a lens array. It shows how the aperture of the movable stop is set so that light passes through only one of the lenses. It is a figure which shows a mode that the pupil of an illumination optical system is limited to various shapes in the modification of 2nd Embodiment, and a modified illumination is performed. It is a figure which shows the deterioration example of a laser light source.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser light source 2 Attenuator 3 Phase shifter 4 Illumination optical system 4d Movable diaphragm 5 Deformable mirror 6 Substrate 7 Substrate stage 8 Imaging optical system 10 Wavefront sensor unit 11 Control part 12 Beam profiler

Claims (14)

A laser light source;
An illumination optical system including a homogenizer for superimposingly illuminating a light modulation element based on light from the laser light source;
An imaging optical system that forms a predetermined light intensity distribution on a predetermined surface based on the light phase-modulated by the light modulation element;
A wavefront correcting optical element disposed between the laser light source and the homogenizer to correct and emit a wavefront of an incident light beam;
A wavefront measuring unit that takes out a light beam from an optical path between the wavefront correcting optical element and the homogenizer and measures a wavefront of the light beam;
And a control unit that controls the wavefront correcting optical element based on the output of the wavefront measuring unit. The wavefront measuring unit includes a beam splitter disposed between the wavefront correcting optical element and the homogenizer, and a wavefront sensor that measures a wavefront of a light beam extracted from the optical path by the beam splitter. The light irradiation apparatus according to claim 1. 3. The light irradiation according to claim 2, wherein the wavefront sensor includes a microlens array disposed on a light incident side and a photodetector having a detection surface at a light collection position of the microlens array. apparatus. The light irradiation apparatus according to claim 1, wherein the wavefront correcting optical element has a reflective surface that can be locally deformed. A movable aperture controlled by the control unit to variably limit the pupil of the illumination optical system; and a beam profiler for measuring a light intensity distribution formed on the predetermined surface, wherein the control unit includes the illumination 5. The light irradiation apparatus according to claim 1, wherein the wavefront correction optical element is controlled based on information of a light intensity distribution measured according to a change in a pupil of the optical system. A laser light source;
An illumination optical system including a homogenizer for superimposingly illuminating a light modulation element based on light from the laser light source;
An imaging optical system that forms a predetermined light intensity distribution on a predetermined surface based on the light phase-modulated by the light modulation element;
A wavefront correcting optical element disposed between the laser light source and the homogenizer to correct and emit a wavefront of an incident light beam;
A movable diaphragm that variably limits the pupil of the illumination optical system;
A beam profiler for measuring the light intensity distribution formed on the predetermined surface;
A control unit for controlling the movable diaphragm and the wavefront correcting optical element,
The light irradiation apparatus, wherein the control unit controls the wavefront correction optical element based on information on a light intensity distribution measured according to a change in a pupil of the illumination optical system. The light irradiation apparatus according to claim 6, wherein the wavefront correction optical element has a locally deformable reflecting surface. An illumination optical system including a homogenizer illuminates the light modulation element with light from a laser light source, and forms an image on the predetermined surface by the imaging optical system with the light modulated in phase by the light modulation element. A method of adjusting a light irradiation device that forms a predetermined light intensity distribution in
A wavefront measuring step for measuring a wavefront of a light beam extracted from the optical path on the light source side of the homogenizer;
And a wavefront correcting step of correcting a wavefront of a light beam incident on the homogenizer based on a measurement result obtained in the wavefront measuring step. An illumination optical system including a homogenizer illuminates the light modulation element with light from a laser light source, and forms an image on the predetermined surface by the imaging optical system with the light modulated in phase by the light modulation element. A method of adjusting a light irradiation device that forms a predetermined light intensity distribution in
A limiting step of variably limiting the pupil of the illumination optical system;
A distribution measuring step for measuring a light intensity distribution formed on the predetermined surface;
And a wavefront correction step of correcting a wavefront of a light beam incident on the homogenizer based on a measurement result obtained in the distribution measurement step according to a change in a pupil of the illumination optical system. An illumination optical system including a homogenizer illuminates the light modulation element with light from a laser light source, and forms an image on the predetermined surface by the imaging optical system with the light modulated in phase by the light modulation element. A method of adjusting a light irradiation device that forms a predetermined light intensity distribution in
A coarse accuracy correction step of correcting the wavefront of the light beam incident on the homogenizer with coarse accuracy using the adjustment method according to claim 8;
An adjustment method comprising: a fine precision correction step of finely correcting a wavefront of a light beam incident on the homogenizer using the adjustment method according to claim 9. A light irradiation apparatus according to claim 1, and a stage for holding a non-single-crystal semiconductor film on the predetermined surface, and a non-single-crystal semiconductor film held on the predetermined surface A crystallizing apparatus for generating a crystallized semiconductor film by irradiating light having the predetermined light intensity distribution. A crystallized semiconductor film obtained by irradiating the non-single crystal semiconductor film held on the predetermined surface with light having the predetermined light intensity distribution using the light irradiation apparatus according to claim 1. A crystallization method characterized by producing Using the light irradiation apparatus adjusted by the adjustment method according to claim 8, the non-single crystal semiconductor film held on the predetermined surface is irradiated with light having the predetermined light intensity distribution. And producing a crystallized semiconductor film. A device manufactured using the crystallization apparatus according to claim 11 or the crystallization method according to claim 12 or 13.

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