JP2007258685A - Light irradiation apparatus, light irradiation method, crystallization apparatus, crystallization method, semiconductor device, and light modulation element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crystallization apparatus that is capable of generating a needle crystal group capable of manufacturing a TFT with a certain response speed without channels being disposed to face one and the same direction. <P>SOLUTION: A light irradiation apparatus according to the present invention comprises: an optical modulation element (1) for modulating the phase of incident light; and an image-forming optical system (3) that is disposed between the optical modulation element and an irradiated surface (4) to form a predetermined light intensity distribution on the irradiated surface. The optical modulation element comprises: a first area ratio variation structure in which the ratio of occupied areas in a phase modulation area in one unit region varies along a first direction; and a second area ratio variation structure in which the ratio of occupied areas in a phase modulation area in a unit region varies along a second direction different from the first direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light irradiation apparatus, a light irradiation method, a crystallization apparatus, a crystallization method, a semiconductor device, and a light modulation element, for example, by irradiating a non-single crystal semiconductor film with a laser beam having a predetermined light intensity distribution. The present invention relates to a technique for generating a crystallized semiconductor film.

  Conventionally, for example, a thin-film-transistor (TFT) used as a switching element for selecting a display pixel of a liquid-crystal display (LCD) is, for example, amorphous silicon or amorphous silicon. It is formed of crystalline silicon (poly-Silicon). Polycrystalline silicon has higher electron or hole mobility than amorphous silicon.

  Therefore, when the transistor is formed of polycrystalline silicon, the switching speed is faster and the response of the display is faster than when the transistor is formed of amorphous silicon. In addition, peripheral LSIs such as driver circuits and DACs can also be configured with thin film transistors to operate at higher speed. In addition, there is an advantage that the design margin of other parts can be reduced.

  Since polycrystalline silicon consists of a collection of crystal grains, for example, when a TFT transistor is formed with this, a crystal grain boundary is formed in the channel region, and these crystal grain boundaries serve as a barrier, and a TFT transistor formed of single crystal silicon. Compared with, the mobility of electrons or holes is low. In addition, in many thin film transistors formed using polycrystalline silicon, the number of crystal grain boundaries formed in the channel portion is different among the respective thin film transistors. It becomes. Therefore, recently, in order to improve the mobility of electrons or holes and to reduce the variation in the number of crystal grain boundaries in the channel portion, a large-grained crystallized silicon having a size capable of forming at least one channel region has been developed. Producing crystallization methods have been proposed.

  Conventionally, as a crystallization method of this type, an incident is performed using a light modulation element (phase shifter) having a phase pattern in which the ratio of the area occupied by the phase modulation region in the unit region changes one-dimensionally along a predetermined direction. A laser beam is modulated into a laser beam having a V-shaped light intensity distribution that changes one-dimensionally along the predetermined direction, and irradiated to a non-single crystal semiconductor film (polycrystalline semiconductor film or non-single crystal semiconductor film). A technique for generating a crystallized semiconductor film by crystal growth along the predetermined direction has been proposed (see, for example, Non-Patent Document 1).

Y. Taniguchi, etc., “A Novel Phase-modulator for ELA-Based Lateral Growth of Si”, The Electrochemical Society's 206th Meeting, Thin Film Transistor Technologies VII (Honolulu, Hawaii)

  In the conventional crystallization technique proposed in Non-Patent Document 1, as shown in FIG. 13A, the ratio of the area occupied by the phase modulation region in the unit region is a predetermined direction (the horizontal direction in FIG. 13A). The light modulation element 101 having a phase pattern that changes one-dimensionally along the line is used. In this figure, a square region 101a indicated by hatching is a phase modulation region, and the area decreases from the center to the periphery. The laser light modulated via the light modulation element 101 has a V-shaped light intensity distribution that changes one-dimensionally on the image plane via the imaging optical system. Specifically, when the phase modulation amount of the phase modulation region 101a of the light modulation element 101 is 60 degrees, a V-shaped light intensity distribution 102 indicated by a thick solid line in FIG. 13B is theoretically generated.

  When the amount of phase modulation in the phase modulation region of the light modulation element 101 is 180 degrees, a V-shaped light intensity distribution 103 indicated by a thick solid line in FIG. 13B is theoretically generated, and FIG. ), A V-shaped light intensity distribution 104 indicated by a thin solid line was actually generated. When the non-single crystal semiconductor film is irradiated with the laser light having the V-shaped light intensity distribution thus generated, a crystal grows along the gradient direction of the light intensity distribution, as shown in FIG. In addition, a needle-like crystal 105 that is elongated along the gradient direction is generated from the central portion where the light intensity is low.

  When a TFT is formed on a needle-like crystal, the carrier mobility that determines the response speed depends on the direction of the channel to be formed (the direction of carrier movement or the direction from the source to the drain). That is, when the channel direction (the direction from the source S to the drain D) is parallel to the longitudinal direction of the needle crystal 111 as shown in FIG. 14A, the channel direction (as shown in FIG. A higher carrier mobility can be obtained than when the direction from the source S to the drain D) is perpendicular to the longitudinal direction of the needle-like crystal 111. In the case shown in FIG. 14B, the crystal grain boundary 111a exists across the channel, whereas the channel direction is the longitudinal direction of the acicular crystal 111 as shown in FIG. This is because the carriers are not scattered by the crystal grain boundaries 111 a between the needle-like crystals 111.

  Thus, in the prior art, TFTs are formed on needle-shaped crystal groups whose longitudinal directions are aligned in one direction. For example, the channel direction is lateral to the acicular crystal growth direction, and the TFT is vertical. And response speed will be different. In other words, in the prior art, if the response speeds of the respective TFTs manufactured on the needle-like crystal group whose longitudinal direction is aligned in one direction are to be aligned, the channel direction must also be aligned in one direction. As a result, the required area of the crystal film is increased, the required wiring for the transistor is lengthened, the free space is increased, the trial and error of the layout is increased, the design takes time, and the circuit is greatly restricted. .

  The present invention relates to a crystallization apparatus and a crystallization method by which a TFT having a constant response speed without generating channel directions in one direction can generate, for example, acicular crystals or acicular crystal groups that can be produced. The first object is to provide an optical modulation element. A second object of the present invention is to provide a semiconductor device such as a TFT having a constant response speed without aligning the channel directions in one direction.

In order to solve the above problems, in the first embodiment of the present invention, there is provided a light irradiation apparatus that irradiates an irradiated surface with light having a light intensity distribution,
A light modulation element for modulating and emitting the phase of incident light;
An imaging optical system disposed between the light modulation element and the irradiated surface for imaging the emitted light so as to irradiate the irradiated surface with light having the light intensity distribution; Comprising
The light modulation element has a plurality of area ratio changing structures including a first area ratio changing structure and a second area ratio changing structure in a unit region, and the first area ratio changing structure has an occupied area ratio. The second area ratio changing structure has at least one first phase modulation region that changes along the first direction, and the ratio of the occupied area changes along a second direction different from the first direction. A light irradiation device having at least one second phase modulation region is provided.

In the second embodiment of the present invention, a light irradiation device for irradiating the irradiated surface with light having a light intensity distribution,
A light modulation element for modulating incident light;
An imaging optical system disposed between the light modulation element and the irradiated surface to form the light intensity distribution on the irradiated surface;
The light modulation element includes at least one first modulation region that generates a first light intensity distribution whose light intensity varies along a first direction on the irradiated surface, and a second direction different from the first direction. A light irradiation apparatus having a plurality of modulation regions including at least one second modulation region that generates a second light intensity distribution whose light intensity varies along the surface on the irradiated surface is provided.

In the third aspect of the present invention, a predetermined light intensity distribution is obtained by using a light modulation element that modulates the phase of incident light and an imaging optical system that is disposed between the light modulation element and the irradiated surface. A light irradiation method for irradiating the irradiated surface with light having:
As the light modulation element, at least one first area ratio changing structure in which the ratio of the area occupied by the phase modulation region in the unit region changes along the first direction, and the ratio of the area occupied by the phase modulation region in the unit region is There is provided a light irradiation method using a light modulation element having at least one second area ratio changing structure that changes along a second direction different from the first direction.

In the fourth embodiment of the present invention, light having a predetermined light intensity distribution is obtained using a light modulation element that modulates incident light and an imaging optical system that is disposed between the light modulation element and the irradiated surface. Is a light irradiation method for irradiating the irradiated surface,
As the light modulation element, at least one first modulation region that generates a first light intensity distribution whose light intensity varies along a first direction on the irradiated surface, and a second direction different from the first direction There is provided a light irradiation method using a light modulation element having at least one second modulation region that generates a second light intensity distribution whose light intensity varies along the irradiation surface on the irradiated surface.

  According to a fifth aspect of the present invention, the light irradiation apparatus according to the first or second aspect and a stage for holding the non-single crystal semiconductor film so that the irradiation surface is the irradiated surface are provided. There is provided a crystallization apparatus for forming a crystallized semiconductor film by irradiating the irradiation surface of the non-single crystal semiconductor film with light having the light intensity distribution.

  In the sixth embodiment of the present invention, the non-single-crystal semiconductor film held on the irradiated surface using the light irradiation device of the first or second embodiment or the light irradiation method of the third or fourth embodiment. Provided is a crystallization method in which at least a part is irradiated with light having the light intensity distribution to form a crystallized semiconductor film.

  According to a seventh aspect of the present invention, there is provided a semiconductor device manufactured using the crystallization method of the sixth aspect.

According to an eighth aspect of the present invention, there is provided a light modulation element that modulates the phase of incident light,
At least one first area ratio changing structure in which the ratio of the area occupied by the phase modulation region in the unit region changes along the first direction, and the ratio of the area occupied by the phase modulation region in the unit region is the first direction. Provided is a light modulation element including a plurality of area ratio changing structures including at least one second area ratio changing structure changing along different second directions.

In a ninth aspect of the present invention, a light modulation element for modulating incident light,
At least one first modulation region that generates a first light intensity distribution whose light intensity varies along the first direction in a part of the irradiated surface, and the light intensity along a second direction different from the first direction. There is provided an optical modulation element comprising: at least one second modulation region that generates a second light intensity distribution with a change in the other part of the irradiated surface.

  In the crystallization apparatus of the present invention, an element such as a TFT having a constant response speed can generate, for example, a needle-shaped crystal group that can be produced without aligning the channel directions in one direction. As a result, the required area of the crystal film is kept small, the required wiring is shortened, the free space is kept small, and a rapid design is possible without the need for trial and error of the layout. Will increase.

  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 crystallization apparatus according to an embodiment of the present invention. FIG. 2 is a diagram schematically showing the internal configuration of the illumination system of FIG. Referring to FIGS. 1 and 2, the crystallization apparatus of the present embodiment includes a light modulation element 1 such as a phase shifter for phase-modulating an incident light beam to form a light beam having a predetermined light intensity distribution, An illumination system 2 for illuminating the modulation element 1, an imaging optical system 3, and a substrate stage 5 for holding a substrate to be processed 4 having a semiconductor film such as non-single crystal silicon.

  The configuration and operation of the light modulation element 1 will be described later. The illumination system 2 includes a XeCl excimer laser light source 2a that supplies laser light having a wavelength of, for example, 308 nm. Instead, as the light source 2a, another appropriate light source having a capability of emitting an energy beam that melts the irradiation region of the substrate to be processed, such as a KrF excimer laser light source or a YAG laser light source, may be used. The laser light supplied from the light source 2a is incident on the first fly-eye lens 2c after the cross section is enlarged by the beam expander 2b.

  As a result, a plurality of small light sources are formed on the rear focal plane of the first fly-eye lens 2c, and light beams from the plurality of small light sources are transmitted through the first condenser optical system 2d to the second fly-eye lens. The incident surface 2e is illuminated in a superimposed manner. As a result, a larger number of small light sources are formed on the rear focal plane of the second fly-eye lens 2e than on the rear focal plane of the first fly-eye lens 2c. Light beams from a plurality of small light sources formed on the rear focal plane of the second fly-eye lens 2e illuminate the light modulation element 1 in a superimposed manner via the second condenser optical system 2f.

  The first fly-eye lens 2c and the first condenser optical system 2d constitute a first homogenizer. With this first homogenizer, the laser beam emitted from the light source 2a is made uniform with respect to the incident angle on the light modulation element 1. The second fly-eye lens 2e and the second condenser optical system 2f constitute a second homogenizer. By this second homogenizer, the light intensity at each position in the plane on the light modulation element 1 is made uniform with respect to the laser light whose incident angle from the first homogenizer is made uniform.

  Thus, the illumination system 2 irradiates the light modulation element 1 with the laser light having a light intensity distribution with a substantially uniform intensity throughout. The laser light that is light-modulated (phase-modulated) by the light modulation element 1 is incident on the substrate 4 to be processed via the imaging optical system 3. Here, the phase pattern surface of the light modulation element 1 and the substrate to be processed 4 are arranged at an optically conjugate position of the imaging optical system 3. In other words, the irradiated surface of the substrate to be processed 4 is set to a surface optically conjugate with the phase pattern surface of the light modulation element 1 (image surface of the imaging optical system 3).

  The imaging optical system 3 includes a positive lens group 3a on the light source side, a positive lens group 3b on the substrate to be processed, and an aperture stop 3c disposed between these lens groups. The size of the aperture (light transmitting portion) of the aperture stop 3c (and consequently the image-side numerical aperture of the imaging optical system 3) has a required light intensity distribution on the semiconductor film (irradiated surface) of the substrate 4 to be processed. It is set to generate. In addition to such a refractive optical system, the imaging optical system 3 may be a reflective optical system or a refractive reflective optical system.

As an example, in the substrate 4 to be processed, a base insulating film, a non-single crystal film such as an amorphous silicon film, and a cap film are sequentially formed on a glass substrate for a liquid crystal display, for example, by chemical vapor deposition (CVD). It has been done. The base insulating film and the cap film are insulating films such as SiO ₂ . The base insulating film directly contacts the amorphous silicon film and the glass substrate to prevent foreign substances such as Na in the glass substrate from entering the amorphous silicon film, and the heat of the amorphous silicon film directly Prevents heat transfer to the glass substrate.

  An amorphous silicon film is a semiconductor film to be crystallized. The cap film is heated by a part of the light beam incident on the amorphous silicon film, and stores the heated temperature. This heat storage effect is that when the incidence of the light beam is interrupted, the high temperature portion of the irradiated surface of the amorphous silicon film cools relatively rapidly, but this temperature gradient is relaxed and the large grain size is reduced in the lateral direction. Promotes crystal growth. The substrate 4 to be processed is positioned and held at a predetermined position on the substrate stage 5 by a vacuum chuck or an electrostatic chuck.

  FIG. 3A to FIG. 3C are diagrams for schematically explaining the configuration of the light modulation element according to the present embodiment, and FIG. 3A is a belt-like pattern that is a basic pattern of the light modulation element. FIG. 3B shows the pattern generated by the area ratio changing structure formed of the set of strip-like patterns shown in FIG. 3A, and FIG. 3C shows the area ratio changing structure shown in FIG. 3B. The light intensity distribution is shown. As shown by a broken line in FIG. 3A, the belt-like pattern 10 has nine (in general, any number if there are a plurality) squares of the same area arranged in a row so as to be adjacent to each other along the horizontal direction. A unit cell (unit region) 10a is provided. Each unit cell 10a includes a reference phase region (shown by a blank portion in the figure) 10aa having a reference phase value of 0 degrees, and a rectangular, for example, square phase modulation region (in the drawing, having a predetermined phase value for modulation). (In this example, only the rightmost unit cell 10a does not have the phase modulation region 10ab).

  The ratio (duty) D of the occupied area of the phase modulation region 10ab in the unit cell 10a varies between 0% and 50%. Specifically, the occupation area ratio D of the phase modulation region 10ab in the leftmost unit cell 10a of the band-shaped pattern 10 is 50%, and the occupation area ratio D of the phase modulation region 10ab in the rightmost unit cell 10a in the drawing is 0% (because the phase modulation region 10ab does not exist), and the occupied area ratio D of the phase modulation region 10ab changes monotonously during this period. Here, the occupied area ratio D is the ratio of the occupied area of the phase modulation region 10ab in the unit cell 10a, and the ratio of the occupied area of the reference phase region (phase modulation region whose phase modulation amount is 0 degree) 10aa in the unit cell 10a. Is defined as the smaller value. Further, the unit cell 10 a has a size of, for example, 1 μm × 1 μm in terms of the image plane of the imaging optical system 3 and has a size equal to or smaller than the point image distribution range of the imaging optical system 3.

  As shown in FIG. 3B, the area ratio changing structure 11 includes nine unit cells 10a arranged in a row so as to be adjacent to each other along the horizontal direction in the drawing, as shown in FIG. There are nine (one or more) belt-like patterns 10 along the vertical direction in the figure. In the area ratio changing structure 11, the changes in the occupied area ratio D in the nine strip patterns 10 are the same. A square 11a indicated by a one-dot chain line in FIG. 3B indicates the outer shape of the area ratio changing structure 11 having 9 × 9 lattice structures.

When the light modulation element 1 having one or a plurality of area ratio changing structures 11 as described above is used, the light intensity I generated on the image plane of the imaging optical system 3 is expressed by the following equation (1). The In Expression (1), D is the occupation area ratio of the phase modulation region 10ab in the unit cell 10a (that is, 0 to 0.5), and θ is the phase modulation amount of the phase modulation region 10ab. The phase modulation amount θ is defined as positive when the wavefront protrudes in the light traveling direction.
I = (2-2 cos θ) D ² − (2-2 cos θ) D + 1 (1)

  Referring to Expression (1), as the occupation area ratio D of the phase modulation region 10ab increases within the range of 0% to 50%, the light intensity I generated at the corresponding position on the image plane of the imaging optical system 3 is increased. It can be seen that decreases. Therefore, as shown in FIG. 3C, the light intensity distribution generated on the image plane of the imaging optical system 3 corresponding to the area ratio changing structure 11 is a square that defines the outer shape of the area ratio changing structure 11. The light intensity I is monotonously increased in a one-dimensional manner from the position corresponding to the left end in the figure to the position corresponding to the right end in the figure. In the present embodiment, the change in the occupied area ratio D in the strip pattern 10 is set so that the light intensity I changes almost linearly in this way.

  FIG. 4 is a diagram schematically illustrating the configuration of the light modulation element according to the present embodiment, and schematically illustrates the light modulation element having a repetitive pattern. Referring to FIG. 4, each repetitive pattern 12 of the light modulation element 1 is composed of four adjacent area ratio changing structures 12a, 12b, 12c and 12d, and is similar to the first to fourth area ratio changing structures 12a to 12d. Have a square outer shape. The first area ratio changing structure 12a of each repeating pattern 12 is set in the same direction as the area ratio changing structure 11 shown in FIG. 3B, and the occupation area ratio D of the phase modulation region is along the horizontal direction in the figure. It has a form that increases from the right end to the left end.

  The second area ratio changing structure 12b is set in a direction in which the first area ratio changing structure 12a is rotated 90 degrees counterclockwise in the figure, and the occupied area ratio D of the phase modulation region is at the upper end along the vertical direction in the figure. From the bottom to the bottom. The third area ratio changing structure 12c is set in a direction in which the first area ratio changing structure 12a is rotated 180 degrees counterclockwise in the drawing, and the occupation area ratio D of the phase modulation region is the left end along the horizontal direction in the drawing. To the right end. The fourth area ratio changing structure 12d is set in a direction in which the first area ratio changing structure 12a is rotated 90 degrees clockwise in the figure, and the occupied area ratio D of the phase modulation region is from the lower end along the vertical direction in the figure. It has a form that increases to the upper end.

  The light modulation element 1 is configured by arranging a plurality of repetitive patterns 12 having a square outer shape vertically and horizontally and densely so as not to have a gap. FIG. 4 shows one repetitive pattern 12 arranged at the center and twelve area ratio changing structures arranged so as to surround the repetitive pattern 12 due to space limitations. For example, in the case of the light modulation element 1 having a rectangular outer shape of several centimeters × several centimeters, for example, about 1000 × 1,000 repeating patterns 12 are included. Thus, in one repetitive pattern 12 in the light modulation element 1, horizontal area ratio changing structures 12a and 12c in which the occupied area ratio D of the phase modulation region changes along the horizontal direction in the figure, and the phase modulation region The vertical area ratio changing structures 12b and 12d in which the occupied area ratio D changes along the vertical direction in the figure are mixed.

  FIG. 5 is a diagram showing a light intensity distribution generated on the image plane of the imaging optical system, that is, on the irradiation region on the substrate 4 to be processed by the light modulation element according to the present embodiment. In FIG. 5, the light intensity distribution theoretically generated on the image plane of the imaging optical system 3 corresponding to one repetitive pattern 12 in the light modulation element 1 is the light intensity (the intensity when unmodulated is set to 1. It is shown in the form of contour lines of (light intensity when normalized). In calculating the light intensity distribution, the light wavelength is 308 nm, the imaging magnification of the imaging optical system 3 is 1/5, the object-side numerical aperture of the imaging optical system 3 is 0.15, and the illumination system 2 The numerical aperture is set to 0.075, and the coherence factor, that is, the σ value (the exit-side numerical aperture of the illumination system 2 / the object-side numerical aperture of the imaging optical system 3) is set to 0.5.

  Referring to FIG. 5, a first area ratio changing structure 12 a is formed in a first irradiation area (a lower left quadrant area in the drawing) 13 a on the substrate 4 to be processed corresponding to the first area ratio changing structure 12 a. Corresponding to the direction of change of the occupied area ratio D of the phase modulation region at, a light intensity distribution is generated in which the light intensity increases almost linearly from the left end to the right end along the horizontal direction in the figure. A second irradiation region (a quadrant region at the lower right in the figure in the whole region) 13b on the substrate 4 to be processed corresponding to the second area ratio changing structure 12b has a phase modulation region in the second area ratio changing structure 12b. Corresponding to the changing direction of the occupied area ratio D, a light intensity distribution is generated in which the light intensity increases almost linearly from the lower end to the upper end along the vertical direction in the figure.

  In the third irradiation region (a quadrant region at the upper right in the figure in the entire region) 13c on the substrate 4 to be processed corresponding to the third area ratio changing structure 12c, the phase modulation region in the third area ratio changing structure 12c is occupied. Corresponding to the changing direction of the area ratio D, a light intensity distribution is generated in which the light intensity increases almost linearly from the right end to the left end along the horizontal direction in the figure. The fourth irradiation area on the substrate to be processed 4 corresponding to the fourth area ratio changing structure 12d (a quadrant area on the upper left in the figure in the entire area) 13d occupies the phase modulation area in the fourth area ratio changing structure 12d. Corresponding to the changing direction of the area ratio D, a light intensity distribution is generated in which the light intensity increases almost linearly from the upper end to the lower end along the vertical direction in the figure.

  It will be understood that the forms of the light intensity distributions generated corresponding to the area ratio changing structures 12a to 12d are basically the same as each other only in the direction. Therefore, in FIG. 5, for the sake of clarity, the light intensity value is given only to the contour lines indicating the light intensity distribution generated corresponding to the second area ratio changing structure 12 b. Thus, in the light intensity distribution generated corresponding to one repetitive pattern 12, the light intensity distribution regions 13a and 13c in which the light intensity increases almost linearly along the horizontal direction in the figure, and the vertical direction in the figure. Are adjacent to the light intensity distribution regions 13b and 13d where the light intensity increases almost linearly.

  FIG. 6 is a diagram illustrating a state where needle crystals are generated on the semiconductor film of the substrate to be processed by the light modulation element according to the present embodiment. In FIG. 6, acicular crystal grains generated on the semiconductor film of the substrate 4 to be processed corresponding to each repeating pattern 12 of the light modulation element 1 are schematically shown. Referring to FIG. 6, the first irradiation region 13a of the substrate 4 to be processed corresponding to the first area ratio changing structure 12a has an arrow from left to right along the light intensity gradient direction, that is, the horizontal direction in the drawing. A group of acicular crystals extending as shown by 14a is produced. Therefore, a TFT having a high response speed is obtained by aligning the channel direction with the group of needle crystals generated in the region 13a in the direction indicated by the arrow 14a or in the opposite direction. be able to.

  Similarly, in the second irradiation region 13b of the substrate 4 to be processed corresponding to the second area ratio changing structure 12b, a group of slenderly extending along the light intensity gradient direction, that is, the vertical direction in the drawing, that is, upward. A needle-like crystal is generated, and a TFT with a high response speed can be manufactured by aligning the channel direction with the direction indicated by the arrow 14b in the figure. In addition, a group of needle-like crystals that are elongated from right to left along the light intensity gradient direction, that is, the horizontal direction in the figure, are generated in the region 13c of the substrate 4 to be processed corresponding to the third area ratio changing structure 12c. Thus, a TFT having a high response speed can be manufactured by aligning the channel direction with the direction indicated by the arrow 14c in the figure. In addition, the fourth irradiation region 13d of the substrate 4 to be processed corresponding to the fourth area ratio changing structure 12d has a group of needles elongated in the light intensity gradient direction, that is, in the vertical direction in the drawing, that is, downward. A crystal having a high response speed can be manufactured by aligning the channel direction with the direction indicated by the arrow 14d in the figure.

  Thus, in the crystallization apparatus of this embodiment, it is possible to generate a needle-like crystal group capable of producing a TFT having a constant response speed without aligning the channel directions in one direction. As a result, the free space is reduced, the required area of the crystal film is reduced, and the required wiring is shortened. As a result, rapid design is possible without the need for trial and error in the layout, and consequently the circuit. The degree of freedom of design increases.

  In the above-described embodiment, the horizontal first and third area ratio changing structures 12a and 12c and the vertical second and fourth area ratio changing structures 12b and 12d are adjacent to each other with no gap therebetween. The light modulation elements 1 mixed together are used to generate a needle crystal group extending vertically and a needle crystal group extending horizontally long on the substrate 4 to be processed. However, in the present invention, the present invention is not limited to this, and the position, direction, dimension, and / or number of the area ratio changing structure constituting the light modulation element is determined according to the desired position and desired direction of the TFT channel. can do. In other words, various modifications are possible with respect to the configuration, the total number, the number of types, the arrangement (position, direction), and the like of the area ratio changing structure constituting the light modulation element.

  In the above-described embodiment, in two adjacent area ratio changing structures, the change direction of the occupied area ratio D may be the same, or the change direction of the occupied area ratio D may be different from each other. In addition, there is a case where the specific side portion of the irradiation region of the substrate to be processed 4 corresponding to one area ratio changing structure is adjacent to a relatively high temperature region having the minimum occupied area ratio D (that is, 0%) In some cases, the area D is adjacent to a relatively low temperature region having the maximum occupied area ratio D (ie, 50%).

  For example, when attention is paid to the second irradiation region 13b of the substrate 4 to be processed corresponding to the second area ratio changing structure 12b, a region adjacent to the right side of the region 13b (the first area of the adjacent repetitive pattern 12 not shown). The portion near the first irradiation region) formed by the rate changing structure 12a is relatively low temperature, and the adjacent portion of the first irradiation region 13a adjacent to the left side in the drawing is relatively high temperature.

The crystal grows after the irradiation of light on the substrate 4 to be processed is completed and the substrate 4 to be processed is cooled to some extent. During the cooling process, the temperature distribution changes. Therefore, the isothermal lines in the molten Si correspond (match) with the contour lines of the light intensity as shown in FIG. 5 immediately after the end of irradiation, but change with time. At this time, since the thermal conductivity of the substrate and the cap layer (for example, SiO ₂ ) is lower than the thermal conductivity of the molten Si, it is only necessary to consider the thermal conduction in the molten Si as the temperature distribution change. Therefore, the temperature distribution T in the molten Si is determined by the following thermal diffusion equation (2). In Expression (2), D is a thermal diffusion constant of molten Si, x and y are coordinates in the molten Si plane, and t is time.

  Referring to equation (2), it can be seen that the temperature rises when the secondary differential value (right side) with respect to the temperature coordinate is positive, and the temperature falls when it is negative. That is, considering the notation of the isothermal line shown in FIG. 7 with the temperature on the vertical axis and the position on the horizontal axis (which coincides with the contour line of the light intensity immediately after the end of irradiation), the isothermal line becomes concave. It can be seen that the temperature rises at the locations where the temperature is present (that is, the valley-like locations), and the temperature decreases at the locations where the isothermal lines are convex (ie, the ridge-like locations). The actual temperature change is determined by accumulating such minute changes over time. As an example, the isothermal line 15 shows how an isothermal line corresponding to a contour line having a light intensity of 0.8 has changed after a predetermined time. As shown in FIG. 7, in the second irradiation region 13b of the substrate 4 to be processed corresponding to the second area ratio changing structure 12b, the isothermal line 15 coincides with the contour line having a light intensity of 0.8 due to the influence of heat conduction. It is easy to become a shape collapsed to some extent without doing.

  On the other hand, crystal growth has the property of proceeding in a direction perpendicular to the isothermal line. For this reason, the needle-like crystal 16a, which is schematically shown as an elongated rectangle at the left end in the figure, tends to bend in a direction approaching the high temperature side (left side in the figure) as it grows. Similarly, the needle-like crystal 16b shown second from the right end in the figure tends to bend in a direction away from the low temperature side (right side in the figure). Further, the needle-like crystal 16b may collide with the needle-like crystal 16c at the right end in the figure growing from the low temperature side, and the crystal growth may be hindered in the middle. As described above, in the above-described embodiment, there is a possibility that the growth direction and the growth distance of the acicular crystals may be disturbed. In this case, only a group of acicular crystals 16d between the acicular crystals 16a and 16b is effectively used. I can't.

  FIG. 8A to FIG. 8C are diagrams for schematically explaining the configuration of the light modulation element according to the modification of the present embodiment, and FIG. 8A shows the first band-like pattern. 8 (b) shows a second belt-like pattern, and FIG. 8 (c) shows an area ratio changing structure comprising a set of the first belt-like pattern shown in FIG. 8 (a) and the second belt-like pattern shown in FIG. 8 (b). Is shown. The first or center side belt-like pattern 20 shown in FIG. 8A has basically the same configuration as the belt-like pattern 10 shown in FIG. On the other hand, the second or end-side belt-like pattern 21 shown in FIG. 8B has a configuration similar to the first belt-like pattern 20, but the form of change in the occupied area ratio D is substantially the same as that of the first belt-like pattern 20. Is different.

  Specifically, the first and second unit cells 21a, 21b (square unit regions indicated by broken lines in the drawing) from the left end of the second strip pattern 21 in the drawing are 1 from the left end in the drawing of the first strip pattern 20. Each of the second and second unit cells 20a, 20b has the same configuration. The third, fourth, fifth, sixth, seventh, and eighth unit cells from the left end of the second strip pattern 21 are the fourth, fifth, and sixth from the left end of the first strip pattern 20 in the drawing. , 7th, 8th and 9th (ie right end) unit cells have the same configuration. The rightmost unit cell 21 i of the second strip pattern 21 in the drawing has the same configuration as the rightmost unit cell 20 i of the first strip pattern 20 in the drawing.

  As shown in FIG. 8C, the area ratio changing structure 22 in the modified example includes seven first belt patterns 20 and two second belt patterns 21 that are adjacent to each other along the vertical direction in the figure. It is constituted by arranging densely. More specifically, one second belt-like pattern 21 is arranged second from the upper end in the figure, and the other second belt-like pattern 21 is arranged second from the lower end in the figure. In the case of this modification, in the light intensity distribution generated on the image plane of the imaging optical system 3 corresponding to the first strip pattern 20, from the position corresponding to the left end of the first strip pattern 20 in the figure to the right end of the figure. The light intensity I increases almost linearly toward the corresponding position.

  On the other hand, in the light intensity distribution generated on the image plane of the imaging optical system 3 corresponding to the second band-shaped pattern 21, the position corresponding to the left end in the figure of the second band-shaped pattern 21 corresponds to the right end in the figure. Although the light intensity I increases monotonously toward the position, it does not change almost linearly like the first strip pattern 20. That is, in the region corresponding to the area between the second unit cell 21b and the third unit cell from the left end of the second strip pattern 21, the second unit cell 20b from the left end of the first strip pattern 20 The light intensity changes in a form different from the area corresponding to the third unit cell.

  As described above, in the area ratio changing structure 22 according to the modification, not all of the forms of changes in the occupied area ratio D in the nine strip-shaped patterns are the same. That is, of the nine strip patterns, the change of the occupied area ratio D in the two second strip patterns 21 arranged in the vicinity of the end is the occupied area ratio D in the other seven first strip patterns 20. The form of change is substantially different. Specifically, the occupied area ratio D in a partial region (unit cell after the third unit cell) of the second band-shaped pattern 21 is smaller than the occupied area ratio D in the corresponding region in the first band-shaped pattern 20. As a result, as described above, in the image plane region corresponding to the second strip pattern 21, there is a partial region where the light intensity changes in a form different from that of the image plane region corresponding to the first strip pattern 20. .

  FIG. 9 is a diagram schematically illustrating the configuration of a light modulation element according to a modification of the present embodiment, and schematically illustrates a light modulation element having a repetitive pattern. Referring to FIG. 9, each repetitive pattern 23 of the light modulation element 1A according to the modification is configured by four area ratio changing structures 23a, 23b, 23c, and 23d, and has a square shape similarly to the area ratio changing structures 23a to 23d. It has an outer shape. Here, the first area ratio changing structure 23a is set in the direction corresponding to the area ratio changing structure 22 shown in FIG. 8C, and the occupation area ratio D of the phase modulation region is from the right end along the horizontal direction in the figure. It has a form that increases to the left end.

  The second area ratio changing structure 23b is set in a direction in which the first area ratio changing structure 23a is rotated 90 degrees counterclockwise in the figure, and the occupied area ratio D of the phase modulation region is at the upper end along the vertical direction in the figure. From the bottom to the bottom. The third area ratio changing structure 23c is set in a direction in which the first area ratio changing structure 23a is rotated 180 degrees counterclockwise in the figure, and the occupation area ratio D of the phase modulation region is the left end along the horizontal direction in the figure. To the right end. The fourth area ratio changing structure 23d is set in a direction in which the first area ratio changing structure 23a is rotated 90 degrees clockwise in the figure, and the occupied area ratio D of the phase modulation region is from the lower end along the vertical direction in the figure. It has a form that increases to the upper end. Also in FIG. 9, similarly to FIG. 4, only one repetitive pattern 23 arranged at the center and 12 area ratio changing structures arranged so as to surround the repetitive pattern 23 are shown.

  In the light modulation element of the present invention, the plurality of repetitive patterns 23 do not necessarily have the same or substantially the same form, and the phase modulation region may include repetitive patterns 23 different from other repetitive patterns 23. In addition, only one repetitive pattern 23 may be provided. Further, the repetitive pattern 23 does not necessarily have four phase modulation regions, and has at least one first phase modulation region in which the ratio of the occupied area changes along the first direction. The two-area ratio changing structure only needs to have at least one second phase modulation region in which the ratio of the occupied area changes along a second direction different from the first direction. The first direction and the second direction are not necessarily orthogonal to each other, and the first phase modulation region and the second phase modulation region can be set to have an arbitrary angle.

  FIG. 10 is a diagram showing a light intensity distribution generated on the image plane of the imaging optical system by the light modulation element according to the modification of FIG. 10, similarly to FIG. 5, the light intensity distribution theoretically generated on the image plane of the imaging optical system 3 corresponding to one repetitive pattern 23 in the light modulation element 1A is expressed by the light intensity (unmodulated). The light intensity when the intensity is normalized to 1) is shown in the form of contour lines. When calculating the light intensity distribution according to this modification, similarly to the above-described embodiment, the wavelength of light is 308 nm, the imaging magnification of the imaging optical system 3 is 1/5, and the object of the imaging optical system 3 The side numerical aperture is set to 0.15, the numerical aperture of the illumination system 2 is set to 0.075, and the coherence factor, that is, the σ value (the numerical aperture of the illumination system 2 / the numerical aperture on the object side of the imaging optical system 3) is set to 0.5. ing.

  Referring to FIG. 10, corresponding to the second belt-shaped pattern 21 in the first irradiation region (lower quadrant region in the figure in the entire region) 24 a of the substrate 4 to be processed corresponding to the first area ratio changing structure 23 a. In the regions other than the region to be illuminated, the light intensity is approximately linear from the left end to the right end along the horizontal direction in the figure corresponding to the changing direction of the area ratio D occupied by the phase modulation region in the first area ratio changing structure 23a. An increasing light intensity distribution is generated. Of the region on the substrate to be processed 4 corresponding to the second area ratio changing structure 23b (outside the whole region, the lower right quadrant region in the drawing) 24b, the region excluding the region corresponding to the second strip pattern 21 is Corresponding to the changing direction of the area ratio D occupied by the phase modulation region in the second area ratio changing structure 23b, a light intensity distribution is generated in which the light intensity increases almost linearly from the lower end to the upper end along the vertical direction in the figure. The

  Of the regions on the substrate 4 to be processed (corresponding to the third area ratio changing structure 23c), the region excluding the region corresponding to the second strip pattern 21 is 24 Corresponding to the changing direction of the area ratio D occupied by the phase modulation region in the three area ratio changing structure 23c, a light intensity distribution is generated in which the light intensity increases almost linearly from the right end to the left end along the horizontal direction in the figure. . Of the region on the substrate 4 to be processed (corresponding to the fourth area ratio changing structure 23d) (outside the whole region, the upper left quadrant region in the drawing) 24d, the region excluding the region corresponding to the second strip pattern 21 Corresponding to the changing direction of the area ratio D occupied by the phase modulation region in the four area ratio changing structure 23d, a light intensity distribution is generated in which the light intensity increases almost linearly from the upper end to the lower end along the vertical direction in the figure. . Also in the modification, the forms of the light intensity distributions respectively generated corresponding to the first to fourth area ratio changing structures 23a to 23d are basically the same as each other except for the direction. Therefore, in FIG. 10, for the sake of clarity, the light intensity value is given only to the contour lines indicating the light intensity distribution generated corresponding to the second area ratio changing structure 23 b.

  FIG. 11 is a diagram schematically illustrating that the growth direction of the needle-like crystal is stabilized in the modification of the present embodiment. In FIG. 11, in the second irradiation region 24b of the substrate 4 to be processed corresponding to the second area ratio changing structure 23b, the isothermal line 25 corresponding to the contour line having the light intensity of 0.8 is indicated by a thick solid line. . Here, a region portion adjacent to the right side of the region 24b in the drawing is relatively low temperature, and a region portion adjacent to the left side in the drawing is relatively high temperature. However, since the region portion corresponding to the second strip pattern 21 acts as a buffer region portion for the adjacent low temperature region portion and high temperature region portion, the temperature distribution in the central region portion excluding the left end and the right end in the drawing of the region 24b is It is difficult to be affected by the adjacent low temperature region and high temperature region.

  As a result, in the modification of the present embodiment, the tendency of the needle-like crystal 26a shown at the left end in the figure to bend in the direction approaching the high temperature side (left side in the figure) is suppressed. Similarly, the tendency of the needle-like crystal 26b shown second from the right end in the figure to bend away from the low temperature side (right side in the figure) is suppressed. Further, the unnecessary needle-like crystal 26c at the right end in the figure does not collide with the needle-like crystal 26b and does not hinder the crystal growth on the way. As described above, in the modification of the present embodiment, the growth direction and the growth distance of the acicular crystals are stabilized without much influence of the adjacent low temperature region or high temperature region (acoustic crystals having a good shape and orientation are generated). Therefore, a group of acicular crystals 26d generated in a relatively wide area between the acicular crystals 26a and 26b can be used effectively. In some cases, needle crystals 26a and 26b having a small bending tendency can also be used effectively.

  In the above-described modification, in the area ratio changing structure 22 shown in FIG. 8C, one second or end-side belt-like pattern 21 is arranged second from the upper end in the figure, and the other second or end-side belt-like pattern. 21 is arranged second from the lower end in the figure. However, the present invention is not limited to this, and the form of the change in the area ratio occupied by the phase modulation region in the second strip pattern, the position and number of the second strip pattern to be arranged at the end of the area ratio changing structure or in the vicinity thereof. Various configurations are possible. For example, in the above modification, one end-side belt-like pattern 21 is disposed on each end of the area ratio changing structure 22, but at least one end-side belt-like pattern 21 is arranged on at least one end side. It only has to be installed.

FIG. 12A to FIG. 12E are process cross-sectional views showing a process of manufacturing an electronic device in a region crystallized using the crystallization apparatus of this embodiment. As shown in FIG. 12A, a base film 81 (for example, SiN having a thickness of 50 nm is formed on a transparent insulating substrate 80 (for example, formed of alkali glass, quartz glass, plastic, polyimide, or the like). A film such as a laminated film with SiO ₂ having a thickness of 100 nm), an amorphous semiconductor film 82 (for example, a semiconductor film such as Si, Ge, SiGe, etc. having a thickness of about 50 nm to 200 nm), and a cap film 82a (for example, a film). A substrate 5 to be processed is prepared in which a SiO ₂ film having a thickness of 30 nm to 300 nm or the like is sequentially formed by chemical vapor deposition or sputtering. Then, for example, using the crystallization method and apparatus according to the present embodiment using the light modulation element shown in FIG. 4 or FIG. 9, the laser beam 83 is applied to a predetermined region on the surface of the amorphous semiconductor film 82. (For example, KrF excimer laser light, XeCl excimer laser light, etc.) are temporarily irradiated once or a plurality of times as indicated by arrows to grow the above-described needle-like crystal.

Thus, as shown in FIG. 12B, a polycrystalline semiconductor film or a single crystallized semiconductor film (crystallized region) 84 having a crystal with a large grain size in the irradiation region of the amorphous semiconductor film 82 is generated. Next, after the cap film 82a is removed from the semiconductor film 84 by etching, as shown in FIG. 12C, a polycrystalline semiconductor film or a single crystallized semiconductor film 84 is formed using a photolithography technique, for example, a thin film transistor. Is processed into an island-shaped semiconductor film (crystallized island-shaped region) 85 to be a region for the purpose, 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. To form a film. Further, as shown in FIG. 12D, a gate electrode 87 (for example, silicide or MoW) is formed on a part of the gate insulating film, and impurity ions 88 (N-channel transistor) are formed using the gate electrode 87 as a mask. In this case, phosphorus is ion-implanted into the semiconductor film 85 as indicated by an arrow. Thereafter, annealing is performed in a nitrogen atmosphere (for example, at 450 ° C. for 1 hour) to activate the impurities and form the source region 91 and the drain region 92 on both sides of the channel region 90 in the island-shaped semiconductor film 85. To do. The positions of the channel regions 90 are set so that carriers move along the growth direction of the needle-like crystal. Next, as shown in FIG. 12E, an interlayer insulating film 89 covering the whole is formed, contact holes are made in the interlayer insulating film 89 and the gate insulating film 86, and the source region 91 and the drain region 92 are formed. A source electrode 93 and a drain electrode 94 to be connected to each other are formed.

  In the above process, the gate electrode is aligned with the position in the planar direction of the large grain crystal of the polycrystalline semiconductor film or the single crystallized semiconductor film 84 generated in the process shown in FIGS. By forming 87, the channel 90 is formed under the gate electrode 87. 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. The to-be-processed object of this invention is not limited to what forms a semiconductor device, and a semiconductor device is not limited to TFT.

  In the above description, the present invention is implemented using a phase modulation type light modulation element as the light modulation element. However, the present invention is not limited to this, and other types such as a transmission type light modulation element having a predetermined transmission pattern and a reflection type light modulation element having a predetermined reflection pattern, or a combination thereof, in the first direction. A first modulation region that generates a first light intensity distribution on the surface to be irradiated along with a second light intensity distribution in which the light intensity changes along a second direction different from the first direction. The present invention can be implemented using a light modulation element having a second modulation region generated on the irradiation surface.

  In the above description, the present invention is applied to a crystallization apparatus and a crystallization method for generating 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 the present invention is generally applicable to a light irradiation apparatus that forms a predetermined light intensity distribution on a predetermined irradiated surface via an imaging optical system.

It is a figure which shows roughly the structure of the crystallization apparatus concerning embodiment of this invention. It is a figure which shows schematically the internal structure of the illumination system of FIG. (A) thru | or (c) is a figure which illustrates schematically the structure of the light modulation element concerning this embodiment, Comprising: FIG. 3 (a) is a figure which shows the strip | belt-shaped pattern which is a basic pattern of a light modulation element. FIG. 3B is a diagram showing an area ratio changing structure composed of a set of strip-like patterns shown in FIG. 3A, and FIG. 3C is an area ratio changing structure shown in FIG. It is a figure which shows the light intensity distribution produced | generated. It is a figure which illustrates schematically the structure of the light modulation element concerning this embodiment, Comprising: The repeating pattern of a light modulation element is shown schematically. It is a figure which shows the light intensity distribution produced | generated on the image surface of an imaging optical system by the light modulation element concerning this embodiment. It is a figure which shows a mode that the acicular crystal | crystallization is produced | generated on the semiconductor film of a to-be-processed substrate by the light modulation element concerning this embodiment. It is a figure which illustrates typically that the growth direction of a needle-like crystal may be disordered in this embodiment. (A) thru | or (c) is a figure explaining roughly the structure of the light modulation element concerning the modification of this embodiment, Comprising: Fig.8 (a) shows a 1st strip | belt-shaped pattern, FIG.8 (b). FIG. 8 (c) shows an area ratio changing structure composed of a set of the first belt-like pattern shown in FIG. 8 (a) and the second belt-like pattern shown in FIG. 8 (b). It is a figure which illustrates schematically the structure of the light modulation element concerning the modification of this embodiment, Comprising: The repeating pattern of a light modulation element is shown schematically. It is a figure which shows the light intensity distribution produced | generated on the image surface of an imaging optical system by the light modulation element concerning the modification of FIG. It is a figure which illustrates typically that the growth direction of a needle-like crystal is stabilized in the modification of this embodiment. It is process sectional drawing which shows the process of producing an electronic device using the crystallization apparatus of this embodiment. (A) thru | or (c) is a figure which illustrates the conventional crystallization technique roughly, FIG.13 (a) is a figure where the ratio of the occupation area of the phase modulation area | region in a unit area | region is primary along a predetermined direction. FIG. 13B is a plan view showing a part of a phase modulation element having an originally changing phase pattern, and FIG. 13B shows the light intensity generated when the phase modulation amount in the phase modulation region is 60 degrees and 180 degrees. FIG. 13C is a diagram schematically showing a needle crystal formed by the laser beam having the light intensity distribution. FIGS. 14A and 14B are diagrams schematically explaining the disadvantages of the conventional crystallization technique, and FIG. 14A shows that the direction of the channel is parallel to the longitudinal direction of the acicular crystal. FIG. 14B shows the case where the source and the drain are formed so that the channel direction is substantially perpendicular to the longitudinal direction of the needle crystal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light modulation element 2 Illumination system 2a Light source 2b Beam expander 2c, 2e Fly eye lens 2d, 2f Condenser optical system 3 Imaging optical system 4 Substrate 5 Substrate stage

Claims (24)

A light irradiation apparatus for irradiating an irradiated surface with light having a light intensity distribution,
A light modulation element for modulating and emitting the phase of incident light;
An imaging optical system disposed between the light modulation element and the irradiated surface for imaging the emitted light so as to irradiate the irradiated surface with light having the light intensity distribution; Comprising
The light modulation element has a plurality of area ratio changing structures including a first area ratio changing structure and a second area ratio changing structure in a unit region, and the first area ratio changing structure has an occupied area ratio. The second area ratio changing structure has at least one first phase modulation region that changes along the first direction, and the ratio of the occupied area changes along a second direction different from the first direction. A light irradiation apparatus having at least one second phase modulation region. The light irradiation apparatus according to claim 1, wherein the first direction and the second direction are substantially orthogonal to each other. The first area ratio changing structure includes a plurality of first unit regions arranged in a line along the first direction, and a plurality of first unit regions arranged along a direction substantially orthogonal to the first direction. Having a first strip pattern;
The second area ratio changing structure includes a plurality of second unit regions arranged in a line along the second direction, and a plurality of second unit regions arranged along a direction substantially orthogonal to the second direction. The light irradiation apparatus of Claim 1 or 2 which has a 2nd strip | belt-shaped pattern. The light irradiation according to claim 3, wherein the ratio change of the occupied area of the plurality of strip-shaped patterns of at least one of the first area ratio changing structure and the second area ratio changing structure has substantially the same form. apparatus. The ratio change of the occupied area of the strip pattern of the plurality of strip patterns of at least one of the first area ratio change structure and the second area ratio change structure is at least one strip pattern and other strip strips. The light irradiation apparatus according to claim 3, wherein the light irradiation apparatus is substantially different from the pattern. The at least one band-shaped pattern includes an end-side band-shaped pattern located on at least one end side in a direction substantially perpendicular to the first direction of the at least one area ratio changing structure, The light irradiation apparatus according to claim 5, comprising a center-side belt-like pattern located on a center side in a direction substantially orthogonal to the first direction of at least one area ratio changing structure. The light irradiation apparatus according to claim 5 or 6, wherein a ratio of the occupied area in a partial region of the at least one strip-shaped pattern is smaller than a ratio of the occupied area in a corresponding region in the plurality of other strip-shaped patterns. . A light irradiation apparatus for irradiating an irradiated surface with light having a light intensity distribution,
A light modulation element for modulating incident light;
An imaging optical system disposed between the light modulation element and the irradiated surface to form the light intensity distribution on the irradiated surface;
The light modulation element includes at least one first modulation region that generates a first light intensity distribution whose light intensity varies along a first direction on the irradiated surface, and a second direction different from the first direction. A light irradiation apparatus having a plurality of modulation regions including at least one second modulation region that generates a second light intensity distribution whose light intensity varies along the surface on the irradiated surface. The light irradiation apparatus according to claim 8, wherein the first direction and the second direction are substantially orthogonal to each other. Using a light modulation element that modulates the phase of the incident light and an imaging optical system disposed between the light modulation element and the irradiated surface, light having a predetermined light intensity distribution is applied to the irradiated surface. A light irradiation method for irradiating,
As the light modulation element, at least one first area ratio changing structure in which the ratio of the area occupied by the phase modulation region in the unit region changes along the first direction, and the ratio of the area occupied by the phase modulation region in the unit region is A light irradiation method using a light modulation element having at least one second area ratio changing structure that changes along a second direction different from the first direction. Using a light modulation element that modulates incident light and an imaging optical system disposed between the light modulation element and the irradiated surface, the irradiated surface is irradiated with light having a predetermined light intensity distribution. A light irradiation method,
As the light modulation element, at least one first modulation region that generates a first light intensity distribution whose light intensity varies along a first direction on the irradiated surface, and a second direction different from the first direction A light irradiation method using a light modulation element having at least one second modulation region that generates a second light intensity distribution whose light intensity varies along the surface on the irradiated surface. A light irradiation apparatus according to claim 1, and a stage for holding the non-single crystal semiconductor film so that an irradiation surface thereof is the irradiated surface, wherein the non-single crystal semiconductor film A crystallization apparatus for irradiating an irradiation surface with light having the light intensity distribution to form a crystallized semiconductor film. Using the light irradiation apparatus according to claim 1 or 8, or the light irradiation method according to claim 10 or 11, the light intensity distribution is applied to at least a part of the non-single-crystal semiconductor film held on the irradiated surface. A crystallization method in which a crystallized semiconductor film is formed by irradiating with light having the following. A semiconductor device manufactured using the crystallization method according to claim 13. A light modulation element for modulating the phase of incident light,
At least one first area ratio changing structure in which the ratio of the area occupied by the phase modulation region in the unit region changes along the first direction, and the ratio of the area occupied by the phase modulation region in the unit region is the first direction. An optical modulation element comprising a plurality of area ratio changing structures including at least one second area ratio changing structure that changes along different second directions. The light modulation element according to claim 15, wherein the first direction and the second direction are substantially orthogonal to each other. The first area ratio changing structure includes a plurality of first unit regions arranged in a line along the first direction, and a plurality of first unit regions arranged along a direction substantially orthogonal to the first direction. Having a first strip pattern;
The second area ratio changing structure includes a plurality of second unit regions arranged in a line along the second direction, and a plurality of second unit regions arranged along a direction substantially orthogonal to the second direction. The light modulation element according to claim 15, wherein the light modulation element has a second strip pattern. The light modulation according to claim 17, wherein the ratio change of the occupied area of the plurality of strip-shaped patterns of at least one of the first area ratio changing structure and the second area ratio changing structure has substantially the same form. element. The ratio change of the occupied area of the strip pattern of the plurality of strip patterns of at least one of the first area ratio change structure and the second area ratio change structure is at least one strip pattern and other strip strips. The light modulation element according to claim 17, wherein the light modulation element is substantially different from the pattern. The at least one band-shaped pattern includes an end-side band-shaped pattern located on at least one end side in a direction substantially perpendicular to the first direction of the at least one area ratio changing structure, The light modulation element according to claim 19, further comprising a center-side belt-like pattern located on a center side in a direction substantially orthogonal to the first direction of at least one area ratio changing structure. The at least one band-shaped pattern includes end-side band-shaped patterns located on both ends of the at least one area ratio changing structure in a direction substantially orthogonal to the first direction, and the other plurality of band-shaped patterns include these end-patterns. The light modulation element according to claim 19, comprising a center side band pattern located between the side band patterns. The ratio of the occupied area in a partial region of the at least one strip-shaped pattern is smaller than the ratio of the occupied area in a corresponding region in the plurality of other strip-shaped patterns. The light modulation element described. A light modulation element for modulating incident light,
At least one first modulation region that generates a first light intensity distribution whose light intensity varies along the first direction in a part of the irradiated surface, and the light intensity along a second direction different from the first direction. A light modulation element comprising: at least one second modulation region that generates a second light intensity distribution that changes in other portions of the irradiated surface. The light modulation element according to claim 23, wherein the first direction and the second direction are substantially orthogonal to each other.

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