JP2008300602A - Radiating apparatus, manufacturing device of semiconductor device, manufacturing method of semiconductor device, and manufacturing method of display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve balanced optical design capable of sufficiently assuring uniformity in radiation while sufficiently coping with miniaturization of a radiation optical system when radiating a beam using a semiconductor laser as light source. <P>SOLUTION: The radiating apparatus radiates the emitted beam from a semiconductor laser to an object. A first wavefront split type integrator 62 and second wavefront split type integrator 64 are respectively configured to satisfy NA<SB>2</SB>≤NA<SB>1</SB>while allowing NA<SB>1</SB>, P<SB>1</SB>, NA<SB>2</SB>, and P<SB>2</SB>to satisfy a specified relationship. Here, the numerical aperture of the first wavefront split type integrator 62 arranged for uniform radiation is NA<SB>1</SB>, a split pitch is P<SB>1</SB>, the numerical aperture of the second wavefront split type integrator 64 arranged closer to the object than to the first wavefront split type integrator 62 is NA<SB>2</SB>, and split pitch is P<SB>2</SB>. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an irradiation apparatus that irradiates a light beam using a semiconductor laser as a light source, a semiconductor device manufacturing apparatus that uses the irradiation of the beam light, a semiconductor device manufacturing method, and a display device. It relates to a manufacturing method.

  In recent years, laser beam light has been used for various purposes. As an example, in the case of manufacturing an active matrix liquid crystal display device, an organic electroluminescent display device (hereinafter referred to as “organic EL display”) using an organic electroluminescent element (hereinafter referred to as “organic EL element”), etc., a thin film transistor ( In order to form a circuit element such as a thin film transistor (hereinafter abbreviated as “TFT”) from polycrystalline silicon, it is known to perform an annealing process on a silicon thin film using continuously oscillating laser beam light. The annealing process using laser beam light partially irradiates the silicon thin film, so that the entire substrate can be prevented from becoming high temperature, and a glass substrate can be used as the substrate. is there.

Incidentally, the intensity of laser beam light is generally not uniform within the beam cross section. For example, the strength of the central portion is high and the strength of the peripheral portion is low. For this reason, various techniques for forming a laser beam having a uniform intensity distribution have been proposed.
Specifically, using a wavefront division type integrator having a large number of microlens elements arranged two-dimensionally, and arranging the integrators in multiple stages to form an irradiation optical system, laser beam light irradiation It has been proposed to improve the uniformity (see, for example, Patent Document 1). However, in such a configuration, the uniformity can be improved by increasing the number of divisions of the integrator. However, depending on the spatial coherency of the laser used for the light source, there is a concern that the influence of interference fringes may occur. The In order to reduce such an adverse effect, it is effective to optimize the number of wavefront divisions, that is, the division pitch of the integrator (see, for example, Patent Document 2). In addition, since the state of the secondary light source generated by the integrator changes depending on the state of the light beam incident on the integrator, it is also necessary to set a condition in which the influence does not occur in uniform irradiation (for example, Patent Document 3). reference).

JP 2002-222761 A JP 2004-93837 A JP 2002-40327 A

However, the above-described conventional technique can obtain a sufficient effect with respect to the uniform irradiation of the laser beam, but is mainly assumed to be applied to a large facility using an excimer laser or a lamp as a light source. It is not an optical design that focuses on the development.
On the other hand, recently, semiconductor lasers are widely used as a light source of laser beam light. With respect to the irradiation optical system corresponding to such a semiconductor laser, since the semiconductor laser is originally small, the optical design can cope with downsizing while sufficiently ensuring the irradiation uniformity of the laser beam light. Should be. In particular, when a semiconductor laser is used as a light source for laser beam light, in order to effectively utilize the small size, it is conceivable to arrange a plurality of semiconductor lasers and perform parallel irradiation of laser beam light. In some cases, for each irradiation optical system corresponding to each semiconductor laser, it is strongly required to cope with downsizing.

  Therefore, the present invention provides a well-balanced structure that can sufficiently cope with downsizing of the irradiation optical system while ensuring sufficient irradiation uniformity when irradiating beam light using a semiconductor laser as a light source. Another object of the present invention is to provide an irradiation apparatus of optical design, a semiconductor device manufacturing apparatus, a semiconductor device manufacturing method, and a display device manufacturing method.

を満足し、かつ、

を満足するように、それぞれが構成されていることを特徴とする。 The present invention has been devised to achieve the above object, and is an irradiation apparatus for irradiating an irradiation object with emitted beam light from a semiconductor laser, and is a first apparatus arranged for uniform irradiation. A wavefront splitting integrator and a second wavefront splitting integrator disposed closer to the irradiated object than the first wavefront splitting integrator; and the first wavefront splitting integrator and the second wavefront splitting When the numerical aperture of the first wavefront split integrator is NA ₁ and the split pitch is P ₁ , the numerical aperture of the second wavefront split integrator is NA ₂ and the split pitch is P ₂ ,

Satisfied, and

Each is configured to satisfy the above.

Since the irradiation apparatus having the above-described configuration includes the first wavefront splitting integrator and the second wavefront splitting integrator, the integrators are arranged in multiple stages, and the irradiation uniformity of the laser beam passing through these integrators Will be improved. Further, by satisfying the condition that the numerical aperture NA ₂ of the _second wavefront splitting integrator is equal to or less than the numerical aperture NA _{1 of} the first wavefront splitting integrator, the first wavefront splitting integrator and the second wavefront splitting type are satisfied. An increase in the overall length of the irradiation optical system including the integrator can be suppressed, and accordingly, an increase in the size of the lens barrel of the irradiation optical system can be suppressed. Furthermore, by satisfying the conditions regarding the relationship between the numerical apertures NA ₁ and NA ₂ and the division pitches P ₁ and P ₂ of each wavefront division type integrator, the required uniform irradiation cannot be obtained due to a decrease in the number of wavefront divisions. It wo n’t happen.

  According to the present invention, when a semiconductor laser is used as a light source and beam light is irradiated, it is possible to easily cope with miniaturization by suppressing the size expansion of the irradiation optical system while ensuring sufficient irradiation uniformity. Therefore, the line beam irradiation optical system for irradiating the irradiated light beam from the inexpensive and high output broad area type semiconductor laser to the irradiated object can be configured inexpensively, practically and in a small size. it can.

  Hereinafter, an irradiation apparatus, a semiconductor device manufacturing apparatus, a semiconductor device manufacturing method, and a display device manufacturing method according to the present invention will be described with reference to the drawings.

First, an outline of a semiconductor device manufactured using laser light irradiation will be described.
The semiconductor device described here is a modification of an amorphous silicon film (amorphous silicon, hereinafter referred to as “a-Si”) from an amorphous state to a polycrystalline state, that is, a-Si to a polycrystalline silicon film ( It is obtained through modification to polysilicon (hereinafter referred to as “p-Si”). Specifically, a TFT which is a thin film semiconductor device is given as an example.

The TFT is used to configure a display device such as an active matrix liquid crystal display device or an organic EL display.
FIG. 1 is an explanatory diagram showing a configuration example of an organic EL display having TFTs.
The organic EL display 1 having the configuration shown in the figure is manufactured by the procedure described below.
First, a gate film 12 made of, for example, a Mo film is patterned on a substrate 11 made of a glass substrate, and then covered with a gate insulating film 13 made of, for example, a SiO / SiN film. Then, a semiconductor layer 14 made of an a-Si film is formed on the gate insulating film 13. The semiconductor layer 14 is subjected to a laser annealing process and is modified from an a-Si film to a p-Si film by crystallization. Next, the semiconductor layer 14 is patterned into an island shape covering the gate film 12. Thereafter, an insulating pattern (not shown) is formed at the position overlapping the gate film 12 of the semiconductor layer 14 by backside exposure from the substrate 11 side, and the semiconductor layer 14 is subjected to ion implantation and activation annealing treatment using the insulating pattern as a mask. A source / drain is formed on the substrate. As described above, the so-called bottom gate type TFT 10 in which the gate film 12, the gate insulating film 13, and the semiconductor layer 14 are sequentially laminated on the substrate 11 is formed. Here, a bottom gate type is taken as an example, but a top gate type TFT may be used.
Thereafter, the TFT 10 is covered with an interlayer insulating film 21, and a pixel circuit is formed by providing a wiring 22 connected to the TFT 10 through a connection hole formed in the interlayer insulating film 21. As described above, a so-called TFT substrate 20 is formed.
After the formation of the TFT substrate 20, the TFT substrate 20 is covered with the planarization insulating film 31 and a connection hole 31 a reaching the wiring 22 is formed in the planarization insulating film 31. Then, the pixel electrode 32 connected to the wiring 22 through the connection hole 31 a is formed on the planarization insulating film 31 as an anode, for example, and an insulating film pattern 33 having a shape covering the periphery of the pixel electrode 32 is formed. Further, the organic EL material layer 34 is laminated and formed on the exposed surface of the pixel electrode 32 so as to cover it. Further, the counter electrode 35 is formed in a state where the insulating property is maintained with respect to the pixel electrode 32. The counter electrode 35 is formed as a cathode made of a transparent conductive material, for example, and is formed in a solid film shape common to all pixels. In this manner, an organic EL element is configured in which an organic EL material layer 34 such as an organic hole transport layer or an organic light emitting layer is disposed between the pixel electrode 32 as an anode and the counter electrode 35 as a cathode. It is. Here, the top emission type is taken as an example, but in the case of the bottom emission type, the pixel electrode 32 may be formed of a conductive transparent film, and the counter electrode 35 may be formed of a highly reflective metal film. . It is also conceivable to employ a microcavity structure in which light is resonated by using a half mirror for the counter electrode 35 or the pixel electrode 32.
Thereafter, a transparent substrate 37 is bonded onto the counter electrode 35 via a light-transmitting adhesive layer 36 to complete the organic EL display 1.

FIG. 2 is an explanatory diagram illustrating an example of a pixel circuit configuration of the organic EL display. Here, an active matrix type organic EL display 1 using an organic EL element as a light emitting element is taken as an example.
As shown in FIG. 2A, on the substrate 40 of the organic EL display 1, a display area 40a and a peripheral area 40b are set. The display area 40a is configured as a pixel array section in which a plurality of scanning lines 41 and a plurality of signal lines 42 are wired vertically and horizontally, and one pixel a is provided corresponding to each intersection. Each pixel a is provided with an organic EL element. In the peripheral area 40b, a scanning line driving circuit 43 that scans and drives the scanning lines 41 and a signal line driving circuit 44 that supplies a video signal (that is, an input signal) corresponding to the luminance information to the signal line 42 are arranged. Yes.
In the display area 40a, organic EL elements corresponding to R, G, and B color components are mixed in order to perform full-color image display, and these are arranged in a matrix pattern according to a predetermined rule. It shall be. Although it is conceivable that the number of installed organic EL elements and the formation area thereof are the same for each color component, for example, they may be made different according to the energy component for each color component.
As shown in FIG. 2B, the pixel circuit provided in each pixel a includes, for example, an organic EL element 45, a driving transistor Tr1, a writing transistor (sampling transistor) Tr2, and a storage capacitor Cs. Then, the video signal written from the signal line 42 via the write transistor Tr2 is held in the holding capacitor Cs by driving by the scanning line driving circuit 43, and a current corresponding to the held signal amount is supplied to the organic EL element 45. Then, the organic EL element 45 emits light with a luminance corresponding to the current value.
Note that the configuration of the pixel circuit as described above is merely an example, and a capacitor element may be provided in the pixel circuit as necessary, or a plurality of transistors may be provided to configure the pixel circuit. In addition, a necessary drive circuit is added to the peripheral region 40b according to the change of the pixel circuit.

The display device represented by the organic EL display 1 described above includes various electronic devices shown in FIGS. 3 to 7, such as a digital camera, a notebook personal computer, a mobile terminal device such as a mobile phone, a video camera, etc. It is used as a display device for electronic devices in various fields that display video signals input to electronic devices or video signals generated in electronic devices as images or videos. Hereinafter, specific examples of electronic devices in which the display device is used will be described.
Note that the display device includes a module having a sealed configuration. For example, a display module formed by being attached to a facing portion such as transparent glass on the pixel array portion corresponds to this. The transparent facing portion may be provided with a color filter, a protective film, and the like, and further the above-described light shielding film. Further, the display module may be provided with a circuit unit for inputting / outputting a signal to the pixel array unit from the outside, an FPC (flexible printed circuit), and the like.

  FIG. 3 is a perspective view illustrating a television which is a specific example of the electronic apparatus. The television shown in the figure includes a video display screen unit 101 including a front panel 102, a filter glass 103, and the like, and is manufactured by using a display device as the video display screen unit 101.

  4A and 4B are perspective views illustrating a digital camera which is a specific example of the electronic device, in which FIG. 4A is a perspective view seen from the front side, and FIG. 4B is a perspective view seen from the back side. The digital camera of the illustrated example includes a light emitting unit 111 for flash, a display unit 112, a menu switch 113, a shutter button 114, and the like, and is manufactured by using a display device as the display unit 112.

  FIG. 5 is a perspective view illustrating a notebook personal computer which is a specific example of the electronic apparatus. The notebook personal computer of the illustrated example includes a keyboard 122 that is operated when characters and the like are input, a display unit 123 that displays an image, and the like. The display unit 123 is used as the display unit 123. .

  FIG. 6 is a perspective view showing a video camera which is a specific example of the electronic apparatus. The video camera of the illustrated example includes a main body 131, a lens 132 for photographing an object on a side facing forward, a start / stop switch 133 at the time of photographing, a display unit 134, and the like, and a display device is used as the display unit 134. It is produced by.

  7A and 7B are diagrams illustrating a mobile terminal device, for example, a mobile phone, which is a specific example of an electronic device, in which FIG. 7A is a front view in an open state, FIG. 7B is a side view thereof, and FIG. (D) is a left side view, (E) is a right side view, (F) is a top view, and (G) is a bottom view. The mobile phone according to this application example includes an upper housing 141, a lower housing 142, a connecting portion (here, a hinge portion) 143, a display 144, a sub-display 145, a picture light 146, a camera 147, and the like. Alternatively, it is manufactured by using a display device as the sub display 145.

Next, feature points in the present embodiment will be described.
In this embodiment, the laser annealing process performed on the semiconductor layer 14 of the TFT 10 during the manufacturing process of the TFT 10 has a great feature.

FIG. 8 is an explanatory view showing a configuration example of a laser annealing apparatus that performs laser annealing, that is, a laser annealing apparatus that is one of manufacturing apparatuses used in the manufacturing process of the TFT 10.
In the laser annealing apparatus exemplified here, as shown in FIG. 8A, one laser irradiation optical unit 51 is constituted by one semiconductor laser 51a and one irradiation optical system 51b.
As shown in FIG. 8B, a plurality (for example, five) of laser irradiation optical units 51 are arranged in parallel.

  The semiconductor laser 51a in each laser irradiation optical unit 51 has a broad area type emitter, and the radial direction of the beam light emitted in the direction perpendicular to the longitudinal direction of the emitter is defined. As such a semiconductor laser 51a, a laser beam having a wavelength of emitted light of 700 to 1000 nm can be used. For example, a high-power semiconductor laser having a wavelength of around 800 nm or a wavelength of 940 nm is used. It is preferable to use a nearby one. By configuring the light source of the irradiation device in this way, the light source can be reduced in size, and the laser beam emitted can be easily formed into a linear beam as described later.

  In addition, as shown in FIG. 8B, the laser annealing apparatus includes a stage 52 that can move on the XY axes in addition to the plurality of laser irradiation optical units 51, and the TFT substrate 20 is set on the stage 52. It has come to be. More specifically, the slow axis direction of each semiconductor laser 51a and the X-axis direction of the stage 52 are parallel to each other.

  The operations of the semiconductor laser 51a and the stage 52 in each laser irradiation optical unit 51 are controlled by a controller (not shown). Specifically, the semiconductor laser 51a oscillates while the stage 52 is scanning in the Y-axis direction, and laser beam light is emitted from the semiconductor laser 51a to the TFT substrate 20 on the stage 52 via the irradiation optical system 51b. Each operation is controlled to irradiate. As a result, the TFT substrate 20 on the stage 52 moves in a direction perpendicular to the broad area direction of the semiconductor laser 51a, and the irradiation state of the laser beam light on the TFT substrate 20 becomes linear. At this time, the irradiation area by each laser irradiation optical unit 51 is equivalent to one pixel of the TFT substrate 20.

  When laser annealing is performed using the laser annealing apparatus configured as described above, it is possible to perform laser annealing simultaneously on the number of pixels corresponding to the number of laser irradiation optical units arranged in parallel. The throughput of the laser annealing process can be improved as compared with the case of performing irradiation with only one axis instead of parallel irradiation. In this case, even if the uniform irradiation state by each laser irradiation optical unit 51 is different, the same annealing treatment can be performed on the entire TFT substrate 20 by adjusting the output of each laser irradiation optical unit 51. become. That is, when a so-called multi-head is realized using a plurality of laser irradiation optical units 51, even if the uniform irradiation of each laser irradiation optical unit 51 is poor, it can be compensated by controlling the output of the semiconductor laser 51a. That doesn't matter.

  By the way, in the laser annealing apparatus having a multi-head, the processing speed when performing the annealing process is determined by the number of multi-heads. Therefore, in order to improve the processing efficiency of the annealing process, it is desirable to mount as many laser irradiation optical units 51 as possible in the laser annealing apparatus. In order to improve the processing efficiency of the annealing process, it is important to reduce the size of the laser irradiation optical unit 51.

  For this reason, in the laser annealing apparatus in the present embodiment, the irradiation optical system 51b in each laser irradiation optical unit 51 is configured as described below.

  FIG. 9 is an explanatory diagram showing a basic configuration example of the irradiation optical system 51 b in each laser irradiation optical unit 51. 9A shows the same direction (X-axis direction) as the emitter direction of the broad area type semiconductor laser 51a, and FIG. 9B shows the direction perpendicular to it (Y-axis direction).

  The irradiation optical system 51b shown in the figure includes a collimator lens 61, a cylindrical lens array pair 62, a condenser lens 63, a cylindrical lens array pair 64, and a condenser along the optical axis direction in order from the semiconductor laser 51a side. A lens 65, a diaphragm 66, and a projection optical system 67 are arranged.

  The collimator lens 61 is a lens having positive power, and makes the Y-axis direction component of the light beam a parallel light beam.

  The cylindrical lens array pair 62 is composed of a pair of cylindrical lens arrays 62a and 62b. The cylindrical lens arrays 62a and 62b are arranged in an array along the X-axis direction. In addition, the cylindrical lens array 62 a is disposed at the back focal position of the collimator lens 61. With such a configuration, in the cylindrical lens array pair 62, the X-axis direction component of the light beam is divided into a plurality of light beams by the cylindrical lens array 62a. The cylindrical lens array pair 62 corresponds to a specific example of “first wavefront splitting integrator” in the invention.

  The condenser lens 63 is a lens having positive power, and superimposes the X-axis direction components of a plurality of light beams from the cylindrical lens array pair 62, and irradiates the cylindrical lens array 64a.

  The cylindrical lens array pair 64 is composed of a pair of cylindrical lens arrays 64a and 64b. The cylindrical lens arrays 64a and 64b are arranged in an array along the X-axis direction. In addition, the cylindrical lens array 64 a is disposed at the back focal position of the collimator lens 61. With such a configuration, in the cylindrical lens array pair 64, the X-axis direction component of the light beam is divided into a plurality of light beams by the cylindrical lens array 64a, and a secondary light source is formed on the cylindrical lens array 64b. . The cylindrical lens array pair 64 corresponds to a specific example of a “second wavefront division integrator” in the present invention.

  The condenser lens 65 is a lens of a spherical optical system, condenses the Y-axis direction components of a plurality of light beams from the secondary light source, overlaps the X-axis direction components, and uniformly irradiates the position of the diaphragm 66. Is. In this way, as will be described later, a linear beam image is formed at the position of the stop 66, with the X-axis direction being the long-axis direction and uniformed in the X-axis direction.

  The aperture 66 controls the opening thereof, thereby adjusting the irradiation area in the X-axis direction of the light beam from the secondary light source that irradiates the TFT substrate 20 that is the irradiation target, and the length of the linear beam described later. Axial region forming is performed.

The projection optical system 67 is for projecting a linear beam image formed at the position of the stop 66 in a reduced scale and irradiating the TFT substrate 20 as an irradiation target, and a pair of lens systems 67a and 67b; A polarizing beam splitter 67c and a ¼λ plate (¼ wavelength plate) 67d disposed between the lens systems 67a and 67b are provided.
The lens systems 67a and 67b perform reduction projection as described above, and play a central role of the projection optical system 67. These lens systems 67a and 67b are arranged so as to constitute a double-sided telecentric optical system.
The polarization beam splitter 67c selectively transmits only a specific polarization component of incident light from the lens system 67a or the ¼λ plate 67d. Specifically, by transmitting a P-polarized component perpendicular to the X-axis direction and reflecting an S-polarized component perpendicular to the Y-axis direction in incident light, the incident light is converted into an S-polarized component and a P-polarized component. Are separated from each other. The quarter λ plate 67d changes the phase of incident light from the polarization beam splitter 67c or the lens system 67b by 90 °. With such a configuration, the polarization beam splitter 67c and the ¼λ plate 67d function as so-called isolators, preventing the reflected light from the irradiation target surface from returning to the semiconductor laser 51a and preventing the irradiation optical system 51b from being destroyed. It has become. Specifically, the P-polarized component selectively transmitted through the polarization beam splitter 67c changes its phase by 90 ° as described above by transmitting through the ¼λ plate 67d, and is further reflected by the irradiation target surface. When the phase changes 90 ° again by passing through the 4λ plate 67d, it becomes an S-polarized component, so that it is reflected by the polarization beam splitter 67c and cannot return to the semiconductor laser 51a.

  In the irradiation optical system 51b having such a configuration, the laser light emitted from the semiconductor laser 51a is divided into a plurality of light beams by the cylindrical lens array pair 62, and after being superimposed by the condenser lens 63, the cylindrical lens array pair. 64 is further divided into a plurality of light beams. Then, the secondary light source is formed on the cylindrical lens array 64b, so that the light flux from the secondary light source is made uniform in the X-axis direction. Therefore, the light beam from the secondary light source can be made uniform in the X-axis direction (long-axis direction), and uneven irradiation can be further prevented.

Here, the feature point in the irradiation optical system 51b having the above configuration will be described in more detail.
FIG. 10 is an explanatory diagram showing a configuration example of a main part of the irradiation optical system 51 b in each laser irradiation optical unit 51. 10A shows the same direction (X-axis direction) as the emitter direction of the broad area type semiconductor laser 51a, and FIG. 10B shows the direction perpendicular to it (Y-axis direction).
FIG. 11 is an explanatory diagram showing a specific example of uniform irradiation by the irradiation optical system 51b.

In the irradiation optical system 51b, the light beam emitted from the semiconductor laser 51a is incident on the cylindrical lens array pair 62 via the collimator lens 61 as shown in FIG. The condenser lens 63 irradiates the cylindrical lens array pair 64 with the light beam emitted from the cylindrical lens array pair 62. As a result, a secondary light source is formed in the cylindrical lens array pair 64. Using the secondary light source generated by the cylindrical lens array pair 64, the condenser lens 65 uniformly irradiates the position of the stop 66 with a profile as shown in FIG.
On the other hand, with respect to the Y-axis direction, as shown in FIG. 10 (b), the light beam emitted from the semiconductor laser 51a is guided in the form of being relayed by the collimator lens 61 and the condenser lens 65 on the emitter end face. Irradiation is performed with a Gaussian profile as shown in FIG.
Thus, the light beam emitted from the semiconductor laser 51a is irradiated as a line beam having a long axis in the X-axis direction via the irradiation optical system 51b.

  This means that the cylindrical lens array pair 62 functions as a “first wavefront splitting integrator” arranged for uniform irradiation, and the cylindrical lens array pair 64 is closer to the irradiated object than the cylindrical lens array pair 62. It means to function as the arranged “second wavefront splitting integrator”. Furthermore, the cylindrical lens array pair 62 functioning as the “first wavefront splitting integrator” and the cylindrical lens array pair 64 functioning as the “second wavefront splitting integrator” are effective only in the longitudinal direction of the semiconductor laser 51a emitter. It means that there is.

In the irradiation optical system 51b having such a configuration, if the numerical aperture of the cylindrical lens array pair 62 is NA ₁ , the division pitch is P ₁ , the numerical aperture of the cylindrical lens array pair 64 is NA ₂ , and the division pitch is P ₂ , The relationship between them satisfies the following expressions (1) and (2). That is, the cylindrical lens array pair 62 and the cylindrical lens array pair 64 are configured so as to satisfy the expressions (1) and (2).

  Further, in the irradiation optical system 51b, in the cylindrical lens array pair 62 and the cylindrical lens array pair 64, the substrate thickness t forming the wavefront division type integrator satisfies the following formula (3).

Among these, the above formula (1) assumes that the irradiation area in the X-axis direction is about 300 μm, and that a 6 W semiconductor laser 51a that is generally available is used as the light source.
In the configuration that does not satisfy the expression (1), the entire length of the irradiation optical system 51b is mainly increased, and accordingly, the barrel size of the irradiation optical system 51b is increased.
Further, regarding the condenser lens 65 in the irradiation optical system 51b and the projection optical system 67 that relays the image formed by the condenser lens 65 (hereinafter simply referred to as “lens system”), the configuration of the irradiation optical system 51b. In order to simplify the above, it is conceivable to use one that is rotationally symmetric with respect to the optical axis of the outgoing beam light (see, for example, JP-A-2006-295068). If the cylindrical lens array pair 62 and the cylindrical lens array pair 64 in the optical system 51b do not satisfy the above formula (1), the numerical aperture of the lens becomes large, resulting in an increase in the manufacturing cost of the irradiation optical system 51b. There is a concern that

  Further, in a configuration that does not satisfy the above formula (2), the number of wavefront divisions related to uniform irradiation is reduced, so that there is a possibility that necessary uniform irradiation cannot be obtained.

  Further, the above expression (3) means that a design matter in configuring the wavefront division type integrator, that is, that the thickness of the substrate on which the integrator is formed needs to be thinner than the focal length.

  As described above, in the laser annealing apparatus having a multi-head in which a plurality of laser irradiation optical units 51 are arranged in parallel, the size of the irradiation optical system 51b in each laser irradiation optical unit 51, the degree of uniform irradiation, and the manufacturing cost thereof are increased. It is desirable that each of these is necessary and sufficient and is balanced, and the optical specifications are different from those of the conventional optical system considering only uniform irradiation accuracy, specifically, at least the above (1). And the structure which satisfies (2) Formula is desirable.

FIG. 12 is a list showing specific examples of design solutions for integrators configured to satisfy the above expressions (1) to (3). In the drawing, “◯” indicates a combination of numerical apertures NA satisfying the above expressions (1) to (3).
However, as a matter of course, a product having a small numerical aperture NA is likely to cause a manufacturing error, and thus the manufacturing cost tends to be actually increased. Therefore, among the combinations corresponding to “◯” in the figure, it can be said that it is preferable to combine those having a large numerical aperture NA.

According to the irradiation optical system 51b configured as described above, it is possible to reduce the size of the irradiation optical system by suppressing the enlargement of the irradiation optical system while sufficiently ensuring the irradiation uniformity when the semiconductor laser is used as the light source. Can be easily accommodated. Therefore, the line beam irradiation optical system for irradiating the irradiated light beam from the inexpensive and high output broad area type semiconductor laser to the irradiated object can be configured inexpensively, practically and in a small size. it can.
That is, if the irradiation optical system 51b is used, a line beam optical system using a broad area type semiconductor laser 51a that is inexpensive and has high output can be configured at low cost, practically, and corresponding to downsizing. It is very suitable for constructing a laser annealing apparatus compatible with a multi-head equipped with a plurality of laser irradiation optical units 51, particularly an inexpensive and highly stable laser annealing apparatus using a semiconductor laser 51a. It is possible to improve the processing speed.

  Further, as shown in FIG. 13, one wavefront division such as a cylindrical lens array pair 62 composed of a pair of cylindrical lens arrays 62a and 62b or a cylindrical lens array pair 64 composed of a pair of cylindrical lens arrays 64a and 64b. In the case where the mold integrator is divided into two parts, the eccentric adjustment mechanisms 73 and 74 are necessary for the respective eccentric adjustments of the divided members 71 and 72. In this case, if the division pitch of the wavefront division type integrator is too small, the adjustment in each can be very severe. However, according to the irradiation optical system 51b configured to satisfy at least the above expressions (1) and (2), that is, the irradiation optical system 51b having a balanced solution combination as shown in FIG. Therefore, the division pitch can be prevented from becoming unnecessarily small, and the severe adjustment can be eliminated.

Here, the irradiation optical system 51b configured as described above will be described with specific numerical examples.
For example, the collimator lens 61 has a focal length of 10 mm, a numerical aperture NA of 0.35, a cylindrical lens array pair 62 has a focal length of 6.25 mm, a numerical aperture NA ₁ of 0.02, and the pitches of the cylindrical lens arrays 62a and 62b. The focal length of the condenser lens 63 is 70 mm, the numerical aperture NA is 0.02, the focal length of the cylindrical lens array pair 64 is 5 mm, the numerical aperture NA ₂ is 0.02, and the pitches of the cylindrical lens arrays 64a and 64b are Consider a case where the focal length of the condenser lens 65 is 0.2 mm, the numerical aperture NA is 0.0875.
In this case, when each numerical value is applied to the above formulas (1) and (2), 0.02 ≦ 0.02 from the formula (1) and 0.02 ≦ 0.0255 from the formula (2). Can be seen to be satisfied.
In this case, if the divergence angle of the semiconductor laser 51a is 9.5 ° (FWHM) in the X-axis direction, 24.1 ° (FWHM) in the Y-axis direction, and the emitter size in the X-axis direction is 400 μm, the irradiation optical system 51b Only the total length is about 500 mm in the case of the conventional configuration, but is about 203 mm when the configuration satisfies at least the above expressions (1) and (2). The irradiation area size in the X-axis direction is 640 μm. Furthermore, when the irradiation area size in the X-axis direction is reduced, for example, when aiming for a half of 320 μm, even if a relay lens of a half is simply added, the total length can be realized by about 60 mm.

Next, an example that does not satisfy the expressions (1) and (2) will be described.
For example, consider a combination of NA ₁ = 0.04, NA ₂ = 0.04, P ₁ = 0.2, and P ₂ = 0.2. In this case, the above equation (2) is not satisfied. Also in FIG. 12, "x mark" is given.
In this combination, if the semiconductor laser 51a having the same specifications as described above is used and the illumination size in the X-axis direction is also 640 μm, the total length of the optical system is 66 mm, and the optical system can be downsized. However, the number of wavefront divisions in the wavefront division type integrator is sufficient as 157 divisions in the case described above, whereas it is as small as 49 divisions, so there is a possibility that the irradiation uniformity in the X-axis direction cannot be maintained.

For example, consider a combination of NA ₁ = 0.01, NA ₂ = 0.02, P ₁ = 0.2, and P ₂ = 0.2. In this case, the above equation (1) is not satisfied.
In this combination, when the illumination size is 320 μm, the number of wavefront divisions in the wavefront division type integrator is sufficient as 392, and the total length of the optical system can be suppressed to 351 mm. However, it is conceivable that the numerical aperture NA of the condenser lens 65 becomes as large as 0.875, which makes it difficult to design and that the working distance of the optical system is shortened.

Further, for example, consider a combination of NA ₁ = 0.02, NA ₂ = 0.002, P ₁ = 0.2, and P ₂ = 0.2. In this case, the above equation (1) is not satisfied.
In this combination, if the illumination size is set to 320 μm, the total length of the optical system is 1635 mm. Thus, when the expression (1) is not satisfied, the total length of the optical system also tends to be long. When designing the lens barrel mechanism, the outer diameter of the lens barrel is generally increased when the total length of the optical system is long. For this reason, even if it is attempted to realize a multi-head laser annealing apparatus, the number of parallel heads decreases, and as a result, it may be difficult to increase the throughput of the laser annealing process.

  In the present embodiment, the preferred specific examples of the present invention have been described. However, the present invention is not limited to the contents, and can be appropriately changed without departing from the gist thereof.

  For example, in the present embodiment, the laser annealing process in the manufacturing process of the organic EL display 1 configured to include the TFT 10 has been described as an example. However, this is only a specific example, and the annealing process is performed on other semiconductor films. Even so, it is possible to apply the present invention in exactly the same manner.

  In the present embodiment, a laser annealing apparatus that performs parallel irradiation of laser light by mounting a plurality of laser irradiation optical units 51 is described as an example. However, an apparatus that includes a semiconductor laser and an irradiation optical system and performs laser irradiation. If there is, the present invention can be applied to whether the laser irradiation is performed alone or the laser irradiation is performed for a purpose other than the laser annealing treatment.

It is explanatory drawing which shows the structural example of the organic electroluminescent display provided with TFT. It is explanatory drawing which shows an example of the pixel circuit structure of an organic EL display. It is a perspective view which shows the television which is a specific example of an electronic device. It is a perspective view which shows the digital camera which is a specific example of an electronic device. It is a perspective view which shows the notebook type personal computer which is a specific example of an electronic device. It is a perspective view which shows the video camera which is a specific example of an electronic device. It is a figure which shows the portable terminal device which is a specific example of an electronic device, for example, a mobile telephone. It is explanatory drawing which shows the structural example of the laser annealing apparatus which is one of the manufacturing apparatuses used in the manufacture process of TFT. It is explanatory drawing which shows the basic structural example of the irradiation optical system to which this invention was applied. It is explanatory drawing which shows the principal part structural example of the irradiation optical system to which this invention was applied. It is explanatory drawing which shows a specific example of the uniform irradiation by an irradiation optical system. It is a table | surface which shows the specific example of the design solution of the integrator of the structure which satisfies the specification to which this invention was applied. It is explanatory drawing which shows the structural example of a wavefront division | segmentation type | mold integrator.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Organic EL display, 10 ... TFT, 11 ... Substrate, 12 ... Gate film, 13 ... Gate insulating film, 14 ... Semiconductor layer, 51 ... Laser irradiation optical unit, 51a ... Semiconductor laser, 51b ... Irradiation optical system, 61 ... Collimator lens, 62, 64 ... Cylindrical lens array pair, 62a, 62b, 64a, 64b ... Cylindrical lens array, 63, 65 ... Condenser lens

Claims (7)

An irradiation apparatus for irradiating an irradiated object with light emitted from a semiconductor laser,
A first wavefront splitting integrator disposed for uniform irradiation and a second wavefront splitting integrator disposed closer to the irradiated object than the first wavefront splitting integrator;
The first wavefront splitting integrator and the second wavefront splitting integrator have a numerical aperture NA ₁ and a split pitch P _{1 of the first} wavefront splitting integrator, respectively. When the numerical aperture is NA ₂ and the division pitch is P ₂ ,

Satisfied, and

Each is configured so as to satisfy the above. An apparatus for manufacturing a semiconductor device that performs an annealing process to irradiate an irradiation object with light emitted from a semiconductor laser and modify the semiconductor film in the irradiation object,
A first wavefront splitting integrator disposed for uniform irradiation and a second wavefront splitting integrator disposed closer to the irradiated object than the first wavefront splitting integrator;
The first wavefront splitting integrator and the second wavefront splitting integrator have a numerical aperture NA ₁ and a split pitch P _{1 of the first} wavefront splitting integrator, respectively. When the numerical aperture is NA ₂ and the division pitch is P ₂ ,

Satisfied, and

Each of them is configured so as to satisfy the requirements. The semiconductor laser has a broad area type emitter,
The apparatus for manufacturing a semiconductor device according to claim 2, wherein the first wavefront division type integrator and the second wavefront division type integrator are effective only in a longitudinal direction of the emitter. A lens system for uniformizing irradiation using a secondary light source generated by the second wavefront splitting integrator;
The semiconductor device manufacturing apparatus according to claim 3, wherein the lens system is configured to be rotationally symmetric with respect to the optical axis of the emitted beam light. A stage for moving the irradiation object in a direction perpendicular to the broad area direction of the semiconductor laser;
A plurality of irradiation optical systems each including the semiconductor laser, the first wavefront splitting integrator, the second wavefront splitting integrator, and the lens system;
The semiconductor device manufacturing apparatus according to claim 4, wherein each semiconductor laser is configured to emit beam light in parallel. A method of manufacturing a semiconductor device including an annealing process for irradiating an irradiated object with light emitted from a semiconductor laser to modify a semiconductor film in the irradiated object,
A first wavefront splitting integrator disposed for uniform irradiation and a second wavefront splitting integrator disposed closer to the irradiated object than the first wavefront splitting integrator;
When the numerical aperture of the first wavefront division integrator is NA ₁ and the division pitch is P ₁ , the numerical aperture of the second wavefront division integrator is NA ₂ and the division pitch is P ₂ ,

Satisfied, and

The annealing process is performed using an irradiation optical system in which the first wavefront splitting integrator and the second wavefront splitting integrator are configured so as to satisfy Method. A method of manufacturing a display device including a thin film semiconductor device,
Through the annealing process for modifying the semiconductor film in the irradiated object by irradiating the irradiated beam light from the semiconductor laser to the irradiated object, the thin film semiconductor device is formed,
A first wavefront splitting integrator disposed for uniform irradiation, and a second wavefront splitting integrator disposed closer to the irradiated object than the first wavefront splitting integrator,
When the numerical aperture of the first wavefront division integrator is NA ₁ and the division pitch is P ₁ , the numerical aperture of the second wavefront division integrator is NA ₂ and the division pitch is P ₂ ,

Satisfied, and

The annealing process is performed using an irradiation optical system in which the first wavefront splitting integrator and the second wavefront splitting integrator are configured so as to satisfy Method.

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