JP2001244213A - Laser beam irradiating device and method of manufacturing semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical system which can reduce the weak interference that is observed when laser annealing is performed on a semiconductor film. SOLUTION: The weak interference seen when laser annealing is performed on semiconductor films can be reduced by irradiating the semiconductor film with a laser beam by using the optical system containing a mirror 1006. The mirror 1006 splits the laser beam into split laser beams, makes the optical path differences from a laser oscillator to the surfaces irradiated with the split laser beams equal to or longer than the coherent length of the original laser beam, and makes the energy of the split laser beams uniform on the irradiated surfaces. Therefore, when the semiconductor film is irradiated with the laser beam through the mirror 1006, the weak interference can be reduced. In addition, the optical system which has been difficult to be adjusted can be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to annealing of a semiconductor film using a laser beam (hereinafter referred to as laser annealing).
About the method. In addition, the present invention relates to an apparatus for manufacturing a semiconductor device having a circuit constituted by a thin film by including the laser annealing in a step. For example, the present invention relates to a method for manufacturing an electro-optical device typified by a liquid crystal display device and a device for manufacturing a configuration of an electric device including the electro-optical device as a component. Note that in this specification, a semiconductor device generally means a device that can function by utilizing semiconductor characteristics, and the above-described electric engineering device and electric device are also semiconductor devices.

[0002]

2. Description of the Related Art In recent years, a technique for performing laser annealing on a semiconductor film formed on an insulating substrate such as glass to crystallize or improve crystallinity has been widely studied. Silicon is often used for the semiconductor film.

The glass substrate is inexpensive, has good processability, and has an advantage that a large-area substrate can be easily manufactured, as compared with a quartz substrate which has been often used in the past. This is the reason for the above research. Laser annealing is preferably performed for crystallization because the glass substrate has a low melting point. Laser annealing can provide high energy only to the semiconductor film without significantly increasing the temperature of the substrate.

[0004] Since a crystalline semiconductor film is formed from many crystal grains, it is also called a polycrystalline semiconductor film. Since a crystalline semiconductor film formed by performing laser annealing has high mobility, a TFT is formed using the crystalline semiconductor film, and, for example, a pixel driving circuit and a driving circuit are formed over one glass substrate. For manufacturing TFTs for use in monolithic liquid crystal electro-optical devices and the like.

[0005] In addition, a pulse laser beam such as an excimer laser having a large output is processed by an optical system so that the shape on the surface to be irradiated becomes a square spot of several cm square, or a linear or rectangular shape having a length of 10 cm or more. The method of performing laser annealing by scanning the laser beam (or moving the irradiation position of the laser beam relatively to the irradiation surface) is preferable because mass productivity is high and industrially superior. Have been.

In particular, when a linear beam is used, unlike when a spot-shaped laser beam that requires scanning in the front, rear, left, and right directions is used on the irradiation surface, scanning is performed only in a direction perpendicular to the linear direction of the linear beam. Since the entire irradiation surface can be irradiated with the laser beam, mass productivity is high. Scanning is performed in a direction perpendicular to the line direction because it is the most efficient scanning direction. Due to this high mass productivity, the current trend in laser annealing is to process the laser beam of a pulsed excimer laser with an appropriate optical system and use a linear beam whose irradiation surface is linear. It is getting.

FIG. 1 shows an example of the configuration of an optical system for processing the shape of a laser beam on an irradiation surface into a linear shape. This configuration is very general, and all the optical systems conform to the configuration of FIG. This configuration not only converts the shape of the laser beam on the irradiation surface to a linear shape,
At the same time, the energy of the laser beam on the irradiation surface is homogenized. In general, an optical system that homogenizes beam energy is called a beam homogenizer.

If an excimer laser, which is ultraviolet light, is used as the light source, it is preferable that the base material of the optical system is made of, for example, quartz. This is because a high transmittance can be obtained. Further, it is preferable to use a coating capable of obtaining a transmittance of 99% or more with respect to the wavelength of the excimer laser to be used.

First, a side view of FIG. 1 will be described. The laser beam emitted from the laser oscillator 101 is split by the cylindrical array lenses 102a and 102b in a direction perpendicular to the direction of travel of the laser beam. The direction will be referred to as a vertical direction in this specification. The vertical direction bends in the direction of the light bent by the mirror when the mirror enters in the middle of the optical system. In this configuration, there are four divisions. These split laser beams are once combined into one laser beam by the cylindrical array lens 104. The light is reflected by the mirror 107, and thereafter, is again condensed by the doublet cylindrical lens 108 into one laser beam on the irradiation surface 109. The doublet cylindrical lens refers to a lens composed of two cylindrical lenses. Thereby, the energy homogenization in the width direction of the linear beam and the length in the width direction are determined.

Next, a top view will be described. The laser beam emitted from the laser oscillator 101 is divided by the cylindrical array lens 103 in a direction perpendicular to the direction of travel of the laser beam and in a direction perpendicular to the longitudinal direction. This direction is referred to herein as the lateral direction. In the lateral direction, when a mirror enters in the middle of the optical system, the mirror bends in the direction of the light bent by the mirror.
In this configuration, there are seven divisions. Thereafter, the laser beam is applied to the irradiation surface 109 by the cylindrical lens 104 for one time.
Are combined into one. This determines the homogenization and length of the energy along the length of the linear beam.

The above-mentioned lenses are made of synthetic quartz for use in an excimer laser. The surface is coated so as to transmit the excimer laser well.
As a result, the transmittance of each lens to the excimer laser became 99% or more.

By irradiating the linear beam processed by the above configuration while overlapping it while gradually shifting it in the width direction of the linear beam, the entire surface of the semiconductor film can be crystallized by laser annealing. Crystallinity can be improved.

Next, a typical manufacturing method of a semiconductor film to be irradiated will be described. First, as a substrate, for example, a thickness of 0.7
A Corning 1737 substrate of 5 mm square and 5 mm square is prepared. 200n thickness using plasma CVD device for substrate
An SiO ₂ film (silicon oxide film) having a thickness of m was formed, and an amorphous silicon film having a thickness of 50 nm was formed on the surface of the SiO ₂ film. Such a substrate was exposed to an atmosphere of nitrogen gas at a temperature of 500 ° C. for one hour to reduce the hydrogen concentration in the film. This significantly improved the laser resistance of the film.

The laser oscillator is a Lambda XeCl excimer laser (wavelength 308 nm, pulse width 30 ns) L33
08 was used. This laser oscillator emits a pulsed laser and has an ability to emit energy of 500 mJ / pulse. The size of the laser beam at the exit of the laser beam is 10 mm × 30 mm (both half width). In this specification, the exit of the laser beam is a plane perpendicular to the traveling direction of the laser beam immediately after the laser beam is emitted from the laser irradiation device.

The shape of a laser beam generated by an excimer laser is generally rectangular, and falls within a range of 3 to 5 in terms of aspect ratio. The intensity of the laser beam shows a Gaussian distribution that is stronger toward the center of the laser beam. The size of the laser beam was converted into a linear beam having a uniform energy distribution of 125 mm × 0.4 mm by the optical system having the configuration shown in FIG.

When the above semiconductor film is irradiated with a laser beam, the superposition pitch is most preferably about 1/10 of the beam width (half width) of the linear beam. Thereby, the uniformity in the crystalline film was improved. In the above example, since the half width was 0.4 mm, the pulse frequency of the excimer laser was 30 Hz, the scanning speed was 1.0 mm / s, and the laser beam was irradiated. At this time, the energy density on the irradiation surface of the laser beam was 420 mJ / cm ² . The methods described so far are very common for crystallization of semiconductor films using linear beams.

When the laser-annealed semiconductor film was observed very carefully using the above linear beam, very faint interference fringes were observed. The cause of the interference fringes is that the laser beams are divided into a single area, and the divided lights interfere with each other. The coherent length of the excimer laser is about several μm to several tens μm.

[0018]

When laser annealing is performed on a semiconductor film using an optical system prior to the present invention, faint interference is observed. Therefore, the present invention has devised an optical system with reduced interference. Although the conventional optical system is complicated as shown in FIG. 1, the present invention obtains a uniform laser beam by using a beam collimator for converting the laser beam into parallel light and an optical system mainly including a reflecting mirror. This makes it possible to simplify an optical system that forms a laser beam having a linear or rectangular shape on the irradiation surface. Note that if the laser beam obtained from the laser oscillator is sufficiently parallel, a beam collimator may not be used, but it is necessary to cope with a change in the spread angle of the laser beam.

[0019]

The laser beams have the characteristic that they do not interfere with each other even if the laser beams are emitted from the same light source, provided that there is an optical path difference longer than the coherent length. First, FIG. 2 will be described. FIG. 2 includes a laser oscillator 201, a half mirror 202, mirrors 203 to 205, and an irradiation surface 206. It is assumed that the distance between the half mirror 202 and the mirror 203 is equal to the distance between the mirror 204 and the mirror 205, and the distance between the mirror 205 and the irradiation surface 206 is equal to the distance between the mirror 205 and the irradiation surface 206. The laser beam emitted from the laser oscillator 201 is split by the half mirror 202 into a laser beam that travels straight through the half mirror and a laser beam that travels in a direction perpendicular to the traveling direction. The laser beam bent at a right angle is reflected by a mirror 203, and then irradiated on an irradiation surface 206.
To reach. On the other hand, the laser beam transmitted through the half mirror 202 reaches the irradiation surface 206 via the mirrors 204 and 205.

In this way, the laser beam split in two directions by the half mirror becomes one again at or near the irradiation surface 206, but the difference in the distance between the half mirror 202 and the mirror 204 becomes smaller. The optical path difference between the divided laser beams is two. If the optical path difference is longer than the coherent length of the laser beam, no interference occurs on the irradiation surface.

For example, when an excimer laser is used for the laser oscillator 201, the coherent length of the excimer laser is about several μm to several tens μm. No interference at surface 206 occurs. When a YAG laser is used as the laser oscillator 201, the coherent length of the YAG laser is longer than the coherent length of the excimer laser.
If the distance from the mirror 204 is longer than that of the excimer laser, no interference occurs on the irradiation surface 206.

[0022]

FIG. 3 shows an example of an optical system according to the present invention. First, the side view of FIG. 3 will be described. The laser beam emitted from the laser oscillator 301 travels at a certain divergence angle. The laser beam is made parallel by a cylindrical lens 304 and a cylindrical lens 305,
Thus, the light is condensed on the irradiation surface 307 of the target held by a stage (not shown). The stage is moved in a direction perpendicular to the longitudinal direction of the laser beam as shown by an arrow 308 so that the entire surface of the object can be processed by the laser beam. The description of the cylindrical lens 304 and the cylindrical lens 305 will be described later. The mirror 306 includes a plurality of flat mirrors 306a to 306d. Here, the number of plane mirrors is four. The energy in the width direction of the linear beam is homogenized by the mirror 306, and the length is determined. The mirror 306 is
By determining the position of the plane mirror 306a, the plane mirror 30
The position of 6b is determined, whereby the position of the plane mirror 306c is determined, thereby determining the position of the plane mirror 306d. The method of determining the positions of these plane mirrors will be described later. As for the mirror 306, the plane mirror 306a and the plane mirror 306b adjacent to each other, the plane mirror 306b and the plane mirror 306c, and the plane mirror 306c and the plane mirror 306d are in contact at end points. However, as shown in FIG. 4, adjacent mirrors do not necessarily need to touch at the end of the mirror. A method for determining the arrangement of the individual mirrors in this case will also be described later. In this figure, a laser beam is irradiated upward from the bottom of the paper for convenience of explanation, but the positional relationship between the target and the mirror may be changed as necessary.

As the laser oscillator 301, an excimer laser has a large output and can oscillate a high repetition pulse of about 300 Hz at present, and thus is often used for crystallization of a semiconductor film. In recent years, an excimer laser is used in a crystallization process of a semiconductor film for manufacturing a liquid crystal display of a low-temperature polysilicon TFT which is being commercialized. In addition to excimer laser, Ar laser, YAG laser, YVO ₄
A laser or the like can also be used.

The function of the cylindrical lens 304 and the cylindrical lens 305 for converting the laser beam emitted from the laser oscillator 301 into parallel light will be described. Generally, a laser beam has a certain divergence angle. The divergence angle of the laser beam differs for each laser oscillator. For example, in the case of an excimer laser, the laser oscillator has to perform tube replacement once every one to three years, and furthermore, the resonance mirrors at both ends of the tube have a frequency of once every several months to one year. They need to be replaced or polished. Due to these operations, the divergence angle of the laser beam can be reduced even with the same device.
It fluctuates by 0.1 to 0.5 mrad. Even with other laser oscillators,
Resonant mirrors need to be replaced or polished once every few months to one year, and these operations change the divergence angle. Since the invention disclosed in this specification is susceptible to a change in the divergence angle, it is necessary to control the divergence angle, and an optical system that produces a parallel beam that is not affected by the change in the divergence angle is necessarily required. The optical system is called a beam collimator.

The beam collimator will be described. Figure 5
(a) is composed of one lens 501 having a focal length f1, and a laser beam traveling at a certain divergence angle is converted into parallel light through the lens 501. When the laser beam is traced in a direction opposite to the traveling direction, the laser beam is condensed at a point at a focal distance f1 from the lens 501. FIG. 5 (b) uses one lens 501 having the same focal length f1 as that of FIG. 5 (a), but the divergence angle of the laser beam incident on the lens 501 is different from that of FIG. 5 (a). Even if the laser beam is traced in the direction opposite to the traveling direction, the lens 501
Is not focused at a point that is a focal distance f1 away from the camera. As described above, the beam collimator composed of one lens cannot cope with the variation in the divergence angle of the laser beam with the same lens, and a new lens must be prepared every time the divergence angle changes. , Costly.

FIG. 5C shows a lens 502 and a lens 503 having a focal length f3. A laser beam traveling at a certain divergence angle is condensed once after passing through the lens 502, and the focal length is determined from the condensed point. The lens 503 is arranged at a distance of f3. When arranged in this manner, the lens 502 has a certain divergence angle.
After being focused once, the laser beam incident on the lens passes through the lens 503 and becomes parallel light. FIG. 5D shows the same lenses 502 and 5 as FIG. 5C.
Although 03 is used, the divergence angle of the incident laser beam is different from that of FIG. 5 (c). But the laser beam is lens
When the distance between the lens 502 and the lens 503 is changed without changing the distance from the point of condensing after 502 to the lens 503 to be the focal length f3 of the lens 503, the lens 502 and the lens 50 are changed.
The laser beam passing through 3 becomes parallel light.

As described above, the beam collimator can cope with only one divergence angle with one lens.
If it is made up of a single lens, it can handle any divergence angle. Therefore, in the case of FIG. 3 as well, on the premise that the divergence angle of the laser beam fluctuates, two lenses, a cylindrical lens 304 and a cylindrical lens 305, are used to convert the laser beam having the divergence angle into parallel light.

Next, the top view of FIG. 3 will be described. The laser beam emitted from the laser oscillator 301 is split by a cylindrical array lens 302 in a direction perpendicular to the direction of travel of the laser beam. The direction will be referred to as a lateral direction in this specification. In the lateral direction, when a mirror enters in the middle of the optical system, the mirror bends in the direction of the light bent by the mirror. In this configuration, there are four divisions. These split laser beams are combined into one beam on an irradiation surface 307 by a cylindrical lens 303.

Here, a method for determining the shape of the mirror 306 will be described. As shown in FIG. 6, a plane perpendicular to the irradiation surface and parallel to the width direction of the laser beam is defined as an xy plane, and the length direction of the laser beam is defined as a z-axis. FIG. 6 is a three-dimensional drawing of FIG. 3, and the numbers in the figure are the same as those in FIG.

As shown in FIG. 7, the mirror 701 includes a plurality of plane mirrors 702 to 704. In each mirror, adjacent mirrors such as the plane mirror 702 and the plane mirror 703 are in contact with each other. A method for determining the position of the plane mirror in such a case will be described. In FIG. 7, similarly to FIG. 6, a plane perpendicular to the irradiation surface and parallel to the width direction of the laser beam is defined as the xy plane, and the length direction of the laser beam is defined as the z-axis.
Also, here, in order to simplify the description of the mirror 701, the arrangement of the mirror 701 and the irradiation surface 705 is on z = 0.

The coordinates A (α 0, β 0) and B (α 1, β 1) at both ends of the irradiation surface 705 in the width direction of the laser beam and an arbitrary point C (x 0, y 0) are determined. A (α 0, β 0)
Is used as the focal point, and a parabola passing through an arbitrary point C (x0, y0) is obtained.
In general, the parabolic equation is

[0032]

(Equation 1)

Where the coordinates of the focal point are

[0034]

(Equation 2)

Therefore, to find the parabola equation passing through an arbitrary point C (x0, y0) with the point A (α0, β0) as the focal point, from the equations (1) and (2),

[0036]

(Equation 3)

[0037]

(Equation 4)

Is obtained, and by solving equations (3) and (4),

[0039]

(Equation 5)

Is obtained. However,

[0041]

(Equation 6)

It is assumed that This is a condition for the obtained mirror not to be located on the back side of the irradiation surface. Equation (5) has two solutions, but here,

[0043]

(Equation 7)

Is adopted. The reason why the expression (5) ′ is adopted is to arrange the mirror 701 at a position where the laser beam is not blocked in FIG.

Next, parallel to a straight line passing through the end point A (α 0, β 0) of the irradiation surface and an arbitrary point C (x0, y0), the end point B (α
An intersection D (x1, y1) of a tangent of a straight line passing through (1, β1) and a parabola at an arbitrary point C (x0, y0) is obtained.

The slope y 'of the tangent of the parabola at an arbitrary point C (x0, y0) is

[0047]

(Equation 8)

Thus, the equation of the tangent of the parabola at any point C (x0, y0) is

[0049]

(Equation 9)

Is as follows. The slope of the straight line passing through the end point A (α 0, β 0) of the irradiation surface and any point C (x0, y0) is

[0051]

(Equation 10)

Therefore, the end point A (α 0, β
0) and a straight line passing through an arbitrary point C (x0, y0) and passing through the end point B (α1, β1) of the irradiation surface,

[0053]

[Equation 11]

Is as follows. Solving equations (7) and (9) to find the intersection,

[0055]

(Equation 12)

[0056]

(Equation 13)

Thus, the point D (x1, y1) is obtained. That is, the coordinates A (α 0,
β0), B (α1, β1) and an arbitrary point C (x0, y0) are determined, and a coefficient p of a parabola passing through the arbitrary point C (x0, y0) is obtained by using the equation (5) ′. For example, the point D (x1, y1) is determined by the equations (10) and (11). If a mirror is arranged on a line connecting the arbitrary point C (x0, y0) and the point D (x1, y1), all the light reflected by this mirror is converged on the irradiation surface.

Next, a parabola passing through the obtained point D (x1, y1) is determined with the end point A (α 0, β 0) of the irradiation surface as the focal point, and the point D (x1, y1)
Tangent of the parabola at, and the end point B of the irradiated surface (α1, β1)
, And an intersection E (x2, y2) of a straight line parallel to a straight line passing through the point A (α 0, β 0) and the point D (x1, y1) is obtained. If a mirror is arranged on a line connecting the point D (x1, y1) and the point E (x2, y2), all the light reflected by this mirror is collected on the irradiation surface.

As described above, if the coordinates of the irradiation surface and any one point are determined first, the positions of the mirrors are determined one after another using the equations (5) ′, (10), and (11). I can do it.

Up to now, the plane mirror 702 and the plane mirror 703
As described above, the case where adjacent flat mirrors are in contact with each other at the end of the mirror has been described, but the case where they are not in contact as shown in FIG. 4 will be described. FIG. 8 is used for describing the mirror 406 in FIG. 8, as in FIG. 7, a plane perpendicular to the irradiation surface and parallel to the beam width direction is defined as an xy plane, and the beam length direction is defined as a z-axis. Also, here
In order to simplify the description of the mirror 801, it is assumed that the arrangement of the mirror 801 and the irradiation surface 805 is on z = 0.

N is an arbitrary positive number, and the coordinates from the coordinates (xn, yn) and (xn + 1, yn + 1) at both ends of the n-th mirror to the end point A (α 0, β 0) of the irradiation surface are obtained. If the optical path difference is not sufficient, (x
From the y-coordinate of (n + 1, yn + 1), a numerical value considering a coherent length that differs depending on the type of the laser oscillator is subtracted, and the newly obtained coordinate is defined as (xn + 1 ′, yn + 1 ′). Using (xn + 1 ', yn + 1') and coordinates A (α 0, β 0) and B (α 1, β 1) at both ends of the irradiation surface, (5) ′, (10), (11 ), (Xn + 2, yn + 2) is calculated, and (xn
+1 ', yn + 1') and (xn + 2, yn + 2), a plane mirror can be placed on the line segment, and a sufficient optical path difference can be obtained. Mirror 703 is required.

Next, an example of an optical system using a mirror 906 composed of a plurality of mirrors having a paraboloid instead of the mirror 306 in FIG. 3 is shown in FIG. First, the side view of FIG. 9 will be described. The laser beam emitted from the laser oscillator 901 travels straight with a certain divergence angle, and the cylindrical lens 904
The light becomes parallel light by the cylindrical lens 905 and is condensed on the irradiation surface 907 by the mirror 906. The principle that a laser beam with a certain divergence angle becomes parallel light by the cylindrical lens 904 and the cylindrical lens 905 is shown in FIG.
Is the same as The shape of the mirror 906 is a collection of parabolic mirrors having different curvatures, and converges once at a focal point, and then reaches an irradiation surface. Here, the number of parabolic mirrors was four. Each paraboloid has a different curvature and therefore a different focus. By these parabolic mirrors 906a to 906d, the energy in the width direction of the linear beam is homogenized, and the length is determined. Like the parabolic mirror 906a and the parabolic mirror 906b, the adjacent mirror may be in contact with the next mirror at the end of the mirror, but may not be in contact with the mirror 1006 in FIG. good. The arrangement of the mirror 1006 in FIG. 10 will be described later.

Next, a top view of FIG. 9 will be described. The laser beam emitted from the laser oscillator 901 is split by a cylindrical array lens 902 in a direction perpendicular to the direction of travel of the laser beam. The direction will be referred to as a lateral direction in this specification. In the lateral direction, when a mirror enters in the middle of the optical system, the mirror bends in the direction of the light bent by the mirror. In this configuration, there are four divisions. These split laser beams are combined into one beam on an irradiation surface 907 by a cylindrical lens 903.

Here, the arrangement of the mirror 1006 in FIG. 10 will be described. In FIG. 10, a plane perpendicular to the irradiation surface and parallel to the beam width direction is defined as an xy plane, and the length direction of the laser beam is defined as a z-axis. A method for deciding an arrangement such as the mirror 1006 will be described. A parabola is a point on an arbitrary point and a line connecting the arbitrary point and a point obtained from the coordinates of both ends in the width direction of the laser beam on the irradiation surface 1007
It will be at position 1006a. A new coordinate is obtained by subtracting a numerical value in consideration of the coherent length of the laser beam from the y coordinate of the obtained point. The position of the parabolic mirror 1006b is on a line segment connecting the coordinates and points obtained from the coordinates and the coordinates of both ends in the beam width direction on the irradiation surface 1007. When the parabolic mirror 1006c and the parabolic mirror 1006d are obtained by such a method, a mirror 1006 in which adjacent mirrors are not in contact with each other but have a sufficient optical path difference to the irradiation surface is obtained.

[0065]

[Embodiment 1] In this embodiment, a case where irradiation is performed using an excimer laser will be described. First, in this embodiment, an example of a laser irradiation apparatus for mass production will be described with reference to FIG. FIG. 32 is a top view of the laser irradiation device.

The substrate is transferred from the load / unload chamber 9001 using the transfer robot arm 9003 installed in the transfer chamber 9002. First, the substrate is transferred to the preheating chamber 9005 after being aligned in the alignment chamber 9004. Here, for example, the substrate temperature is previously heated to a desired temperature, for example, about 300 ° C. using an infrared lamp heater. After that, the gate valve 90
The substrate is set in the laser irradiation chamber 9007 via the control unit 06. Thereafter, the gate valve 9006 is closed.

After leaving the laser oscillator 9000, the laser beam is bent downward 90 degrees by a mirror (not shown) installed immediately above the quartz window 9010 via the optical system 9009.
The laser beam is processed into a linear laser beam on the irradiation surface in the laser irradiation chamber 9007 through the quartz window 9010. The laser beam is applied to the substrate provided on the irradiation surface. Optical system 9
For 009, the one shown in this embodiment may be used. Further, a structure having a similar structure may be used.

The basic configuration of the laser irradiation apparatus according to the present embodiment is the same as that shown in FIG. 3, but the calculation of the position of each mirror in the mirror according to the present invention is specifically shown in FIG.
In FIG. 11, a plane perpendicular to the irradiation surface and parallel to the beam width direction is defined as an xy plane, and the beam length direction is defined as a z-axis. Further, here, in order to simplify the description of the mirror 1101, the arrangement of the mirror 1101 and the irradiation surface 1105 is assumed to be on z = 0.

The mirror 1101 has a plurality of flat mirrors 1102-1104.
Consists of A plane perpendicular to the irradiation surface and parallel to the beam width direction is defined as an xy plane, and the beam length direction is defined as a z-axis. Here, in order to make the description of the mirror 1101 simpler, it is assumed that the arrangement of the mirror 1101 and the irradiation surface 1105 is on z = 0.

The coordinates of both ends in the beam width direction on the irradiation surface 1105 are (0,200) and (0,199). In this specification, it is assumed that 1 in the coordinate corresponds to 1 mm.
Since the width of the laser beam obtained on the irradiation surface 1005 is desired to be about 1 mm, the coordinates are set as described above. Set any point to (x0,
y0) = (200,190), the end point (0,200) of the irradiation surface is regarded as the focal point, and the coefficient p of the parabola passing through the point (200,190) is obtained as (5) ′
Since p = 0.00237812 is obtained from the equation, when (x1, y1) is obtained by using the equations (10) and (11), (x1, y1) = (199.001, 189.050). When the obtained (x1, y1) is regarded as a new arbitrary point and the coefficient of the parabola passing through this point is obtained, p = 0.00237809 is obtained.Therefore, (x2, y2) is obtained by using the equations (10) and (11). ), (X2, y2) = (198.003,188.105). When (x3, y3) is obtained in the same manner, (x3, y3) = (197.005, 187.165). (x0, y0) and (x1, y1) The optical path difference to the end point (0, 200) in the beam width direction on each irradiation surface 1105 is

[0071]

[Equation 14]

Then, the optical path difference to the end point (0,200) in the beam width direction on the irradiation surface 1105 of each of (x1, y1) and (x2, y2) is

[0073]

(Equation 15)

The optical path difference to the end point (0,200) in the beam width direction on the irradiation surface 1105 of each of (x2, y2) and (x3, y3) is

[0075]

(Equation 16)

Is obtained. The coherent length of the excimer laser is about several μm to several tens μm, and since these units are mm, no interference occurs because the unit is longer than the coherent length. However, in order to further increase the optical path length and increase the optical path difference, once the first coordinate (x1, y1) is determined, subtract 1 from the y coordinate, for example, and set it again as (x1 ', y1'). If the coordinates of the other end of the mirror are obtained first, a mirror with reduced interference can be manufactured.

FIG. 7 is a diagram illustrating a method of manufacturing the mirror.
See Figure 12. In FIG. 12, similarly to FIG. 11, a plane perpendicular to the irradiation surface and parallel to the width direction of the laser beam is defined as an xy plane, and the length direction of the laser beam is defined as a z-axis. Also, here, in order to simplify the description of the mirror 1201, the mirror
The arrangement of 1201 and the irradiation surface 1206 is on z = 0.

The coordinates of both ends in the width direction of the laser beam are (0,200), (0,199), and an arbitrary point is (x0, y0) = (200,19).
0), (x1, y1) = (199.001,
189.050), but subtract 1 from the y coordinate to get (x1 ', y1') =
(199.001,188.050). When (x2, y2) is calculated based on this, (x2, y2) = (198.003,187.110), and
Subtract 1 from the y coordinate to get (x2 ', y2') = (198.003,186.110)
When (x3, y3) is obtained, (x3, y3) = (197.005, 18
5.180), shifted by 1 in the x direction, and (x3 ', y3') = (197.0
05, 184.180).

Based on the coordinates obtained as described above, the irradiation surface
The optical path difference to the end point (0,200) in the width direction of the laser beam 1206 is obtained. The optical path difference between (x0, y0) and (x1 ', y1') is
2.84018, the optical path difference between (x1 ', y1') and (x2 ', y2') is 2.81013,
The optical path difference between (x2 ', y2') and (x3 ', y3') is 2.77999, and the optical path difference is larger than the arrangement in which adjacent mirrors are in contact at the end points, so that interference can be further suppressed. Was.

[Embodiment 2] In this embodiment, the case of irradiation using a YAG laser will be described. The basic configuration of the laser irradiation apparatus of the present embodiment is the same as that of FIG. 9, but the calculation of the position of the mirror was specifically performed.

Since the coherent length of the YAG laser is longer than the coherent length of the excimer laser, interference is not so much suppressed by merely shifting the mirror by 1 mm as shown in FIG. 12 of the first embodiment. It is better to shift.

As in the first embodiment, the coordinates of both ends in the width direction of the laser beam on the irradiation surface 1306 are (0,200), (0,1).
99). Since the actual laser beam width is desired to be about 1 mm, the coordinates are set as described above. Any point (x0, y0) = (200,1
90), and using equations (5) ′, (10), and (11) in the same manner as in Example 1.
When (x1, y1) is obtained, (x1, y1) = (199.001,189.050). However, subtracting 10 from the y coordinate, (x1 ′, y1 ′) = (199.001,17)
9.050). When (x2, y2) is obtained using this, (x2, y2)
y2) = (198.007,178.155), subtracting 10 from the y coordinate, (x2 ', y2') = (198.007,168.155), and (x3, y3)
Is obtained, (x3, y3) = (197.019,167.313), and y
Subtract 10 from the coordinates to get (x3 ', y3') = (197.019,157.313).

Using the coordinates obtained as described above, the irradiation surface
The optical path difference to the end point (0,200) in the width direction of the laser beam in 1306 is obtained. The optical path difference between (x0, y0) and (x1 ', y1') is 11.0989, and the optical path difference between (x1 ', y1') and (x2 ', y2') is 10.
4450, the optical path difference between (x2 ′, y2 ′) and (x3 ′, y3 ′) is 9.80177.
It turns out that it is a mirror which suppressed interference.

[Embodiment 3] This embodiment will be described with reference to FIGS. Here, a method of manufacturing a pixel TFT in a display region and a TFT of a driver circuit provided around the display region on the same substrate and a display device using the same are described.
This will be described in detail according to the manufacturing process. However, for the sake of simplicity, the control circuit shows a CMOS circuit as a basic circuit such as a shift register circuit and a buffer circuit, and an n-channel TFT forming a sampling circuit.

In FIG. 15A, a low alkali glass substrate or a quartz substrate can be used as a substrate 1501. In this embodiment, a low alkali glass substrate was used. On the surface of the substrate 1501 on which the TFT is formed, the substrate 1501
In order to prevent impurity diffusion from above, a base film 1502 such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film is formed. For example, SiH ₄ , NH ₃ , N
_A silicon oxynitride film made of ₂ O is 100 nm, and a silicon oxynitride film similarly made of SiH ₄ and N ₂ O is 20 nm.
The layer is formed to a thickness of 0 nm.

Next, 20 to 150 nm (preferably 30 nm)
Semiconductor film 15 having an amorphous structure with a thickness of
03a is formed by a known method such as a plasma CVD method or a sputtering method. In this example, an amorphous silicon film was formed to a thickness of 55 nm by a plasma CVD method. Examples of the semiconductor film having an amorphous structure include an amorphous semiconductor film and a microcrystalline semiconductor film, and a compound semiconductor film having an amorphous structure such as an amorphous silicon germanium film may be used. Since the base film 1502 and the amorphous silicon film 1503a can be formed by the same film formation method, both may be formed continuously. After the formation of the base film, it is possible to prevent the surface from being contaminated by not once exposing it to the atmosphere, thereby reducing the variation in the characteristics of the TFT to be manufactured and the fluctuation of the threshold voltage. (FIG. 15 (A))

Then, a crystalline silicon film 1503b is formed from the amorphous silicon film 1503a by using a crystallization technique.
In this embodiment, laser crystallization was performed according to the first embodiment using the laser irradiation apparatus of the present invention. Prior to the crystallization step, depending on the hydrogen content of the amorphous silicon film, 40
It is desirable to perform a heat treatment at 0 to 500 ° C. for about 1 hour to reduce the hydrogen content to 5 atom% or less before crystallization. (FIG. 15 (B))

Then, the crystalline silicon film 1503b is divided into islands, and island-like semiconductor layers 1504 to 1507 are formed. Thereafter, a mask layer 1 of a silicon oxide film having a thickness of 50 to 100 nm is formed by a plasma CVD method or a sputtering method.
508 are formed. (FIG. 15 (C))

Then, a resist mask 1509 is provided, and n
Island semiconductor layers 1505-1 forming a channel type TFT
1 × 10 for the purpose of controlling the threshold voltage on the entire surface of 507
Boron (B) was added as an impurity element imparting p-type at a concentration of about ^{16 to} 5 × 10 ¹⁷ atoms / cm ³ . Boron (B) may be added by an ion doping method, or may be added simultaneously with the formation of the amorphous silicon film. Although the addition of boron (B) is not always necessary here, the semiconductor layers 1510 to 15 to which boron (B) is added are added.
12 is preferably formed to keep the threshold voltage of the n-channel TFT within a predetermined range. (Figure 1
5 (D))

In order to form an LDD region of an n-channel TFT of a driver circuit, an impurity element imparting n-type is selectively added to the island-shaped semiconductor layers 1510 and 1511. Therefore, resist masks 1513 to 1516 were formed in advance. As an impurity element imparting n-type, phosphorus (P) or arsenic (As) may be used. Here, an ion doping method using phosphine (PH ₃ ) is applied to add phosphorus (P). Impurity region 15 formed
The phosphorus (P) concentration of 17, 1518 is 2 × 10 ^{16 to} 5 × 1.
The range may be 0 ¹⁹ atoms / cm ³ . In this specification,
The concentration of the impurity element imparting n-type contained in the impurity regions 1517 to 1519 formed here is represented by (n ⁻ ). The impurity region 1519 is a semiconductor layer for forming a storage capacitor of the pixel matrix circuit, and phosphorus (P) is added to this region at the same concentration. (FIG. 16
(A))

Next, a step of removing the mask layer 1508 with hydrofluoric acid or the like to activate the impurity element added in FIGS. 15D and 16A is performed. The activation can be performed by a heat treatment at 500 to 600 ° C. for 1 to 4 hours in a nitrogen atmosphere or a laser activation method. Further, both may be performed in combination. Further, the laser irradiation described in the first embodiment may be performed. In the present embodiment, a KrF excimer laser (wavelength 248 n
m) to form a linear beam and generate an oscillation frequency of 5 to 5
Scanning was performed at 0 Hz, an energy density of 100 to 500 mJ / cm ^{2 and an} overlap ratio of the linear beam of 80 to 98%, and the entire surface of the substrate on which the island-shaped semiconductor layer was formed was processed. The irradiation conditions of the laser beam are not particularly limited, and may be appropriately determined by the practitioner.

Then, the gate insulating film 1520 is formed of an insulating film containing silicon with a thickness of 10 to 150 nm by a plasma CVD method or a sputtering method. For example, 120n
A silicon oxynitride film is formed with a thickness of m. As the gate insulating film, another insulating film containing silicon may be used as a single layer or a stacked structure. (FIG. 16 (B))

Next, a first conductive layer is formed to form a gate electrode. The first conductive layer may be formed as a single layer, or may be formed as a two-layer or three-layer structure as necessary. In this embodiment, a conductive layer (A) 1521 made of a conductive metal nitride film and a conductive layer (B) 1522 made of a metal film are stacked. Conductive layer (B) 152
2 is an element selected from tantalum (Ta), titanium (Ti), molybdenum (Mo), and tungsten (W), an alloy containing the above elements as a main component, or an alloy film combining the above elements (typically, The conductive layer (A) 1521 may be formed of tantalum nitride (TaN), tungsten nitride (WN), titanium nitride (TiN), or molybdenum nitride (MoN). Form. The conductive layer (A) 1521 is an alternative material.
Tungsten silicide, titanium silicide, or molybdenum silicide may be used. The conductive layer (B) may have a low impurity concentration in order to reduce the resistance, and it is particularly preferable that the oxygen concentration be 30 ppm or less. For example, tungsten (W) has an oxygen concentration of 30.
A specific resistance of 20 μΩcm or less could be realized by setting the content to ppm or less.

The conductive layer (A) 1521 has a thickness of 10 to 50 nm.
(Preferably 20 to 30 nm), and the conductive layer (B) 15
22 is 200 to 400 nm (preferably 250 to 350 nm)
nm). In this embodiment, the conductive layer (A) 15
A 21 nm thick tantalum nitride film and a 350 nm thick Ta film for the conductive layer (B) 1522 were formed by sputtering, respectively. In the film formation by the sputtering method, if an appropriate amount of Xe or Kr is added to Ar of the gas for sputtering, the internal stress of the film to be formed can be relaxed and the film can be prevented from peeling. Although not shown, it is effective to form a silicon film doped with phosphorus (P) with a thickness of about 2 to 20 nm under the conductive layer (A) 1521. Thereby, the adhesion of the conductive film formed thereon is improved and oxidation is prevented, and at the same time, a small amount of the alkali metal element contained in the conductive layer (A) or the conductive layer (B) diffuses into the gate insulating film 1520. Can be prevented. (FIG. 16 (C))

Next, the resist masks 1523 to 1527
And a conductive layer (A) 1521 and a conductive layer (B) 152
2 and the gate electrodes 1528-15
31 and a capacitor wiring 1532 are formed. Gate electrode 152
8 to 1531 and the capacitor wiring 1532 are formed integrally with 1528a to 1532a made of a conductive layer (A) and 1528b to 1532b made of a conductive layer (B). At this time, a gate electrode 1529 formed in the driver circuit,
1530 is formed so as to overlap with part of the impurity regions 1517 and 1518 with the gate insulating film 1520 interposed therebetween.
(FIG. 16 (D))

Next, in order to form a source region and a drain region of the p-channel TFT of the driving circuit, a step of adding an impurity element imparting p-type is performed. Here, the impurity regions are formed in a self-aligned manner using the gate electrode 1528 as a mask. At this time, the n-channel TFT
Is formed with a resist mask 1533. Then, an impurity region 1534 was formed by an ion doping method using diborane (B ₂ H ₆ ). The boron (B) concentration in this region is set to 3 × 10 ^{20 to} 3 × 10 ²¹ atoms / cm ³ . In this specification, the concentration of the impurity element imparting p-type contained in the impurity region 1534 formed here is expressed as (p ⁺ ). (FIG. 17A)

Next, in the n-channel TFT, an impurity region functioning as a source region or a drain region was formed. Resist masks 1535 to 1537 were formed, and impurity regions 1538 to 1542 were formed by adding an impurity element imparting n-type. This is performed by an ion doping method using phosphine (PH ₃ ), and the concentration of phosphorus (P) in this region is set to 1 × 10 ²⁰ to 1 × 10 ²¹ atoms / cm ^3.
And In this specification, the concentration of the impurity element imparting n-type contained in the impurity regions 1538 to 1542 formed here is expressed as (n ⁺ ). (FIG. 17B)

Although impurity regions 1538 to 1542 contain phosphorus (P) or boron (B) already added in the previous step, phosphorus (P) is added at a sufficiently high concentration. Therefore, it is not necessary to consider the influence of phosphorus (P) or boron (B) added in the previous step.
Further, the concentration of phosphorus (P) added to impurity region 1538 is の of the concentration of boron (B) added in FIG.
Since it was １ ／, p-type conductivity was ensured, and there was no effect on the characteristics of the TFT.

Then, an n-type impurity-adding step for forming an LDD region of an n-channel TFT of the pixel matrix circuit was performed. Here, the gate electrode 153
Using n as a mask, an impurity element imparting n-type in a self-aligned manner was added by an ion doping method. The concentration of phosphorus (P) to be added is 1 × 10 ^{16 to} 5 × 10 ¹⁸ atoms / cm ³ , and FIG.
6A, 17A, and 17B, the impurity element is added at a lower concentration than the impurity element, and substantially only the impurity regions 1543 and 1544 are formed. In this specification, the impurity regions 1543, 154
The concentration of the impurity element imparting n-type contained in No. 4 is represented by (n ⁻ ). (FIG. 17C)

Thereafter, a heat treatment step is performed to activate the n-type or p-type imparting impurity elements added at the respective concentrations. This step can be performed by a furnace annealing method, a laser annealing method, or a rapid thermal annealing method (RTA method). Here, the activation step was performed by the furnace annealing method. The heat treatment is performed in a nitrogen atmosphere having an oxygen concentration of 1 ppm or less, preferably 0.1 ppm or less, at 400 to 800 ° C, typically 500 to 600 ° C.
In this embodiment, the heat treatment was performed at 550 ° C. for 4 hours. When a substrate having heat resistance such as a quartz substrate is used for the substrate 1501,
The heat treatment may be performed for a long time, and the activation of the impurity element and the junction between the impurity region to which the impurity element is added and the channel formation region can be favorably formed.

In this heat treatment, the gate electrode 1528
Film 1528 for forming the capacitor wiring 1532 with the wiring 1532
As for b to 1532b, conductive layers (C) 1528c to 1532c are formed with a thickness of 5 to 80 nm from the surface. For example, when the conductive layers (B) 1528b to 1532b are tungsten (W), tungsten nitride (WN) is formed, and when the conductive layers (B) 1528b to 1532b are tantalum (Ta), tantalum nitride (Ta) is formed.
N) can be formed. In addition, the conductive layer (C) 15
28c to 1532c are gate electrodes 1528 to 2832 in a plasma atmosphere containing nitrogen using nitrogen or ammonia.
Even if 1531 is exposed, it can be formed similarly. Further, in an atmosphere containing 3 to 100% hydrogen, 300 to 4
Heat treatment was performed at 50 ° C. for 1 to 12 hours to perform a step of hydrogenating the island-shaped semiconductor layer. In this step, dangling bonds in the semiconductor layer are terminated by thermally excited hydrogen. As another means of hydrogenation, plasma hydrogenation (using hydrogen excited by plasma) may be performed. (FIG. 17D)

When the activation and hydrogenation steps are completed,
A second conductive film serving as a gate wiring is formed. This second conductive film is formed by adding a conductive layer (D) mainly composed of aluminum (Al) or copper (Cu), which is a low-resistance material, to titanium (T
i) or a conductive layer (E) made of tantalum (Ta), tungsten (W), or molybdenum (Mo). In this embodiment, titanium (Ti) is contained in an amount of 0.1 to 2% by weight.
The containing aluminum (Al) film was formed as a conductive layer (D) 1545, and the titanium (Ti) film was formed as a conductive layer (E) 1546. The conductive layer (D) 1545 has a thickness of 200 to 400 nm.
(Preferably 250 to 350 nm), and the conductive layer (E) 1546 is 50 to 200 (preferably 100 to
150 nm). (FIG. 18A)

The conductive layer (E) 1546 and the conductive layer (D) are formed to form a gate wiring connected to the gate electrode.
1545 and the gate wiring 154 by etching.
7, 1548 and a capacitor wiring 1549 were formed. In the etching treatment, first, a part of the conductive layer (D) is removed from the surface of the conductive layer (E) by a dry etching method using a mixed gas of SiCl ₄ , Cl ₂ and BCl _3, and then a phosphoric acid-based etching solution is used. Conductive layer (D) by wet etching
As a result, the gate wiring could be formed while maintaining the selectivity with the base. (FIG. 18 (B))

The first interlayer insulating film 1550 has a thickness of 500 to 15
A contact hole which is formed of a silicon oxide film or a silicon oxynitride film with a thickness of 00 nm and reaches a source region or a drain region formed in each of the island-shaped semiconductor layers is formed. The wirings 1555 to 1558 are formed. Although not shown, in this embodiment, this electrode is formed by
Aluminum film containing i 300 nm, Ti film 150 nm
Was formed into a three-layer laminated film continuously formed by a sputtering method.

Next, as a passivation film 1559, a silicon nitride film, a silicon oxide film, or a silicon nitride oxide film is formed with a thickness of 50 to 500 nm (typically 100 to 300 nm). When hydrogenation is performed in this state, TFT
Preferable results were obtained for the improvement in the characteristics of For example,
300 to 450 in an atmosphere containing 3 to 100% hydrogen.
The same effect was obtained by performing heat treatment at 1 ° C. for 1 to 12 hours, or by using a plasma hydrogenation method. In addition,
Here, an opening may be formed in the passivation film 159 at a position where a contact hole for connecting the pixel electrode and the drain wiring is formed later. (Figure 1
8 (C))

Thereafter, a second interlayer insulating film 1560 made of an organic resin is formed to a thickness of 1.0 to 1.5 μm. As the organic resin, polyimide, acrylic, polyamide,
Polyimide amide, BCB (benzocyclobutene) and the like can be used. Here, a polyimide of a type that is thermally polymerized after being applied to the substrate and baked at 300 ° C. is used. Then, a contact hole reaching the drain wiring 1558 is formed in the second interlayer insulating film 1560, and pixel electrodes 1561 and 1562 are formed. As the pixel electrode, a transparent conductive film may be used for a transmission type liquid crystal display device, and a metal film may be used for a reflection type liquid crystal display device. In this embodiment, in order to obtain a transmissive liquid crystal display device, an indium tin oxide (ITO) film has a thickness of 100 n.
m was formed by a sputtering method. (FIG. 19)

Thus, the TFT of the driving circuit is formed on the same substrate.
And a substrate having pixel TFTs in the display area. The driving circuit includes a p-channel TFT 160
1, a first n-channel TFT 1602, a second n-channel TFT 1603, and a pixel TFT 160 in a display area.
4. A storage capacitor 1605 was formed. In this specification, such a substrate is referred to as an active matrix substrate for convenience.

FIG. 20 is a top view showing almost one pixel of the display area. The cross-sectional structure along AA ′ shown in FIG. 20 corresponds to the cross-sectional view of the display region shown in FIG.
In FIG. 20, common reference numerals are used to correspond to the cross-sectional structure diagrams of FIGS. Gate wiring 154
Reference numeral 8 intersects a semiconductor layer 1507 thereunder via a gate insulating film (not shown). Although not shown, an Loff region including a source region, a drain region, and an n ⁻ region is formed in the semiconductor layer. Also, 1563
Denotes a contact portion between the source wiring 1554 and the source region 1624, 1564 denotes a contact portion between the drain wiring 1558 and the drain region 1626, and 1565 denotes a contact portion between the drain wiring 1558 and the pixel electrode 1561. The storage capacitor 1605 is formed in a region where the capacitor wirings 1532 and 1549 overlap with the semiconductor layer 1627 extending from the drain region 1626 of the pixel TFT 1604 via a gate insulating film.

The p-channel TFT 16 of the driving circuit
01, the channel formation region 1 is formed in the island-shaped semiconductor layer 1504;
606, source regions 1607a and 1607b, and drain regions 1608a and 1608b. The first n-channel TFT 1602 includes a channel formation region 1609 in the island-shaped semiconductor layer 1505, an LDD region 1610 overlapping with the gate electrode 1529 (hereinafter, such an LDD region is referred to as Lov), a source region 1611, and a drain region 16.
12. The length of the Lov region in the channel length direction is 0.5 to 3.0 μm, preferably 1.0 to 1.5 μm.
m. The second n-channel TFT 1603 includes a channel formation region 1613 in the island-shaped semiconductor layer 1506 and an LD.
D regions 1614 and 1615, a source region 1616, and a drain region 1617 are provided. This LDD region is Lov
An LDD region that does not overlap the region and the gate electrode 1530 (hereinafter, such an LDD region is referred to as Loff) is formed, and the length of the Loff region in the channel length direction is 0.3 to
It is 2.0 μm, preferably 0.5 to 1.5 μm. In the pixel TFT 1604, channel-forming regions 1618, 1619, Loff regions 1620 to
1623, source or drain regions 1624 to 162
6. The length of the Loff region in the channel length direction is 0.5 to 3.0 μm, preferably 1.5 to 2.5 μm. Further, the capacitor wirings 1532 and 1549, an insulating film made of the same material as the gate insulating film, and the pixel TFT 160
The storage capacitor 1605 is formed from the semiconductor layer 1627 to which the impurity element imparting n-type is added and which is connected to the drain region 1626 of the semiconductor device 16. Further, the present invention does not need to be limited to the structure of the storage capacitor shown in this embodiment. For example, Japanese Patent Application No. 9-316567, Japanese Patent Application No. 9-273444 or Japanese Patent Application No. 10-254 filed by the present applicant.
The storage capacitor having the structure described in the '097 application can also be used.

In FIG. 19, the pixel TFT 1604 has a double gate structure, but may have a single gate structure or a multi-gate structure provided with a plurality of gate electrodes.

A process for manufacturing an active matrix type liquid crystal display device from the active matrix substrate will be described. As shown in FIG. 21, an orientation film 1701 is formed on the active matrix substrate in the state of FIG. 19 manufactured by the above method. Usually, a polyimide resin is often used for an alignment film of a liquid crystal display element. A light-shielding film 1703 and a transparent conductive film 170 are provided on the opposite substrate 1702 on the opposite side.
4 and an alignment film 1705 were formed. After forming the alignment film, a rubbing treatment was performed so that the liquid crystal molecules were aligned with a certain pretilt angle. Then, the pixel matrix circuit, the active matrix substrate on which the CMOS circuit is formed, and the counter substrate are bonded to each other via a sealing material (not shown), a columnar spacer 1707, and the like by a known cell assembling process. Thereafter, a liquid crystal material 1706 was injected between the two substrates, and completely sealed with a sealant (not shown). A known liquid crystal material may be used as the liquid crystal material. Thus, the active matrix type liquid crystal display device shown in FIG. 21 was completed.

As described above, an active matrix type liquid crystal display device in which the structures of the TFTs constituting each circuit are optimized in accordance with the specifications required by the pixel TFT and the driving circuit was able to be manufactured.

[Embodiment 4] In this embodiment, an example in which another crystallization method is used instead of the crystallization step in Embodiment 3 will be described below with reference to FIG.

First, according to the third embodiment, the state shown in FIG. Note that FIG. 22A corresponds to FIG.

Next, catalytic elements (nickel, cobalt, germanium, tin, lead, palladium,
Crystallization is performed using one or more elements selected from iron and copper, typically nickel). Specifically, laser crystallization is performed while a catalytic element is held on the surface of the amorphous silicon film to change the amorphous silicon film into a crystalline silicon film. In this embodiment, an aqueous solution containing a nickel element (aqueous nickel acetate solution) is applied by a spin coating method.
A catalyst element-containing layer 1801 is formed over the entire surface of the amorphous semiconductor film 1503a. (FIG. 22 (B)) In this example, a method of adding nickel by a spin coating method was used.
Means for forming a thin film made of a catalytic element (a nickel film in this embodiment) on the amorphous semiconductor film by an evaporation method, a sputtering method, or the like may be used.

Next, a crystalline silicon film 1802 was formed by using the laser irradiation method of the present invention described in the first embodiment. (FIG. 22 (C))

The subsequent steps are the same as those shown in FIG.
According to the steps after (C), the structure shown in FIG. 21 is obtained.

Note that, as in this embodiment, the island-like semiconductor layer
When produced from the amorphous silicon film by a crystallization method using a catalytic element, a trace amount of the catalytic element remained in the island-shaped semiconductor layer. Of course, the TFT can be completed in such a state, but it is more preferable to remove the remaining catalyst element from at least the channel formation region. One of the means for removing the catalytic element is a means utilizing the gettering action of phosphorus (P). The concentration of phosphorus (P) necessary for gettering is almost the same as that of the impurity region (n ⁺ ) formed in FIG. 17B, and the heat treatment in the activation step shown in FIG. And p
The catalyst element could be gettered from the channel forming region of the channel type TFT.

There are other means for removing the catalytic element, and there is no particular limitation. For example, after forming the island-shaped semiconductor layer, in an atmosphere containing 3 to 10% by volume of hydrogen chloride with respect to an oxygen atmosphere, the temperature of the crystalline semiconductor film where the catalytic element remains is 800 to 1150 ° C. ( Preferably 9
(1000-1000 ° C.), and a heat treatment for a treatment time of 10 minutes to 4 hours (preferably 30 minutes to 1 hour). Through this step, nickel in the crystalline semiconductor film becomes a volatile chloride compound (nickel chloride) and is released into the processing atmosphere.
That is, nickel can be removed by the gettering action of the halogen element.

Further, a plurality of means for removing the catalytic element may be used. Further, gettering may be performed before forming the island-shaped semiconductor layer.

[Embodiment 5] In this embodiment, an example in which another crystallization method is used in place of the crystallization step in Embodiment 3 will be described below with reference to FIG.

First, according to the third embodiment, the state shown in FIG. Note that FIG. 23A corresponds to FIG.

Next, an aqueous solution (aqueous nickel acetate solution) containing a catalytic element (nickel in this embodiment) is applied by a spin coating method to form a catalytic element containing layer 1902 over the entire surface of the amorphous semiconductor film 1503a. (FIG. 23 (B)) In addition to nickel (Ni), the catalytic elements usable here are germanium (Ge), iron (Fe), palladium (Pd), tin (Sn), lead (Pb), and cobalt. (C
o), platinum (Pt), copper (Cu), and gold (Au).

In this embodiment, a method of adding nickel by spin coating is used. However, a thin film made of a catalytic element (a nickel film in this embodiment) is formed of an amorphous semiconductor by vapor deposition or sputtering. Means for forming on a film may be used. In this embodiment, an example in which the catalyst element-containing layer 1902 is formed over the entire surface of the amorphous semiconductor film 1503a is described.
A step of forming a mask and selectively forming a catalyst element-containing layer may be employed.

Next, at 500 to 650 ° C. (preferably 5 to
50 to 600 ° C.) for 6 to 16 hours (preferably 8 to 14 hours)
Time). As a result, crystallization proceeds, and a crystalline semiconductor film (crystalline silicon film in this embodiment) 1902 is formed. (FIG. 23C) In the case where the catalytic element-containing layer is selectively formed, crystallization proceeds in a direction substantially parallel to the substrate (direction indicated by an arrow) starting from the opening of the mask, and A crystalline silicon film in which macroscopic crystal growth directions are aligned is formed.

The crystalline silicon film crystallized by the above method has a low crystallization temperature and therefore contains a lot of defects, and may be insufficient as a material for a semiconductor element. Therefore, in order to improve the crystallinity of the crystalline silicon film, the laser irradiation method described in Embodiment 2 was used to form a crystalline silicon film 1903 having good crystallinity by irradiating the film with a laser beam. . (FIG. 23 (D))

The subsequent steps are the same as those shown in FIG.
According to the steps after (C), the structure shown in FIG. 21 is obtained.

As in Example 4, it was more preferable to remove the remaining catalyst element from at least the channel formation region. Therefore, it is desirable to perform gettering using the method described in the third embodiment.

Embodiment 6 The structure of the active matrix type liquid crystal display device shown in Embodiment 3 will be described with reference to the perspective view of FIG. In FIG. 14, common reference numerals are used in order to correspond to FIGS.

In FIG. 14, the active matrix substrate is a display region 17 formed on a glass substrate 1501.
06, a scanning signal driving circuit 1704, and an image signal driving circuit 1705. The display area includes a pixel TFT 16.
04 is provided, and a peripheral driving circuit is a CMOS.
It is configured on a circuit basis. Scan signal drive circuit 1
704 and the image signal driving circuit 1705 are connected to the pixel TFT 160 by the gate wiring 1531 and the source wiring 1554, respectively.
K connected to 4. Further, the FPC 71 is connected to the external input terminal 74, and is connected to each drive circuit via input wirings 75 and 76. Reference numeral 1702 denotes a counter substrate.

[Embodiment 7] In this embodiment, an example in which an EL (electroluminescence) display device is manufactured as a light emitting device by using the present invention will be described.

[0132] A light-emitting device is a device in which a layer (a light-emitting element) containing an organic compound capable of obtaining luminescence generated by applying an electric field is used as a light source. The light-emitting element using an organic compound includes light emission when returning from a singlet excited state to a ground state (fluorescence) and light emission when returning from a triplet excited state to a ground state (phosphorescence).

FIG. 24A is a top view of an EL display device using the present invention. In FIG. 24A, reference numeral 4010 denotes a substrate,
011 is a pixel portion, 4012 is a source side driver circuit, 401
Reference numeral 3 denotes a gate-side drive circuit, and each drive circuit reaches an FPC 4017 via wirings 4014 to 4016 and is connected to an external device.

At this time, at least the pixel portion, preferably the driving circuit and the pixel portion are surrounded so as to surround the cover member 600.
0, sealing material (also referred to as housing material) 7000,
A sealing material (a second sealing material) 7001 is provided.

FIG. 24B shows a cross-sectional structure of the EL display device of this embodiment, in which a TFT for a driving circuit (here, an n-channel type TF) is provided on a substrate 4010 and a base film 4021.
1 illustrates a CMOS circuit combining a T and a p-channel TFT. ) 4022 and TFT 402 for pixel portion
3 (However, in this case, the TFT controlling the current to the EL element
Is only shown. ) Is formed. These TFs
T may be a known structure (top gate structure or bottom gate structure).

The present invention can be applied to the TFT 4022 for the driving circuit and the TFT 4023 for the pixel portion.

Using the present invention, the TFT 402 for the driving circuit
2. When the pixel portion TFT 4023 is completed, the pixel portion TFT is formed on an interlayer insulating film (flattening film) 4026 made of a resin material.
A pixel electrode 4027 made of a transparent conductive film electrically connected to the drain of the FT 4023 is formed. As the transparent conductive film, a compound of indium oxide and tin oxide (called ITO) or a compound of indium oxide and zinc oxide can be used. After the pixel electrode 4027 is formed, an insulating film 4028 is formed, and an opening is formed over the pixel electrode 4027.

Next, an EL layer 4029 is formed. The EL layer 4029 is formed of a known EL material (a hole injection layer, a hole transport layer,
A light-emitting layer, an electron transport layer, or an electron injection layer) may be freely combined to form a stacked structure or a single-layer structure. A known technique may be used to determine the structure. Also, E
The L material includes a low molecular material and a high molecular (polymer) material. When a low molecular material is used, an evaporation method is used, but when a high molecular material is used, a spin coating method,
A simple method such as a printing method or an inkjet method can be used.

[0139] In this embodiment, an EL layer is formed by an evaporation method using a shadow mask. By forming light-emitting layers (red light-emitting layer, green light-emitting layer, and blue light-emitting layer) capable of emitting light of different wavelengths for each pixel using a shadow mask,
Color display becomes possible. In addition, the color conversion layer (CC
M) and a color filter are combined, and a white light-emitting layer and a color filter are combined. Either method may be used. Needless to say, a monochromatic EL display device can be used.

After forming the EL layer 4029, a cathode 4030 is formed thereon. Cathode 4030 and EL layer 4029
It is desirable to remove as much as possible moisture and oxygen existing at the interface. Therefore, the EL layer 4029 and the cathode 40 in vacuum
It is necessary to devise a method of continuously forming the film 30 or forming the EL layer 4029 in an inert atmosphere and forming the cathode 4030 without opening to the atmosphere. In this embodiment, the above-described film formation is made possible by using a multi-chamber type (cluster tool type) film formation apparatus.

In this embodiment, the cathode 4030 is
A laminated structure of a LiF (lithium fluoride) film and an Al (aluminum) film is used. Specifically, a 1-nm-thick LiF (lithium fluoride) film is formed over the EL layer 4029 by a vapor deposition method, and a 300-nm-thick aluminum film is formed thereover. Of course, a MgAg electrode which is a known cathode material may be used. The cathode 4030 is connected to the wiring 4016 in a region indicated by 4031. A wiring 4016 is a power supply line for applying a predetermined voltage to the cathode 4030, and the FPC 401 via the conductive paste material 4032.
7 is connected.

In the region indicated by 4031, the cathode 40
In order to electrically connect the wiring 30 and the wiring 4016, it is necessary to form contact holes in the interlayer insulating film 4026 and the insulating film 4028. These are interlayer insulating films 4026
May be formed at the time of etching (at the time of forming a contact hole for a pixel electrode) or at the time of etching of an insulating film 4028 (at the time of forming an opening before forming an EL layer). When the insulating film 4028 is etched, etching may be performed at a time up to the interlayer insulating film 4026. In this case, if the interlayer insulating film 4026 and the insulating film 4028 are made of the same resin material, the shape of the contact hole can be improved.

The passivation film 6003 and the filler 600 cover the surface of the EL element thus formed.
4. The cover material 6000 is formed.

Further, a sealing material is provided inside the cover material 6000 and the substrate 4010 so as to surround the EL element portion, and a sealing material (second sealing material) 7001 is formed outside the sealing material 7000.

At this time, the filler 6004 also functions as an adhesive for bonding the cover material 6000.
As the filler 6004, PVC (polyvinyl chloride), epoxy resin, silicone resin, PVB (polyvinyl butyral), or EVA (ethylene vinyl acetate) can be used. It is preferable to provide a desiccant inside the filler 6004 because a moisture absorbing effect can be maintained.

[0146] The filler 6004 may contain a spacer. At this time, the spacer may be a granular substance made of BaO or the like, and the spacer itself may have hygroscopicity.

When a spacer is provided, the pressure of the spacer in the passivation film 6003 can be reduced.
Further, a resin film or the like for relaxing the spacer pressure may be provided separately from the passivation film.

As the cover material 6000, a glass plate, an aluminum plate, a stainless steel plate, FRP (Five)
rglass-Reinforced Plastic
s) plate, PVF (polyvinyl fluoride) film,
Mylar film, polyester film or acrylic film can be used. The filling material 600
When PVB or EVA is used as 4, it is preferable to use a sheet having a structure in which aluminum foil of several tens of μm is sandwiched between PVF films or Mylar films.

However, depending on the direction of light emission (the direction of light emission) from the EL element, the cover material 6000 needs to have a light transmitting property.

The wiring 4016 is made of the sealing material 700.
0 and through the gap between the sealing material 7001 and the substrate 4010, and is electrically connected to the FPC 4017. Although the wiring 4016 has been described here, the other wiring 401
4, 4015 are similarly electrically connected to the FPC 4017 under the sealant 7000 and the sealant 7001.

[Embodiment 8] In this embodiment, an example in which an EL display device having a mode different from that of Embodiment 7 is manufactured by using the present invention will be described with reference to FIGS. . Fig. 24
Elements having the same numbers as in (A) and 25 (B) indicate the same parts, and thus description thereof will be omitted.

FIG. 25A is a top view of the EL display device of this embodiment, and FIG. 25B is a cross-sectional view of FIG. 25A taken along the line CC ′.

According to the seventh embodiment, a passivation film 6003 is formed to cover the surface of the EL element.

[0154] Further, the filling material 6 is formed so as to cover the EL element.
004 is provided. This filler 6004 is used for the cover material 60.
It also functions as an adhesive for bonding 00. As the filler 6004, PVC (polyvinyl chloride),
Epoxy resin, silicone resin, PVB (polyvinyl butyral) or EVA (ethylene vinyl acetate) can be used. It is preferable to provide a desiccant inside the filler 6004 because a moisture absorbing effect can be maintained.

[0155] A spacer may be contained in the filler 6004. At this time, the spacer may be a granular substance made of BaO or the like, and the spacer itself may have hygroscopicity.

When a spacer is provided, the passivation film 6003 can reduce the spacer pressure.
Further, a resin film or the like for relaxing the spacer pressure may be provided separately from the passivation film.

As the cover material 6000, a glass plate, an aluminum plate, a stainless steel plate, FRP (Five)
rglass-Reinforced Plastic
s) plate, PVF (polyvinyl fluoride) film,
Mylar film, polyester film or acrylic film can be used. The filling material 600
When PVB or EVA is used as 4, it is preferable to use a sheet having a structure in which aluminum foil of several tens of μm is sandwiched between PVF films or Mylar films.

However, depending on the direction of light emission (the direction of light emission) from the EL element, the cover material 6000 needs to have a light transmitting property.

Next, the cover material 6
After bonding 000, the side surface of filler 6004 (exposed surface)
Frame material 6001 is attached so as to cover. The frame material 6001 is a sealing material (functions as an adhesive)
Glued by 6002. At this time, a photocurable resin is preferably used as the sealing material 6002, but a thermosetting resin may be used as long as the heat resistance of the EL layer is allowed. Note that the sealing material 6002 is preferably a material that does not transmit moisture or oxygen as much as possible. Further, a desiccant may be added to the inside of the sealing material 6002.

The wiring 4016 is made of the sealing material 600.
2 is electrically connected to the FPC 4017 through a gap between the substrate 2 and the substrate 4010. Note that although the wiring 4016 has been described here, the other wirings 4014 and 4015 are also electrically connected to the FPC 4017 under the sealing material 6002 in the same manner.

[Embodiment 9] The present invention can be applied to an EL display panel having a structure as in Embodiments 7 and 8. Here, a more detailed cross-sectional structure of the pixel portion is shown in FIG. 26, an upper surface structure is shown in FIG. 27A, and a circuit diagram is shown in FIG.
Shown in 26, 27 (A) and 27 (B) use the same reference numerals, so they may be referred to each other.

In FIG. 26, a switching TFT 3502 provided on a substrate 3501 is formed using the NTFT of the present invention (see Examples 1 to 6). In this embodiment, a double gate structure is used. However, since there is no significant difference between the structure and the manufacturing process, the description is omitted. However, the double gate structure has a structure in which two TFTs are substantially connected in series, and has an advantage that an off-current value can be reduced. In this embodiment, a double gate structure is used. However, a single gate structure may be used.
A triple gate structure or a multi-gate structure having more gates may be used. Further, it may be formed using the PTFT of the present invention.

The current control TFT 3503 is made of NTF
It is formed using T. At this time, the switching TF
The drain wiring 35 of T3502 is electrically connected to the gate electrode 37 of the current controlling TFT by the wiring 36. The wiring indicated by 38 is a switching TF.
This is a gate wiring for electrically connecting the gate electrodes 39a and 39b of T3502.

At this time, the current controlling TFT 3503
Since it is an element for controlling the amount of current flowing through the L element, a large amount of current flows, and the element has a high risk of deterioration due to heat or deterioration due to hot carriers. Therefore, a structure in which an LDD region is provided on the drain side of the current control TFT so as to overlap with the gate electrode via the gate insulating film is extremely effective.

In this embodiment, the current controlling TFT 35 is used.
03 is shown with a single gate structure.
A multi-gate structure in which FTs are connected in series may be used.
Further, a structure in which a plurality of TFTs are connected in parallel to substantially divide the channel formation region into a plurality of regions so that heat can be radiated with high efficiency may be employed. Such a structure is effective as a measure against deterioration due to heat.

As shown in FIG. 27A, the wiring which becomes the gate electrode 37 of the current controlling TFT 3503 is
4 overlaps with the drain wiring 40 of the current controlling TFT 3503 via an insulating film. At this time, 35
In a region indicated by 04, a capacitor is formed. This capacitor 3504 functions as a capacitor for holding a voltage applied to the gate of the current control TFT 3503. The drain wiring 40 is a current supply line (power supply line)
3506, and a constant voltage is always applied.

A first passivation film 41 is provided on the switching TFT 3502 and the current control TFT 3503, and a planarizing film 4 made of a resin insulating film is provided thereon.
2 are formed. It is very important to flatten the steps due to the TFT using the flattening film 42. Since an EL layer formed later is extremely thin, poor light emission may be caused by the presence of a step. Therefore, it is desirable that the EL layer be flattened before forming the pixel electrode so that the EL layer can be formed as flat as possible.

Reference numeral 43 denotes a pixel electrode (cathode of an EL element) made of a conductive film having high reflectivity.
503 is electrically connected to the drain. Pixel electrode 43
It is preferable to use a low-resistance conductive film such as an aluminum alloy film, a copper alloy film, or a silver alloy film, or a stacked film thereof. Of course, a stacked structure with another conductive film may be employed.

A light emitting layer 45 is formed in a groove (corresponding to a pixel) formed by banks 44a and 44b formed of an insulating film (preferably resin). Although only one pixel is shown here, R (red), G (green),
Light emitting layers corresponding to each color of B (blue) may be separately formed.
As the organic EL material for the light emitting layer, a π-conjugated polymer material is used. Typical polymer-based materials include polyparaphenylenevinylene (PPV), polyvinylcarbazole (PVK), and polyfluorene.

There are various types of PPV-based organic EL materials, for example, “H. Shenk, H. Becker, O. Ge.
lsen, E. Kluge, W. Kreuder, and H. Spreitzer, “Polymers
forLight Emitting Diodes ”, Euro Display, Proceeding
s, 1999, p.33-37 "and JP-A-10-92576.

As specific light emitting layers, cyanopolyphenylene vinylene is used for a red light emitting layer, polyphenylene vinylene is used for a green light emitting layer, and polyphenylene vinylene or polyalkylphenylene is used for a blue light emitting layer. Good. The film thickness is 30-150n
m (preferably 40 to 100 nm).

However, the above example is an example of the organic EL material that can be used as the light emitting layer, and it is not necessary to limit the invention to this. An EL layer (a layer for performing light emission and carrier movement therefor) may be formed by freely combining a light emitting layer, a charge transport layer, or a charge injection layer.

For example, in this embodiment, an example is shown in which a polymer material is used for the light emitting layer, but a low molecular organic EL material may be used. It is also possible to use an inorganic material such as silicon carbide for the charge transport layer and the charge injection layer. Known materials can be used for these organic EL materials and inorganic materials.

In this embodiment, PEDOT is formed on the light emitting layer 45.
The EL layer has a laminated structure in which a hole injection layer 46 made of (polythiophene) or PAni (polyaniline) is provided. An anode 47 made of a transparent conductive film is provided on the hole injection layer 46. In the case of this embodiment, since the light generated in the light emitting layer 45 is emitted toward the upper surface side (toward the upper side of the TFT), the anode must be translucent. As the transparent conductive film, a compound of indium oxide and tin oxide or a compound of indium oxide and zinc oxide can be used; however, it is possible to form after forming a light-emitting layer or a hole-injecting layer with low heat resistance. A material that can form a film at a temperature as low as possible is preferable.

When the anode 47 is formed, the EL element 3
505 is completed. Note that the EL element 3505 mentioned here
Are the pixel electrode (cathode) 43, the light emitting layer 45, the hole injection layer 4
6 and the anode 47. Figure 27
As shown in (A), the pixel electrode 43 substantially matches the area of the pixel, and the entire pixel functions as an EL element. Therefore, the efficiency of light emission is extremely high, and a bright image can be displayed.

In the present embodiment, a second passivation film 48 is further provided on the anode 47. Second
As the passivation film 48, a silicon nitride film or a silicon nitride oxide film is preferable. The purpose of this is to shut off the EL element from the outside, and has both the meaning of preventing the organic EL material from being deteriorated due to oxidation and the effect of suppressing outgassing from the organic EL material. Thereby, the reliability of the EL display device is improved.

As described above, the EL display panel has a pixel portion composed of pixels having a structure as shown in FIG. 26, and includes a switching TFT having a sufficiently low off-current value and a current control TFT which is strong against hot carrier injection. Having. Therefore, an EL display panel having high reliability and capable of displaying a good image can be obtained.

The configuration of the present embodiment can be implemented by freely combining with the configurations of Embodiments 1 to 6.
It is effective to use the EL display panel of this embodiment as a display unit of an electronic device.

[Embodiment 10] In this embodiment, a structure in which the structure of the EL element 3505 is inverted in the pixel portion shown in Embodiment 9 will be described. FIG. 28 is used for the description. 26 is different from the structure of FIG. 26 only in the portion of the EL element and the current controlling TFT, and the other description is omitted.

In FIG. 28, the current controlling TFT 3503
Are formed using PTFT. Embodiments 1 to 12 may be referred to for the manufacturing process.

In this embodiment, a transparent conductive film is used as the pixel electrode (anode) 50. Specifically, a conductive film formed using a compound of indium oxide and zinc oxide is used. Needless to say, a conductive film made of a compound of indium oxide and tin oxide may be used.

The banks 51a and 51b made of insulating films
Is formed, a light emitting layer 52 made of polyvinyl carbazole is formed by applying a solution. An electron injection layer 53 made of potassium acetylacetonate (denoted as acacK) and a cathode made of an aluminum alloy are formed thereon. In this case, the cathode 54 also functions as a passivation film. Thus, an EL element 3701 is formed.

In the case of this embodiment, the light generated in the light emitting layer 52 is radiated toward the substrate on which the TFT is formed as shown by the arrow.

The structure of this embodiment can be implemented by freely combining with the structures of Embodiments 1 to 6.
It is effective to use the EL display panel of this embodiment as a display unit of an electronic device.

[Embodiment 11] In this embodiment, FIGS. 29A to 29C show an example in which a pixel having a structure different from that of the circuit diagram shown in FIG. 27B is used. In this embodiment, reference numeral 3801 denotes a source wiring of the switching TFT, 3
803 is a gate wiring of the switching TFT 3802,
3804 is a current controlling TFT, 3805 is a capacitor,
Reference numerals 3806 and 3808 denote current supply lines, and 3807 denotes an EL element.

FIG. 29A shows an example in which a current supply line 3806 is shared between two pixels. That is, the feature is that two pixels are formed to be line-symmetric with respect to the current supply line 3806. In this case, the number of power supply lines can be reduced, so that the pixel portion can have higher definition.

FIG. 29B shows a current supply line 3808.
Is provided in parallel with the gate wiring 3803.
Note that in FIG. 29B, the current supply line 3808 and the gate wiring 3803 are provided so as not to overlap with each other; however, if the wiring is formed in a different layer, the two overlap with an insulating film. It can also be provided as follows. in this case,
Since the power supply line 3808 and the gate wiring 3803 can share an occupied area, the pixel portion can have higher definition.

In FIG. 29C, a current supply line 3808 is provided in parallel with the gate wiring 3803 as in the structure of FIG. 29B, and two pixels are line-symmetrical about the current supply line 3808. The feature is that it is formed so that It is also effective to provide the current supply line 3808 so as to overlap with one of the gate wirings 3803. In this case, the number of power supply lines can be reduced, so that the pixel portion can have higher definition.

The configuration of the present embodiment can be implemented by freely combining with the configurations of Embodiments 1 to 10.
In addition, it is effective to use an EL display panel having a pixel structure of this embodiment as a display portion of an electronic device.

[Embodiment 12] FIG. 27 shown in Embodiment 9
27A and 27B, a capacitor 3504 for holding a voltage applied to the gate of the current controlling TFT 3503 is shown.
Is provided, but the capacitor 3504 can be omitted. In the case of the ninth embodiment, the current control T
NTF as shown in Examples 1 to 12 as FT3503
Since T is used, the semiconductor device has an LDD region provided so as to overlap the gate electrode with the gate insulating film interposed therebetween. A parasitic capacitance generally called a gate capacitance is formed in the overlapped region. The present embodiment is characterized in that this parasitic capacitance is actively used instead of the capacitor 3504.

Since the capacitance of the parasitic capacitance changes depending on the area where the gate electrode and the LDD region overlap, it is determined by the length of the LDD region included in the overlapping region.

Further, FIG. 29A and FIG.
Similarly, in the structures (B) and (C), the capacitor 3
It is possible to omit 805.

The structure of this embodiment is similar to that of the first to eleventh embodiments.
Can be freely combined with the above configuration. It is effective to use the EL display panel having the pixel structure of this embodiment as the display unit of the electronic devices of Embodiments 13 to 15.

[Embodiment 13] The present invention can be applied to all conventional IC technologies. That is, the present invention can be applied to all semiconductor circuits currently on the market. For example, the present invention may be applied to a microprocessor such as a RISC processor and an ASIC processor integrated on one chip,
The present invention may be applied to a signal processing circuit represented by a driver circuit for liquid crystal (D / A converter, gamma correction circuit, signal dividing circuit, etc.) and a high frequency circuit for portable equipment (mobile phone, PHS, mobile computer).

A semiconductor circuit such as a microprocessor is mounted on various electronic devices and functions as a central circuit. Representative electronic devices include personal computers, portable information terminal devices, and all other home appliances. Further, a computer for controlling a vehicle (an automobile, a train, or the like) is also included. The present invention is applicable to such a semiconductor device.

In manufacturing the semiconductor device shown in this embodiment, any one of the first to twelfth embodiments may be employed, or each embodiment may be freely combined and used. .

[Embodiment 14] The TFT formed by carrying out the present invention can be used for various electro-optical devices. That is, the present invention can be applied to all electronic devices in which these electro-optical devices are incorporated as display media.

Such electronic devices include a video camera, a digital camera, a head mounted display (goggle type display), a wearable display,
Examples include a car navigation system, a personal computer, and a portable information terminal (a mobile computer, a mobile phone, an electronic book, or the like). One example of them is shown in FIG.

FIG. 30A shows a personal computer, which includes a main body 2001, an image input section 2002, and a display device 20.
03, a keyboard 2004. The present invention can be applied to the image input unit 2002, the display device 2003, and other signal control circuits.

FIG. 30B shows a video camera,
101, display device 2102, audio input unit 2103, operation switch 2104, battery 2105, image receiving unit 210
6. The present invention can be applied to the display device 2102, the audio input unit 2103, and other signal control circuits.

FIG. 30C shows a mobile computer (mobile computer), which includes a main body 2201 and a camera unit 2.
202, an image receiving unit 2203, operation switches 2204, and a display device 2205. The present invention relates to a display device 2205.
And other signal control circuits.

FIG. 30D shows a goggle type display, which includes a main body 2301, a display device 2302, and an arm portion 230.
3 The present invention can be applied to the display device 2302 and other signal control circuits.

FIG. 30E shows a player using a recording medium (hereinafter, referred to as a recording medium) on which a program is recorded, and includes a main body 2401, a display device 2402, and a speaker unit 24.
03, a recording medium 2404, and operation switches 2405. This device uses a DVD (Di) as a recording medium.
It is possible to watch music, watch a movie, play a game, or use the Internet by using a CD (g. Versatile Disc) or a CD. The present invention can be applied to the display device 2402 and other signal control circuits.

FIG. 30F shows a digital camera, which comprises a main body 2501, a display device 2502, an eyepiece section 2503, operation switches 2504, and an image receiving section (not shown).
The present invention can be applied to the display device 2502 and other signal control circuits.

As described above, the applicable range of the present invention is extremely wide, and can be applied to electronic devices in all fields. Further, the electronic apparatus of the present embodiment can be realized by using a configuration composed of any combination of the embodiments 1 to 12.

[Embodiment 15] A TFT formed by carrying out the present invention can be used for various electro-optical devices. That is, the present invention can be applied to all electronic devices in which these electro-optical devices are incorporated as display media.

As such electronic equipment, a projector (rear type or front type) and the like can be mentioned. One example of them is shown in FIG.

FIG. 31A shows a front type projector, which comprises a display device 2601 and a screen 2602. The present invention can be applied to a display device and other signal control circuits.

FIG. 31B shows a rear type projector, which includes a main body 2701, a display device 2702, and a mirror 270.
3. It is composed of a screen 2704. The present invention can be applied to a display device and other signal control circuits.

FIG. 31 (C) is the same as FIG. 31 (A) and FIG.
FIG. 31 is a diagram showing an example of the structure of the display devices 2601 and 2702 in FIG. Display devices 2601, 2702
Are the light source optical system 2801, the mirrors 2802, 2804-
2806, dichroic mirror 2803, prism 2
807, a liquid crystal display device 2808, a retardation plate 2809, and a projection optical system 2810. Projection optical system 2810
Is composed of an optical system including a projection lens. In the present embodiment, an example of a three-plate type is shown, but there is no particular limitation, and for example, a single-plate type may be used. In addition, in the optical path indicated by the arrow in FIG. 31 (C), the practitioner may appropriately set an optical lens, a film having a polarizing function, a film for adjusting a phase difference,
An optical system such as an R film may be provided.

FIG. 31D shows an example of the structure of the light source optical system 2801 in FIG. 31C.
In this embodiment, the light source optical system 2801 includes the reflector 2
811, light sources 2812, 2813, and 2814, a polarization conversion element 2815, and a condenser lens 2816. Note that the light source optical system shown in FIG. 31D is an example and is not particularly limited. For example, a practitioner may appropriately provide an optical system such as an optical lens, a film having a polarizing function, a film for adjusting a phase difference, and an IR film in the light source optical system.

As described above, the applicable range of the present invention is extremely wide, and can be applied to electronic devices in all fields. Further, the electronic apparatus of the present embodiment can be realized by using a configuration composed of any combination of the embodiments 1 to 12.

[0213]

The use of the laser irradiation apparatus according to the present invention makes it possible to reduce the faint interference that has been seen so far. Further, it is possible to simplify an optical system which has been difficult to adjust until now.

Furthermore, a lens that transmits a laser beam deteriorates as it is used and becomes unusable. However, unlike a lens, a mirror does not transmit a laser beam but reflects a laser beam on the surface of the mirror. Deterioration is limited to the surface only. Therefore, even if the mirror is used for a long period of time, it can be used again by recoating the surface of the mirror, which is economical. In addition, the mirror is effective because it does not cause aberration unlike a lens. Further, if the mirror is made movable by a micrometer or the like, fine adjustment is possible, which is convenient.

In the embodiments described above, the optical system for suppressing the interference of the linear beam in the width direction has been described. However, even in the longitudinal direction of the linear beam, it is possible to suppress interference by using the structure of the present invention if necessary. Also,
The beam collimator does not need to be limited to the structure disclosed in the embodiment, and can be omitted if a sufficiently parallel laser beam can be obtained. Further, although a laser beam having a linear or rectangular shape on the irradiation surface has been described in the embodiments, the present invention can be applied to laser beams having other shapes.

[Brief description of the drawings]

FIG. 1 is a diagram showing a conventional optical system for forming a linear beam.

FIG. 2 is a diagram showing that laser beams split in two directions by a half mirror are combined into one on an irradiation surface.

FIG. 3 is a diagram showing an example of a laser irradiation apparatus disclosed by the present invention.

FIG. 4 is a diagram showing an example of a laser irradiation apparatus disclosed by the present invention.

FIG. 5 is a diagram showing an example of a beam collimator.

FIG. 6 is a diagram showing an example of a laser irradiation apparatus disclosed by the present invention.

FIG. 7 is a diagram showing an example of the arrangement of mirrors disclosed by the present invention.

FIG. 8 is a diagram showing an example of the arrangement of mirrors disclosed by the present invention.

FIG. 9 is a diagram showing an example of a laser irradiation apparatus disclosed by the present invention.

FIG. 10 is a diagram showing an example of a laser irradiation apparatus disclosed by the present invention.

FIG. 11 is a diagram showing an example of the arrangement of mirrors disclosed by the present invention.

FIG. 12 is a diagram showing an example of the arrangement of mirrors disclosed by the present invention.

FIG. 13 is a diagram showing an example of the arrangement of mirrors disclosed by the present invention.

FIG. 14 is a diagram showing an overview of an AM-LCD.

FIG. 15 illustrates an example of a manufacturing process of a pixel TFT and a TFT of a driver circuit.

FIG. 16 illustrates an example of a manufacturing process of a pixel TFT and a TFT of a driver circuit.

FIG. 17 illustrates an example of a manufacturing process of a pixel TFT and a TFT of a driver circuit.

FIG. 18 illustrates an example of a manufacturing process of a pixel TFT and a TFT of a driver circuit.

FIG. 19 illustrates an example of a manufacturing process of a pixel TFT and a TFT of a driver circuit.

FIG. 20 illustrates a top view of a pixel.

FIG. 21 illustrates a cross-sectional structure of a liquid crystal display device.

FIG. 22 illustrates an example of a manufacturing process of the present invention.

FIG. 23 illustrates an example of a manufacturing process of the present invention.

FIG 24 illustrates a structure of an active matrix EL display device.

FIG. 25 illustrates a structure of an active matrix EL display device.

FIG 26 illustrates a structure of an active matrix EL display device.

FIG. 27 illustrates a structure of an active matrix EL display device.

FIG 28 illustrates a structure of an active matrix EL display device.

FIG. 29 is a diagram illustrating a circuit diagram of an active matrix EL display device.

FIG. 30 illustrates an example of an electronic device.

FIG. 31 illustrates an example of an electronic device.

FIG. 32 is a diagram showing an example of an overview of a laser irradiation apparatus.

[Explanation of symbols]

 101 Laser oscillator 102a Cylindrical array lens 102b Cylindrical array lens 103 Cylindrical array lens 104 Cylindrical array lens 105 Cylindrical lens 107 mirror 108 Doublet cylindrical lens 109 Irradiation surface 201 Laser oscillator 202 Half mirror 203 mirror 204 Mirror 205 mirror 206 Irradiation surface 301 Laser oscillator 302 Cylindrical array lens 303 cylindrical lens 304 cylindrical lens 305 cylindrical lens 306 mirror 307 irradiation surface 401 laser oscillator 402 cylindrical array lens 403 cylindrical lens 404 cylindrical lens 405 cylindrical lens 406 mirror 407 irradiation surface 501 lens 502 lens 503 lens 504 lens 701 mirror 702 plane Mirror 703 plane mirror 704 plane mirror 705 irradiation plane 801 mirror 802 plane mirror 803 plane mirror 804 irradiation plane 901 ray The oscillator 902 cylindrical array lens 903 cylindrical lens 904 cylindrical lens 905 cylindrical lens 906 mirror 906a parabolic mirror 906b parabolic mirror 906c parabolic mirror 906d parabolic mirror 907 irradiation surface 1001 laser oscillator 1002 cylindrical array lens 1003 cylindrical lens 1004 cylindrical lens 1005 cylindrical lens 1006 mirror 1006a parabolic mirror 1006b parabolic mirror 1006c parabolic mirror 1006d parabolic mirror 1007 irradiation surface 1101 mirror 1102 plane mirror 1103 plane mirror 1104 plane mirror 1105 irradiation plane 1201 mirror 1202 plane mirror 1203 plane mirror 1204 plane mirror 1205 plane mirror 1206 irradiation surface 1301 mirror 1302 plane mirror 1303 plane mirror 1304 plane mirror 1305 plane mirror 1306 irradiation plane 1501 substrate 1502 underlayer film 1503a amorphous silicon film 1503b crystalline silicon film 15 4 island-shaped semiconductor layer 1505 island-shaped semiconductor layer 1506 island-shaped semiconductor layer 1507 island-shaped semiconductor layer 1508 mask layer 1509 resist mask 1510 semiconductor layer 1511 semiconductor layer 1512 semiconductor layer 1513 resist mask 1514 resist mask 1515 resist mask 1516 resist mask 1517 impurity region 1518 impurity region 1519 impurity region 1520 gate insulating film 1521 conductive layer 1522 conductive layer 1523 resist mask 1524 resist mask 1525 resist mask 1526 resist mask 1527 resist mask 1528 gate electrode 1529 gate electrode 1530 gate electrode 1531 gate electrode 1532 capacitance wiring 1533 resist mask Impurity region 1535 Resist mask 1536 Cash register Mask 1537 resist mask 1538 impurity region 1539 impurity region 1540 impurity region 1541 impurity region 1542 impurity region 1543 impurity region 1544 impurity region 1545 conductive layer 1546 conductive layer 1547 gate wiring 1548 gate wiring 1549 capacitance wiring 1550 interlayer insulating film 1551 source wiring 1552 source wiring 1553 source wiring 1554 source wiring 1555 drain wiring 1556 drain wiring 1557 drain wiring 1558 drain wiring 1559 passivation film 1560 second interlayer insulating film 1561 pixel electrode 1562 pixel electrode 1563 contact portion 1564 contact portion 1565 contact portion 1601 p-channel TFT 1602 1 n-channel TFT 1603 2nd n Channel type TFT 1604 pixel TFT 1605 storage capacitor 1606 channel forming region 1607 source region 1608 drain region 1609 channel forming region 1610 LDD region 1611 source region 1612 drain region 1613 channel forming region 1614 LDD region 1615 LDD region 1616 source region 1617 drain region 1618 channel Formation region 1619 channel formation region 1620 Loff region 1621 Loff region 1622 Loff region 1623 Loff region 1624 source or drain region 1625 source or drain region 1626 source or drain region 1627 semiconductor layer 1701 light distribution film 1702 opposing substrate 1703 light shielding film 1704 transparent conductive film 1705 Alignment film 1706 Liquid crystal material 1707 Columnar spacer 1801 Catalyst element containing layer 1802 Crystalline silicon film 1901 Catalyst element containing layer 1902 Crystalline semiconductor film 1903 Crystalline silicon film 71 FPC 72 External input terminal 73 Input wiring 74 Input wiring 35 Drain wiring 36 Wiring 37 Gate electrode 38 Wiring 39a shown Gate electrode 39b Gate electrode 40 Drain wiring 41 First passivation film 42 Flattening film 43 Pixel electrode 44a Bank 44b Bank 45 Light emitting layer 46 Hole injection layer 47 Anode 48 Second passivation film 50 Pixel electrode (anode) 51a Bank 51b Bank 52 Light emitting layer 53 Electron injection layer 54 Cathode 3501 Substrate 3502 Switching TFT 3503 Current control TFT 3504 Capacitor 3505 EL element 3506 Current supply line (power supply line) 3701 EL element 3801 Source wiring 3802 Switching TFT 3803 Gate wiring 3804 Current control TFT 3805 Capacitor 3806 Current supply line 3807 EL element 3808 Current Supply line 4010 Substrate 4011 Pixel section 4012 Source side drive circuit 4013 Gate side drive circuit 4014 Wiring 4015 Wiring 4016 Wiring 4017 FPC 4021 Base film 4022 Drive circuit TFT 4023 Pixel part TFT 4026 Interlayer insulating film 4027 Pixel electrode 4028 Insulating film 4029 EL Layer 4030 Cathode 4031 Area shown 4032 Conductive paste material 6000 Cover material 6001 Frame material 6002 Sealing material 6003 Passivation film 6004 Filler 7000 Sealant 7001 Sealant

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) H01L 29/786 H01L 29/78 616L 21/336 627G

Claims (19)

[Claims] 1. A laser irradiation apparatus having a laser oscillator, an optical system, and a stage that moves in at least one direction, wherein the optical system is configured to:
An optical system 1 that divides the laser beam in the first direction and mixes the irradiated surface or the vicinity of the irradiated surface to make the energy of the laser beam uniform on the irradiated surface; In two directions, an optical system 2 for splitting the laser beam in the second direction of the laser beam, and mixing the split laser beam near the irradiation surface or the irradiation surface, and Optical system 3 for equalizing laser beam energy
Wherein the first direction and the second direction are orthogonal to each other with respect to the traveling direction of the laser beam,
The laser irradiation apparatus according to claim 1, further comprising means for setting an optical path difference of the divided laser beam from the laser oscillator to the irradiation surface to be equal to or longer than a coherent length of the laser beam. 2. A laser irradiation device having a laser oscillator, an optical system, and a stage that moves in at least one direction, wherein the optical system is configured to:
A mirror that divides the laser beam in the first direction, and mixes the laser beam at or near the irradiation surface to equalize the energy of the laser beam on the irradiation surface; and a second direction of the laser beam. A cylindrical array lens that splits the laser beam in the second direction of the laser beam, and the split laser beam is mixed near the irradiation surface or the irradiation surface, and the laser beam on the irradiation surface is mixed. A cylindrical lens for equalizing energy, wherein the first direction and the second direction are orthogonal to each other with respect to a traveling direction of the laser beam, and the mirror is a laser oscillator of the divided laser beam. Means for making each optical path difference from the laser beam to the irradiation surface equal to or longer than the coherent length of the laser beam. The laser irradiation apparatus according to. 3. A laser irradiation apparatus for irradiating a linear or rectangular laser beam on an irradiation surface, comprising: a laser oscillator; and an optical device for processing the laser beam on the irradiation surface into a linear or rectangular shape. And a stage that moves in at least one direction, wherein the optical system divides the laser beam in the width direction of the laser beam in the width direction of the laser beam, and An optical system 1 that mixes in the vicinity and equalizes the energy of a laser beam whose shape on the irradiation surface becomes linear or rectangular, and the laser beam in the longitudinal direction of the laser beam, The optical system 2 for splitting in the length direction is mixed with the split laser beam in the irradiation surface or in the vicinity of the irradiation surface, and the shape on the irradiation surface is linear. Or an optical system 3 for equalizing the energy of a rectangular laser beam, wherein the optical system 1 calculates the optical path difference between the laser oscillator and the irradiation surface of the divided laser beam, A laser irradiation apparatus, comprising: means for increasing the coherence length of the laser beam. 4. A laser irradiation apparatus for irradiating a linear or rectangular laser beam on an irradiation surface, comprising: a laser oscillator; and an optical device for processing the laser beam on the irradiation surface into a linear or rectangular shape. And a stage that moves in at least one direction, wherein the optical system divides the laser beam in the width direction of the laser beam in the width direction of the laser beam, and Mixing in the vicinity, a mirror for equalizing the energy of the laser beam whose shape on the irradiation surface becomes linear or rectangular, and in the longitudinal direction of the laser beam,
A cylindrical array lens that divides the laser beam in the length direction of the laser beam; and the divided laser beam is mixed in the irradiation surface or in the vicinity of the irradiation surface, and the shape of the irradiation surface is linear or rectangular. A cylindrical lens for equalizing the energy of the laser beam to be shaped, and the mirror is configured to determine the optical path difference between the laser oscillator and the irradiation surface of the divided laser beam by cohering the laser beam. A laser irradiation apparatus, comprising: means for increasing the length. 5. A laser irradiation apparatus for irradiating a linear or rectangular laser beam on an irradiation surface, comprising: a laser oscillator; and an optical device for processing the laser beam on the irradiation surface into a linear or rectangular shape. And a stage that moves in at least one direction, wherein the optical system divides the laser beam in the length direction of the laser beam in the length direction of the laser beam, and the irradiation surface or the irradiation. An optical system 1 that mixes in the vicinity of the surface to equalize the energy of the laser beam whose shape on the irradiation surface becomes linear or rectangular; and that the laser beam is applied in the width direction of the laser beam. The optical system 2 for splitting in the width direction and the split laser beam are mixed in the irradiation surface or in the vicinity of the irradiation surface, and the shape on the irradiation surface is linear. And an optical system 3 for equalizing the energy of the laser beam having a rectangular or rectangular shape, wherein the optical system 1 determines the optical path difference of the divided laser beam from the laser oscillator to the irradiation surface. And a means for making the laser beam coherent length or longer. 6. A laser irradiation apparatus for irradiating a linear or rectangular laser beam on an irradiation surface, comprising: a laser oscillator; and an optical device for processing the laser beam on the irradiation surface into a linear or rectangular shape. And a stage that moves in at least one direction, wherein the optical system divides the laser beam in the length direction of the laser beam in the length direction of the laser beam, and the irradiation surface or the irradiation. A mirror that mixes near the surface to equalize the energy of the laser beam so that the shape on the irradiation surface becomes linear or rectangular; and the width of the laser beam in the width direction of the laser beam. A cylindrical array lens that divides the laser beam in the direction, and mixes the divided laser beam in the vicinity of the irradiation surface or the irradiation surface; A cylindrical lens for equalizing the energy of the laser beam whose shape is linear or rectangular, and wherein the mirror has a light path difference between the laser oscillator and the irradiation surface of the divided laser beam. A laser irradiating device for making the length of the laser beam longer than the coherent length of the laser beam. 7. The method according to claim 1, wherein
A laser irradiation apparatus, wherein a laser beam incident on the optical system is converted into parallel light by the optical system. 8. The method according to claim 1, wherein
A laser irradiation apparatus, wherein a laser beam incident on the optical system is converted into parallel light by a beam collimator. 9. The method according to claim 1, wherein:
A laser irradiation apparatus, wherein a laser beam incident on the optical system is converted into parallel light by two cylindrical lenses. 10. The laser irradiation apparatus according to claim 1, wherein the optical system 1 is composed of a combination of a plurality of mirrors. 11. The laser irradiation apparatus according to claim 2, wherein the mirror is a combination of a plurality of mirrors. 12. The stage according to claim 3, wherein the shape of the laser beam on the irradiation surface is linear or rectangular, and the stage moves in at least one direction. Is a right angle. 13. The laser irradiation apparatus according to claim 1, wherein the laser irradiation apparatus has a load / unload chamber, a robot arm, and a laser irradiation chamber. 14. A step of forming a semiconductor film on an insulating surface, a step of irradiating a surface of the semiconductor film with a laser beam, and forming a TFT having the semiconductor film irradiated with the laser beam as an active region. And a mirror that splits the laser beam so that each optical path difference from the laser oscillator to the semiconductor film is equal to or longer than the coherent length, and equalizes the energy of the laser beam. A method for manufacturing a semiconductor device, characterized by being processed by an optical system including: 15. A step of forming a semiconductor film on an insulating surface, a step of irradiating a laser beam having a linear or rectangular shape on an irradiation surface to a surface of the semiconductor film, and a step of irradiating the surface of the semiconductor film with the laser beam. T with semiconductor film as active region
Forming an FT, wherein the laser beam divides the laser beam so that each optical path difference from the laser oscillator to the semiconductor film has a coherent length or more, and reduces the energy of the laser beam. A method for manufacturing a semiconductor device, wherein a shape of the semiconductor film is processed into a linear shape or a rectangular shape by an optical system including a mirror for uniformization. 16. The method for manufacturing a semiconductor device according to claim 14, wherein the mirror comprises a combination of a plurality of mirrors. 17. The method for manufacturing a semiconductor device according to claim 14, wherein the semiconductor film is an amorphous semiconductor film or a crystalline semiconductor film. 18. The method for manufacturing a semiconductor device according to claim 14, wherein the semiconductor device is a liquid crystal display device or a light emitting device. 19. The semiconductor device according to claim 14, wherein the semiconductor device is a mobile phone, a video camera,
A method for manufacturing a semiconductor device, which is a digital camera, a projector, a goggle-type display, a personal computer, a DVD player, an electronic book, or a portable information terminal.