JP2003249460A - Laser irradiation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of prior art that once in a manufacturing process for a semiconductor device a semiconductor film is irradiated with a CW laser while being relatively scanned with the CW laser, some elongated crystal grains extending in a scanning direction are formed, and the semiconductor film formed as such has characteristics substantially similar to a single crystal in the scanning direction, but productivity and uniformity of laser annealing are bad to result in difficulty in mass production. <P>SOLUTION: A plurality of laser beams are formed into a linear beam respectively, and are brought into an adjacent arrangement and are overlapped to form a longer linear beam and hence improve productivity. The linear beams adjoining each other have a position relationship satisfying a predetermined limit equation to greatly improve the uniformity of laser annealing. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser beam irradiation method and a laser beam irradiation apparatus (a device including a laser oscillator and an optical system for guiding the laser beam output to an irradiation object) for performing the method. The present invention also relates to a method for manufacturing a semiconductor device, which includes crystallization, activation, heating, or the like of a semiconductor film by irradiation with laser light. Note that the semiconductor device mentioned here includes an electro-optical device such as a liquid crystal display device and a light-emitting device, and an electronic device including the electro-optical device as a component.

[0002]

2. Description of the Related Art In recent years, a technique for crystallizing an amorphous semiconductor film formed on an insulating substrate such as glass to form a semiconductor film having a crystalline structure (hereinafter referred to as a crystalline semiconductor film) has been widely studied. ing. As a crystallization method, a thermal annealing method using a furnace annealing furnace, a rapid thermal annealing method (RTA method), a laser annealing method, and the like are being studied. At the time of crystallization, any one of these methods or a combination of a plurality of methods may be used.

A crystalline semiconductor film has a much higher mobility than an amorphous semiconductor film. Therefore, a thin film transistor (hereinafter referred to as a TFT) is formed using this crystalline semiconductor film, and for example, a pixel portion, or a pixel portion and a driver circuit TFT is formed over one glass substrate. It is used for active matrix type liquid crystal display devices and the like.

Usually, in order to crystallize an amorphous semiconductor film in a furnace annealing furnace, heat treatment at 600 ° C. or higher for 10 hours or longer is required. The substrate material applicable to this crystallization is quartz, but the quartz substrate is expensive, and it is very difficult to process it particularly in a large area. Increasing the area of the substrate can be mentioned as one of the means for increasing the production efficiency, and this is the reason why research is conducted to form a semiconductor film on a glass substrate which is inexpensive and can be easily processed into a large area substrate. .
In recent years, the use of glass substrates having a side of more than 1 m has been considered.

As an example thereof, the thermal crystallization method using a metal element can lower the crystallization temperature which has been a problem in the past (see, for example, Patent Document 1).
The method involves adding a trace amount of an element such as nickel, palladium, or lead to the amorphous semiconductor film, and then adding 550
The crystalline semiconductor film can be formed by heat treatment at 4 ° C. for 4 hours. If the temperature is 550 ° C., the temperature is not higher than the strain point temperature of the glass substrate, so that the temperature is free from deformation.

On the other hand, since the laser annealing method can give high energy only to the semiconductor film without raising the temperature of the substrate so much, it is used not only for the glass substrate having a low strain point temperature but also for the plastic substrate and the like. This is a technology that is drawing attention because it can be used.

As an example of the laser annealing method, a pulsed laser beam typified by an excimer laser is shaped by an optical system so that a square spot of several cm square or a linear shape with a length of 100 mm or more is formed on the irradiation surface. In this method, annealing is performed by moving the irradiation position of the laser light relative to the irradiation target. Note that the term "linear" does not mean "line" in a strict sense, but means a rectangle (or a long ellipse or a shape that can be approximated thereto) having a large aspect ratio. For example, the aspect ratio is 2 or more (preferably 10 to 10000), but it is included in the laser light (rectangular beam) whose irradiation surface has a rectangular shape. Note that the linear shape is for ensuring energy density for performing sufficient annealing on the irradiation target, and sufficient annealing can be performed on the irradiation target even if it is rectangular or planar. It doesn't matter.

The crystalline semiconductor film thus produced is formed by aggregating a plurality of crystal grains, and the positions and sizes of the crystal grains are random. A TFT manufactured on a glass substrate is formed by separating a crystalline semiconductor into island-shaped patterning for element separation. In that case, it was not possible to form by specifying the position and size of the crystal grain. Compared with the inside of crystal grains, the interface (crystal grain boundary) of crystal grains has innumerable recombination centers and trap centers due to an amorphous structure and crystal defects. It is known that when carriers are trapped in the trap centers, the potential of the crystal grain boundary rises and becomes a barrier against the carriers, so that the current transport characteristics of the carriers are deteriorated.
Although the crystallinity of the semiconductor film in the channel formation region has a significant influence on the characteristics of the TFT, it is almost impossible to form the channel formation region with a single crystal semiconductor film by eliminating the influence of grain boundaries. It was

Recently, by continuously irradiating a semiconductor film with a continuous wave (CW) laser while scanning it in one direction, crystals grow in connection with the scanning direction and countless single crystal grains elongated in that direction are formed. Techniques have been reported (for example, see Non-Patent Document 1).

It is believed that this method can be used to form a TFT having almost no crystal grain boundaries at least in the channel direction of the TFT.

[0011]

[Patent Document 1] JP-A-7-183540

[Non-Patent Document 1] Hara, 5 others, “Ultra-high Perform
ance Poly-Si TFTs on a Glass by a Stable Scanning
CW Laser Lateral Crystallization ”, AMC L'01 (AMLCD '01), 2001, p.227-230.

[0012]

However, in the present method, the CW in the wavelength range sufficiently absorbed by the semiconductor film is used.
Because of the use of a laser, only a laser with an output as small as about 10 W can be applied, which is inferior to the technique using an excimer laser in terms of productivity. A CW laser suitable for this method has a high output, a wavelength of visible light or less, and a remarkably high output stability. For example, the second harmonic of a YVO ₄ laser or a YAG laser is used. The second harmonic, the second harmonic of a YLF laser, the second harmonic of a YAlO ₃ laser, an Ar laser, etc. are applicable. However, if the lasers listed above are applied to the crystallization of semiconductor films, it is necessary to make the spot size of the beam extremely small in order to compensate for the insufficient output. There's a problem. The present invention is
It is an object to overcome such a drawback.

[0013]

In the crystallization process of a semiconductor film by a CW laser, a laser beam is processed into an elongated shape on an irradiation surface in order to increase productivity even a little, and an elongated laser beam (hereinafter referred to as a linear shape) is used. (Hereinafter referred to as a beam), the semiconductor film is actively crystallized by scanning in the direction perpendicular to the longitudinal direction.

The shape of the elongated laser beam is greatly influenced by the shape of the laser beam emitted from the laser oscillator. For example, when the rod used in the solid-state laser has a round shape, the emitted laser beam also has a round shape, and when it is extended, it becomes an elliptical laser beam, or the rod used in the solid-state laser. Is a slab, the shape of the emitted laser beam is rectangular, and when it is extended, it becomes a rectangular laser beam. However, in the case of the slab laser, since the divergence angle differs between the major axis direction and the minor axis direction of the beam, it should be noted that the shape of the beam greatly differs depending on the distance from the laser oscillator. In the present invention, those beams are generically called linear beams. Further, in the present invention, the linear beam refers to a beam whose length in the longitudinal direction is 10 times or more the length in the lateral direction. Further, in the present invention, when the maximum energy density of the linear beam is 1, the range having energy of e ⁻² or more is defined as the linear beam. Further, in the present specification, the length of the linear beam is expressed as a major axis and the width thereof is expressed as a minor axis.

According to the present invention, a plurality of lasers each having a small output are used, each laser beam is shaped into a linear beam, and then the laser beams are combined to form a longer linear beam. Improve the uniformity of laser annealing. Further, the present invention provides a laser irradiation apparatus and an irradiation method with which the degree of synthesis is quantified and the uniformity of laser annealing is higher, and a method for manufacturing a semiconductor device. The present invention will be listed below.

The configuration relating to the laser irradiation method disclosed in the present invention is such that when a plurality of laser beams emitted from a plurality of laser oscillators have a round shape, the plurality of laser beams are stretched to have a long diameter e ^-2 width. Is a, a short-diameter e- ² is processed into a linear beam of width b, the ends in the major axis direction of each other are overlapped, and when forming a longer linear beam, lasers that overlap each other among a plurality of laser beams When the center coordinates of the beam are (x, y) and (x ', y'), respectively, if the major axis and the x-axis are set in parallel, and the minor axis and the y-axis are set in parallel, then (( The laser irradiation method is characterized by satisfying xx ′) / a) ² + ((y−y ′) / b) ² <(R) ² . The above R is 0.72, preferably 0.63. Outside the range of the above inequality, a region where elongated single crystal grains are not formed is formed between the adjacent (overlapping) linear beams, so that the region of the semiconductor film having high characteristics is not continuously connected and the beam is not emitted. The meaning of becoming one becomes thin.

According to another configuration of the invention relating to the laser irradiation method disclosed in the present invention, when the plurality of laser beams emitted from the plurality of laser oscillators have a rectangular shape, the plurality of laser beams are stretched to have a long diameter. e ^-2 width
a, a short-diameter e- ² is processed into a linear beam with a width of b, the ends in the major axis direction are overlapped with each other, and when forming a longer linear beam, laser beams that overlap each other among a plurality of laser beams When the center coordinates of (x, y) and (x ', y') are defined, the major axis and the x-axis are set in parallel, and the minor axis and y
The laser irradiation method is characterized by satisfying | y−y ′ | / b <R and | xx−x ′ | <a when the axes are set in parallel. The above R is 0.72, preferably 0.63. The above inequality can be applied to a linear beam having a Gaussian energy distribution in the minor axis direction and a uniform energy distribution in the major axis direction. Outside the range of the above inequality, a region where elongated single crystal grains are not formed is formed between the adjacent (overlapping) linear beams, so that the region of the semiconductor film having high characteristics is not continuously connected and the beam is not emitted. The meaning of becoming one becomes thin.

According to another configuration of the invention relating to the laser irradiation method disclosed in the present invention, when the laser beams emitted from the laser oscillators have a rectangular shape, the laser beams are stretched to have a long diameter. e ^-2 width
a, a short-diameter e- ² is processed into a linear beam with a width of b, the ends in the major axis direction are overlapped with each other, and when forming a longer linear beam, laser beams that overlap each other among a plurality of laser beams When the center coordinates of (x, y) and (x ', y') are defined, the major axis and the x-axis are set in parallel, and the minor axis and y
The laser irradiation method is characterized by satisfying | x−x ′ | / a <R and | y−y ′ | <b when the axes are arranged in parallel. The above R is 0.72, preferably 0.63. The above inequality can be applied to a linear beam having a Gaussian energy distribution in the major axis direction and a uniform energy distribution in the minor axis direction. Outside the range of the above inequality, a region where elongated single crystal grains are not formed is formed between the adjacent (overlapping) linear beams, so that the region of the semiconductor film having high characteristics is not continuously connected and the beam is not emitted. The meaning of becoming one becomes thin.

According to another configuration of the invention relating to the laser irradiation method disclosed in the present invention, when a plurality of laser beams emitted from a plurality of laser oscillators have a rectangular shape, the plurality of laser beams are stretched to have a long diameter. e ^-2 width a, e ^-2 width of minor axis is processed into a linear beam of b, overlapping the major axis direction of the end portion of each other, when forming a longer linear beam, a plurality of laser beams When the central coordinates of the laser beams that overlap each other are (x, y) and (x ', y'), respectively, the major axis and the x-axis are parallel, and the minor axis and the y-axis are parallel. And a laser irradiation method satisfying | x−x ′ | / a <R and | y−y ′ | / b <R. The above R is 0.72, preferably 0.63. The above inequality can be applied to a linear beam having a Gaussian energy distribution in the minor axis direction and a Gaussian energy distribution in the major axis direction. Outside the range of the above inequality, a region where elongated single crystal grains are not formed is formed between the adjacent (overlapping) linear beams, so that the region of the semiconductor film having high characteristics is not continuously connected and the beam is not emitted. The meaning of becoming one becomes thin.

Another configuration of the invention relating to the laser irradiation method disclosed in the present invention is to stretch a plurality of laser beams when the plurality of laser beams emitted from a plurality of laser oscillators have a round shape or a rectangular shape. Long axis e ^-2
When a linear beam having a width of a and a short diameter of e ^{−2 and a} width of b is processed and the ends in the major axis direction are overlapped with each other to form a longer linear beam, a plurality of laser beams are overlapped with each other. The center coordinates of the laser beam are (x, y), (x ',
y '), if the major axis and the x-axis are parallel to each other and the minor axis and the y-axis are parallel to each other, ((x-x') / a) ² + ((y-y ' ) / B) ² <(R) ² laser irradiation method. The above R is 0.72, preferably 0.63. Outside the range of the above inequality, a region where elongated single crystal grains are not formed is formed between the adjacent (overlapping) linear beams, so that the region of the semiconductor film having high characteristics is not continuously connected and the beam is not emitted. The meaning of becoming one becomes thin.

In the above invention, it is preferable that 0.52 <| xx- | 'a is satisfied because the linear beam can be made longer and the productivity is increased.

In the above invention, if b <[50 μm] is satisfied, the linear beam can be made longer, which is preferable because the productivity is increased.

In the structure of the above invention, the laser is a continuous wave gas laser, a solid-state laser or a metal laser. As the gas laser, there are Ar laser, Kr laser, CO ₂ laser, etc., and as the solid-state laser, YAG laser, YVO ₄ laser, YLF laser,
There are YAlO ₃ lasers, Y ₂ O ₃ lasers, glass lasers, ruby lasers, alexandrite lasers, Ti: sapphire lasers, and the like. Examples of metal lasers include helium cadmium laser, copper vapor laser, gold vapor laser, and the like. The excimer laser is usually pulsed, but there is also a theory that continuous oscillation is possible in principle. If such a thing is possible, a continuous wave excimer laser can be applied to the present invention.

Further, in the structure of the above invention, the laser beam is converted into a harmonic by a non-linear optical element. Crystals used for nonlinear optical elements are, for example, LBO, BBO, KDP, KTP, KB5, CLB.
The one called O is excellent in terms of conversion efficiency.
By putting these non-linear optical elements in the resonator of the laser, the conversion efficiency can be greatly increased.

Further, in the above-mentioned constitution of the invention, it is preferable that the laser beam is oscillated by TEM ₀₀ because the energy uniformity of the obtained long beam can be improved.

The configuration of the invention relating to the laser irradiation apparatus disclosed in the present invention comprises a plurality of laser oscillators, and means for stretching a plurality of laser beams emitted from the plurality of laser oscillators and having a round spot shape. And a means for forming a linear beam on the irradiation surface or in the vicinity thereof by superimposing a plurality of stretched laser beams on each other in the major axis direction, and the plurality of stretched laser beams. The major axis e ^-2 width on each irradiation surface of the beam is a, the minor axis e ^-2 width is b, and the major axis and x
Taking the coordinates parallel to the axes and the coordinates parallel to the minor axis and the y-axis, the central coordinates of the overlapping laser beams among the plurality of stretched laser beams are respectively (x,
y) and (x ', y'), a laser irradiation device characterized by satisfying ((x-x ') / a) ² + ((y-y') / b) ² <R ² is there. The above R is 0.72, preferably 0.63. Outside the range of the above inequality, a region where elongated single crystal grains are not formed is formed between the adjacent (overlapping) linear beams, so that the region of the semiconductor film having high characteristics is not continuously connected and the beam is not emitted. The meaning of becoming one becomes thin.

Another configuration of the invention relating to the laser irradiation apparatus disclosed in the present invention is to expand a plurality of laser oscillators and a plurality of laser beams emitted from the plurality of laser oscillators and having a rectangular spot shape. A laser irradiation device comprising: a means, and a means for forming a linear beam on an irradiation surface or in the vicinity thereof by superimposing the ends of the plurality of stretched laser beams on each other in the major axis direction,
The major axis of the e ^-2 width of each of the irradiated surface of the stretched plurality of laser beams a, the e ^-2 width of minor and is b, taken parallel to coordinate the major axis and the x-axis, the minor axis and y-axis Are parallel to each other, when the central coordinates of the laser beams that overlap each other among the plurality of stretched laser beams are (x, y) and (x ′, y ′), respectively, | y−y ′ | / b <R and | xx ′ | <a is satisfied, which is a laser irradiation apparatus. The above R is 0.72, preferably 0.63. Outside the range of the above inequality, a region where elongated single crystal grains are not formed is formed between the adjacent (overlapping) linear beams, so that the region of the semiconductor film having high characteristics is not continuously connected and the beam is not emitted. The meaning of becoming one becomes thin.

Another configuration of the invention relating to the laser irradiation apparatus disclosed in the present invention is to expand a plurality of laser oscillators and a plurality of laser beams emitted from the plurality of laser oscillators and having a rectangular spot shape. A laser irradiation device comprising: a means, and a means for forming a linear beam on an irradiation surface or in the vicinity thereof by superimposing the ends of the plurality of stretched laser beams on each other in the major axis direction,
The major axis of the e ^-2 width of each of the irradiated surface of the stretched plurality of laser beams a, the e ^-2 width of minor and is b, taken parallel to coordinate the major axis and the x-axis, the minor axis and y-axis Are parallel to each other, the center coordinates of the laser beams that overlap each other among the plurality of stretched laser beams are (x, y) and (x ′, y ′), respectively, | x−x ′ | / a <R and | y−y ′ | <b. The above R is 0.72, preferably 0.63. Outside the range of the above inequality, a region where elongated single crystal grains are not formed is formed between the adjacent (overlapping) linear beams, so that the region of the semiconductor film having high characteristics is not continuously connected and the beam is not emitted. The meaning of becoming one becomes thin.

Another configuration of the invention relating to the laser irradiation apparatus disclosed in the present invention is to extend a plurality of laser oscillators and a plurality of laser beams emitted from the plurality of laser oscillators and having a rectangular spot shape. A laser irradiation device having a means and a means for forming a linear beam on the irradiation surface or in the vicinity thereof by overlapping the ends of the plurality of stretched laser beams in the major axis direction of each other,
The major axis e ^-2 width is a and the minor axis e ^-2 width is b, and the major axis and the x axis are parallel to each other on the irradiation surface of each of the stretched laser beams. Are parallel to each other, when the central coordinates of the laser beams that overlap each other among the stretched laser beams are (x, y) and (x ′, y ′), respectively, | x−x ′ | / a <R, and | y−y ′ | / b <R is satisfied. The above R is 0.72, preferably 0.63. Outside the range of the above inequality, a region where elongated single crystal grains are not formed is formed between the adjacent (overlapping) linear beams, so that the region of the semiconductor film having high characteristics is not continuously connected and the beam is not emitted. The meaning of becoming one becomes thin.

Another structure of the invention relating to the laser irradiation apparatus disclosed in the present invention is a plurality of laser oscillators, and a cross section which is emitted from the plurality of laser oscillators and which is perpendicular to the traveling direction is circular or rectangular. A means for stretching a plurality of laser beams, and a means for forming a linear beam on the irradiation surface or in the vicinity thereof by overlapping the ends of the plurality of stretched laser beams with each other in the major axis direction, and a plurality of stretched laser beams. The major axis e ^-2 width on each irradiation surface of the laser beam is a, and the minor axis e ^-2 width is b, and the major axis and the x-axis are parallel to each other, and the minor axis and the y-axis are parallel to each other. If the center coordinates of the laser beams that overlap each other among the plurality of stretched laser beams are (x, y) and (x ′, y ′), respectively, ((x−x ′) / a) ² + ( (Yy ') / ) ² <is a laser irradiation apparatus and satisfies the R ^2. The above R is 0.72, preferably 0.63. Outside the range of the above inequality, a region where elongated single crystal grains are not formed is formed between the adjacent (overlapping) linear beams, so that the region of the semiconductor film having high characteristics is not continuously connected and the beam is not emitted. The meaning of becoming one becomes thin.

Further, in the structure of the invention relating to the method for manufacturing a semiconductor device disclosed in the present invention, a plurality of laser beams are processed into a plurality of linear beams on or near the semiconductor film and emitted from a plurality of laser oscillators. When the shape of the multiple laser beams is circular, the multiple laser beams have a major axis e ^-2 width on or near the semiconductor film.
a, a short-diameter e- ² is processed into a linear beam with a width of b, the ends in the major axis direction are overlapped with each other, and when forming a longer linear beam, laser beams that overlap each other among a plurality of laser beams When the center coordinates of (x, y) and (x ', y') are defined, the major axis and the x-axis are set in parallel, and the minor axis and y
When the coordinates are set in parallel with each other, the method is a method for manufacturing a semiconductor device satisfying ((x−x ′) / a) ² + ((y−y ′) / b) ² <(R) ² To do. The above R is 0.72, preferably 0.63.
Outside the range of the above inequality, a region where elongated single crystal grains are not formed is formed between the adjacent (overlapping) linear beams, so that the region of the semiconductor film having high characteristics is not continuously connected and the beam is not emitted. The meaning of becoming one becomes thin.

Another structure of the invention relating to the method for manufacturing a semiconductor device disclosed in the present invention is to process a plurality of laser beams into a plurality of linear beams on or near a semiconductor film,
When the shape of the plurality of laser beams emitted from the plurality of laser oscillators is rectangular, the plurality of laser beams on the semiconductor film or in the vicinity thereof has a major axis e ^-2 width a,
When the e ^-2 width of the minor axis is processed into a linear beam of b, and the ends in the major axis direction of each other are overlapped to form a longer linear beam,
When the center coordinates of the laser beams that overlap each other among the plurality of laser beams are (x, y) and (x ′, y ′), respectively, the major axis and the x axis are aligned in parallel, and the minor axis and the y axis are When the coordinates are extended in parallel, it is a method of manufacturing a semiconductor device that satisfies | y−y ′ | / b <R and | x−x ′ | <a. The above R is 0.72, preferably 0.63.
Outside the range of the above inequality, a region where elongated single crystal grains are not formed is formed between the adjacent (overlapping) linear beams, so that the region of the semiconductor film having high characteristics is not continuously connected and the beam is not emitted. The meaning of becoming one becomes thin.

Another structure of the invention relating to the method for manufacturing a semiconductor device disclosed in the present invention is to process a plurality of laser beams into a plurality of linear beams on or near a semiconductor film,
When the shape of the plurality of laser beams emitted from the plurality of laser oscillators is rectangular, the plurality of laser beams on the semiconductor film or in the vicinity thereof has a major axis e ^-2 width a,
When the e ^-2 width of the minor axis is processed into a linear beam of b, and the ends in the major axis direction of each other are overlapped to form a longer linear beam,
When the center coordinates of laser beams that overlap each other among a plurality of laser beams are (x, y) and (x ′, y ′), respectively, the major axis and the x axis are aligned in parallel, and the minor axis and the y axis are defined as When the coordinates are extended in parallel, it is a method of manufacturing a semiconductor device which satisfies | x−x ′ | / a <R and | y−y ′ | <b. The above R is 0.72, preferably 0.63.
Outside the range of the above inequality, a region where elongated single crystal grains are not formed is formed between the adjacent (overlapping) linear beams, so that the region of the semiconductor film having high characteristics is not continuously connected and the beam is not emitted. The meaning of becoming one becomes thin.

Another structure of the invention relating to the method for manufacturing a semiconductor device disclosed in the present invention is to process a plurality of laser beams into a plurality of linear beams on or near a semiconductor film,
In the case where the shape of the plurality of laser beams emitted from a plurality of laser oscillators are rectangular, the long diameter of e ^-2 width a plurality of laser beams at the semiconductor film on or in the vicinity thereof is a, the short diameter e ^-2 When the linear beams having a width b are processed, the ends in the major axis direction are overlapped with each other, and a longer linear beam is formed, the central coordinates of the laser beams that overlap each other among the plurality of laser beams are respectively (x, y), (x ', y'), when the major axis and the x-axis are parallel to each other and the minor axis and the y-axis are parallel to each other, | x-x '| / a <R, In addition, the method is a method for manufacturing a semiconductor device satisfying | y−y ′ | / b <R. The above R is 0.72, preferably 0.63.
Outside the range of the above inequality, a region where elongated single crystal grains are not formed is formed between the adjacent (overlapping) linear beams, so that the region of the semiconductor film having high characteristics is not continuously connected and the beam is not emitted. The meaning of becoming one becomes thin.

In the method for manufacturing a semiconductor device disclosed in the present invention,
Another structure of the invention relates to a semiconductor device comprising a plurality of laser beams.
Process into multiple linear beams on or near the film,
Multiple laser beams emitted from multiple laser oscillators
If the shape of the circle is round or rectangular,
The beam with a long diameter e on or near the semiconductor film ^-2
Width is a and minor axis is e^-2Processed into linear beams of width b,
The longer ends of the above are overlapped to form a longer linear beam.
In shaping, laser beams that overlap each other among multiple laser beams are formed.
The center coordinates of the beam are (x, y), (x ',
y '), set the major axis and the x-axis in parallel,
If the coordinates are set in parallel with the minor axis and the y-axis, ((Xx-') / a)²+ ((Y-y ') / b)²<(R)² A method for manufacturing a semiconductor device that satisfies the above
It The above R is 0.72, preferably 0.63.
Outside the range of the above inequality, adjacent (overlapping) linear
Between the beams, there are areas where elongated single crystal grains are not formed.
Therefore, the regions of the semiconductor film with high characteristics can be connected continuously.
The meaning of having only one beam is diminished.

In the above invention, if 0.52 <| xx−x ′ | / a is satisfied, the linear beam can be made longer, which is preferable because the productivity is increased.

In the structure of the above invention, the laser is a continuous wave gas laser, solid-state laser or metal laser. As the gas laser, there are Ar laser, Kr laser, CO ₂ laser, etc., and as the solid-state laser, YAG laser, YVO ₄ laser, YLF laser,
There are YAlO ₃ lasers, glass lasers, ruby lasers, alexandrite lasers, Ti: sapphire lasers, and the like, and examples of metal lasers include helium cadmium laser, copper vapor laser, gold vapor laser, and the like. The excimer laser is usually pulsed, but there is also a theory that continuous oscillation is possible in principle. If you can do that,
A continuous wave excimer laser can be applied to the present invention.

Further, in the structure of the above invention, the laser beam is converted into a harmonic by a non-linear optical element. Crystals used for nonlinear optical elements are, for example, LBO, BBO, KDP, KTP, KB5, CLB.
The one called O is excellent in terms of conversion efficiency.
By putting these non-linear optical elements in the resonator of the laser, the conversion efficiency can be greatly increased.

Further, in the above-mentioned constitution of the invention, it is preferable that the laser beam is oscillated by TEM ₀₀ because the energy uniformity of the obtained long beam can be improved.

In this specification, the energy distribution having a Gaussian shape means that the energy profile of the laser beam on the irradiation surface has a Gaussian distribution or a shape corresponding thereto.

Irradiating the semiconductor film with a plurality of laser beams satisfying the above-described formula of the present invention enables more uniform laser annealing. Further, the present invention is particularly suitable for crystallization of a semiconductor film, improvement of crystallinity, and activation of an impurity element. Further, since a plurality of linear beams are combined with each other, it is possible to improve throughput. In a semiconductor device represented by an active matrix type liquid crystal display device utilizing the present invention, it is possible to improve the operating characteristics and reliability of the semiconductor device.
Furthermore, since a solid-state laser can be used instead of a gas laser used in the conventional laser annealing method, the manufacturing cost of the semiconductor device can be reduced.

[0042]

BEST MODE FOR CARRYING OUT THE INVENTION (Embodiment 1) This embodiment will be described with reference to FIGS. 1 to 4, 6 and 7. In this embodiment, a condition for uniformly laser annealing a semiconductor film when a plurality of linear beams are overlapped with each other to form a longer linear beam is derived.

First, the laser output conditions for uniformly irradiating the semiconductor film were calculated. In FIG. 4, the LD excitation type 10
A W laser oscillator 100 (Nd: YVO ₄ laser, CW, second harmonic) is prepared. The laser oscillator is in TEM ₀₀ oscillation mode, and the LBO crystal is built in the resonator.
Has been converted to harmonics. The beam diameter is 2.25 mm. The divergence angle is about 0.3 mrad. The 45 [deg.] Reflection mirror converts the traveling direction of the laser beam to a downward direction inclined by 20 [deg.] From the vertical direction. Next, in order to set the major axis of the linear beam 103 to about 250 μm and the minor axis to about 40 μm on the surface 104 of the semiconductor film arranged on the horizontal plane, the laser beam is directed to the plano-convex lens 102 having a focal length of 20 mm at an angle of 20 °. To make it incident. At this time, the plano-convex lens 1
The plane of 02 is aligned with the horizontal plane. In this way, the beam that has been elongated due to astigmatism will be reflected by the semiconductor film 104.
Formed on. From the plano-convex lens 102 to the semiconductor film 104
The distance between and was adjusted at a pitch of 100 μm. By this adjustment, a long linear beam 103 was formed in the direction of the line of intersection between the incident surface and the semiconductor film 104. The positional relationship between the lens and the semiconductor film described above is based on the horizontal plane, the vertical direction, etc. for the sake of clarity, but it goes without saying that the present invention can be implemented without any problem if the relative positions are the same.

The semiconductor film 104 is formed on the substrate. Specifically, a silicon oxide film having a thickness of about 200 nm was formed on a glass substrate, and an a-Si film having a thickness of 150 nm was further formed thereon. After that, heat treatment was performed for 1 hour in a nitrogen atmosphere at 500 ° C. in order to increase laser resistance of the semiconductor film.

In FIG. 3, the linear beam 103 is applied to the semiconductor film 10.
4 shows the relationship between the change in the semiconductor film and the laser output when the semiconductor film is annealed by scanning in the minor axis direction. The horizontal axis of the figure shows the major axis direction of the beam, and the vertical axis shows the output of the laser oscillator. The curve showing the Gaussian distribution in the figure shows the energy distribution in the major axis direction of the linear beam. The scanning speed was fixed at 50 cm / s, the laser output was changed from 3.2 W to 6.2 W, and the change in the semiconductor film was observed. When the laser output was 3.2 W or less, the long single crystal grains described above were not formed at all. Laser power is 3.7
At W, a number of long single crystal grains were formed over a width of about 40 μm. A region filled with long single crystal grains will be referred to as a large grain crystal formation region. Similarly, as the laser output was increased to 5.2 W and 6.2 W, the width increased and became 100 μm and 120 μm. When the laser output was raised to 6.2 W, the semiconductor film flew at the center of the laser beam with the highest laser output. The width of the region where the semiconductor film flew was about 20 μm. From the above results, it is possible to identify the range of the laser output in which the large grain crystal forming region is formed in FIG. That is, a horizontally long line A in the center of FIG. 3 represents the threshold value of laser output that forms a large grain crystal forming region, and a horizontally long line B above it indicates the laser output that the semiconductor film flies and becomes unusable. Indicates a threshold.

From the results of this experiment, it can be seen that if the maximum value of the energy in the energy distribution of the cross section of the linear beam in the minor axis direction is between the line A and the line B, the linear beam is formed. That is, it is possible to obtain a large grain crystal forming region that uniformly spreads in the major axis direction of the linear beam. If there is an energy distribution exceeding the line B in the major axis direction of the linear beam, the semiconductor film will be skipped and uniform laser annealing cannot be performed. Further, in the major axis direction of the linear beam, if the energy distribution below the line A is at a position that divides the major axis direction of the linear beam, a microcrystalline region or crystallized between the two large grain crystal forming regions. Again, this does not allow for uniform laser annealing, as there are no amorphous regions.

To combine a plurality of linear beams to form a longer linear beam and perform uniform laser annealing, the energy distributions of the combined linear beams should be line A and line B.
Must be in between. Expressed numerically, ±
If the energy distribution is within 25%, there is a laser output capable of performing uniform laser annealing. This will be described with reference to FIGS. 1 and 2.

FIG. 1 shows a state in which two linear beams are adjacent to each other and overlap each other. The energy distribution of the cross section AA 'at the center of the linear beam 1 is shown in 1) of FIG. The energy distribution of the cross section BB 'in the middle of the linear beams 1 and 2 is shown in 2) of FIG. If the maximum energies in each cross section are E1 and E2, | E1-E2 | / | E1 + E2 | ≦ 0.25 ... 1), it means that uniform laser annealing can be performed. However, under such conditions, the energy margin is very small, so from a safety point of view, if | E1-E2 | / | E1 + E2 | ≦ 0.10 ... It becomes possible to perform annealing.

FIG. 6 shows the result of calculation as to what is the distance between the centers of two linear beams adjacent to each other so as to obtain the condition satisfying the formula 1) or the formula 2). The graph shown in FIG. 6 shows the difference between the energies E1 and E2 when the offset amount is 0 in FIG. That is, the vertical axis is | E1-E2 | / | E1 + E2 | × 100 (%). From the graph of FIG. 6, it can be said that the center-to-center distance of the two linear beams satisfying the formula 1) is within 0.72, and that the formula 2) satisfies is within 0.63. Become.

FIG. 7 shows the relationship between the offset amount and the distance between the two beam centers. If the relationship between the two beams is within the range within the circle in the figure, the difference between energies E1 and E2 is ± 1.
It falls within 0%. Similarly, if a circle with a radius of 0.72 is drawn in FIG. 7, the difference between the energies E1 and E2 is within ± 25% if the relationship between the two beams is within the range of the circle. The inequalities indicating the ranges are described in [Means for Solving the Problems]. When the inequality is described again, ((x−x ′) / a) ² + ((y−y ′) / b) ² <(R) ² is obtained. However, R is 0.63 or 0.72.

Here, the distance is standardized by the e ⁻² width of the major axis of the linear beam. Further, when the center-to-center distance is 0.52 or less, the energy difference between E1 and E2 becomes 0, and it is irrational to bring the two beams closer to each other because the length of the linear beam is only shortened. Therefore, the center-to-center distance is preferably 0.52 or more.

Irradiating the semiconductor film with a plurality of linear beams satisfying the above-described formula of the present invention enables more uniform laser annealing. Further, the present invention is particularly suitable for crystallization of a semiconductor film, improvement of crystallinity, and activation of an impurity element. Further, by combining a part of the plurality of linear beams with each other and optimizing them, it is possible to form a uniform laser beam in the major axis direction, so that it is possible to improve the throughput. Then, by crystallizing using the highly uniform laser beam, a highly uniform crystalline semiconductor film can be formed and variation in electrical characteristics of the TFT can be reduced. Further, in a semiconductor device represented by an active matrix type liquid crystal display device using the present invention, it is possible to realize improvement in operating characteristics and reliability of the semiconductor device. In addition, unlike the conventional laser annealing method, a solid-state laser can be used instead of a gas laser, so that the manufacturing cost of a semiconductor device can be reduced.

(Embodiment 2) This embodiment shows an example in which four lasers are combined to form a longer linear beam. An example of laser annealing a semiconductor film using the apparatus will be shown.

First, a method of forming a long linear beam using four laser oscillators will be described with reference to FIG. Cylindrical lenses 201 and 202 are plano-convex cylindrical lenses having a focal length of 20 mm, arranged so that their generatrices are parallel to each other, and symmetrical with respect to a plane perpendicular to the plane 200 including the major axis of the linear beam in the plane 200 on which the linear beam is formed. Deploy. The surface with the curvature of the cylindrical lens faces upward. At this time, the busbar is parallel to the major axis. The cylindrical lenses 201 and 202 are arranged at an angle of 25 ° with respect to the surface 200. The reason why the cylindrical lens is tilted in this way is to form four linear beams, which are very small as compared with the optical element, on the irradiation surface 200.

The optical axis A and the optical axis B are arranged on a plane which is perpendicular to the plane portion of the cylindrical lens 201 and includes the major axis of the linear beam.
Plano-convex cylindrical lenses 203 and 205 having a focal length of 150 mm are arranged so as to include and. The angle between the optical axis A and the major axis is 80 °, and the angle between the optical axis B and the major axis is 8
0 °, the plane part of the cylindrical lens 203 and the optical axis
A is made vertical, and the plane part of the cylindrical lens 205 and the optical axis B are made vertical. In addition, the cylindrical lens 20
The optical path length of the laser beam emitted from 3, 205 to the irradiation surface 200 may be about 120 mm. Further, at this time, the generatrixes of the cylindrical lenses 203 and 205 are arranged so that the major axis direction of the linear beam is vertical.

The cylindrical lenses 206 and 204 are arranged in plane symmetry with respect to the cylindrical lenses 205 and 203, and their focal lengths are 150 mm.
The plane is a plane that includes the major axis of the linear beam and is perpendicular to the plane 200. When four laser beams passing through the optical axes A, B, C and D are made incident on such an optical system, a linear beam 207 shown in an enlarged view in FIG. 5 can be formed. The degree of overlap of these linear beams is combined according to the mathematical formula shown in the first embodiment.

Next, an example of a method for manufacturing a semiconductor film will be described. The semiconductor film is formed on the glass substrate. For example, 0.7m thick
A 200-nm-thick silicon oxynitride film is formed on one surface of a glass substrate having a thickness of m, and a 150-nm-thick a-Si film is formed thereon by a plasma CVD method. Further, in order to increase the resistance of the semiconductor film to laser, thermal annealing was performed on the semiconductor film at 500 ° C. for 1 hour. Besides thermal annealing,
The semiconductor film may be crystallized with the metal element described in the section of the prior art. Regardless of which film is used, the optimum laser beam irradiation conditions are almost the same.

Next, an example of laser irradiation of the semiconductor film will be shown. The maximum output of each of the four laser oscillators (not shown) is about 10 W. These are adjusted to an output suitable for laser annealing. It is preferably about 3 W to 10 W, and the optimum output changes depending on the scanning speed of the semiconductor film. The surface of the semiconductor film is placed on the surface 200, placed on an appropriate stage, and scanned in a direction perpendicular to the major axis of the linear beam 207. Here, output 5W,
If the scanning speed is about 50 cm / s, the width is 1-2 mm.
A large grain size crystal forming region can be formed. When the surface area of the semiconductor film is large, by forming large grain crystal forming regions having a width of 1 to 2 mm in parallel, the entire surface of the semiconductor film can be a large grain crystal forming region.

As described above, a more uniform laser annealing can be performed by synthesizing a plurality of laser beams according to the mathematical formula shown in the first embodiment and irradiating the semiconductor film with the laser beams formed by the synthesis. Further, the present invention is particularly suitable for crystallization of a semiconductor film, improvement of crystallinity, and activation of an impurity element. Further, by combining a part of the plurality of linear beams with each other and optimizing them, it is possible to form a uniform laser beam in the major axis direction, so that it is possible to improve the throughput. Then, by crystallizing using the highly uniform laser beam, a highly uniform crystalline semiconductor film can be formed and variation in electrical characteristics of the TFT can be reduced. Further, in a semiconductor device typified by an active matrix type liquid crystal display device manufactured by utilizing the present invention, it is possible to improve the operating characteristics and reliability of the semiconductor device. In addition, unlike the conventional laser annealing method, a solid-state laser can be used instead of a gas laser, so that the manufacturing cost of a semiconductor device can be reduced.

[0060]

[Embodiment 1] In this embodiment, a method for manufacturing an active matrix substrate will be described with reference to FIGS. In this specification, a substrate in which a pixel portion including a CMOS circuit and a driver circuit, a pixel TFT, and a storage capacitor is formed over one substrate is referred to as an active matrix substrate for convenience.

First, in this embodiment, a substrate 400 made of glass such as barium borosilicate glass or aluminoborosilicate glass is used. Note that as the substrate 400, a quartz substrate, a silicon substrate, a metal substrate, or a stainless substrate on which an insulating film is formed may be used.
Further, a plastic substrate having heat resistance that can withstand the processing temperature of this embodiment may be used, or a flexible substrate may be used. Since the present invention can easily form a linear beam having the same energy distribution, it is possible to efficiently anneal a large area substrate with a plurality of linear beams.

Then, a base film 401 made of an insulating film such as a silicon oxide film, a silicon nitride film or a silicon oxynitride film is formed on the substrate 400 by a known method. Although a two-layer structure is used as the base film 401 in this embodiment, a single layer film of an insulating film or a structure in which two or more layers are stacked may be used.

Next, a semiconductor film is formed on the base film.
The semiconductor film is formed by known means (sputtering method, LPCVD method, or
25 to 200 nm (preferably by plasma CVD method)
A semiconductor film is formed with a thickness of 30 to 150 nm)
Then, it is crystallized by the laser crystallization method. Laser crystallization
The method is the method according to the first embodiment or the second embodiment, or these
Irradiate the semiconductor film with laser light by combining the embodiments.
It The laser used is a continuous wave solid-state laser or gas.
Lasers or metal lasers are preferred. In addition, solid-state laser
As a continuous wave YAG laser, YVO_FourLaser, Y
LF laser, YAlO₃Laser, glass laser, ruby
Laser, Alexandride laser, Ti: Sapphire
There are lasers and the like, and gas lasers include Ar laser and Kr.
Laser, CO ₂There are lasers, etc.
Continuous oscillation helium cadmium laser, copper vapor laser, gold
A vapor laser or the like can be used. If it can be put to practical use, it will continuously fire
A swing excimer laser can also be applied to the present invention. of course,
Not only the laser crystallization method but also other known crystallization methods (RT
Thermal crystallization method using A or furnace annealing furnace, crystallization
Combined with a thermal crystallization method that uses a metal element that promotes
You may let me go. As the semiconductor film, an amorphous semiconductor film
, Microcrystalline semiconductor film, crystalline semiconductor film, etc.
Silicon germanium film, amorphous silicon carbide film, etc.
The compound semiconductor film having the amorphous structure of
Yes.

In this embodiment, the plasma CVD method is used,
A 50 nm amorphous silicon film is formed, and a thermal crystallization method and a laser crystallization method using a metal element that promotes crystallization are performed on the amorphous silicon film. Using nickel as the metal element,
After being introduced onto the amorphous silicon film by a solution coating method, 550
A first crystalline silicon film is obtained by performing heat treatment at 5 ° C. for 5 hours. Then, after converting the laser light emitted from the continuous oscillation YVO ₄ laser with an output of 10 W into the second harmonic by the non-linear optical element, laser annealing is performed according to the first embodiment to obtain the second crystalline silicon film. . By irradiating the first crystalline silicon film with laser light to form the second crystalline silicon film, the crystallinity is improved. The energy density at this time is about 0.01 to 100 MW / cm ² (preferably 0.1.
1 to 10 MW / cm ² ) is required. And 0.5
The stage is moved relative to the laser beam at a speed of about 2000 cm / s for irradiation to form a second crystalline silicon film.

Of course, using the first crystalline silicon film, T
Although an FT can be manufactured, the crystallinity of the second crystalline silicon film is improved, which is preferable because the electrical characteristics of the TFT are improved.

The crystalline semiconductor film thus obtained is subjected to a patterning process using a photolithography method to form semiconductor layers 402 to 406.

After forming the semiconductor layers 402 to 406, a slight amount of impurity element (boron or phosphorus) may be doped to control the threshold value of the TFT.

Next, a gate insulating film 407 which covers the semiconductor layers 402 to 406 is formed. The gate insulating film 407 is formed by a plasma CVD method or a sputtering method and has a thickness of 40 to
It is formed of an insulating film containing silicon with a thickness of 150 nm. In this embodiment, a silicon oxynitride film is formed with a thickness of 110 nm by a plasma CVD method. Of course, the gate insulating film is not limited to the silicon oxynitride film, and other insulating films may be used as a single layer or a laminated structure.

Next, a film thickness of 20 is formed on the gate insulating film 407.
A first conductive film 408 having a thickness of 100 nm and a thickness of 100 to 4
A second conductive film 409 having a thickness of 00 nm is stacked. In this embodiment, a first conductive film 408 made of a TaN film having a thickness of 30 nm and a second conductive film 409 made of a W film having a thickness of 370 nm are stacked. The TaN film is formed by a sputtering method and is sputtered in an atmosphere containing nitrogen using a Ta target. The W film was formed by the sputtering method using a W target. Alternatively, it can be formed by a thermal CVD method using tungsten hexafluoride (WF ₆ ). In any case, it is necessary to reduce the resistance in order to use it as a gate electrode, and the resistivity of the W film is 20 μΩc.
It is desirable to be m or less.

In this embodiment, the first conductive film 408 is used.
Is TaN and the second conductive film 409 is W, but is not particularly limited, and Ta, W, Ti, Mo, Al, and C are all used.
It may be formed of an element selected from u, Cr and Nd, or an alloy material or a compound material containing the element as a main component.
Alternatively, a semiconductor film typified by a polycrystalline silicon film doped with an impurity element such as phosphorus may be used. Also, AgP
You may use dCu alloy.

Next, masks 410 to 415 made of resist are formed by photolithography, and a first etching process for forming electrodes and wirings is performed. The first etching treatment is performed under the first and second etching conditions (FIG. 8B). In this embodiment, as the first etching condition, ICP (Inductively Coupled Plasma) etching method is used, CF ₄ , Cl ₂ and O ₂ are used as etching gas, and the gas flow rate ratio of each is 25. : 25:10 (sccm), RF power (13.56 MHz) of 500 W is applied to the coil-shaped electrode at a pressure of 1 Pa to generate plasma, and etching is performed. RF (13.56 MHz) power of 150 W is also applied to the substrate side (sample stage) to apply a substantially negative self-bias voltage.
The W film is etched under the first etching condition so that the end portion of the first conductive layer is tapered.

After that, the masks 410 to 110 made of resist are formed.
415 is not removed, the second etching condition is changed, CF ₄ and Cl ₂ are used as etching gases, and the flow rate ratio of each gas is set to 30:30 (sccm). RF (13.56 MHz) power of 500 W is applied to generate plasma and etching is performed for about 30 seconds. 20 W RF (13.56) on the substrate side (sample stage)
MHz) power is applied and a substantially negative self-bias voltage is applied. Under the second etching condition in which CF ₄ and Cl ₂ are mixed, the W film and the TaN film are etched to the same extent. Note that in order to perform etching without leaving a residue on the gate insulating film, the etching time may be increased at a rate of about 10 to 20%.

In the first etching process, the shape of the mask made of resist is adjusted to
The edges of the first conductive layer and the second conductive layer are tapered due to the effect of the bias voltage applied to the substrate side. The angle of this tapered portion is 15 to 45 °. Thus, the first shape conductive layers 417 to 422 (first conductive layers 417a to 422a and second conductive layers 417b to 42) including the first conductive layer and the second conductive layer are formed by the first etching treatment.
2b) is formed. 416 is a gate insulating film,
The area not covered with the conductive layers 417 to 422 in the shape of 20 is 20
A thinned region is formed by etching about 50 nm.

Next, a second etching process is performed without removing the resist mask. (FIG. 8 (C)) Here, CF ₄ , Cl _2, and O ₂ are used as etching gas,
The W film is selectively etched. At this time, the second conductive layers 428b to 433b are formed by the second etching treatment. On the other hand, the first conductive layers 417a to 422a are hardly etched, and the second shape conductive layers 428 to 422a are not etched.
33 is formed.

Then, the first doping process is performed without removing the resist mask, and the impurity element imparting n-type is added to the semiconductor layer at a low concentration. The doping treatment may be performed by an ion doping method or an ion implantation method. The condition of the ion doping method is that the dose amount is 1 × 10 ^{13 to} 5
The acceleration voltage is set to × 10 ¹⁴ / cm ² and the acceleration voltage is set to 40 to 80 keV. In this embodiment, the dose amount is 1.5 × 10 ¹³ / c.
m ² and the accelerating voltage is 60 keV. An element belonging to Group 15 is used as the impurity element imparting n-type, typically phosphorus (P) or arsenic (As), but phosphorus (P) is used here. In this case, the conductive layers 428 to 433
Serves as a mask for the impurity element imparting n-type, and impurity regions 423 to 427 are formed in a self-aligned manner. In the impurity regions 423 to 427, 1 × 10 ¹⁸ to 1 × 10 ²⁰ /
An impurity element imparting n-type is added within the concentration range of cm ³ .

After removing the mask made of resist, new masks 434a to 434c made of resist are formed, and the second doping process is performed at an acceleration voltage higher than that of the first doping process. The conditions of the ion doping method are a dose amount of 1 × 10 ¹³ to 1 × 10 ¹⁵ / cm ² and an acceleration voltage of 60.
~ 120 keV. In the doping process, the second conductive layers 428b, 430b, and 432b are used as a mask for the impurity element, and doping is performed so that the semiconductor layer below the tapered portion of the first conductive layer is added with the impurity element. Subsequently, the acceleration voltage is lowered from the second doping process and the third doping process is performed to obtain the state of FIG. The condition of the ion doping method is that the dose amount is 1 × 10 ¹⁵ to
The acceleration voltage is set to 1 × 10 ¹⁷ / cm ² and the acceleration voltage is set to 50 to 100 keV. By the second doping treatment and the third doping treatment, 1 × 10 ^{18 to} 5 × 10 ¹⁹ / c are formed in the low-concentration impurity regions 436, 442, and 448 which overlap with the first conductive layer.
An impurity element imparting n-type is added in the concentration range of m ³ ,
An impurity element imparting n-type is added to the high-concentration impurity regions 435, 441, 444, and 447 in a concentration range of 1 × 10 ^{19 to} 5 × 10 ²¹ / cm ³ .

Of course, by setting an appropriate acceleration voltage,
The second doping process and the third doping process are 1
It is possible to form the low-concentration impurity region and the high-concentration impurity region by performing the doping process once.

Next, after removing the resist masks, new resist masks 450a to 450a are formed.
c is formed and a fourth doping process is performed. By the fourth doping process, impurity regions 453, 454, and 45 in which an impurity element imparting a conductivity type opposite to one conductivity type is added to a semiconductor layer which is an active layer of a p-channel TFT are added.
9 and 460 are formed. Second conductive layers 429a and 432
Using a as a mask for the impurity element, an impurity element imparting p-type is added to form an impurity region in a self-aligned manner. In this embodiment, the impurity regions 453, 454, 4
59 and 460 are formed by an ion doping method using diborane (B ₂ H ₆ ) (FIG. 9B). During the fourth doping process, the semiconductor layer forming the n-channel TFT is covered with resist masks 450a to 450c. Although phosphorus is added to the impurity regions 439, 447, and 448 at different concentrations by the first to third doping processes, the concentration of the impurity element imparting p-type conductivity is 1 × 10 ^{19 in} any of the regions. ~ 5 x 1
By performing the doping treatment so that the concentration becomes 0 ²¹ atoms / cm ³ , there is no problem because it functions as the source region and the drain region of the p-channel TFT.

Through the above steps, the impurity regions are formed in the respective semiconductor layers.

Next, a mask 450a made of resist
To 450c are removed to form a first interlayer insulating film 461. As the first interlayer insulating film 461, plasma C is used.
The thickness is 100 to 200 using the VD method or the sputtering method.
It is formed of an insulating film containing silicon as nm. In this embodiment, a silicon oxynitride film having a thickness of 150 nm is formed by a plasma CVD method. Of course, the first interlayer insulating film 461 is not limited to the silicon oxynitride film, and another insulating film containing silicon may be used as a single layer or a laminated structure.

Next, for example, laser light is irradiated to recover the crystallinity of the semiconductor layers and activate the impurity elements added to the respective semiconductor layers. For laser activation, for example, the semiconductor film is irradiated with laser light by using Embodiment 1, Embodiment 2, or a combination of Embodiments.
The laser used is preferably a continuous wave solid-state laser, a gas laser, or a metal laser. The solid-state laser may be a continuous wave YAG laser, YVO ₄ laser, YLF laser.
There are lasers, YAlO ₃ lasers, glass lasers, ruby lasers, alexandrite lasers, Ti: sapphire lasers, etc., gas lasers include Ar lasers, Kr lasers, CO ₂ lasers, etc., and metal lasers include continuous oscillation helium cadmium. Lasers, copper vapor lasers, gold vapor lasers and the like can be mentioned. If it can be put to practical use,
A continuous wave excimer laser can also be applied to the present invention. At this time, if using a continuous wave laser, the energy density of the laser beam is about 0.01 to 100 MW / cm ² (preferably 0.01~10MW / cm ²⁾ is required, with respect to the laser beam Relative substrate 0.5-2000
Move at a speed of cm / s. Further, in the case of activation, a pulsed laser may be used, but at this time, the frequency is 300 Hz or more and the laser energy density is 50 to
It is desirable to set it to 1000 mJ / cm ² (typically 50 to 500 mJ / cm ² ). At this time, the laser beams may be overlapped by 50 to 98%. In addition to the laser annealing method, a thermal annealing method, a rapid thermal annealing method (RTA method), or the like can be applied.

Further, activation may be performed before forming the first interlayer insulating film. However, when the wiring material used is weak against heat, activation is performed after forming an interlayer insulating film (insulating film containing silicon as a main component, for example, a silicon nitride film) to protect the wiring and the like as in this embodiment. It is preferable to carry out a chemical treatment.

Then, heat treatment (at 300 to 550 ° C. 1 to
Hydrogenation can be performed by performing heat treatment for 12 hours. This step is a step of terminating the dangling bond of the semiconductor layer with hydrogen contained in the first interlayer insulating film 461. The semiconductor layer can be hydrogenated regardless of the presence of the first interlayer insulating film.

Next, a second interlayer insulating film 462 made of an inorganic insulating film material or an organic insulating material is formed on the first interlayer insulating film 461. In this embodiment, the film thickness is 1.6 μm
The acrylic resin film of
cp, preferably 40 to 200 cp, and the one having irregularities on the surface is used.

In this embodiment, in order to prevent specular reflection, the second interlayer insulating film having unevenness is formed on the surface to form the unevenness on the surface of the pixel electrode. Further, in order to make the surface of the pixel electrode uneven so as to achieve light scattering, a convex portion may be formed in a region below the pixel electrode. In that case, since the projection can be formed using the same photomask as that for forming the TFT, the projection can be formed without increasing the number of steps. Note that this convex portion may be appropriately provided on the substrate in the pixel portion region other than the wiring and the TFT portion. Thus, the unevenness is formed on the surface of the pixel electrode along the unevenness formed on the surface of the insulating film covering the convex portion.

A film having a flat surface may be used as the second interlayer insulating film 462. In that case, after forming the pixel electrode, a step such as a known sandblasting method or etching method is added to make the surface uneven so as to prevent specular reflection and scatter reflected light to increase the whiteness. Is preferred.

Then, in the drive circuit 506, wirings 463 to 467 electrically connected to the respective impurity regions.
To form. Note that these wirings have a thickness of 50 nm.
A laminated film of an i film and an alloy film (alloy film of Al and Ti) having a film thickness of 500 nm is formed by patterning. Of course, the structure is not limited to the two-layer structure, and may be a single-layer structure or a laminated structure of three or more layers. Also, as the wiring material,
It is not limited to Al and Ti. For example, Al or C on the TaN film
Wiring may be formed by patterning the laminated film in which u is formed and a Ti film is further formed (FIG. 10).

In the pixel portion 507, the pixel electrode 470, the gate wiring 469, and the connection electrode 468 are formed. By this connection electrode 468, the source wiring (a stack of 443a and 443b) is electrically connected to the pixel TFT. The gate wiring 469 is electrically connected to the gate electrode of the pixel TFT. Also, the pixel electrode 4
70 is electrically connected to the drain region 442 of the pixel TFT, and further electrically connected to the semiconductor layer 458 which functions as one electrode forming a storage capacitor. Further, as the pixel electrode 471, it is desirable to use a material having excellent reflectivity such as a film containing Al or Ag as a main component, or a laminated film thereof.

As described above, the n-channel TFT 50
1 and a p-channel TFT 502 CMOS circuit,
And driving circuit 506 having n-channel TFT 503
Then, the pixel portion 507 including the pixel TFT 504 and the storage capacitor 505 can be formed over the same substrate. Thus, the active matrix substrate is completed.

N-channel TFT 50 of drive circuit 506
Reference numeral 1 denotes a channel formation region 437, and a low-concentration impurity region 4 overlapping with the first conductive layer 428a forming part of the gate electrode.
36 (GOLD region), a high-concentration impurity region 452 which functions as a source region or a drain region.
A channel formation region 440, a high-concentration impurity region 454 functioning as a source region or a drain region, and an impurity element imparting n-type are provided in the p-channel TFT 502 which is connected to the n-channel TFT 501 with an electrode 466 to form a CMOS circuit. And an impurity region 453 in which an impurity element imparting p-type conductivity is introduced. Further, in the n-channel TFT 503, a channel forming region 443, a low concentration impurity region 442 (GOLD region) overlapping with the first conductive layer 430a forming a part of a gate electrode, and a high concentration impurity functioning as a source region or a drain region. Area 4
Has 56.

The pixel TFT 504 in the pixel portion has a channel formation region 446, a low concentration impurity region 445 (LDD region) formed outside the gate electrode, and a high concentration impurity region 458 which functions as a source region or a drain region. There is. In the semiconductor layer functioning as one electrode of the storage capacitor 505, an impurity element imparting n-type conductivity and p
An impurity element that imparts a mold is added. Storage capacity 5
05 is an electrode (432a) using the insulating film 416 as a dielectric.
And 432b) and a semiconductor layer.

A top view of the pixel portion of the active matrix substrate manufactured in this embodiment is shown in FIG. The same reference numerals are used for the portions corresponding to FIGS.
The chain line AA ′ in FIG. 10 corresponds to the cross-sectional view taken along the chain line AA ′ in FIG. 11. Also, a chain line B in FIG.
-B 'corresponds to the cross-sectional view taken along the chain line BB' in FIG.

The active matrix substrate manufactured as described above has a TFT manufactured using a semiconductor film whose characteristics are close to those of a single crystal, and the semiconductor film has extremely high uniformity in physical properties. , Operating characteristics and reliability can be sufficient. Further, by combining a part of the plurality of linear beams with each other and optimizing them, it is possible to form a uniform laser beam in the major axis direction, so that it is possible to improve the throughput. Then, by crystallizing using the highly uniform laser beam, a highly uniform crystalline semiconductor film can be formed and variation in electrical characteristics of the TFT can be reduced. Further, in a semiconductor device represented by an active matrix type liquid crystal display device using the present invention, it is possible to realize improvement in operating characteristics and reliability of the semiconductor device. In addition, unlike the conventional laser annealing method, a solid-state laser can be used instead of a gas laser, so that the manufacturing cost of a semiconductor device can be reduced.

[Embodiment 2] In this embodiment, a process of manufacturing a reflective liquid crystal display device from the active matrix substrate manufactured in Embodiment 1 will be described below. Figure 12
To use.

First, according to the first embodiment, after obtaining the active matrix substrate in the state of FIG. 10, an alignment film 567 is formed on at least the pixel electrode 470 on the active matrix substrate of FIG. 10, and rubbing treatment is performed. In this embodiment, before forming the alignment film 567, the organic resin film such as the acrylic resin film is patterned to form the columnar spacers 572 for holding the substrate distance at desired positions. Further, spherical spacers may be dispersed over the entire surface of the substrate instead of the columnar spacers.

Next, a counter substrate 569 is prepared. Next, the coloring layers 570 and 571 and the planarization film 573 are formed over the counter substrate 569. The red colored layer 570 and the blue colored layer 571 are overlapped with each other to form a light shielding portion. In addition, the light-shielding portion may be formed by partially overlapping the red colored layer and the green colored layer.

In this embodiment, the substrate shown in Example 1 is used. Therefore, in FIG. 11 showing the top view of the pixel portion of the first embodiment, at least the gate wiring 469 and the pixel electrode 47 are shown.
It is necessary to shield the gap of 0, the gap of the gate wiring 469 and the connection electrode 468, and the gap of the connection electrode 468 and the pixel electrode 470 from light. In this example, the colored layers were arranged so that the light-shielding portions formed by stacking the colored layers were overlapped with each other at the positions where they should be shielded, and the counter substrates were bonded together.

As described above, it is possible to reduce the number of steps by forming a light-shielding portion formed of a stack of colored layers so as to shield the gaps between pixels without forming a light-shielding layer such as a black mask.

Next, a counter electrode 576 made of a transparent conductive film was formed on at least the pixel portion on the flattening film 573, an alignment film 574 was formed on the entire surface of the counter substrate, and a rubbing treatment was performed.

The active matrix substrate having the pixel portion and the drive circuit formed thereon and the counter substrate are sealed with a sealant 568.
Stick together. A filler is mixed in the sealing material 568, and the two substrates are bonded to each other with a uniform interval by the filler and the columnar spacers. afterwards,
A liquid crystal material 575 is injected between both substrates and completely sealed with a sealant (not shown). A known liquid crystal material may be used as the liquid crystal material 575. In this way, the reflection type liquid crystal display device shown in FIG. 12 is completed. Then, if necessary, the active matrix substrate or the counter substrate is cut into a desired shape. Further, a polarizing plate (not shown) was attached only to the counter substrate. Then, using a known technique, F
I stuck a PC.

The liquid crystal display device manufactured as described above is manufactured by using a semiconductor film whose characteristics are close to those of a single crystal.
Since it has T and the uniformity of the physical properties of the semiconductor film is very high, the operating characteristics and reliability of the liquid crystal display device can be sufficient. Further, by combining a part of the plurality of linear beams with each other and optimizing them, it is possible to form a uniform laser beam in the major axis direction, so that it is possible to improve the throughput. Then, by crystallizing using the highly uniform laser beam, a highly uniform crystalline semiconductor film can be formed and variation in electrical characteristics of the TFT can be reduced. Further, it is possible to improve the operating characteristics and reliability of the liquid crystal display device manufactured by utilizing the present invention. Further, since a solid-state laser can be used instead of a gas laser used in the conventional laser annealing method, the manufacturing cost of the liquid crystal display device can be reduced. Then, such a liquid crystal display device can be used as a display portion of various electronic devices.

Note that this embodiment can be freely combined with Embodiment Modes 1 and 2.

[Embodiment 3] In this embodiment, a TFT when the active matrix substrate shown in Embodiment 1 is manufactured.
An example in which a light-emitting device is manufactured by using the manufacturing method of will be described. In the present specification, a light emitting device is a generic term for a display panel in which a light emitting element formed on a substrate is enclosed between the substrate and a cover material, and a display module including a TFT on the display panel. is there. Note that the light-emitting element has a luminescence (Elec
It has a layer (light emitting layer) containing an organic compound for which tro luminescence is obtained, an anode layer, and a cathode layer. In addition, luminescence in 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). Alternatively, it includes both luminescence.

All layers formed between the anode and the cathode in the light emitting element are defined as organic light emitting layers. The organic light emitting layer specifically includes a light emitting layer, a hole injection layer, an electron injection layer, a hole transport layer, an electron transport layer, and the like. Basically, a light emitting device has a structure in which an anode layer, a light emitting layer, and a cathode layer are sequentially stacked. In addition to this structure, an anode layer, a hole injection layer, a light emitting layer, a cathode layer, and an anode layer are provided. It may have a structure in which a hole injecting layer, a light emitting layer, an electron transporting layer, a cathode layer and the like are laminated in this order.

FIG. 13 is a sectional view of the light emitting device of this embodiment. In FIG. 13, the switching TFT 603 provided on the substrate 700 is the n-channel TFT 50 of FIG.
3 is used. Therefore, the description of the structure may be referred to the description of the n-channel TFT 503.

The driving circuit provided on the substrate 700 is shown in FIG.
It is formed by using a 0 CMOS circuit. Therefore, the description of the structure is given by the n-channel TFT 501 and the p-channel TFT.
The description of 502 may be referred to. Although a single gate structure is used in this embodiment, a double gate structure or a triple gate structure may be used.

Further, the wirings 701 and 703 function as a source wiring of the CMOS circuit, and 702 functions as a drain wiring.
The wiring 704 is connected to the source wiring 708 and the switching T.
The wiring 705 functions as a wiring that electrically connects the source region of the FT, and the wiring 705 is connected to the drain wiring 709 and the switching T.
It functions as a wiring that electrically connects the drain region of the FT.

The current control TFT 604 has the p-type of FIG.
It is formed using the channel TFT 502. Therefore,
For the description of the structure, the description of the p-channel TFT 502 may be referred to. Although a single gate structure is used in this embodiment, a double gate structure or a triple gate structure may be used.

Further, the wiring 706 is a source wiring (corresponding to a current supply line) of the current control TFT, and 707 is an electrode electrically connected to the pixel electrode 711 by being overlapped on the pixel electrode 711 of the current control TFT. is there.

711 is a pixel electrode (anode of a light emitting element) made of a transparent conductive film. As the transparent conductive film,
A compound of indium oxide and tin oxide, a compound of indium oxide and zinc oxide, zinc oxide, tin oxide, or indium oxide can be used. Alternatively, a transparent conductive film to which gallium is added may be used. Pixel electrode 71
1 is a flat interlayer insulating film 710 before forming the wiring.
Form on top. In this embodiment, it is very important to flatten the step due to the TFT by using the flattening film 710 made of resin. Since the light emitting layer that is formed later is very thin, the light emitting failure may occur due to the existence of the step. Therefore, it is desirable to flatten the light emitting layer before forming the pixel electrode so that the light emitting layer can be formed as flat as possible.

After forming the wirings 701 to 707, a bank 712 is formed as shown in FIG. Bank 712 is 10
It may be formed by patterning an insulating film containing 0 to 400 nm of silicon or an organic resin film.

Since the bank 712 is an insulating film,
Attention must be paid to the electrostatic breakdown of the device during film formation.
In this embodiment, carbon particles or metal particles are added to the insulating film that is the material of the bank 712 to lower the resistivity and suppress the generation of static electricity. At this time, the resistivity is 1 × 10 ⁶ to 1 × 1.
The addition amount of carbon particles or metal particles may be adjusted so as to be 0 ¹² Ωm (preferably 1 × 10 ⁸ to 1 × 10 ¹⁰ Ωm).

A light emitting layer 713 is formed on the pixel electrode 711. Although only one pixel is shown in FIG. 13, light emitting layers corresponding to each color of R (red), G (green), and B (blue) are separately formed in this embodiment. Further, in this embodiment, the low molecular weight organic light emitting material is formed by the vapor deposition method.
Specifically, a 20-nm-thick copper phthalocyanine (CuPc) film is provided as a hole injection layer, and a 7-nm light emitting layer is formed thereon.
It has a laminated structure in which a 0 nm thick tris-8-quinolinolato aluminum complex (Alq ₃ ) film is provided. The emission color can be controlled by adding a fluorescent dye such as quinacridone, perylene or DCM1 to Alq ₃ .

However, the above example is an example of an organic light emitting material that can be used as a light emitting layer, and it is not necessary to limit to this. The light emitting layer (charge transporting layer or charge injecting layer) may be freely combined to form a light emitting layer (a layer for emitting light and for moving carriers therefor). For example, in this embodiment, an example in which a low molecular weight organic light emitting material is used as the light emitting layer is shown, but a medium molecular weight organic light emitting material or a high molecular weight organic light emitting material may be used. In the present specification, an organic light-emitting material having no sublimability and having a number of molecules of 20 or less or a chain of molecules having a length of 10 μm or less is referred to as a medium molecule organic light-emitting material. In addition, as an example of using a polymer organic light emitting material, the hole injection layer has a thickness of 20 nm.
Alternatively, a polythiophene (PEDOT) film may be provided by a spin coating method, and a para-phenylene vinylene (PPV) film having a thickness of about 100 nm may be provided on the polythiophene (PEDOT) film as a laminated structure. By using a PPV π-conjugated polymer, the emission wavelength can be selected from red to blue. Further, 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 as these organic light emitting materials and inorganic materials.

Next, a cathode 714 made of a conductive film is provided on the light emitting layer 713. In this embodiment, an alloy film of aluminum and lithium is used as the conductive film. Of course, a well-known MgAg film (an alloy film of magnesium and silver)
May be used. As the cathode material, a conductive film made of an element belonging to Group 1 or 2 of the periodic table or a conductive film to which those elements are added may be used.

The light emitting element 715 is completed when the cathode 714 is formed. The light emitting element 71 referred to here
Reference numeral 5 denotes a diode formed by the pixel electrode (anode) 711, the light emitting layer 713 and the cathode 714.

It is effective to provide the passivation film 716 so as to completely cover the light emitting element 715. As the passivation film 716, an insulating film including a carbon film, a silicon nitride film, or a silicon nitride oxide film is used, and the insulating films are used as a single layer or a stacked layer in which they are combined.

At this time, it is preferable to use a film having good coverage as a passivation film, and a carbon film, especially D
It is effective to use an LC film. Since the DLC film can be formed in a temperature range from room temperature to 100 ° C. or lower, it can be easily formed over the light-emitting layer 713 having low heat resistance. In addition, the DLC film has a high blocking effect on oxygen and can suppress oxidation of the light emitting layer 713. Therefore, it is possible to prevent the problem that the light emitting layer 713 is oxidized during the subsequent sealing step.

Further, a sealing material 717 is provided on the passivation film 716, and a cover material 718 is attached. An ultraviolet curable resin may be used as the sealing material 717, and it is effective to provide a substance having a moisture absorption effect or a substance having an antioxidant effect inside. In this embodiment, the cover material 718 is a glass substrate, a quartz substrate, a plastic substrate (including a plastic film), or a flexible substrate having a carbon film (preferably a DLC film) formed on both sides. Besides carbon film, aluminum film (AlON, Al
N, AlO, etc.), SiN, etc. can be used.

Thus, the light emitting device having the structure as shown in FIG. 13 is completed. Note that it is effective to continuously perform the steps from the formation of the bank 712 to the formation of the passivation film 716 using a multi-chamber system (or in-line system) film formation apparatus without exposing to the atmosphere. . Further, it is also possible to further develop and continuously process up to the step of attaching the cover material 718 without exposing to the atmosphere.

Thus, the n-channel type T
FTs 601 and 602, a switching TFT (n-channel type TFT) 603 and a current control TFT (n-channel type TFT) 604 are formed.

Further, as described with reference to FIG.
By providing an impurity region overlapping the gate electrode with an insulating film interposed therebetween, n which is resistant to deterioration due to the hot carrier effect is used.
A channel TFT can be formed. for that reason,
It is possible to realize a highly reliable light emitting device.

Although only the configuration of the pixel portion and the driving circuit is shown in this embodiment, a signal dividing circuit, a D / A converter, an operational amplifier, a γ correction circuit, etc. may also be used according to the manufacturing process of this embodiment. Can be formed on the same insulator, and also a memory and a microprocessor can be formed.

The light-emitting device manufactured as described above has a TFT manufactured using a semiconductor film whose characteristics are close to those of a single crystal, and the physical properties of the semiconductor film are extremely high. The operating characteristics and reliability of the light emitting device can be sufficient. Further, by combining a part of the plurality of linear beams with each other and optimizing them, it is possible to form a uniform laser beam in the major axis direction, so that it is possible to improve the throughput. Then, by crystallizing using the highly uniform laser beam, a highly uniform crystalline semiconductor film can be formed and variation in electrical characteristics of the TFT can be reduced. Furthermore, it is possible to improve the operating characteristics and reliability of the light emitting device manufactured by utilizing the present invention. Further, since a solid-state laser can be used instead of a gas laser used in the conventional laser annealing method, the manufacturing cost of the light emitting device can be reduced. Then, such a light emitting device can be used as a display portion of various electronic devices.

Note that this embodiment can be freely combined with Embodiment Modes 1 and 2.

[Embodiment 4] By applying the present invention, various semiconductor devices (active matrix type liquid crystal display device, active matrix type light emitting device, active matrix type EC display device) can be manufactured. That is, the present invention can be applied to various electronic devices in which those electro-optical devices are incorporated in the display unit.

Examples of such electronic devices include video cameras, digital cameras, projectors, head mounted displays (goggles type displays), car navigations, car stereos, personal computers, personal digital assistants (mobile computers, mobile phones, electronic books, etc.). ) And the like. Examples of these are shown in FIGS. 14, 15 and 16.

FIG. 14A shows a personal computer, which has a main body 3001, an image input section 3002, and a display section 30.
03, keyboard 3004 and the like. By applying the semiconductor device manufactured according to the present invention to the display portion 3003,
The personal computer of the present invention is completed.

FIG. 14B shows a video camera, which includes a main body 3101, a display section 3102, a voice input section 3103, operation switches 3104, a battery 3105, and an image receiving section 310.
Including 6 etc. The video camera of the present invention is completed by applying the semiconductor device manufactured by the present invention to the display portion 3102.

FIG. 14C shows a mobile computer (mobile computer), which includes a main body 3201, a camera portion 3202, an image receiving portion 3203, operation switches 3204, a display portion 3205, and the like. The mobile computer of the present invention is completed by applying the semiconductor device manufactured by the present invention to the display portion 3205.

FIG. 14D shows a goggle type display, which includes a main body 3301, a display section 3302 and an arm section 330.
Including 3 etc. The display portion 3302 uses a flexible substrate as a substrate, and the display portion 3302 is bent to manufacture a goggle type display. It also realizes a lightweight and thin goggle type display. The goggle type display of the present invention is completed by applying the semiconductor device manufactured by the present invention to the display portion 3302.

FIG. 14E shows a player that uses a recording medium (hereinafter referred to as a recording medium) in which a program is recorded, and includes a main body 3401, a display portion 3402, and a speaker portion 340.
3, a recording medium 3404, operation switches 3405 and the like. This player uses a DVD (D
digital Versatile Disc), CD
It is possible to play music, watch movies, play games, and use the internet. The recording medium of the present invention is completed by applying the semiconductor device manufactured according to the present invention to the display portion 3402.

FIG. 14F shows a digital camera which includes a main body 3501, a display portion 3502, an eyepiece portion 3503, operation switches 3504, an image receiving portion (not shown) and the like. By applying the semiconductor device manufactured according to the present invention to the display portion 3502, the digital camera according to the present invention is completed.

FIG. 15A shows a front type projector including a projection device 3601, a screen 3602 and the like. The projection device 36 is a semiconductor device manufactured by the present invention.
01 is applied to the liquid crystal display device 3808 which constitutes a part of No. 01 and other drive circuits, the front type projector of the present invention is completed.

FIG. 15B shows a rear type projector, which includes a main body 3701, a projection device 3702, and a mirror 370.
3, screen 3704 and the like. By applying the semiconductor device manufactured by the present invention to the liquid crystal display device 3808 which forms a part of the projection device 3702 and other drive circuits, the rear projector of the present invention is completed.

Note that FIG. 15C is a diagram showing an example of the structure of the projection devices 3601 and 3702 in FIGS. 15A and 15B. Projection devices 3601, 37
02 is a light source optical system 3801, mirrors 3802, 380
4 to 3806, dichroic mirror 3803, prism 3807, liquid crystal display device 3808, retardation plate 380.
9, a projection optical system 3810. Projection optical system 38
Reference numeral 10 is composed of an optical system including a projection lens. Although the present embodiment shows an example of a three-plate type, it is not particularly limited and may be, for example, a single-plate type. Further, the practitioner may appropriately provide an optical system such as an optical lens, a film having a polarization function, a film for adjusting the phase difference, an IR film, etc. in the optical path indicated by the arrow in FIG. Good.

Further, FIG. 15D is a diagram showing an example of the structure of the light source optical system 3801 in FIG. 15C. In this embodiment, the light source optical system 3801 includes the reflector 3811, the light source 3812, the lens arrays 3813, and 3.
814, a polarization conversion element 3815, and a condenser lens 3816. The light source optical system shown in FIG. 15D is an example and is not particularly limited. For example, the practitioner may appropriately provide an optical system such as an optical lens, a film having a polarization function, a film for adjusting a phase difference, and an IR film in the light source optical system.

However, the projector shown in FIG. 15 shows a case where a transmissive electro-optical device is used, and an application example in a reflective electro-optical device and a light emitting device is not shown.

FIG. 16A shows a mobile phone, which is a main body 39.
01, voice output unit 3902, voice input unit 3903, display unit 3904, operation switch 3905, antenna 3906
Including etc. The mobile phone of the present invention is completed by applying the semiconductor device manufactured according to the present invention to the display portion 3904.

FIG. 16B shows a portable book (electronic book) including a main body 4001, display portions 4002 and 4003, a storage medium 4004, operation switches 4005, an antenna 4006.
Including etc. By applying the semiconductor device manufactured by the present invention to the display portions 4002 and 4003, the portable book of the present invention is completed. Portable books can be made as large as paperback books, making them easy to carry.

FIG. 16C shows a display, which includes a main body 4101, a support base 4102, a display portion 4103 and the like.
The display portion 4103 is manufactured using a flexible substrate,
A lightweight and thin display can be realized. In addition, the display unit 4
It is also possible to bend 103. The display of the present invention is completed by applying the semiconductor device manufactured by the present invention to the display portion 4103. The display of the present invention is particularly advantageous when it has a large screen, and is advantageous for a display having a diagonal of 10 inches or more (particularly 30 inches or more).

The electronic device manufactured as described above has a TFT manufactured using a semiconductor film whose characteristics are close to those of a single crystal, and the physical properties of the semiconductor film are extremely high. The operating characteristics and reliability of the electronic device can be sufficient. Further, by combining a part of the plurality of linear beams with each other and optimizing them, it is possible to form a uniform laser beam in the major axis direction, so that it is possible to improve the throughput. Then, by crystallizing using the highly uniform laser beam, a highly uniform crystalline semiconductor film can be formed and variation in electrical characteristics of the TFT can be reduced. Further, in a semiconductor device represented by an active matrix type liquid crystal display device using the present invention, it is possible to realize improvement in operating characteristics and reliability of the semiconductor device. In addition, unlike the conventional laser annealing method, a solid-state laser can be used instead of a gas laser, so that the manufacturing cost of a semiconductor device can be reduced.

Further, the applicable range of the present invention is extremely wide, and the present invention can be applied to electronic devices in various fields.
Note that the electronic device of the present example can also be realized by using a configuration including a combination of the first and second embodiments and the first, second, or first and third examples.

[0144]

By adopting the structure of the present invention, the following basic significance can be obtained. (A) By irradiating the irradiated body with a plurality of laser beams satisfying the formula shown by the present invention, more uniform laser annealing can be performed. (B) The object to be irradiated can be uniformly annealed. In particular, it is suitable for crystallization of a semiconductor film, improvement of crystallinity, and activation of an impurity element. (C) Since some of the plurality of linear beams are combined with each other, the throughput can be improved. (D) Since a solid-state laser can be used instead of a gas laser used in the conventional laser annealing method, the manufacturing cost of a semiconductor device can be reduced. (E) In addition to satisfying the above advantages, in a semiconductor device typified by an active matrix liquid crystal display device,
It is possible to improve the operating characteristics and reliability of the semiconductor device. Further, it is possible to reduce the manufacturing cost of the semiconductor device.

[Brief description of drawings]

FIG. 1 is a diagram illustrating Embodiment 1;

FIG. 2 is a diagram illustrating Embodiment 1;

FIG. 3 is a diagram illustrating Embodiment 1;

FIG. 4 is a diagram illustrating Embodiment 1;

FIG. 5 is a diagram illustrating Embodiment 2;

6A and 6B are diagrams illustrating Embodiment 1;

7A and 7B are diagrams illustrating Embodiment 1;

8A to 8C are cross-sectional views illustrating a manufacturing process of a pixel TFT and a driver circuit TFT.

9A to 9C are cross-sectional views illustrating a manufacturing process of a pixel TFT and a driver circuit TFT.

FIG. 10 is a cross-sectional view showing a manufacturing process of a pixel TFT and a driver circuit TFT.

FIG. 11 is a top view showing a configuration of a pixel TFT.

FIG. 12 is a cross-sectional view showing a manufacturing process of an active matrix liquid crystal display device.

FIG. 13 is a cross-sectional structural diagram of a driver circuit and a pixel portion of a light emitting device.

FIG. 14 illustrates an example of a semiconductor device.

FIG. 15 illustrates an example of a semiconductor device.

FIG. 16 illustrates an example of a semiconductor device.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01S 3/00 F term (reference) 2H088 FA21 FA30 HA01 HA02 HA03 HA04 HA06 HA13 HA14 HA15 HA18 HA21 HA23 HA24 HA25 HA28 MA20 5F052 AA02 AA11 AA17 AA24 BA02 BA07 BA11 BA14 BA18 BB01 BB02 BB05 BB06 BB07 CA07 CA10 DA02 DA03 DA10 DB02 DB03 DB07 EA12 EA15 FA06 FA19 JA01 JA04 5F072 AA02 DD0802 5110BB04 AB05 AB07 BB08 AB05 AB07 AB08 AB05 AB07 AB15 AB20 AB07 AB15 AB08 AB07 AB15 AB20 AB07 AB15 AB08 AB07 AB15 AB08 AB07 AB15 AB08 DD03 DD05 DD13 DD14 DD15 DD17 EE01 EE02 EE03 EE04 EE06 EE11 EE14 EE23 EE44 EE45 FF04 FF09 FF28 FF30 GG01 GG02 GG13 GG25 GG32 GG43 GG34 NN NN HL HL HL HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL15 HL17 HL15 HL15 HL15 HL15 HL17 HL15 HL15 HL15 HL17 HL15 HL17 HL15 HL17 HL15 HL15 HL17 HL17 HL17 HL17 HL17 HL17 HL17 HL17 HL15 HL17 HL17 HL17 HL17 HL17 HL17 HL17 HL17 HL17 HL17 NN72 NN73 NN78 PP01 PP02 PP03 PP05 PP06 PP07 PP10 PP29 PP31 PP34 QQ04 QQ11 QQ19 QQ23

Claims (9)

[Claims] 1. A plurality of laser oscillators, a means for extending a plurality of laser beams emitted from the plurality of laser oscillators and having a round spot shape, and a plurality of the extended laser beams. A laser irradiation device having means for forming a linear beam on the irradiation surface or in the vicinity thereof, by overlapping the ends in the direction of the major axis of the irradiation area of the irradiation surface of each of the plurality of stretched laser beams. The width of e ^-2 is a, and the width of e ^{-2 of} minor axis is b,
When the coordinates of the major axis and the x-axis are taken in parallel, and the coordinates of the minor axis and the y-axis are taken in parallel, the central coordinates of the overlapping laser beams among the plurality of stretched laser beams are respectively (x, y). , (X ′, y ′), ((x−x ′) / a) ² + ((y−y ′) / b) ² <0.72
² or ((x−x ′) / a) ² + ((y−y ′) / b) ² <0.63
^2. A laser irradiation device characterized by satisfying ² . 2. A plurality of laser oscillators, a means for stretching a plurality of laser beams emitted from the plurality of laser oscillators and having a rectangular spot shape, and a plurality of the stretched laser beams. A laser irradiation device having means for forming a linear beam on the irradiation surface or in the vicinity thereof, by overlapping the ends in the direction of the major axis of the irradiation area of the irradiation surface of each of the plurality of stretched laser beams. e ^-2 width a, the e ^-2 width of minor and is b, parallel to take coordinates the major axis and the x-axis, the minor axis and y
If the axes are taken in parallel, the central coordinates of the overlapping laser beams among the plurality of stretched laser beams are (x, y) and (x ′, y ′), respectively, then | y−y ′ | /b<0.72 and | x−x ′ | <a or | y−y ′ | / b <0.63 and | xx−x ′ | <a, and the stretched plurality is satisfied. The laser irradiation device is characterized in that the laser beam has a uniform energy distribution in the major axis direction and a Gaussian energy distribution in the minor axis direction. 3. A plurality of laser oscillators, a means for stretching a plurality of laser beams emitted from the plurality of laser oscillators and having a rectangular spot shape, and a plurality of the stretched laser beams. A laser irradiation device having means for forming a linear beam on the irradiation surface or in the vicinity thereof, by overlapping the ends in the direction of the major axis of the laser beam, and e ^-2 width a, the e ^-2 width of minor and is b, parallel to take coordinates the major axis and the x-axis, the minor axis and y
If the axes are taken in parallel, then the central coordinates of the overlapping laser beams among the plurality of stretched laser beams are (x, y) and (x ′, y ′), then | x−x ′ | /a<0.72 and | y−y ′ | <b or | x−x ′ | / a <0.63 and | y−y ′ | <b, and the stretched plurality is satisfied. The laser irradiation device is characterized in that the laser beam has a uniform energy distribution in the minor axis direction and a Gaussian energy distribution in the major axis direction. 4. A plurality of laser oscillators, a means for stretching a plurality of laser beams emitted from the plurality of laser oscillators and having a rectangular spot shape, and a plurality of the stretched plurality of laser beams. A laser irradiation device having means for forming a linear beam on the irradiation surface or in the vicinity thereof, by overlapping the ends in the direction of the major axis of the irradiation area of the irradiation surface of each of the plurality of stretched laser beams. e ^-2 width a, the e ^-2 width of minor and is b, parallel to take coordinates the major axis and the x-axis, the minor axis and y
If the axes are taken in parallel, then the central coordinates of the overlapping laser beams among the plurality of stretched laser beams are (x, y) and (x ′, y ′), then | x−x ′ | /a<0.72 and | y−y ′ | / b <0.
72 or | x−x ′ | / a <0.63 and | y−y ′ | / b <0.
63, the energy distribution in the major axis direction of the plurality of stretched laser beams is Gaussian, and the energy distribution in the minor axis direction is also Gaussian. 5. A plurality of laser oscillators, and means for stretching a plurality of laser beams emitted from the plurality of laser oscillators and having spot shapes of round and rectangular.
Means for forming linear beams in the irradiation surface or in the vicinity thereof, by overlapping the ends of the plurality of stretched laser beams in the major axis direction, and in the irradiation surface of each of the plurality of stretched laser beams. Major axis e ^-2
If the width is a, the short diameter e ⁻² width is b, and the major axis and the x-axis are parallel to each other and the minor axis and the y-axis are parallel to each other,
The central coordinates of the laser beams that overlap each other among the plurality of stretched laser beams are (x, y),
Assuming that (x ', y'), ((x-x ') / a) ² + ((y-y') / b) ² <0.72
² or ((x−x ′) / a) ² + ((y−y ′) / b) ² <0.63
^2. A laser irradiation device characterized by satisfying ² . 6. The method according to any one of claims 1 to 5,
The e ⁻² width a of the major axis and the center coordinates (x, y), (x ′, y ′) of the laser beams adjacent to each other satisfy | xx−x ′ | / a> 0.52. Laser irradiation device. 7. The method according to any one of claims 1 to 6,
The laser irradiation apparatus is characterized in that the laser oscillator is selected from a continuous wave gas laser, a solid-state laser, and a metal laser. 8. The method according to any one of claims 1 to 7,
A laser irradiation device characterized in that the e ⁻² width b of the short diameter is 50 μm or less. 9. The method according to any one of claims 1 to 8,
The laser oscillator is an Ar laser, a Kr laser, CO ₂
Laser, YAG laser, YVO ₄ laser, YLF laser, YAlO ₃ laser, Y ₂ O ₃ laser, glass laser,
A laser irradiation device characterized by being selected from a ruby laser, an alexandride laser, a Ti: sapphire laser, a helium cadmium laser, a copper vapor laser, and a gold vapor laser.