JP2003100639A - Method for manufacturing semiconductor thin film and thin-film transistor, and electro-optical apparatus, and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a large-grain polycrystalline silicon film at a low process temperature, high throughput rate, and low cost. SOLUTION: A 1st insulating layer, a light absorbing layer using W, and a 2nd insulating layer are provided on a semiconductor layer, and irradiation is performed by a lamp with the peak wavelength in the vicinity of 1 μm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor thin film formed on a single crystal semiconductor substrate or an insulator, a thin film transistor, and a logic circuit, a memory circuit, a liquid crystal display device and an organic electroluminescence (EL) display formed by the semiconductor thin film. The present invention relates to a method of manufacturing a thin film transistor used as a display pixel of a device or a constituent element of a display device drive circuit, and a method of manufacturing a solar cell formed on an insulator.

[0002]

2. Description of the Related Art Conventionally, polycrystalline silicon (poly-S) has been used.
Semiconductor thin films such as i) are widely used in thin film transistors (TFTs) and solar cells. Especially poly-Si
A TFT has a high carrier mobility and can be manufactured on a transparent insulating substrate such as a glass substrate. Therefore, a switching element of a liquid crystal display device, a liquid crystal projector or an organic EL display device, or a driver for driving a liquid crystal is utilized. Widely used as a circuit element.

As a method for producing a high-performance TFT on a glass substrate, a manufacturing method called a high temperature process has already been put into practical use. Among the TFT manufacturing processes, a process using a high temperature with a maximum temperature of about 1000 ° C. is generally called a high temperature process. The characteristics of the high temperature process are that a relatively good quality polycrystalline silicon can be formed by solid phase growth of silicon, a good quality gate insulating layer can be obtained by thermal oxidation of silicon, and a clean polycrystalline The point is that an interface between silicon and the gate insulating layer can be formed. Due to these characteristics in the high temperature process, a high-performance TFT having high mobility and high reliability can be stably manufactured. However, in the high temperature process, since the Si film is crystallized by solid phase growth, a heat treatment at a temperature of about 600 ° C. for a long time of about 48 hours is required. This is a very long process and inevitably requires a large number of heat treatment furnaces to increase the throughput of the process.
The problem is that cost reduction is difficult. In addition, since quartz glass has to be used as an insulating substrate having high heat resistance, the substrate price is high and it is not suitable for increasing the area.

On the other hand, a technique for lowering the process temperature and producing a poly-Si TFT on an inexpensive large area glass substrate is a technique called a low temperature process. In the TFT manufacturing process, pol is on a relatively inexpensive heat-resistant glass substrate under a temperature environment where the maximum temperature is approximately 600 ° C or less.
The process of manufacturing the y-Si TFT is generally called a low temperature process. In the low temperature process, a laser crystallization technique for crystallizing a silicon film using a pulse laser with an extremely short oscillation time is widely used. Laser crystallization is a technique that utilizes the property that a silicon thin film on a substrate is instantly melted by irradiating it with high-power pulsed laser light and is crystallized in the process of solidification. Recently, a technique of forming a large-area poly-Si film by scanning an amorphous silicon film on a glass substrate while repeatedly irradiating an excimer laser beam has been widely used. Further, as the gate insulating layer, a silicon dioxide (SiO ₂ ) film can be formed on a large area substrate by a film forming method using plasma CVD. With these technologies, poly-Si TFTs are now mounted on a large glass substrate, which is now several tens of centimeters on a side.
Can be manufactured.

However, the problem with this low-temperature process is that when the semiconductor layer (poly-Si film) to be the active layer is formed by laser crystallization, the crystal grain size is as small as 0.5 micron, and therefore this poly is used. That is, the threshold voltage of the TFT manufactured using the -Si film is high and the mobility is low.
In the excimer laser crystallization method, polycrystallized
There was a problem that unevenness having a height corresponding to 30 to 40% of the film thickness was generated on the surface of the -Si film. This occurs at the grain boundaries where the crystals grown from the crystal growth nuclei collide with each other. Since the gate insulating film thickness is effectively thinned at this protruding portion, the withstand voltage becomes low, and the T insulating film having a particularly thin gate insulating film is formed.
It was a big issue in FT. In addition, the excimer laser widely used in the laser crystallization process is a gas laser, so the energy stability between pulses is low,
There is a problem that it is difficult to reduce variations in TFT elements. Further, since the excimer laser has a high unit cost, a high running cost due to replacement of the laser tube (oscillator), and a low throughput, there is a problem that the manufacturing cost of the product cannot be reduced.

As a means for solving the above problems, there are the following conventional techniques.

In JP-A-57-113217, a step of depositing a semiconductor film on one main surface of an insulating plate, a step of depositing an insulating film on the semiconductor film, and a step of depositing a light absorbing layer on the insulating film are disclosed. The technique of crystallization of the semiconductor layer by irradiating a laser on the light absorption layer and heating is disclosed.

In Japanese Patent Laid-Open No. 59-158515, an energy absorption layer is provided on a non-single crystal semiconductor layer via a heat resistance layer.
A technique is disclosed in which the semiconductor layer is heated and melted through the heat resistance layer to be single-crystallized by raising the temperature of the energy absorption layer by irradiation with energy rays.

In Japanese Patent Laid-Open No. 59-205712, a semiconductor region made of a non-single crystal semiconductor is provided on an insulating layer, a film covering at least the semiconductor region and its vicinity is formed, and the film is irradiated with energy rays. A technique is disclosed in which the non-single-crystal semiconductor in the semiconductor region is melted into a single crystal by heating the coating film.

In JP-A-60-18913, a step of providing a recrystallized amorphous or polycrystalline compound semiconductor layer on an insulating substrate, and a heating layer having a melting point higher than that of the compound semiconductor is provided on the compound semiconductor layer. Disclosed is a method for manufacturing a semiconductor device, which comprises the steps of: irradiating the heating layer with an energy ray to be absorbed, and conducting the heat of the heating layer to heat and recrystallize the compound semiconductor layer.

In JP-A-60-126815, an energy ray absorbing layer in which a non-single crystal semiconductor layer partially in contact with a single crystal seed is provided on an insulating film, and the non-single crystal semiconductor layer is provided via a separation layer Irradiating the energy ray absorbing layer of the sample covered with with energy rays to heat, melting the non-single crystal semiconductor layer by heat flow using this as a heat source, and laterally epitaxially growing from the single crystal seed. Discloses a method for manufacturing a semiconductor device, which includes the step of single-crystallizing the non-single-crystal semiconductor layer.

In JP-A-60-231319, a first layer that contributes as a heat conduction layer is provided on an insulating substrate, and a semiconductor island region to be single-crystallized is formed on the first layer.
Next, a second layer which covers the upper surface and the side surface of the semiconductor island region and contributes as an energy ray absorber is formed.
A method of irradiating an energy ray from above the layer to single crystallize the semiconductor island region, a method for manufacturing a semiconductor device is disclosed.

In JP-A-61-30025, a step of forming a polycrystalline or amorphous semiconductor film on a substrate whose surface is at least covered with an amorphous insulating layer, and at least two different light absorption coefficients on the substrate. A step of forming a kind of amorphous insulating film and an affirmative of melting and recrystallizing the semiconductor film by irradiating the substrate with light having a wavelength component that can be absorbed by the semiconductor and irradiating with an electron beam. A method for producing a characteristic single crystal semiconductor thin film is disclosed.

In JP-A-4-332120, when a semiconductor layer to be annealed is formed on a substrate and a refractory metal film is formed on the semiconductor layer, an intermediate layer is formed between the semiconductor layer and the refractory metal film. Is formed, an intermediate layer and a refractory metal film are formed on the semiconductor layer, and then an energy beam for annealing the semiconductor layer is irradiated from the refractory metal film side. A method of manufacturing a crystal layer is disclosed.

In Japanese Patent Application Laid-Open No. 6-291034, in a thin film heat treatment method in which a thin film is heat-treated by irradiation with light, after forming a structure in which the thin film is laminated on a heating layer, the thin film is substantially treated. Irradiating the structure with a first light having a first wavelength which is transparent and which is absorbed by the heating layer, and then a second light which is absorbed by the thin film;
A heat treatment method for a thin film is disclosed, wherein the structure is irradiated with a second light having a wavelength of.

In Japanese Patent Application Laid-Open No. 8-51076, a step of forming a light reflecting film on an insulating substrate, a step of forming a buffer layer on the reflecting film, a step of forming an amorphous silicon film on the buffer layer, A technique of forming a polycrystalline silicon film by irradiating a crystalline silicon film with lamp light a plurality of times in an extremely short time to melt and crystallize the silicon film is disclosed.

By using the above technique, a polycrystal having a crystal grain size of 1 micron or more even on an insulating substrate.
Since it becomes possible to form a -Si film, the crystal grain boundaries in the active layer region of the TFT can be dramatically reduced, resulting in TF.
The performance of T can be improved.

[0018]

In the above-mentioned prior art, since the absorption efficiency of the light energy of the irradiation light source by the absorption layer is low, the absorption layer temperature is sufficiently raised by the light emitted from a low-priced light source such as a general-purpose halogen lamp. Things were difficult. In addition, since it was not possible to locally heat-treat only the vicinity of the absorption layer on the surface of the substrate, the temperature of the entire substrate during the processing increased and S
Although it can be applied to a substrate having a high heat resistance such as an i-wafer or quartz, an inexpensive glass substrate having a low strain point cannot withstand the temperature and the substrate is distorted or cracked. For this reason, application to low temperature processes has not yet been realized. Further, there is a problem that the surface of the crystallized poly-Si film is not perfectly flat. The main cause of these problems is that the materials suitable for the light absorption layer, the film structure of the absorption layer, the irradiation light source, and the light irradiation conditions are unclear, and both efficient heat input to the absorption layer and suppression of substrate temperature rise are controlled. That was not possible. As a result, it was impossible to form a high quality poly-Si film having a large grain size on an inexpensive glass substrate.

In view of the above-mentioned problems, the present invention discloses a technique for forming a poly-Si film having a large grain size and a flat surface in a large area by a low temperature process.
The present invention also provides a semiconductor thin film and a method of manufacturing a thin film transistor, which realizes improvement of circuit characteristics, and an electro-optical device and electronic equipment using the same.

[0020]

In order to solve the above problems, a method of manufacturing a semiconductor thin film according to the present invention comprises a step of forming a first insulating layer on a semiconductor layer formed on a substrate, and the first insulating layer. A step of forming a light absorbing layer on the layer, and a step of crystallizing the semiconductor layer by irradiating the light absorbing layer with light emitted from a light source while moving a light source and the substrate relatively. The light source has an output peak wavelength in the infrared region, and the light absorption layer is made of any one of W, Ti, and Cr. By using the above-mentioned material as the light absorbing layer, light in the infrared region, which is the peak output of a halogen lamp that is inexpensive and can produce a large output, is absorbed most efficiently, and the light absorbing layer itself has high heat resistance. Most suitable for heat treatment of layers.

More preferably, a second insulating layer is provided on the light absorbing layer. This can prevent the light absorption layer material from being oxidized during the heat treatment to significantly reduce the light absorption efficiency. In addition, the thickness of the second insulating layer is 50 to 250n.
By setting m, the function as an antireflection film can be imparted at the same time, and more efficient absorption of light energy by the absorption layer can be achieved than when the film is not provided.

Preferably, when an insulating layer is not provided on the light absorption layer, light irradiation is carried out in an inert gas. This makes it possible to prevent oxidation of the light absorption layer without increasing the number of steps for providing an insulating layer for preventing oxidation, and thus the steps are simple.

Preferably, the light source has an output peak wavelength at a wavelength of 1 μm, the light absorbing layer is W, and the thickness of the second insulating layer is 100 to 200 nm.
The combination of the light source, the light absorption layer, and the insulating film on the light absorption layer that can be applied to the present invention is a combination having the highest absorption efficiency of light energy into the absorption layer.

The thickness of the light absorption layer is preferably 100 nm or more. In order to shorten the time required for forming the absorption layer, it is naturally preferable that the absorption layer is thin, but W, Ti, and Cr suitable for the present invention completely absorb infrared light and are stable independent of the thickness. A film thickness of at least 100 nm is required to obtain the desired reflectance. Therefore, at least 100 nm is a condition for efficient absorption of irradiation light by the absorption layer.

Preferably, the light irradiation to the light absorption layer is
Peak power density is 700 W / cm ^{2 at} any point on the substrate
The irradiation time is 300 milliseconds or less. Considering an arbitrary point on the substrate, the light energy irradiated to this point gradually increases when the irradiation light starts to hit, and gradually decreases when the intensity of the peak is exceeded. In the present specification, the time change of the irradiation power is called an irradiation profile (see FIGS. 5 to 9). The irradiation profile is simply determined by the spatial intensity distribution of the irradiation light on the absorption layer and the speed at which the irradiation light and the substrate move relatively. Here, the peak power density means the maximum value of the irradiation light power density in the irradiation profile, and the irradiation time means the full width at half maximum of the irradiation profile. By irradiating light under the condition that the power density is 700 W / cm ² or more and the irradiation time is 300 ms or less at any point on the substrate, the temperature of the light absorption layer and the semiconductor layer is increased to the melting point of the semiconductor layer or more, Since the temperature can be set to 600 ° C. or lower, the present invention can be applied to the low temperature process.

Preferably, the light irradiation to the light absorption layer is
Peak power density is 950 W / cm ^{2 at} any point on the substrate
The irradiation time is 150 milliseconds or less. As a result, the temperature rise of the substrate can be suppressed to about 400 ° C., so that the present invention can be applied to a large area substrate or a thin substrate.

Preferably, the light irradiation to the light absorption layer is
Peak power density is 1800 W / cm at any point on the substrate
^The irradiation time is ² or more and the irradiation time is 44 milliseconds or less. As a result, the temperature rise of the substrate can be suppressed to about 200 ° C., so that the present invention can be applied to a plastic substrate.

The method of manufacturing a thin film transistor of the present invention is
A semiconductor layer formed by the method for manufacturing a semiconductor thin film is used as an active layer. With such a method, a large grain size poly-Si film formed by a low temperature process can be used as an active layer, so that a thin film transistor with high mobility can be provided.

The electro-optical device of the present invention includes the thin film transistor manufactured by the above method as a driving element of a display pixel and a constituent element of a peripheral circuit. This makes LC
It becomes possible to equip a D or organic EL display device with a memory, a fingerprint sensor, and a circuit group having an arithmetic function,
A more highly functional display device can be provided.

Electronic equipment of the present invention includes the above-mentioned electro-optical device. Examples of such electronic devices include mobile phones, video cameras, personal computers, head-mounted displays, projectors, fax machines,
Digital cameras, portable televisions, personal digital assistants, electronic organizers, multifunction cards, etc. are suitable.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 illustrates a semiconductor thin film manufacturing process of the present invention.

(1. Formation of Semiconductor Layer) In order to carry out the present invention, a base protective film (10) is usually formed on a substrate (100).
Since 1) is formed and the semiconductor thin film 102 is formed thereon, this series of forming methods will be described.

The substrate (100) to which the present invention can be applied is a conductive material such as metal, silicon carbide (Si).
C), alumina (Al ₂ O ₃ ) and aluminum nitride (A
In addition, ceramic materials such as 1N), transparent or non-transparent insulating materials such as fused quartz and glass, semiconductor materials such as silicon and germanium wafers, and LSI substrates obtained by processing the same are possible. The semiconductor film is deposited directly on the substrate or via the underlayer protection film, the lower electrode, and the like.

As the base protection film (101), a silicon oxide film (SiO _X : 0 <x ≦ 2) or a silicon nitride film (Si ₃ N _x :
An insulating material such as 0 <x ≦ 4) may be used. When it is important to control impurities in a semiconductor film such as when a thin film semiconductor device such as a TFT is formed on an ordinary glass substrate, sodium (Na), potassium (K), etc. contained in the glass substrate are It is preferable to deposit the semiconductor film after forming the base protective film so that mobile ions are not mixed in the semiconductor film. When a conductive material such as a metal material is used as the substrate and the semiconductor film must be electrically insulated from the metal substrate, the underlying protective film is naturally indispensable to ensure the insulation. Further, when forming a semiconductor film on a semiconductor substrate or an LSI element, an interlayer insulating film between transistors and between wirings simultaneously serves as a base protective film.

The base protective film is prepared by first cleaning the substrate with pure water or an organic solvent such as alcohol, and then applying atmospheric pressure chemical vapor deposition (APCVD) or low pressure chemical vapor deposition (LPCV) on the substrate.
D method), plasma-enhanced chemical vapor deposition method (PECVD method), or other CVD method or sputtering method. When a silicon oxide film is used as the base protection film, monosilane (SiH ₄ ) or oxygen can be deposited as a raw material at a substrate temperature of about 250 ° C. to 450 ° C. in the atmospheric pressure chemical vapor deposition method. In the plasma chemical vapor deposition method and the sputtering method, the substrate temperature is about room temperature to 400 ° C. The film thickness of the base protective film must be sufficient to prevent the diffusion and mixing of the impurity element from the substrate, and the minimum value is about 100 nm or more. In consideration of variations between lots and substrates, the thickness is preferably about 200 nm or more, and if it is about 300 nm, the function as a protective film can be sufficiently fulfilled. When the underlayer protection film also serves as an interlayer insulating film between IC elements or wiring connecting these, it is usually 4
The film thickness is about 00 nm to 600 nm. If the insulating film becomes too thick, cracks occur due to the stress of the insulating film. Therefore, the maximum film thickness is preferably about 2 μm. When productivity must be taken into consideration, the upper limit of the insulating film thickness is about 1 μm.

Next, the semiconductor thin film (102) will be described.
It As a semiconductor film to which the present invention is applied, silicon (S
i) and germanium (Ge) etc.
In addition, silicon-germanium (Si_xGe_1-x: 0
<X <1) and Silicon Carbide (Si_xC_1-x:
0 <x <1) and germanium carbide (Ge_xC
_1-xA semiconductor film of a Group IV element composite such as 0 <x <1),
Gallium arsenide (GaAs) and indium antimony
Complex compound of Group 3 element such as (InSb) and Group 5 element
Semiconductor film or cadmium selenium (CdSe), etc.
There are composite compound semiconductor films of Group 2 elements and Group 6 elements.
It Or silicon, germanium, gallium, arsenic
(Si_xGe_yGa_zAs_z: X + y + z = 1)
In addition, further compound compound semiconductor films and phosphorus in these semiconductor films
Donors such as (P), arsenic (As), antimony (Sb)
-N-type semiconductor film to which an element is added, or boron (B),
Aluminum (Al), gallium (Ga), indium
P-type semiconductor film added with an acceptor element such as (In)
The present invention can also be applied to the above. These semiconductor thin films
Is CV such as APCVD method, LPCVD method, PECVD method, etc.
D method or PVD method such as sputtering method or vapor deposition method
To achieve. When a silicon film is used as the semiconductor film, LP
In the CVD method, the substrate temperature is about 400 to 700 ° C.
As disilane (Si_TwoH₆) Is used as a raw material
obtain. In the PECVD method, monosilane (SiH _Four) Etc.
As a raw material, if the substrate temperature is about 100 ° C to 500 ° C
Can be deposited. Substrate temperature when using the sputter method
Is from room temperature to about 400 ° C. Half deposited like this
The initial state of the conductor film (as-deposited state) is
Various properties such as amorphous, mixed crystal, microcrystalline, or polycrystalline
However, in the present invention, the initial state is any state.
It doesn't matter. In the present specification, an amorphous crystal
Not only crystallization but also recrystallization of polycrystalline and microcrystalline materials
All are called crystallization. The thickness of the semiconductor film is
It is suitable to use about 20 nm to 100 nm when using
There is.

(2. Formation of First Insulating Layer) Next, a first insulating layer (103) is formed on the semiconductor layer. The role of this insulating layer is to separate the light absorption layer (104) and the semiconductor layer (102) to be formed in the next step. In order to prevent the diffusion of impurities from the light absorption layer to the semiconductor layer in the subsequent heat treatment step,
An insulating material such as a silicon oxide film (SiO _x : 0 <x ≦ 2) or a silicon nitride film (Si ₃ N _x : 0 <x ≦ 4) can be applied to this insulating layer. The first insulating layer is formed by etching the natural oxide film on the semiconductor layer with hydrofluoric acid, washing with pure water, and then applying AP.
It is formed by a CVD method such as a CVD method, an LPCVD method, a PECVD method, or a sputtering method. When a silicon oxide film is used as the insulating layer, the substrate temperature is set to 2 by the atmospheric pressure chemical vapor deposition method.
SiH ₄ or oxygen can be deposited as a raw material at about 50 ° C. to 450 ° C. In the PECVD method and the sputtering method, the substrate temperature is from room temperature to 400 ° C. The thickness of the first insulating layer needs to be thick enough to prevent diffusion and mixing of the impurity element from the light absorption layer, while the heat conduction from the light absorption layer to the semiconductor layer can be efficiently performed. Is the condition. Therefore, the film thickness of the insulating layer naturally has an optimum range, and the minimum value is about 50 nm and the maximum value is about 1 μm, which is the same as the thermal diffusion length.

(3. Formation of Light Absorption Layer) Next, a light absorption layer (104) is formed on the first insulating layer (103). The light absorption layer has a role of efficiently absorbing the light applied in the next step and raising the temperature of the semiconductor layer to a high temperature by heat generation and heat conduction by the light. Therefore, the relationship between the wavelength range of the irradiated light, the reflectance and the absorption coefficient in that wavelength range, and the heat resistance are important. A refractory metal material is suitable for this purpose. Since a high concentration of free carriers (electrons) exists in the metal, the components other than the reflected component of the irradiation light are completely absorbed. For this reason, it is important to use a refractory metal thin film having a low reflectance in order to efficiently absorb light by the metal thin film. FIG. 2 shows the reflectance spectra of various refractory metal films. As will be described later, in the present invention, a halogen lamp which is relatively inexpensive and can obtain a high output is used as a light source for light irradiation. Suitable as As can be seen from FIG. 2, the reflectance at the same wavelength gradually decreases in the order of Ta, Mo, Cr, Ti, and W. In order to apply the semiconductor forming method of the present invention to a large area substrate with the output of a halogen lamp which is relatively easy to obtain at present, a slight difference in the reflectance of the absorption layer material is a decisive factor. Especially one side is 400mm
In order to apply the above large area substrate, the absorption layer material is C
Any one of r, Ti and W is most suitable.

The thickness of the absorption layer is preferably thin in order to reduce the takt time in the manufacturing process, but the thickness is required to be at least sufficient to absorb the irradiation light. FIG. 3 shows the film thickness dependence of the reflectance at a wavelength of 1 μm when Cr and W are used for the absorption layer. In both materials, the reflectance is extremely small when the film thickness is 50 nm or less. This is because the film is too thin to absorb the irradiation light and generate a transmission component. With a film thickness of 50 to 100 nm, the reflectivity increases due to the interference effect of the light reflected from the lower surface of the film and the light reflected on the film surface. As can be seen from this, in order to sufficiently absorb the irradiation light and realize a stable reflectance, it is important that the film thickness of the light absorption layer is 100 nm or more, and more preferably 150 nm or more.

As a method of forming these materials as a light absorbing layer on the insulating layer, there are a vacuum vapor deposition method and a sputtering method. Since these materials are high melting point metals, the sputtering method is most effective, and the sputtering method is also advantageous in that it can be formed in a large area.

(4. Formation of Second Insulating Layer) A second insulating layer is formed on the light absorption layer thus formed. This second insulating layer has two important roles.

One is to prevent the light absorption layer from being oxidized by the temperature rise of the absorption layer due to light irradiation. Upon irradiation with light, the absorption layer easily rises to a temperature of 1000 ° C. or higher, and when this treatment is performed in the atmosphere, oxygen in the atmosphere reacts with the metal of the light absorption layer to form an oxide. Since the metal oxide becomes optically transparent, the light absorption efficiency of the light absorption layer decreases during the process, and the temperature of the semiconductor layer cannot be increased or the reproducibility of the process cannot be ensured. Cause By providing the second insulating layer, it is possible to shield the light absorbing layer from the atmosphere, so that the problem of oxidation of the light absorbing layer during such processing can be completely prevented. When the second insulating layer is not provided, it is also effective to carry out the light irradiation treatment in an inert gas atmosphere. This method has an advantage that oxidation of the light absorption layer can be prevented without increasing the step of forming the second insulating layer.

Another role of the second insulating layer is to reduce the reflectance of the light absorption layer by the antireflection film effect.
In FIG. 4, the wavelength is 1 μ when Cr and W are used as the light absorption layer and the SiO ₂ film (n = 1.47) is used as the second insulating layer.
The dependence of the light reflectance of m on the thickness of the second insulating layer is shown. Since the light absorption layer suitable for the present invention is a metal film, it has a large difference in refractive index from air. Therefore, in order to reduce the reflectance of the light absorption layer, it is extremely effective to provide a layer having a refractive index (n) closer to that of air than the metal film. Since the antireflection film lowers the reflectance due to the interference effect, the reflectance periodically changes depending on the thickness of the second insulating layer on the light absorption layer, as shown in FIG. Naturally, there are some film thicknesses under the condition of functioning as an antireflection film, but the minimum film thickness with a short film formation time is most preferable for shortening the process tact. Although it depends on what is used as the material of the second insulating film, a film thickness of about 50 to 250 nm is preferable as such a condition. Thus, for example, when W is used as the light absorbing material, the reflectance can be dramatically reduced from 48% to less than 20% by forming a 140 to 150 nm SiO ₂ film as the second insulating layer. It is extremely effective in efficiently absorbing light into the light absorption layer.

(5. Light Irradiation) The laminated structure formed as described above is irradiated with light. As described above, the irradiation light is required to be efficiently absorbed by the light absorption layer, and therefore its spectrum is important. In other words, what kind of light source is used greatly affects the wavelength of the light source. As a light source applicable to the present invention, a halogen lamp, a metal halide lamp, a mercury lamp, a Xe lamp,
There are arc lamps, etc. In order to enable treatment in a large area, a high lamp output is required and a low running cost is required due to lamp replacement. For this reason, the halogen lamp is most suitable as the light source of the present invention. Although there are various types of halogen lamps, they have a peak wavelength in the vicinity of 1 μm and can easily achieve an output of 8 kW or more. Further, the price of one linear lamp light source having an effective light source length of 400 mm is about 100,000 yen at most, which is very low as compared with 15 million yen of one excimer laser tube.

In the present invention, for example, two line-shaped halogen lamps (111) having a length of 400 mm are arranged in parallel, and the light emitted from each light source is reflected by a reflecting mirror (11).
The method of condensing (106) on the substrate to be processed in 2) is effective. FIG. 1 schematically shows the sectional structure of the lamp unit (110). The parabolic surface is coated with gold, and as shown in the figure, the light from the two halogen lamp light sources is efficiently focused at the same location on the substrate. In addition, in order to block the light radiated on the substrate other than the condensing point,
It is effective to provide the light shielding slit (115). Without this slit, the substrate temperature rises more than necessary, which is a problem in applying the present invention to the low temperature process. In this way, the lamp and the lamp unit are moved relative to each other as indicated by 114 while the lamp light is continuously irradiated in a state of being condensed on the substrate, and the processing is performed. As a result, the temperature of the lamp light condensing portion (107) of the light absorption layer rapidly rises, and the heat diffused through the first insulating layer locally raises the temperature of the semiconductor layer (108). By appropriately selecting the irradiation conditions, the temperature of the processed portion 108 of the semiconductor layer reaches the melting point or higher and melts. Since the molten portion 108 moves in the direction of 114 along with the movement of the lamp unit, a large particle size poly-Si (1) crystallized in the cooling process after melting is located behind the molten portion 108.
09) is formed. High quality poly in this way
The -Si film can be easily provided at low cost.

The lamp unit of the present invention has the radiation thermometer (113) at the intermediate position of the two halogen lamps, and has the cylindrical collimator or lens on the front surface so that the measurement range is not widened. Measuring the substrate temperature at this position has the advantage that the problem that infrared light emitted from the lamp light source directly enters the radiation thermometer and shows an abnormally high temperature, and the substrate temperature can be measured accurately .
As a result, the temperature of the substrate to be processed is measured, and the lamp output is fed back to enable stable lamp irradiation processing.

The above-mentioned reflection optical system is formed in a cylindrical shape in the long axis direction of the halogen lamp, and as a result, a large area can be processed by linearly irradiating light condensed on the substrate as shown in FIG. It will be possible. FIG. 5 shows a state of scanning (505) while irradiating the substrate (100) with the linear irradiation light (500). As described above, since a halogen lamp can easily form a 400 mm line-shaped light source, for example, for a large substrate of 400 mm x 500 mm, once the 400 mm side and the long axis direction of the halogen lamp are parallel, By performing the scan, a high quality poly-Si film having a large grain size can be formed on the large area substrate. For example, if the lamp unit is 10 mm /
When the processing is performed while moving at a speed of s, the processing of the entire surface of the substrate is completed in only 50 seconds. Therefore, the manufacturing method of the semiconductor thin film of the present invention is not only low in manufacturing apparatus cost but also high in process throughput. Thus, a high-performance thin film transistor can be provided.

In particular, as the light absorbing layer material disclosed in the present invention, for example, a W film of 150 nm and a second insulating layer of 150 nm (for example, SiO ₂ film) are used, and output as a light source for light irradiation 8
When two linear light sources with linear kW halogen lamps are used, the absorption efficiency of light by the absorption layer is extremely high. Therefore, crystallization of a semiconductor thin film on a large glass substrate of 50 cm on a side is performed by one irradiation light scan. It becomes possible with.

Next, specific lamp irradiation conditions will be described. When the lamp light is condensed and applied to the substrate as shown in FIG. 5, the intensity distribution of the lamp light on the substrate (light absorbing layer) (503) is typically a Gaussian distribution shape as shown by 501. Becomes The irradiation light shape suitable for the present invention has a half-value width of this spatial distribution of about 1 to 10 mm. When the irradiation light is scanned on the substrate at a constant speed, the temporal change of the optical power irradiated to an arbitrary point (for example, 504) on the substrate becomes an irradiation profile like 511 when the scanning speed is fast, and conversely. If it is slow, the irradiation profile will be 512. In the light irradiation of the present invention, the peak power of the irradiation profile and the irradiation time (in this specification, the full width at half maximum of the irradiation profile is defined as the irradiation time) are important. For example, in FIG. 6, the irradiation peak power is 500 W / cm ² The temperature changes at the light absorption layer / semiconductor layer and the depth positions of the respective substrates when light irradiation is performed under the irradiation time of 600 ms are shown. Here, a trapezoidal shape having a shape close to a Gaussian distribution is used as a substitute for the irradiation light profile, the light absorption layer is W, and a second insulating layer is provided to provide an effective reflectance of 25.
% Is shown. Since the thicknesses of the light absorption layer and the semiconductor layer are sufficiently smaller than the thermal diffusion length in the time order as considered here, the temperatures of these two layers are exactly the same. As can be seen from FIG. 6, the light irradiation of the present invention causes the temperature of the light absorption layer / semiconductor layer to rapidly rise locally, and the maximum temperature is 1
Since the temperature reaches about 780 K, the Si film melts. When the irradiation light passes and the temperature decreases, the Si film solidifies and crystallizes at the same time. Under this light irradiation condition, since the irradiation time is relatively long, the substrate temperature also rises and finally reaches about 1200K. Therefore, the irradiation conditions shown in FIG. 6 are suitable when a heat resistant substrate such as quartz is used as the substrate. In order to locally raise the temperature of only the light absorption layer / semiconductor layer without raising the substrate temperature, it is necessary to irradiate high power in a shorter time. As is clear from the above description, this can be achieved by reducing the half-value width (converging) in the spatial distribution of the irradiation light, or by increasing the scan speed and simultaneously increasing the lamp output. For example, as shown in FIG. 7, irradiation peak power 700 W / cm
^{2. If} the irradiation time is 300 ms, the temperature of the light absorption layer / semiconductor layer reaches 1750 K, but the substrate temperature finally rises to about 900 K only. This is because the light irradiation conditions became high power for a shorter time, and the light absorption layer / semiconductor layer near the substrate surface was heat-treated in a non-thermal equilibrium manner. As described above, the semiconductor thin film manufacturing method of the present invention can be easily applied to a low temperature process by controlling the light irradiation profile.

In addition, in the method for manufacturing a semiconductor thin film of the present invention, the crystal growth direction is horizontal, and since the semiconductor layer is sandwiched between the upper and lower insulating layers, the surface of the semiconductor layer after crystallization is extremely flat. Since this does not lower the withstand voltage even when a thin film transistor having a thin gate insulating film is formed, it can be applied to a finer TFT having a thinner gate insulating film, resulting in excimer laser crystallization. It has an advantage that a higher-speed circuit can be formed than when a poly-Si film is used.

Furthermore, since the poly-Si film produced by the method for producing a semiconductor thin film of the present invention utilizes lateral crystal growth, crystals grow with a preferential orientation. This is because the crystal growth rate is different depending on the plane orientation. In particular, the <100> plane grows preferentially in the crystal growth direction.
The y-Si film is characterized in that the <110> plane grows in the vertical direction. Since the crystal orientation can be controlled in the present invention as described above, ordered grain boundaries are easily formed in the crystal grain boundary portions. Such ordered grain boundaries have a low probability of generating electrically active defects. The TFT manufactured using the poly-Si film manufactured in this manner has the characteristics that the plane orientation is aligned, the mobility variation is extremely small, and the defect density is low, so that the threshold voltage is low.

According to the method of forming a semiconductor thin film of the present invention, the irradiation light source has a high power of kW order and the heat treatment time is of millisecond order.
Crystallization is possible even with a thickness exceeding 00 nm. In the conventional laser crystallization method, the irradiation time for one pulse is as short as nanoseconds, and the energy density to be input is 1 J per cm ² as a practical upper limit. Therefore, it is a principle to crystallize a semiconductor layer with a thickness of 100 nm or more. Was impossible. On the other hand, the method of forming a semiconductor thin film of the present invention can sufficiently crystallize even a semiconductor layer having a thickness of about 1 micron, and thus can be applied to the formation of a polycrystalline silicon film used for solar cell applications. Have.

In order to apply the method for producing a semiconductor thin film of the present invention to a low temperature process, it is also effective to set the initial substrate temperature to room temperature or to cool the substrate during processing. If the substrate is cooled, the substrate temperature rise can be prevented and the low temperature process can be applied even if the light irradiation profile as shown in FIG. 6 is used.

Although the conditions for melting and crystallizing the semiconductor layer have been described above, the semiconductor layer can be crystallized without necessarily melting in the method for producing a semiconductor thin film of the present invention. In the conventional solid phase growth method, heat treatment was performed at 600 ° C. for about 48 hours. However, in the method of manufacturing a semiconductor thin film of the present invention, the temperature of the semiconductor layer easily reaches 1000 ° C. or higher, so that the heat treatment time is, for example, about 1 second. But solid phase growth occurs. For example, an irradiation peak power of 400 W / cm ² and an irradiation time of 1 second are examples of an irradiation profile that causes such solid phase growth. Although a large grain crystal such as in the case of melting / crystallization cannot be obtained, a poly-Si film having a grain size of 1 μm or more and a flat surface can be easily obtained. However, in this case, since the substrate temperature also becomes high, it is suitable for application to a high temperature process.

[0055]

Example 1 Example of the method for producing a semiconductor thin film of the present invention
Description will be given with reference to FIG. Substrate used in the present invention and bottom
The ground protection film is similar to the above description, but here is the basic
300 mm x 300 mm square general purpose plate as an example
Non-alkali glass (100) is used. First, the substrate 100
Form a base protective film (101) that is an insulating material on top
It Here, the substrate temperature is set to 150 ° C. and the ECR-PEC is set.
A silicon oxide film having a thickness of about 200 nm is formed by the VD method.
accumulate. Then the true layer that will later become the active layer of the thin film transistor
A semiconductor film (102) such as a conductive silicon film is deposited. Semi-conductor
The body membrane has a thickness of about 50 nm. In this example, high vacuum type L
Using a PCVD device, disilane (Si
_TwoH₆) At a flow rate of 200 SCCM and a deposition temperature of 425 ° C.
Amorphous silicon film 102 is deposited. First, high vacuum LP
Inside the reaction chamber with the reaction chamber of the CVD device at 250 ° C
Multiple (for example, 17) substrates in the part with the front side facing down
Place it. After this, the operation of the turbo molecular pump was started.
Start. After the turbo molecular pump reaches steady rotation, the reaction
It takes about 1 hour for the room temperature to reach a temperature of 250 ° C to 425 ° C
Raise to the product temperature. For the first 10 minutes after the start of heating
No gas was introduced into the reaction chamber and the temperature was raised in vacuum.
Nitrogen gas with a purity of 99.9999% or higher after 300 S
Continue to flow CCM. Equilibrium pressure in the reaction chamber at this time
Is 3.0 × 10^-3It is Torr. Reach deposition temperature
After that, the raw material gas disilane (Si _TwoH₆) 20
Purity of 99.9999% or more while flowing 0 SCCM
Flow 1000 SCCM of helium (He) for dilution. Accumulation
The pressure in the reaction chamber immediately after the start was about 0.85 Torr.
It As the deposition progresses, the pressure in the reaction chamber gradually rises,
The pressure immediately before the end of deposition is approximately 1.25 Torr. Such
The silicon film (102) deposited in the same manner as in the peripheral portion of the substrate.
The film thickness within the 286 mm square area excluding mm
The fluctuation is within ± 5%. Then the first insulating layer (103)
Form. Here, 100 n is obtained by the ECR-PECVD method.
SiO having a film thickness of about m_TwoThe film was deposited. Raw material gas
As SiH_FourAnd O_Two30 sccm and 4 respectively
Flow at 0 sccm and heat the substrate to 100 ° C
Zuma discharge was started to form a film. Next, the light absorption layer (10
4) W film is formed to 150 nm by sputtering
did. As shown in FIG. 3, to form W of this film thickness
Therefore, the irradiation light can be stably absorbed, and during processing
The temperature of the light absorption layer was extremely stable. This is light absorption
SiO as the second insulating layer (105) on the collecting layer_TwoMembrane 14
5 nm was formed. This is exactly the same line as the first insulation layer
The film was formed according to the circumstances. W is used as a light absorbing material,
145 nm SiO as second insulating layer_TwoFormed a film
Dramatically reduces the effective reflectance from 50% to less than 25%
I was able to. After this, there is an intensity peak near 1 μm
Halogen lamp light of 300 mm long and 5.5 mm short axis
Shaped into a line, power density 950 W / cm^TwoAt the light
Irradiation was performed from the absorption layer side. In order to suppress the rise in substrate temperature,
The substrate is scanned at a speed of 36 mm / s in the short axis direction of the irradiation light.
I did. Light irradiation time at any point is 150 ms
It As a result, the molten silicon layer (10
8) is formed, and the solid-liquid interface (108
The crystal growth occurs at the boundary between the and
Formed a polycrystalline silicon layer (109) on the entire surface of the substrate.
With such a method, the width is 20 to 50 μm and the length is 1
A poly-Si film having a large grain size of 00 μm or more can be formed.
Light absorption layer / semiconductor layer in this irradiation profile and
FIG. 8 shows the temperature change at each depth of the substrate. Half of the invention
In the manufacturing method of the conductor thin film, the substrate temperature is about 400 ° C at most.
It rises only once, and even conventional non-alkali glass is enough.
Can be extinguished. Irradiation profile shown in Fig. 7 (irradiation peak
Power 700W / cm^Two, Irradiation time 300 ms)
Minutes are applicable. The irradiation profile of Fig. 8 is thermal
Thin glass with a substrate thickness of 0.5 mm, because the effect is small
The method of manufacturing a semiconductor thin film of the present invention can be applied to a substrate.
It was. With the above light irradiation method, crystal grains can be processed in a low temperature process.
A large poly-Si film of the system could be easily formed.

[0056]

[Embodiment 2] A second embodiment of the present invention will be described with reference to FIG. The method for forming the base protective film, the semiconductor layer, the first insulating layer, and the light absorption layer is exactly the same as in the first embodiment. Thereafter, light irradiation was performed without forming the second insulating layer. However, in order to prevent oxidation of the light absorption layer, the irradiation atmosphere was completely replaced with Ar gas at the time of lamp light irradiation, and light irradiation was performed after confirming that the oxygen concentration in the atmosphere was 0.1% or less. . The light irradiation conditions are exactly the same as in the example.
As a result, it was possible to obtain a high quality poly-Si film which was exactly the same as that of Example 1 without forming the second insulating layer. When the semiconductor thin film of the present invention is applied to a TFT, a first insulating layer, a light absorption layer, and a second insulating layer are formed on the semiconductor layer, light irradiation is performed, and then these three layers are removed by etching to make the semiconductor layer an active layer. To use as. Therefore, by simplifying the laminated structure on the semiconductor layer, the time required for the process, that is, the time for forming the second insulating layer and the etching can be shortened.

[0057]

Example 3 In the third example of the present invention, a semiconductor thin film was manufactured under different light irradiation conditions. The method of forming the substrate to be processed is exactly the same as that of the first embodiment except that a plastic substrate having relatively high heat resistance is used as the substrate.
Then, halogen lamp light having an intensity peak near 1 μm was shaped into a linear shape having a long length of 300 mm and a short axis of 1 mm, and the light was irradiated from the light absorption layer side at a power density of 1800 W / cm ² . In order to suppress the rise in substrate temperature, the substrate is
Scanning was performed in the short axis direction of the irradiation light at a speed of 3 mm. The light irradiation time at an arbitrary point is 44 ms. FIG. 9 shows changes in temperature at each depth of the light absorption layer / semiconductor layer and the substrate due to this irradiation profile. As a result, the temperature rise of the substrate can be further reduced, and the temperature rises to 220 ° C. at most. In addition, the large grain size poly-Si film is formed in the first embodiment.
The same quality as 2 can be formed. In this example, it was confirmed that the method for manufacturing a semiconductor thin film of the present invention can be applied even if a plastic substrate is used.

[0058]

[Embodiment 4] Implementation of a method for manufacturing a thin film transistor according to the present invention
An example will be described with reference to FIG. Samples used in this example
The structure may be that of either Example 1 or 2.
However, the structure of Example 1 was used here. Light irradiation is 1 μm
Long halogen lamp light with intensity peak near 300
mm, short axis 5.5 mm line shaped, power density
700 W / cm^TwoAt the moving speed of 18 from the light absorption layer side
Irradiation in mm. This enables large particle size and high quality poly-
A Si film was formed. In this embodiment, the pol thus formed is
In order to use the y-Si film as an active layer, a second insulating layer,
The absorbing layer and the first insulating layer were removed by etching.
SiO_Two5% HF solution for film etching and light absorption
The layer W is a plasma generated by chlorine-based gas plasma discharge.
It was removed by dry etching using Zical. Like this
Then, the substrate with the exposed poly-Si film 901 is plated.
Set in the processing chamber. Plasma processing chamber
Substrate temperature is 250 ° C and hydrogen gas is 80 scc
m flow, pressure 1 Torr and parallel plate RF electrode 1
Plasma discharge was performed with a power of kW. This
Capture level (defect) passivation treatment of poly-Si film and
And surface hydrogen termination treatment was performed for 160 seconds. After this,
Photolithography is performed on the polycrystalline silicon film by photolithography.
Form a photoresist pattern and use CF_FourAnd O_TwoMixed gas
Dry etching by remote plasma discharge used
I did it. Island-patterned poly-Si
A substrate is formed to form a gate insulating film (902) on the film.
Set in the insulating film forming chamber. 1 in the chamber
0^-6After evacuating to a vacuum level of (torr) table,
Gas and oxygen gas at a flow rate ratio of 1: 6, and chamber pressure
2 x 10⁻³Adjust to (Torr). Inside the chamber
When the gas pressure of is stable, ECR discharge is started and the insulation film
Start film formation. Input microwave power is 1kW
Then, the microwave was introduced through the introduction window parallel to the magnetic field lines.
There is an ECR point 14 cm from the introduction window. Success
The film was formed at a film formation rate of 10 nm / min. By this
Thus, a gate insulating film (902) having a thickness of 100 nm was formed. Pull
Then, the thin film to be the gate electrode (905) is formed by PVD or
Or deposited by the CVD method or the like. Normally, the gate electrode and gate
Since the wiring is made of the same material in the same process, this material
Has low electrical resistance and is stable to thermal processes around 350 ° C
Is desired. In this example, the film thickness of 600 nm
A Tal thin film is formed by a sputtering method. Tantalum thin film
The substrate temperature is 180 ° C when forming
Argon gas containing 6.7% nitrogen gas is used as the gas.
It The tantalum thin film thus formed has a crystal structure of α structure.
And its specific resistance is approximately 40 μΩcm. Ge
After depositing a thin film to be the gate electrode, patterning
Next, impurity ions are implanted into the semiconductor film to
Shape the rain area (903, 904) and the channel area.
To achieve. At this time, the gate electrode serves as a mask for ion implantation.
Therefore, the channel is formed only under the gate electrode.
It becomes a self-aligned structure. Ion doping raw material
As a gas, the concentration diluted with hydrogen is about 0.1% to 1
About 0% phosphine (PH_Three) And diborane (B
_TwoH₆) Or the like is used as a hydride of an implanted impurity element. This example
Then, aiming at NMOS formation, an ion doping system
Using phosphine (P with a concentration of 5% diluted in hydrogen
H_Three) Is injected at an acceleration voltage of 100 keV. PH_Three ⁺Or
H_Two ⁺Total ion implantation amount including ions is 1 x 10¹⁶
cm^-2Is.

Next, an interlayer insulating film was formed by PECVD. The source gas is TEOS (tetraethoxysilane), N ₂ O and Ar gas, and the pressure is 1.5 Torr.
Discharge was performed with a power of r and 1 kW to form an interlayer insulating film having a thickness of 800 nm. Next, contact holes are opened on the source / drain, and the source / drain extraction electrodes (907, 908) and the wiring are made of aluminum by PVD or C
The thin film transistor is completed by forming the thin film transistor by the VD method or the like.

The thin film transistor obtained by the manufacturing method of the present invention can be applied to various electronic devices including an electro-optical device. FIG. 11 shows examples of electronic devices to which the electro-optical device can be applied. FIG. 1A shows an application example to a mobile phone, and the mobile phone 230 includes an antenna unit 231, a voice output unit 232, a voice input unit 233, an operation unit 234, and the electro-optical device 10 of the present invention. . As described above, the electro-optical device 10 of the present invention can be used as the display unit of the mobile phone 230. FIG. 2B shows an example of application to a video camera. The video camera 240 includes an image receiving unit 241 and an operating unit 24.
2 and the electro-optical device 10 of the present invention. As described above, the electro-optical device of the present invention can be used as a finder or a display unit. In addition, it can be applied to portable personal computers, head mounted displays, rear type projectors, and front type projectors. As described above, the electro-optical device of the present invention can be used as an image display source.

The electro-optical device 10 of the present invention is not limited to the above example.
Can be applied to any electronic device to which an active matrix electro-optical device can be applied. For example, in addition to this, it can also be utilized in a fax machine with a display function, a finder of a digital camera, a portable TV, a DSP machine, a PDA, an electronic notebook, an electronic bulletin board, a display for advertisement and the like.

As described above, in the conventional technique, an effective process for forming a high quality poly-Si film having a large crystal grain size and a flat surface by a low temperature process, a high throughput and a low cost was not clear. However, as described above, by using the method for manufacturing a semiconductor thin film and a thin film transistor according to the present invention, an extremely high quality poly is obtained.
-Si film formation becomes possible. As a result, it is possible to manufacture a thin film transistor having high mobility, low threshold voltage and extremely small variation, and it is possible to realize an ultra-low power consumption circuit, which provides a multifunctional electro-optical device and electronic device at low cost. it can.

[Brief description of drawings]

FIG. 1 is a process sectional view showing a method for manufacturing a semiconductor thin film of the present invention.

FIG. 2 is a diagram showing reflectance spectra of various refractory metal films.

FIG. 3 is a diagram showing the film thickness dependence of reflectance of Cr and W films at a wavelength of 1 μm.

FIG. 4 is a film thickness of a second insulating layer provided on Cr and W and a wavelength of 1 μm.
The figure which showed the relationship of the reflectance in m.

FIG. 5 is a diagram illustrating a method and an irradiation profile in which the light irradiation method of the present invention is applied to a large area substrate.

FIG. 6 is a diagram showing a light irradiation profile of the present invention and temperature rises at respective depths of a light absorption layer / semiconductor layer and a glass substrate.

FIG. 7 is a diagram showing a light irradiation profile of the present invention and temperature rises at respective depths of a light absorption layer / semiconductor layer and a glass substrate.

FIG. 8 is a diagram showing a light irradiation profile of the present invention and temperature rises at respective depths of a light absorption layer / semiconductor layer and a glass substrate.

FIG. 9 is a diagram showing a light irradiation profile of the present invention and temperature rises at respective depths of a light absorption layer / semiconductor layer and a glass substrate.

FIG. 10 is a process sectional view showing the method of manufacturing the thin film transistor of the present invention.

FIG. 11 is a diagram showing an example of an electronic apparatus including the electro-optical device of the invention.

[Explanation of symbols]

100. ． ． Substrate 101. ． ． Base protection film 102. ． ． Semiconductor film 103. ． ． First insulating layer 104. ． ． Light absorbing layer 105. ． ． Second insulating layer 106. ． ． Condensing point of irradiation light on substrate 107. ． ． Temperature rising portion of light absorption layer 108. ． ． Liquid silicon 109. ． ． poly-Si 110. ． ． Lamp unit 111. ． ． Lamp light source 112. ． ． Reflective optical system / reflection surface 113. ． ． Radiation thermometer 114. ． ． Scan direction 115. ． ． Slit 500. ． ． Irradiation light 501. ． ． Irradiation end area 502. ． ． Unirradiated area 503. ． ． Irradiation light irradiation position 504. ． ． Arbitrary point on substrate 510. ． ． Irradiation light intensity distributions 511, 512. ． ． Illumination profile example 901. ． ． poly-Si film 902. ． ． Gate insulating films 903, 904. ． ． Source / drain regions 905. ． ． Gate electrode 906. ． ． Interlayer insulating films 907, 908. ． ． Source / drain electrodes 10. ． ． TFT manufactured using the semiconductor thin film of the present invention
Electro-optical device using

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme coat (reference) H01L 21/26 TF term (reference) 2H092 GA60 JA05 JA24 KA04 MA29 NA05 NA24 NA27 NA29 PA01 5F052 AA24 BA07 BA18 CA04 DA01 DA03 DA04 DA06 DB01 DB02 DB03 DB04 DB07 EA06 JA01 5F110 AA01 AA17 AA30 BB01 CC02 DD01 DD02 DD03 DD05 DD13 DD14 EE04 EE43 EE44 EE45 FF02 FF31 GG01 GG02 GG03 GG03 GG04 GG03 GG04 GG04 GG04 GG04 GG04 GG04 GG04 GG04 GG04 GG04 GG04 GG04 GG04 GG04 GG04 GG32 GG04 GG04 NN23 NN35 PP02 PP05 PP06 PP11 PP23 QQ11 QQ25

Claims (11)

[Claims] 1. A step of forming a first insulating layer on a semiconductor layer formed on a substrate, a step of forming a light absorbing layer on the first insulating layer, and a light source and the substrate relatively. A method of manufacturing a semiconductor thin film comprising crystallization of the semiconductor layer by irradiating the light absorption layer with light emitted from a light source while moving, wherein the light source has an output peak wavelength in an infrared region. And the light absorption layer has W, Ti, Cr
A method for manufacturing a semiconductor thin film, which is any one of the above materials. 2. A step of forming a first insulating layer on a semiconductor layer formed on a substrate, a step of forming a light absorbing layer on the insulating layer, and a second insulating layer on the light absorbing layer. Forming process,
A method of manufacturing a semiconductor thin film, which comprises crystallizing the semiconductor layer by irradiating the light absorption layer with light emitted from a light source while moving the light source and the substrate relatively. Has an output peak wavelength in the infrared region, the light absorption layer is made of any one of W, Ti, and Cr, and the thickness of the second insulating layer is 50 to 25.
A method for manufacturing a semiconductor thin film having a thickness of 0 nm. 3. The method for producing a semiconductor thin film according to claim 1, wherein the light irradiation is performed in an inert gas atmosphere. 4. The semiconductor according to claim 2, wherein the light source has an output peak wavelength near a wavelength of 1 μm, the light absorbing layer is W, and the thickness of the second insulating layer is 100 nm to 200 nm. Thin film manufacturing method. 5. The method for manufacturing a semiconductor thin film according to claim 1, wherein the thickness of the light absorption layer is 100 nm or more. 6. The light irradiation to the light absorption layer has a peak power density of 700 W / cm ² or more and an irradiation time of 300 milliseconds or less at an arbitrary point on the substrate. Item 1. A method for manufacturing a semiconductor thin film according to item 1. 7. The light irradiation to the light absorption layer has a peak power density of 950 W / cm ² or more and an irradiation time of 150 milliseconds or less at an arbitrary point on the substrate. Item 1. A method for manufacturing a semiconductor thin film according to item 1. 8. The light irradiation to the light absorption layer has a peak power density of 1800 W / cm ² or more and an irradiation time of 44 milliseconds or less at an arbitrary point on the substrate. Item 1. A method for manufacturing a semiconductor thin film according to item 1. 9. The semiconductor layer formed by the method of manufacturing a semiconductor thin film as described above is used as an active layer.
The method of manufacturing a thin film transistor according to any one of the above. 10. A thin film transistor manufactured by the method according to claim 9 is provided as a driving element of a display pixel.
Electro-optical device. 11. An electronic apparatus comprising the electro-optical device according to claim 10.