JPH0870129A - Semiconductor device and its fabrication - Google Patents

Abstract

PURPOSE: To obtain a thin film transistor having characteristics identical to those of a transistor employing single crystal silicon. CONSTITUTION: An amorphous silicon film formed on a glass substrate 101 is irradiated with laser light while being heated at 450 deg.C or above to form a mono-domain region 104. That region can be considered equivalent to a single crystal. When the region shown at 104 is employed in the formation of an active layer 106, a thin film transistor having characteristics identical to those of a transistor employing a single crystal silicon can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention disclosed in this specification relates to a thin film semiconductor device, and more particularly to a structure of a thin film transistor and a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, a transistor using a thin film semiconductor on a glass or quartz substrate (referred to as a thin film transistor)
Techniques for forming the are studied. In particular, a technique using amorphous silicon as a thin film semiconductor has been put to practical use and is used for an active matrix type liquid crystal display device and the like.

However, a thin film transistor using amorphous silicon has a problem that its characteristics are low. For example, when a higher display function of an active matrix liquid crystal display device is desired, the characteristics of a thin film transistor using an amorphous silicon film are too low.

There is also known a technique of forming a thin film transistor by using a crystalline silicon film obtained by crystallizing an amorphous silicon film. This technique transforms an amorphous silicon film into a crystalline silicon film by performing heat treatment or laser light irradiation after forming the amorphous silicon film. A crystalline silicon film obtained by crystallizing an amorphous silicon film generally has a polycrystalline structure or a microcrystalline structure.

When a thin film transistor is formed by using a crystalline silicon film, as compared with the case where an amorphous silicon film is used,
Much higher characteristics can be obtained. For example, in terms of mobility, which is one index for evaluating the characteristics of thin film transistors, a thin film transistor using an amorphous silicon film has a mobility of 1 to ² cm ² / Vs or less, but a crystalline silicon film is used. In the thin film transistor, 100 cm ² / Vs
It can be more or less.

However, the crystalline silicon film obtained by crystallizing the amorphous silicon film has a polycrystalline structure, and has various problems due to crystal grain boundaries. For example, there is a problem in that the withstand voltage of the thin film transistor is greatly limited because there are carriers that move through the crystal grain boundaries. In addition, there is a problem that characteristics change or deterioration is likely to occur when performing high-speed operation. In addition, there is a problem that the leakage current (leakage current) increases when the thin film transistor is turned off because there are carriers that move through the crystal grain boundaries.

Further, when the active matrix type liquid crystal display device is to be constructed in a more integrated form, it is desired that not only the pixel region but also the peripheral circuit be formed on one glass substrate. In such a case, in order to drive hundreds of thousands of pixel transistors arranged in a matrix, the thin film transistors arranged in the peripheral circuit are required to be able to handle a large current.

In order to obtain a thin film transistor capable of handling a large current, it is necessary to adopt a structure having a large channel width. However, a thin film transistor using a polycrystalline silicon thin film or a microcrystalline silicon thin film has a problem that it cannot be put into practical use due to the problem of withstand voltage even if the channel width thereof is widened. Further, there is a problem that the fluctuation of the threshold value is large and it is not practical.

[0009]

SUMMARY OF THE INVENTION An object of the invention disclosed in the present specification is to provide a thin film transistor which is not affected by crystal grain boundaries. Another object of the invention disclosed in this specification is to provide a thin film transistor which has a high withstand voltage and can handle a large current. Also,
Another object of the invention disclosed in this specification is to provide a thin film transistor without deterioration or fluctuation of characteristics. Another object of the invention disclosed in this specification is to provide a thin film transistor having characteristics similar to those of the case of using a single crystal semiconductor.

[0010]

One of the inventions disclosed in the present specification is a semiconductor device using a thin film semiconductor formed on a substrate having an insulating surface, wherein the thin film semiconductor has crystallinity. And contains hydrogen or a halogen element, and there is no crystal grain boundary in the thin film semiconductor forming the active layer of the semiconductor device.

Another structure of the invention is a semiconductor device using a thin film semiconductor formed on a substrate having an insulating surface, wherein the thin film semiconductor has crystallinity, and an active layer of the semiconductor device is formed. There is no grain boundary in the thin film semiconductor to be formed, and the point defects to be neutralized are 1 × 1.
It is characterized by containing 0 ¹⁶ cm ^-3 or more and containing hydrogen or a halogen element for neutralizing the point defects in a concentration of 1 × 10 ¹⁵ to 1 × 10 ²⁰ cm ^-3 .

Generally, the point defects existing in a single crystal silicon wafer made of molten silicon are below the measurement limit (1 ×
10 ¹⁵ cm ^-3 ) or less. In this sense, it can be said that the region having a thin film shape disclosed in the present specification and having no crystal grain boundary (monodomain region) is different from a conventionally known single crystal silicon wafer.

In the thin film silicon semiconductor disclosed in the present specification, atoms of carbon and nitrogen are 1 × 10 ¹⁶ cm ^{−3 to} 5 × 10 5.
It is contained at a concentration of ¹⁸ cm ^-3 and contains 1 x oxygen atom.
It is contained at a concentration of 10 ¹⁷ cm ^{−3 to} 5 × 10 ¹⁹ cm ⁻³ .

The thin film silicon semiconductor disclosed in the present specification has a thickness of 200Å to 2000Å. this is,
This is because the thin film amorphous silicon film formed by the plasma CVD method or the low pressure thermal CVD method is used as the starting film. The existence of the point defects (dangling bonds) to be neutralized as described above also results from the fact that the starting film is a thin film silicon semiconductor formed by the CVD method.

In the thin film silicon semiconductor disclosed in the present specification, it is effective to utilize a metal element that promotes crystallization of silicon in the manufacturing process thereof. As the metal element, Fe, Co, Ni, Ru, Rh, Pd, O
One or more elements selected from s, Ir, Pt, Cu, Zn, Ag and Au can be used. These elements have an invasion property with respect to silicon, and diffuse into the silicon film by performing heat treatment or laser light irradiation. Among the above elements, Ni (nickel) is an element that can obtain a particularly remarkable effect.

In order to introduce these metal elements, a metal element alone or a layer containing the metal element is formed in contact with the upper surface or the lower surface of the amorphous silicon film, and then laser light irradiation is performed while heating. Good. Further, laser light may be irradiated after the heat treatment.

Finally, the concentration of the metal element that promotes the crystallization that remains in the film is 1 × 10 ¹⁶ cm ^{−3 to} 5 × 10 ^19.
It needs to be cm ^-3 . This is because when the concentration of the metal element is higher than this concentration range, the characteristics as a semiconductor are impaired and the function as a device is impaired, and when the concentration of the metal element is lower than this concentration range, crystallization occurs. This is because the action of promoting

Another structure of the invention is a semiconductor device in which an active layer is formed of a thin film semiconductor formed on a substrate having an insulating surface, wherein the thin film semiconductor has crystallinity, and the active layer is A semiconductor device having a source region, a drain region, and a channel-shaped region, wherein no crystal grain boundary exists in the channel formation region.

The above structure is characterized in that the channel forming region is a monodomain region. A thin film transistor having high characteristics can be obtained by employing a structure in which crystal grain boundaries do not exist at least in the channel formation region as in the above structure. this is,
This is because carrier scattering, characteristic variation, and characteristic deterioration due to the presence of crystal grain boundaries are eliminated.

Of course, it is more preferable that the entire active layer including the source region and the drain region is a monodomain region.

Another structure of the invention is a semiconductor device in which an active layer is formed of a thin film semiconductor formed on a substrate having an insulating surface, wherein the thin film semiconductor has crystallinity, and the active layer is It has a source region, a drain region, and a channel-shaped region, no grain boundaries exist in the channel formation region, and 1 × point defects exist in the channel formation region.
It is characterized by the presence of 10 ¹⁶ cm ^-3 or more.

According to another aspect of the invention, a step of forming an amorphous silicon film on a substrate having an insulating surface, and 450.degree. C. to 750.degree.
Irradiating a laser beam or intense light in a state of being heated to a temperature of ℃ to form a crystalline thin film silicon semiconductor having a spin density of 1 × 10 ¹⁵ to 1 × 10 ¹⁹ cm ^-3. Characterize.

To form the monodomain region disclosed in this specification, it is useful to perform irradiation with laser light while heating. At this time, the heating temperature is 450 ° C to 750 ° C.
It is important to irradiate the laser beam with the sample (formation surface) heated to a temperature range of preferably 500 to 600 ° C. In addition to laser light, intense light such as infrared light may be irradiated.

When the above-mentioned metal element that promotes crystallization of silicon is introduced, it is effective to perform heat treatment before irradiating the laser beam to crystallize or generate crystal nuclei. Further, heat treatment after irradiation with laser light is effective in reducing defects in the film.

Further, it is effective to perform a hydrogenation treatment after the crystallization process to neutralize the defects in the film. In this hydrogenation step, heat treatment or plasma treatment may be performed in hydrogen or an atmosphere containing hydrogen.

The region where no crystal grain boundary exists can be regarded as one domain (mono domain). A thin film transistor formed using this region that can be regarded as a single crystal is referred to as a monodomain TFT.

To form a region that can be regarded as a single crystal in a silicon thin film, there is, for example, the following method.
First, an amorphous silicon film is formed on a glass substrate or a quartz substrate,
Then, a film containing nickel is formed on the surface of the amorphous silicon film. The nickel-containing film may be formed by forming a very thin nickel thin film by a sputtering method or the like. A method of contacting the surface of the film may be adopted.

After the nickel element is introduced into the amorphous silicon film, the amorphous silicon film is crystallized by heat treatment. This heat treatment can be performed at a temperature of 750 ° C. or lower by the action of nickel element. When a glass substrate is used as the substrate, the temperature of this heat treatment is preferably 600 ° C. or lower, but considering the efficiency of the crystallization step, it is performed at a temperature of 500 ° C. or higher, preferably 550 ° C. or higher. Is useful. Note that when a quartz substrate is used as the substrate, this heat treatment can be performed at a temperature of 800 ° C. or higher, and a crystalline silicon film can be obtained in a single hour. The crystalline silicon film obtained in this step has a polycrystalline or microcrystalline state, and crystal grain boundaries exist in the film.

Therefore, by irradiating the laser beam with the sample heated to a temperature of 450 ° C. or higher, the crystallinity of the region irradiated with the laser beam is locally promoted.
By this step, a region which can be regarded as a single crystal can be formed. It is important to heat the sample or the surface to be irradiated at a temperature of 450 ° C. or higher when irradiating this laser light. This heating temperature is 450 ° C. to 750 ° C., and particularly 450 ° C. to 600 ° C. when a glass substrate is used as the substrate.
The temperature is preferably set to ° C.

As another method of forming a region that can be regarded as a single crystal, an amorphous silicon film is formed, and after introducing a metal element that promotes crystallization, laser light is irradiated without heat treatment. A method for forming a region that can be regarded as a single crystal can be given. Also in this case, the sample is heated at a temperature of 450 ° C to 750 ° C at the time of laser light irradiation, particularly when a glass substrate is used as a substrate, a temperature of 450 ° C to 600 ° C (750 ° C if the heat resistance of the substrate permits). is important.

After the irradiation of the laser beam is completed, 450 ° C.
The heat treatment at a temperature of ˜600 ° C. (750 ° C. if the heat resistance of the substrate allows) is useful for reducing defects existing in the film.

Of course, the highest effect can be obtained by continuously performing the heat treatment, the laser light irradiation, and the heat treatment.

Defects existing in the film (unpaired bonds)
It is extremely effective to perform a heat treatment in a hydrogen atmosphere after the irradiation of the laser beam in order to neutralize the heat.

The region which can be regarded as this single crystal is plasma C
A silicon film formed by a VD method or a low pressure thermal CVD method is used as a starting film, and carbon and nitrogen are contained in the film at 1 × 10 ¹⁶
Up to 5 × 10 ¹⁸ cm ⁻³ , oxygen 1 × 10 ^{17 to} 5 × 10 ¹⁹ c
It is contained at a concentration of m ^-3 .

In addition, since there is a lattice defect in principle, 1 × 10 of hydrogen is used to neutralize dangling bonds of silicon.
It is contained at a concentration of ^{17 to} 5 × 10 ²⁰ cm ^-3 . That is, the region that can be regarded as a single crystal has a point defect, but has no line defect or plane defect. In addition,
The concentrations of these contained elements are defined as the lowest values measured by SIMS (secondary ion analysis method).

5 and 6 show a conventionally known single crystal MOS.
Type transistor and polycrystalline silicon thin film transistor (PS)
i TFT) and amorphous silicon thin film transistor (a-Si)
A table comparing various characteristics and features of a TFT) and a monodomain thin film transistor is shown.

[0037]

By forming a thin film transistor by using an area that can be regarded as a single crystal of a thin film silicon semiconductor as an active layer, a thin film transistor having a high breakdown voltage and no fluctuation or deterioration in characteristics can be obtained.

[0038]

【Example】

Example 1 In this example, a glass substrate is used as the substrate. The glass substrate has a glass strain point of 350 ° C to 70 ° C.
What is 0 degreeC can be used. In this embodiment, (Corning 7059) is used as a glass substrate, and a thin film transistor is manufactured at a temperature lower than the strain point temperature of the glass substrate. The strain point of the Corning 7059 glass substrate is 593 ° C., and heat treatment at a temperature higher than this temperature is not preferable because it causes shrinkage or deformation of the glass substrate. Particularly when a glass substrate having a large area is used for use in a large-sized liquid crystal display device, the influence of shrinkage or deformation of the glass substrate becomes remarkable.

Therefore, the thin film transistor described in this embodiment is characterized in that the maximum temperature in the heat treatment step is set to 600 ° C. or lower, preferably 550 ° C. or lower, so that the influence of heat on the substrate is significantly reduced.

FIG. 1 shows a manufacturing process of the thin film transistor shown in this embodiment. First, Corning 7059 glass substrate 1
A silicon oxide film 102 having a thickness of 3000 Å is formed as a base film on 01 by sputtering. Next, an amorphous silicon film is formed to a thickness of 500 Å by plasma CVD method or reduced pressure heat CV.
The film is formed by the D method.

After forming the amorphous silicon film, 450 ° C. to 7 ° C.
Laser light (KrF excimer laser) is irradiated in a state where the sample is heated to a temperature of 50 ° C., here 550 ° C., to form monodomain regions 103, 104 and 105 which can be regarded as a single crystal as shown in FIG. To do. FIG. 2A shows the state shown in FIG. 1A as viewed from above. The mono-domain regions 103 to 105 are in contact with each other at the grain boundaries 100. Although only three monodomain regions are shown in FIG. 2, a large number of monodomains are actually formed. The shape of the mono domain is not limited to the circular shape, and various shapes can be cited.

As shown in this embodiment, a sample is heated to a high temperature of 550 ° C. at the time of irradiation with laser light to form a monodomain (which can be regarded as a single crystal) region having a grain size of 50 μm or more. be able to.

In the above process, it is effective to introduce a metal element that promotes crystallization into the amorphous silicon film. By doing so, a region which can be regarded as a single crystal can be formed over a larger area.

After obtaining the regions 103 to 105 which can be regarded as single crystals, an active layer of a thin film transistor is formed by patterning using these regions. Most preferably, the active layer is formed in a region that can be regarded as a single crystal as a whole. Here, the active layer 106 is formed in the region indicated by 104. Thus, the region 100 shown in FIG. 1B is formed as an active layer.

There is substantially no crystal grain boundary in the mono domain 104, so that a thin film transistor having characteristics comparable to those of the case of using a single crystal can be obtained. Fig. 7 shows KrF heating at 550 ° C.
3 is a photograph showing a crystal structure of a thin film silicon semiconductor obtained by irradiating an excimer laser beam. And
By configuring the active layer of the thin film transistor by using the mono domain region as shown in FIG.
FT can be obtained.

After forming the active layer 106, a silicon oxide film 112 is formed as a gate insulating film to a thickness of 1000 Å by the plasma CVD method. Then, a film whose main component is aluminum containing 0.2% of scandium is formed to a thickness of 6000Å. Next, the gate electrode 113 is obtained by patterning the film containing aluminum as a main component.

Then, an oxide layer 114 is formed by performing anodic oxidation using the gate electrode 113 as an anode in an ethylene glycol solution containing 10% tartaric acid. The thickness of the oxide layer 114 is about 2000Å. The presence of the oxide layer 114 enables the formation of the offset gate region in the subsequent impurity ion implantation step.

Next, phosphorus ions are implanted into the active layer as impurity ions in the case of an N-channel type thin film transistor and boron ions as impurity ions in the case of a P-channel type thin film transistor. In this step, the gate electrode 113 and the surrounding oxide layer 114 serve as a mask, and 107 and 111
Impurity ions are implanted into the region indicated by. The region 107 in which the impurity ions are implanted is the source region,
The region 111 is formed as a drain region. Further, the offset gate regions 108 and 110 are formed simultaneously by using the oxide layer 114 around the gate electrode 113 as a mask. The channel formation region 109 is also formed in a self-aligned manner. (Fig. 1 (C))

After the step of implanting the impurity ions is finished, laser light is irradiated to anneal the active layer damaged by the implantation of the impurity ions and activate the implanted impurities. This step may be performed by irradiating strong light such as infrared light.

Further, a silicon oxide film 115 is used as an interlayer insulating film.
Is deposited by plasma CVD to a thickness of 7,000 Å. Further, a source electrode 116 and a drain electrode 117 are formed through a hole making process. Further, heat treatment is performed in a hydrogen atmosphere at 350 ° C. to complete the thin film transistor. (Fig. 1 (D))

In the thin film transistor shown in this embodiment, since the active layer is composed of a region (monodomain region) having a structure that can be regarded as a single crystal, the problem of low breakdown voltage due to the grain boundary and the leakage current. Can solve the problem of large.

In this embodiment, an example in which one thin film transistor is provided has been shown, but it is naturally possible to form a plurality of thin film transistors by using a plurality of monodomain regions.

[Embodiment 2] In this embodiment, a crystal region that can be regarded as a single crystal is formed by introducing a metal element that promotes crystallization into an amorphous silicon film, and the region having this crystallinity is used. An example in which a thin film transistor is configured by the following.

The manufacturing process of this embodiment is the same as that of the first embodiment except the step of introducing the metal element that promotes crystallization. In this embodiment, after forming the amorphous silicon film, an ultrathin oxide film (not shown) is formed on the surface of the amorphous silicon film by the UV oxidation method. This oxide film is for improving the wettability of the solution in the subsequent solution applying step. The UV oxidation step performed here is to irradiate UV light in an oxidizing atmosphere to form an extremely thin oxide film on the surface to be irradiated.

Next, a nickel acetate solution is coated on the surface of the amorphous silicon film on which an extremely thin oxide film is formed by spin coating to form a film containing nickel. Due to the presence of this coating, the nickel element is placed in contact with the amorphous silicon film through the extremely thin oxide film.

In this state, heat treatment is performed at 550 ° C. for 4 hours to transform the amorphous silicon film into a crystalline silicon film. Since nickel, which is a metal element that promotes crystallization, is introduced here, a crystalline silicon film can be obtained by heat treatment at 550 ° C. for about 4 hours.

After the silicon film transformed into the crystalline silicon film by the heat treatment is obtained, laser light is irradiated to form monodomain regions as shown by 103 to 104 in FIG. In the case of the present embodiment, nickel, which is a metal element that promotes crystallization, is introduced, so that a larger monodomain region can be obtained. After obtaining the monodomain region, a thin film transistor is formed in the same manner as in Example 1.

[Embodiment 3] This embodiment shows an example in which a channel formation region of a thin film transistor is formed by using one monodomain. FIG. 3 shows a manufacturing process of the thin film transistor shown in this embodiment.

First, a silicon oxide film 102 is formed as a base film on a glass substrate 101 to a thickness of 3000 Å by a sputtering method. Then, an amorphous silicon film is formed to a thickness of 500 Å by using the plasma CVD method or the low pressure thermal CVD method. Then, the sample is irradiated with laser light (KrF excimer laser) while being heated to a temperature of 550 ° C. to form a plurality of mono-demain regions 103 to 105. (Fig. 3 (A))

FIG. 4A shows the state of FIG. 3A viewed from the top. The mono-domains 103 to 105 are in contact with each other by the crystal grain boundary 100. Grain boundary 100
The inside partitioned by is a region that can be regarded as a single crystal, that is, a monodomain region.

Then, the active layer 106 is formed so that the channel formation region (region indicated by 109 in FIG. 3C) is included in the inside of the monodemain region 104. (Fig. 3
(B))

After forming the active layer 106, a silicon oxide film 112 is formed as a gate insulating film to a thickness of 1000 Å by the plasma CVD method. Then, a film whose main component is aluminum containing 0.2% of scandium is formed to a thickness of 6000Å. Next, the gate electrode 113 is obtained by patterning the film containing aluminum as a main component.

Then, an oxide layer 114 is formed by performing anodic oxidation using the gate electrode 113 as an anode in an ethylene glycol solution containing 10% tartaric acid. The thickness of the oxide layer 114 is about 2000Å. The presence of the oxide layer 114 enables the formation of the offset gate region in the subsequent impurity ion implantation step.

Next, phosphorus ions are implanted into the active layer as impurity ions in the case of an N-channel type thin film transistor and boron ions as impurity ions in the case of a P-channel type thin film transistor. In this step, the gate electrode 113 and the surrounding oxide layer 114 serve as a mask, and 107 and 111
Impurity ions are implanted into the region indicated by. The region 107 in which the impurity ions are implanted is the source region,
The region 111 is formed as a drain region. Further, the offset gate regions 108 and 110 are formed simultaneously by using the oxide layer 114 around the gate electrode 113 as a mask. The channel formation region 109 is also formed in a self-aligned manner. (Fig. 3 (C))

After the step of implanting the impurity ions is finished, laser light is irradiated to anneal the active layer damaged by implanting the impurity ions and activate the implanted impurities. This step may be performed by irradiating strong light such as infrared light.

Further, a silicon oxide film 115 is formed as an interlayer insulating film.
Is deposited by plasma CVD to a thickness of 7,000 Å. Further, a source electrode 116 and a drain electrode 117 are formed through a hole making process. Further, heat treatment is performed in a hydrogen atmosphere at 350 ° C. to complete the thin film transistor. (Fig. 3 (D))

In the thin film transistor described in this embodiment, since the channel formation region is composed of a region (mono domain region) having a structure that can be regarded as a single crystal, there are few obstacles to carrier movement and high characteristics. Can be obtained.

When the structure of this embodiment is adopted, the region of the monodomain needs to have at least the size of the channel formation region, and therefore the degree of freedom in manufacturing a thin film transistor can be increased.

In the present embodiment, an example in which one thin film transistor is provided has been shown, but it is naturally possible to form a plurality of thin film transistors by using a plurality of monodomain regions.

[0070]

By utilizing the invention disclosed in this specification, it is possible to obtain a thin film transistor which is not affected by the grain boundaries. And withstand voltage is high, there is no change in characteristics,
Further, a thin film transistor which can handle a large current can be obtained. Further, since the operation of the thin film transistor can be made unaffected by the crystal grain boundary, the OF
The characteristic of the F current can be small.

[Brief description of drawings]

FIG. 1 is a diagram showing a manufacturing process of a thin film transistor of an example.

FIG. 2 is a diagram showing a shape of a mono domain and an active layer.

FIG. 3 is a diagram showing a configuration of a thin film transistor of an example.

FIG. 4 is a diagram showing a shape of a mono domain and an active layer.

FIG. 5 is a diagram showing a comparison table between a single crystal thin film transistor and a monodomain thin film transistor.

FIG. 6 is a diagram showing a comparison table between a single crystal thin film transistor and a monodomain thin film transistor.

FIG. 7 is a photograph showing a crystal structure of a thin silicon semiconductor film.

[Explanation of symbols]

Reference Signs List 101 glass substrate 102 base film (silicon oxide film) 103 to 104 monodomain region (region that can be regarded as a single crystal) 106 active layer 107 source region 108 offset gate region 109 channel formation region 110 offset gate region 111 drain region 112 gate insulating film 113 Gate electrode 114 Oxide layer 115 Interlayer insulating film 116 Source electrode 117 Drain electrode 100 Crystal grain boundary (grain boundary)

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical indication location H01L 21/261 21/268 Z 23/15 H01L 23/14 C 9056-4M 29/78 627 G

Claims (16)

[Claims] 1. A semiconductor device using a thin film semiconductor formed on a substrate having an insulating surface, wherein the thin film semiconductor has crystallinity and contains hydrogen or a halogen element. 2. A semiconductor device having no crystal grain boundary in the thin film semiconductor forming the active layer. 2. A semiconductor device using a thin film semiconductor formed on a substrate having an insulating surface, wherein the thin film semiconductor has crystallinity, and the thin film semiconductor forming an active layer of the semiconductor device. There are no grain boundaries therein, and there are 1 × 10 ¹⁶ cm ⁻³ or more of point defects to be neutralized, and 1 × of hydrogen or a halogen element which should neutralize the point defects.
A semiconductor device, characterized in that it is contained at a concentration of 10 ¹⁵ to 1 × 10 ²⁰ cm ⁻³ . 3. The thin film semiconductor according to claim 1 or 2, wherein carbon and nitrogen atoms are 1 × 10 ¹⁶ cm ⁻³ to.
A semiconductor device which is contained at a concentration of 5 × 10 ¹⁸ cm ⁻³ and oxygen atoms at a concentration of 1 × 10 ¹⁷ cm ^{−3 to} 5 × 10 ¹⁹ cm ⁻³ . 4. The semiconductor device according to claim 1, wherein the thin film semiconductor has a thickness of 200Å to 2000Å. 5. The thin film semiconductor according to claim 1 or 2, wherein F is a metal element that promotes crystallization of silicon.
e, Co, Ni, Ru, Rh, Pd, Os, Ir, P
A semiconductor device comprising one or more kinds of elements selected from t, Cu, Zn, Ag, and Au in a concentration of 1 × 10 ¹⁶ cm ^{−3 to} 5 × 10 ¹⁹ cm ⁻³ . 6. A semiconductor device comprising an active layer made of a thin film semiconductor formed on a substrate having an insulating surface, wherein the thin film semiconductor has crystallinity, and the active layer has a source region and a drain region. And a channel-shaped region, wherein no crystal grain boundary exists in the channel formation region. 7. A semiconductor device comprising an active layer made of a thin film semiconductor formed on a substrate having an insulating surface, wherein the thin film semiconductor has crystallinity, and the active layer has a source region and a drain region. And a channel-shaped region, no grain boundary exists in the channel formation region, and point defects are 1 × 10 ¹⁶ cm ^{−3 in the} channel formation region.
A semiconductor device having the above existence. 8. The thin film semiconductor according to claim 6 or 7, wherein carbon and nitrogen atoms are 1 × 10 ¹⁶ cm ⁻³ to.
A semiconductor device which is contained at a concentration of 5 × 10 ¹⁸ cm ⁻³ and oxygen atoms at a concentration of 1 × 10 ¹⁷ cm ^{−3 to} 5 × 10 ¹⁹ cm ⁻³ . 9. The semiconductor device according to claim 6 or 7, wherein the thin film semiconductor has a thickness of 200Å to 2000Å. 10. A region having a crystal structure which can be regarded as a substantially single crystal according to claim 6 or 7, wherein Fe, Co, Ni, which is a metal element for promoting crystallization of silicon,
Ru, Rh, Pd, Os, Ir, Pt, Cu, Zn, A
1x of one or more kinds of elements selected from g and Au
A semiconductor device containing 10 ^{16 to} 5 × 10 ¹⁹ cm ⁻³ . 11. A process of forming an amorphous silicon film on a substrate having an insulating surface, and irradiating with laser light or strong light in a state of being heated to a temperature of 450 ° C. to 750 ° C., and a spin density of 1 × 10. ¹⁵ ~ 1 x 1
And a step of forming a thin film silicon semiconductor having a crystallinity of 0 ¹⁹ cm ⁻³ . 12. A method for manufacturing a semiconductor device according to claim 11, further comprising a step of performing heat treatment before irradiation with laser light. 13. A method for manufacturing a semiconductor device according to claim 11, further comprising a step of performing heat treatment after irradiation with laser light. 14. The semiconductor device according to claim 11, further comprising the step of neutralizing dangling bonds existing in the thin film silicon semiconductor after the irradiation of the laser beam is completed. 15. The thin film silicon semiconductor according to claim 11, wherein carbon and nitrogen atoms are 1 × 10 ¹⁶ cm ^{−3 to} 5 × 10.
It is contained at a concentration of ¹⁸ cm ^-3 and contains 1 x oxygen atom.
A semiconductor device, which is contained at a concentration of 10 ¹⁷ cm ^{−3 to} 5 × 10 ¹⁹ cm ⁻³ . 16. The thin film silicon semiconductor according to claim 11, wherein Fe and C are metal elements that promote crystallization of silicon.
o, Ni, Ru, Rh, Pd, Os, Ir, Pt, C
A semiconductor device comprising one or more elements selected from u, Zn, Ag, and Au in a concentration of 1 × 10 ¹⁶ cm ^{−3 to} 5 × 10 ¹⁹ cm ⁻³ .