JP2000323421A - Manufacture and equipment for semiconductor and thin film thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method and equipment for forming a crystalline silicon film of more excellent quality at lower temperatures in the crystalline silicon film for use for a semiconductor thin film element; and a thin film transistor superior in characteristics and reliability. SOLUTION: This manufacturing method and equipment for a semiconductor thin film comprises a first step in which a raw material gas is decomposed by electric discharge to generate a plasma of which electronic density is 1010 to 1013 pieces/cm3, and ions and radicals in the plasma are irradiated on a substrate to form a thin film; and a second step in which the raw material gas activated by a heating catalyzer 14 is directly irradiated on a substrate surface or is decomposed with the plasma to irradiate, so that a crystalline semiconductor thin film is formed on a substrate 17. Furthermore, in a semiconductor device, the crystalline semiconductor thin film obtained by the above steps in an active layer.

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 device in the semiconductor industry and a method of manufacturing the same, and more particularly, to a thin film transistor (TFT) used for an active matrix type liquid crystal display and a method of manufacturing the same.

[0002]

2. Description of the Related Art In an active matrix type liquid crystal display, transistors used include:
There is a transistor for switching each pixel, and a high mobility transistor of a peripheral circuit that sends a control signal based on image information to be displayed on each pixel transistor. Conventionally, a TFT using an active layer of hydrogenated amorphous silicon (a-Si: H) has been used for a pixel transistor, and a plasma-enhanced chemical vapor deposition (PCVD) is applied as a manufacturing method thereof. It had been. This a-Si: H
The TFT has an advantage that it can be manufactured at a temperature of about 300 ° C. where an inexpensive light-transmitting glass substrate can be sufficiently applied. However, the mobility of the n-type TFT is as small as 1 cm ² / Vs, and the p-type TF
T has a drawback that practical mobility cannot be obtained and cannot be applied to peripheral circuits, and a peripheral circuit is configured by mounting an IC chip on a substrate.

On the other hand, polycrystalline silicon (poly-Si)
Has an advantage that it has high mobility in both n-type and p-type and can be applied to peripheral circuits. However, poly-Si usually has a problem that a high-temperature step of 600 ° C. or more is required, such as film formation by a low-pressure CVD method, for which an inexpensive glass substrate cannot be applied.

In recent years, poly-Si (low-temperature poly-Si) manufactured at a low temperature to which an inexpensive glass substrate can be applied.
Research and development are being actively conducted on the technology described above, and its practical application is being promoted. One of them is an excimer laser beam having a wavelength in the ultraviolet region, which is extremely large in absorption by the a-Si: H film.
By irradiating the a-Si: H film in a pulsed manner,
A method in which a Si: H film is rapidly heated, melted, and cooled to recrystallize to produce a polycrystalline film (Japanese Patent No. 272566).
9 etc.). This method can be applied to a glass substrate.
Although high mobility TFTs can be formed at a low temperature of 0 ° C. or lower, it is difficult to form poly-Si over a large area and with high productivity because a laser is used. Further, generally, the a-Si: H film contains 10 atom% or more of hydrogen, and if it is used as it is, rapid heating by excimer laser light causes bumping of hydrogen to cause film peeling and surface roughness. In addition, there is a problem that a heat treatment step for desorbing hydrogen in the film must be added in advance.

In order to solve these problems, the following techniques have been proposed for producing a crystalline silicon film at a low temperature. The catalyst is heated to a temperature higher than the melting temperature of Si, and a part of the molecules of the raw material gas is brought into contact with the heated catalyst to be decomposed to form a film by CVD and crystal growth on a substrate. The formation of a thin film is described in JP-A-8-250438. According to this method, some of the flying species become extremely hot, and the substrate surface behaves as if it were hot, and polycrystalline silicon is generated at a low substrate temperature. In practice, the raw material gas is a mixed gas of a silicon (Si) compound gas and another substance, and the catalyst is heated by the supplied electric power to reduce the pressure of the reaction chamber for forming the silicon thin film to a low pressure, And the conditions of the mixing ratio of the raw material gas to increase the ratio of the gas of the other substance to the gas of the silicon compound in the raw material gas, and the power supplied to the catalyst to the catalyst whose catalyst body temperature is higher than the silicon melting temperature By setting the condition of the supplied power to such a degree that the silicon thin film generated by the deposited species becomes a polycrystalline thin film, a polycrystalline silicon thin film is generated on a low-temperature substrate.

A technique for providing a thermal catalyst between an electrode for generating plasma and a gas inlet and supplying an activated source gas to a plasma generation region to form a film is disclosed in
0-310867.

High frequency inductively coupled plasma (ICP: Induct)
Japanese Patent Application Laid-Open No. 10-265212 and Japanese Patent Application Laid-Open No. 11-265212 describe a method of producing a crystalline silicon film by a chemical vapor deposition process using the decomposed raw material gas by a plasma decomposition using ive coupled plasma. 7420
No. 4 publication. In this method, for example, I
Electrodes (antennas) for generating CP (Literature: Hideaki Kanai: Applied Physics, Vol. 63, No. 6, 1994,
pp. 559 to 567), high-frequency power is applied to generate high-density plasma of the source gas, and the source gas is decomposed and highly excited to form a film. JP-A-10-
According to Japanese Patent No. 265212, a polycrystalline silicon thin film having an electric conductivity higher by one digit or more can be obtained by setting the high-frequency power to 800 W or more. It is shown that a crystalline silicon thin film was not obtained.

[0008]

However, when the above-described method is adopted, it is considered that a crystalline silicon film can be manufactured at a temperature at which a glass substrate can be applied. There was such a problem.

In the catalytic CVD method (JP-A-8-250438), a film is formed only by active species (radicals) generated by thermal decomposition in a gas phase. As noted,
In order to form a crystalline silicon film without increasing the substrate temperature, not only decomposition but also raising the temperature (kinetic energy) of some radicals sufficiently is performed by contacting with a thermal catalyst. . In order to obtain such an effect, there is a problem in that electric power must be supplied to the thermal catalyst to heat it so that the temperature of the thermal catalyst becomes as high as 1700 to 1800 ° C. This problem becomes more prominent when formed on a large-area substrate such as a liquid crystal display. Further, there is a problem that the temperature of the structure of the apparatus or a substrate such as inexpensive glass must be lower than a temperature that can withstand the radiation generated from such a high-temperature thermal catalyst.

In PCVD, the method of heating a raw material gas through a thermal catalyst in advance and supplying it to a plasma generating unit (Japanese Patent Laid-Open No. 10-310867) differs from the catalytic CVD method in that the gas is decomposed and excited. From the place,
Since there is a distance to a region contributing to film formation, such as plasma or the substrate surface and its vicinity, there is a problem that gas molecules decomposed and excited cannot be used effectively. Therefore, usable gases and film-forming targets are limited, and only examples of formation of a protective film such as diamond-like carbon or an insulating film of carbide, nitride, or oxide are disclosed.

A method of forming a crystalline silicon film by PCVD using ICP (JP-A-10-265212, JP-A-11-74204) generates a high-density plasma of a source gas by high-frequency inductive coupling. Thus, decomposition and excitation of the source gas are performed more actively than in the conventional parallel plate high-frequency PCVD to form a crystalline silicon film.

However, the film obtained was confirmed by Raman spectroscopy to be microcrystals (JP-A-10-26).
No. 5212), and those which have been confirmed in terms of electric characteristics have a problem that sufficient crystallinity and film quality are not obtained, such as high photoconductivity (Japanese Patent Application Laid-Open No. 11-74204). These problems are all technologies that focus on high decomposition and high excitation of the raw material gas, and are caused by the lack of means for promoting crystallization and reducing the hydrogen concentration in the film. It is considered something.

The present invention solves the above-mentioned problems of the prior art, and provides a manufacturing method and a manufacturing apparatus for forming a more excellent crystalline silicon film at a low temperature, and a TFT having excellent characteristics and reliability. The purpose is to provide.

[0014]

In order to achieve the above object, a method and an apparatus for manufacturing a semiconductor thin film according to the present invention are provided.
The electron density of the plasma generated by discharge decomposition of the source gas
10 ^10-10 a ¹³ / cm ^3, wherein the steps of the ions and radicals in the plasma to form a thin film by irradiating the substrate, directly or the plasma activated raw material gas by heating the catalyst to the substrate surface Forming a crystalline semiconductor thin film on the substrate by the step of decomposing and irradiating. Further, a semiconductor device according to the present invention is characterized in that the crystalline semiconductor thin film obtained in the above steps is used as an active layer. This makes it possible to form a crystalline semiconductor film or a semiconductor film with a low hydrogen content at a temperature at which an inexpensive substrate such as glass can be used.

In the structure of the present invention or the method of the present invention,
High frequency induction of discharge decomposition of raw materials containing constituent elements of conductive thin films
Inductively coupled plasma, helicon wave plasma, electron cyclot
Ron resonance plasma, UHF plasma, VHF plasma,
Plasma is generated by any of the methods of arc discharge plasma
It is necessary to generate an electron density of 10 in the plasma.^Ten~Ten ¹³
Pieces / cm^ThreeHigh density and high excitation plasma
Good.

In the structure of the present invention or the method of the present invention, it is preferable to include a gas containing silicon as a raw material gas, since a silicon TFT required for a liquid crystal display or the like can be manufactured.

In the constitution of the present invention or the method of the present invention, it is preferable that the raw material containing the constituent elements of the semiconductor thin film is diluted with a hydrogen gas or an inert gas from the viewpoint of controlling the film forming rate and the crystallinity.

In the constitution of the present invention or the method of the present invention,
By setting the temperature of the substrate at 100 ° C. to 600 ° C. during film formation, an inexpensive substrate such as glass can be used, which is preferable.

In the structure of the present invention or the method of the present invention, it is preferable to use a light-transmitting substrate as a substrate in order to manufacture a product that transmits light, such as a transmissive liquid crystal display.

In the structure of the present invention, the content of hydrogen contained in the obtained semiconductor thin film is set to 10 atom% or less.
It is preferable when it is necessary to improve the characteristics and reliability of the semiconductor film and the semiconductor device to be formed and to improve the quality such as laser recrystallization.

In the structure of the present invention or the method of the present invention, at least one kind of an insulating film and a conductive film is formed on a part or the whole surface of a substrate, and a crystalline semiconductor thin film is formed on the insulating film or the conductive film. Is formed, when a semiconductor device is manufactured on an inexpensive substrate such as glass, the influence of impurities from the substrate such as glass is reduced, and the semiconductor device is formed, for example, as in a bottom gate type TFT. Is preferred because it can be designed in various ways according to the purpose.

In the preferred embodiment of the present invention, the semiconductor thin film is a polycrystalline silicon thin film.
This is preferable because the field effect mobility of the TFT is higher than that of the -Si: H film, and the dehydrogenation treatment is not required when high quality such as recrystallization is required.

In the structure of the present invention or the method of the present invention, the semiconductor thin film having a thickness of 5 nm or more and 200 nm or less can be applied to a TFT with the same thickness without additional etching or film formation. ,preferable.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically with reference to examples.

FIG. 1 is a schematic view of a first embodiment of an apparatus for manufacturing a semiconductor thin film according to the present invention.

More specifically, an induction coil 12 for generating plasma is attached to a vacuum vessel 11 which is evacuated to a vacuum from an exhaust port. At least a part of the installation location of the induction coil 12 is made of an insulating material such as a quartz tube. High-frequency power generated by the high-frequency oscillator 16 and set to a predetermined parameter (for example, frequency) by the matching unit 15 is applied to the induction coil 12. Is applied.

[0027] Monosilane (SiH_Four) Silicon such as gas
Is supplied to the gas inlet 1 provided with the heating catalyst 14.
3 is introduced into the vacuum vessel 11. At this time,
The catalyst becomes excited and dissociated by the reaction with the heating catalyst 14.
Activated. The activated source gas is supplied to the induction coil
12 generated by applying high-frequency power to
Further by inductively coupled plasma (ICP)
Is decomposed into ions and radicals. These Io
And radicals are heated by the substrate heater 18.
And a crystalline silicon film is formed on the
You. In FIG. 1, a heating catalyst 14 is provided at the gas inlet 13.
The material having a catalytic function is used as the gas inlet 13
May be used.

In the first embodiment of the present invention, a raw material gas is used.
Monosilane (SiH_Four) And hydrogen (H_Two) Using gas
These mixed raw material gases are activated by the heating catalyst 14 (mainly
To SiH _ThreeAnd H) and introduced into the vacuum vessel 11. true
In the empty container 11, the source gas has already been activated.
The dissociation reaction in the plasma is promoted,
In Inductively Coupled Plasma Generated by Twelve
And ions are converted to the conventional high density without using the heating catalyst 14.
Compared to plasma, ions and ions with less Si-H bonds
And radical (SiH_x, SiH_x+: X = 0-1) and original
Large amounts of dendritic hydrogen (H, H +) are produced.

The formation of a silicon thin film by high-density plasma is based on silicon radicals and ions (SiH _x , SiH _x +: x = 0−
Since 3) is caused by depositing on the surface of the substrate 17, the hydrogen content in the film is reduced by reducing the amount of bonded hydrogen contained in the silicon-based radicals and ions in the plasma using the heating catalyst 14. . In addition, atomic hydrogen generated by high-density plasma or the heating catalyst 14 has an annealing effect on the film formation surface, improves the crystallinity of the silicon thin film, and reacts with the bonded hydrogen on the film formation surface to generate hydrogen molecules. The reaction of pulling out is expected.

Therefore, the silicon thin film formed according to the first embodiment of the present invention is a polycrystalline silicon film having a hydrogen content of 10 atom% or less.

The frequency of the high-frequency power applied to the induction coil 12 may be set to a frequency at which coupling by the induction coil 12 is possible and a plasma can be generated. For example, it is preferable to set 13.56 MHz. In addition,
In the above-mentioned frequency range, when the frequency is low, the condition range in which discharge can be performed is widened, and there is a degree of freedom in the device configuration, which is desirable.
Conversely, when the frequency is high, the electron density in the plasma increases, and the plasma potential decreases. Therefore, the film formation speed is high, and a silicon film with little damage during film formation is preferable.

The electron density in the generated plasma is in the range of 10 ¹⁰ to 10 ¹³ / cm ³ , for example, 10 ¹¹ / cm ^3.
It is desired to set discharge conditions such as pressure, high-frequency power, gas flow rate, and the like so as to obtain cm ³ .

Further, the substrate temperature during film formation is 10
By setting the temperature in the range of 0 ° C. to 600 ° C., for example, 300 ° C., an inexpensive substrate such as glass can be used, which is desirable.

In this embodiment, the plasma is ICP
Is applied, but the electron density of the plasma is 10 ¹⁰ to 10 ¹³
/ high-density plasma cm ^3, helicon wave plasma, electron cyclotron resonance plasma, UHF plasma, VH
Either F plasma or arc discharge plasma may be applied. In addition, not limited to these plasma generation methods, if it is possible to generate plasma with high density and high excitation,
The present invention may be applied to a semiconductor manufacturing apparatus according to the present invention.

FIG. 2 is a schematic view of a second embodiment of the apparatus for manufacturing a semiconductor thin film according to the present invention.

More specifically, an induction coil 12 for generating plasma is attached to a vacuum vessel 11 which is evacuated to a vacuum from an exhaust port. At least a part of the installation location of the induction coil 12 is made of an insulating material such as a quartz tube. High-frequency power generated by the high-frequency oscillator 16 and set to a predetermined parameter (for example, frequency) by the matching unit 15 is applied to the induction coil 12. Is applied.

A source gas containing silicon such as monosilane (SiH ₄ ) gas is introduced into the vacuum vessel 11 through the gas inlet 21. The source gas is discharged and decomposed into ions and radicals by inductively coupled plasma (ICP) having a high electron density generated by applying high-frequency power to the induction coil 12. Furthermore, gas inlet 2 for plasma generation
Gas inlet 13 provided with heating catalyst 14 of a different system from
Is provided, and a reactive gas such as a monosilane (SiH ₄ ) gas or a hydrogen (H ₂ ) gas, which is excited and dissociated by the heating catalyst 14, is supplied to the substrate surface.
The ions and radicals generated by these methods are deposited on the substrate 17 heated by the substrate heater 18 to form a crystalline silicon film. Although the heating catalyst 14 is provided in the gas inlet 13 in FIG. 2, a material having a catalytic function may be used as the gas inlet 13.

As a second embodiment of the present invention, a plasma decomposition
Monosilane (SiH _Four) And hydrogen (H_Two)
Gas into the vacuum chamber 11 through the gas inlet 21 and guide
By applying a high frequency power of 500 W to the coil 12,
Therefore, the electron density is about 1 × 10 ¹¹Pieces / cm^ThreeInductive coupling plug
Generate zuma. The source gas is separated in this high-density plasma.
Is solved and becomes many ions and radicals on the substrate 17
To form a silicon thin film. This
Is formed only by inductively coupled plasma such as
The recon thin film is a microcrystalline silicon film,
As a reactive gas from the gas inlet 13 provided with the medium 14
Monosilane (SiH_Four) Thermal decomposition on substrate surface when gas is introduced
SiH_ThreeRadicals and H atoms are provided. this
At the time, SiH_ThreeThe probability of radical attachment is
Is almost an order of magnitude smaller than other silicon radicals
Therefore, its contribution to film formation is not so large. However
However, H atoms improve the crystallinity of the silicon thin film and
Hydrogen abstraction that reacts with bound hydrogen on the surface to produce hydrogen molecules
It has an effect on the reaction. In addition, H atoms are neutral
No need to worry about ion impact damage to the film surface
Good.

Due to the above effects, the silicon thin film formed according to the second embodiment of the present invention has a hydrogen content of 10 at.
It is a polycrystalline silicon film of om% or less.

The frequency of the high-frequency power applied to the induction coil 12 may be set to a frequency at which coupling by the induction coil 12 is possible and a plasma can be generated. For example, it is preferable to set 13.56 MHz. In addition,
In the above-mentioned frequency range, when the frequency is low, the condition range in which discharge can be performed is widened, and there is a degree of freedom in the device configuration, which is desirable.
Conversely, when the frequency is high, the electron density in the plasma increases, and the plasma potential decreases. Therefore, the film formation speed is high, and a silicon film with little damage during film formation is preferable.

The electron density in the generated plasma is in the range of 10 ¹⁰ to 10 ¹³ / cm ³ , for example, 10 ¹¹ / cm ^3.
It is desired to set discharge conditions such as pressure, high-frequency power, gas flow rate, and the like so as to obtain cm ³ .

The gas inlet 13 provided with the heating catalyst 14
Hydrogen (H _TwoThe same applies when using gas.
Effect is obtained, but the H—H bond energy is
_Three-H binding energy, the heating catalyst 1
It is necessary to raise the temperature of 4.

Further, the substrate temperature during film formation is 10
By setting the temperature in the range of 0 ° C. to 600 ° C., for example, 300 ° C., an inexpensive substrate such as glass can be used, which is desirable.

In this embodiment, ICP is used as the plasma.
Is applied, but the electron density of the plasma is 10 ¹⁰ to 10
^As the high-density plasma of ¹³ cells / cm ³ , any of helicon wave plasma, electron cyclotron resonance plasma, UHF plasma, VHF plasma, and arc discharge plasma may be used. The present invention is not limited to these plasma generation methods, and may be applied to the semiconductor manufacturing apparatus according to the present invention as long as plasma can be generated with high density and high excitation.

FIG. 3 is a schematic diagram showing the steps of a TFT manufactured by the method for manufacturing a semiconductor thin film according to the present invention.

First, a normal pressure CV is placed on a substrate 31 such as glass.
The silicon oxide film 32 is formed to a thickness of 100 to 500 nm by the D method or the like.
It is formed with a film thickness of.

Next, a crystalline silicon film 33 is formed with a thickness of 10 to 50 nm using the apparatus of FIG. 1 (FIG. 3).
(A)). The film thickness is not limited to this range,
5 to 20 depending on the structure of the TFT and compatibility with other processes, etc.
Set in the range of 0 nm. If necessary, the crystalline silicon film 33 may be subjected to heat treatment at 450 to 600 ° C., irradiation of excimer laser, or the like.

Next, a silicon oxide film 34 is formed in a thickness of 50 to 300 nm by normal pressure CVD (FIG. 3).
(B)) The method for forming the silicon oxide film is as follows.
Other means such as a plasma CVD method, a sputtering method, an evaporation method, and a low pressure CVD method may be used.

Next, a metal film made of Ti, Mo, W, Al, Ta, or the like is formed to a thickness of 50 to 300 nm, and the metal film is etched using a photoresist patterned by photolithography as a mask to form a gate electrode. 35 are formed (FIG. 3C).

The gate electrode 35 is not limited to a metal film but may be a silicon film.

Next, using the gate electrode 35 as a mask,
Ions 36 containing impurities are implanted to form an impurity doping layer 37 serving as source / drain regions.
(D)).

This doping layer is formed, for example, by an n-type layer.
In the formation of hydrogen, hydrogen dilution 5% PH_ThreeIs the ion source gas
Performed by ion doping. Apply ion doping
Conditions are as follows: acceleration voltage: 5 to 100 kV, total ions
Injection volume: 10¹⁴-10¹⁶cm ^-2And These conditions
Is the thickness of the mask, the thickness of the doping layer to be formed, etc.
Depending on the configuration, optimal conditions and gas concentrations are appropriately selected. Ma
In the formation of the p-type layer, hydrogen dilution was used as the ion source gas.
5% B_TwoH₆This is performed by ion doping using, for example.
In the ion doping method, impurities serving as dopants
Since the object and hydrogen are implanted simultaneously, implantation defects due to hydrogen
Compensation and acceleration of activation and crystallization
A low resistance doping layer is formed. In this example,
Then, the silicon oxide film in the region to be implanted is removed and
On implantation, but also on the surface of the region to be implanted
Implantation of ions may be performed while leaving the silicon oxide film.
In that case, acceleration of ions depends on conditions such as film thickness.
The voltage is preferably 10 kV or more.

Next, a silicon oxide film serving as an interlayer insulating film is formed to a thickness of 100 to 500 nm by normal pressure CVD, plasma CVD, sputtering, or the like, and is used for making electrode contact to source / drain regions. Next, a silicon oxide film is opened by photolithographic etching to form source / drain electrodes, thereby completing a thin film transistor.

FIG. 4 is a process schematic diagram showing a second embodiment of a TFT manufactured by the method of manufacturing a semiconductor thin film according to the present invention.

First, a normal pressure CV is placed on a substrate 41 such as glass.
The silicon oxide film 42 is formed to a thickness of 100 to 500 nm
Then, a metal film made of Ti, Mo, W, Al, Ta, or the like is formed to a thickness of 100 to 500 nm, and the metal film is etched using a photoresist patterned by photolithography as a mask. Then, a gate electrode 43 is formed (FIG. 4A).

Next, a silicon oxide film 44 is formed to a thickness of 50 to 300 nm by normal pressure CVD (FIG. 4).
(B)) Note that the silicon oxide film 44 is formed by a plasma CVD method, a sputtering method, an evaporation method,
Other means such as the D method may be used.

Next, a crystalline silicon film 45 is formed to a thickness of 10 to 50 nm using the apparatus of FIG. 1 (FIG. 4).
(C)). The film thickness is not limited to this range,
5 to 20 depending on the structure of the TFT and compatibility with other processes, etc.
Set in the range of 0 nm. If necessary, the crystalline silicon film 45 may be subjected to heat treatment at 450 to 600 ° C., irradiation of excimer laser, or the like.

Next, using the photoresist 46 patterned by photolithography as a mask, ions 47 containing impurities are implanted into the crystalline silicon thin film 45 to form an impurity doping layer 48 to be a source / drain region (FIG. 4 (d)). )). The doping layer 48 is formed by, for example, ion doping using 5% hydrogen diluted PH ₃ as an ion source gas in the case of forming an n-type layer. Conditions for applying ion doping are as follows: acceleration voltage: 5 to 100 k
V, total ion implantation amount: 10 ¹⁴ to 10 ¹⁶ cm ^-2 . For these conditions, optimal conditions and gas concentrations are appropriately selected according to the thickness of the mask, the thickness of the doping layer to be formed, and the like. The formation of the p-type layer is performed by ion doping using hydrogen diluted 5% B ₂ H ₆ or the like as an ion source gas.

In the ion doping method, since impurities as dopants and hydrogen are implanted at the same time, the implantation defects are compensated by hydrogen, and activation and crystallization are promoted. Is formed. Although a photoresist is used as a mask for ion doping in this embodiment, a silicon oxide film or a silicon nitride film may be formed on a silicon thin film, and these films and the photoresist may be used as a mask.

Next, a silicon oxide film serving as an interlayer insulating film is formed to a thickness of 100 to 500 nm by normal pressure CVD, plasma CVD, sputtering, or the like, and is used for making electrode contact to source / drain regions. Next, the correlation insulating film is opened by photolithography and etching, and electrodes are formed to complete the TFT.

By employing the above method,
A semiconductor thin film with excellent crystallinity can be formed in a temperature range in which a glass substrate can be used. Therefore, even when a thin film transistor is manufactured over a large-area glass substrate such as an active matrix liquid crystal display, a thin film transistor having excellent characteristics and reliability can be manufactured.

If the substrate is heated during film formation, a semiconductor thin film having more excellent crystallinity can be formed, and thus a thin film transistor having better characteristics can be manufactured.

When a glass substrate is used as the substrate as in this embodiment, the heating temperature is preferably 100 to 600 ° C., and more preferably 300 to 500 ° C. to minimize the distortion of the glass. It is more preferable in terms of minimization and improving the characteristics of the oxide film.

[0064]

As described above, according to the structure of the present invention, a semiconductor thin film having excellent crystallinity can be manufactured at a low temperature. Therefore, even when a thin film transistor is manufactured on a glass substrate having a large area such as an active matrix liquid crystal display, a thin film transistor having excellent characteristics and reliability can be manufactured with high productivity.

Further, in the constitution of the present invention or the method of the present invention, the gas containing silicon as the raw material gas is
It is possible to manufacture a silicon TFT required for a liquid crystal display or the like.

In the structure of the present invention or the method of the present invention, the film forming rate and crystallinity can be more controlled by diluting the raw material containing the constituent elements of the semiconductor thin film with hydrogen gas or an inert gas.

In the structure of the present invention or the method of the present invention, by setting the temperature of the substrate at 100 ° C. to 600 ° C. at the time of film formation, an inexpensive substrate such as glass can be used.

In the structure of the present invention or the method of the present invention, by using a light-transmitting substrate as the substrate, a product that transmits light, such as a transmissive liquid crystal display, can be manufactured.

In the structure of the present invention, the content of hydrogen contained in the obtained semiconductor thin film is set to 10 atom% or less to improve the characteristics and reliability of the semiconductor film and the semiconductor device to be formed, and to further improve the laser re-use. When high quality such as crystallization is required, dehydrogenation treatment is not required.

Further, in the constitution of the present invention or the method of the present invention, at least one kind of an insulating film and a conductive film is formed on a part or the whole surface of the substrate, and a crystalline film is formed on the insulating film or the conductive film. The formation of a semiconductor thin film reduces the influence of impurities from a substrate such as glass when manufacturing a semiconductor device on a substrate such as an inexpensive glass, and also reduces the influence of impurities such as a bottom gate type TFT. The structure of the semiconductor device can be variously designed according to the purpose.

In the structure of the present invention, according to the preferable structure that the semiconductor thin film is a polycrystalline silicon thin film, the field effect mobility of the TFT can be made higher than that of the a-Si: H film. it can.

In the structure of the present invention or the method of the present invention, the fact that the thickness of the semiconductor thin film is 5 nm or more and 200 nm or less can be directly applied to the active layer of the TFT.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an apparatus for manufacturing a semiconductor thin film according to a first embodiment of the present invention.

FIG. 2 is a schematic view of an apparatus for manufacturing a semiconductor thin film according to a second embodiment of the present invention.

FIG. 3 is a schematic process diagram showing a first embodiment of a TFT manufactured by the method for manufacturing a semiconductor thin film according to the present invention.

FIG. 4 is a schematic process diagram showing a second embodiment of a TFT manufactured by the method of manufacturing a semiconductor thin film according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 Vacuum container 12 Induction coil 13 Gas inlet 14 Heating catalyst 15 Matching unit 16 High frequency oscillator 17 Substrate 18 Substrate heater 21 Gas inlet 31 Substrate 32 Silicon oxide film 33 Crystalline silicon film 34 Silicon oxide film 35 Gate electrode 36 Ion 37 Impurity doping layer 41 Base 42 Silicon oxide film 43 Gate electrode 44 Silicon oxide film 45 Crystalline silicon film 46 Photoresist 47 Ions 48 Impurity doping layer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mikihiko Nishitani 1006 Kazuma Kadoma, Osaka Pref.Matsushita Electric Industrial Co., Ltd. 72) Inventor Tetsuhisa Yoshida 1006 Kazuma Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. (72) Inventor Kentaro Seto 1006 Odaka Kadoma, Kadoma City, Osaka Pref. 1006, Kadoma, Kamon, Fumonma-shi F-term (reference) in Matsushita Electric Industrial Co., Ltd. AD06 AD07 AD08 AD09 AD10 AF07 BB08 BB16 CA15 DA68 DP03 DP04 EB02 EH11

Claims (33)

[Claims] 1. A step of introducing a raw material containing a constituent element of a semiconductor thin film through a gas inlet provided with a heating catalyst into a vacuum vessel connected to a gas inlet and a vacuum exhaust port. The electron density of plasma generated by discharge decomposition of the raw material activated by the heating catalyst under reduced pressure is 10 ¹⁰ to 10 ¹³ / cm ³ , and the substrate is irradiated with ions and radicals in the plasma. A method for manufacturing a semiconductor thin film, comprising forming a crystalline semiconductor thin film on the substrate by a step of forming a thin film. 2. A step of introducing a raw material containing a constituent element of a semiconductor thin film through a gas inlet provided with a heating catalyst into a vacuum vessel connected to a gas inlet and a vacuum exhaust port; The electron density of plasma generated by discharge decomposition of the raw material activated by the heating catalyst under reduced pressure is 10 ¹⁰ to 10 ¹³ / cm ³ , and the substrate is irradiated with ions and radicals in the plasma. An apparatus for manufacturing a semiconductor thin film, wherein a crystalline semiconductor thin film is formed on the substrate by a step of forming a thin film. 3. In a vacuum vessel connected to a gas introduction port and a vacuum exhaust port, the electron density of plasma generated by discharge decomposition of a raw material containing a constituent element of a semiconductor thin film under reduced pressure is 10 ¹⁰
1010 ¹³ ions / cm ³ , a step of irradiating the substrate with ions and radicals in the plasma to form a thin film, and being activated by a heating catalyst provided at a gas inlet in the vacuum vessel. A method for manufacturing a semiconductor thin film, comprising forming a crystalline semiconductor thin film on the substrate by irradiating the substrate surface with a gas. 4. In a vacuum vessel connected to a gas introduction port and a vacuum exhaust port, the electron density of plasma generated by discharge decomposition of a raw material containing a constituent element of a semiconductor thin film under reduced pressure is 10 ¹⁰
1010 ¹³ ions / cm ³ , a step of irradiating the substrate with ions and radicals in the plasma to form a thin film, and being activated by a heating catalyst provided at a gas inlet in the vacuum vessel. An apparatus for manufacturing a semiconductor thin film, wherein a crystalline semiconductor thin film is formed on the substrate by a step of irradiating a gas to the surface of the substrate. 5. A step of introducing a raw material containing a constituent element of a semiconductor thin film through said gas inlet provided with a heating catalyst;
The electron density of plasma generated by discharge decomposition of the raw material activated by the heating catalyst in the vacuum vessel under reduced pressure is 10 ¹⁰ to 10 ¹³ / cm ³ , and ions and radicals in the plasma are A semiconductor device, wherein a crystalline semiconductor thin film formed on a substrate by a step of irradiating the substrate to form a thin film is used as an active layer. 6. An electron density of plasma generated by discharge decomposition of a raw material containing constituent elements of a semiconductor thin film is 10 ¹⁰ to 10 ¹³ / cm 3.
³ , the process of irradiating the substrate with ions and radicals in the plasma to form a thin film, and irradiating the substrate surface with a gas activated by a heating catalyst provided in a gas inlet, the substrate A semiconductor device comprising a crystalline semiconductor thin film formed thereon as an active layer. 7. A discharge decomposition of a raw material containing a constituent element of a semiconductor thin film is performed by a high frequency inductively coupled plasma, a helicon wave plasma,
Electron cyclotron resonance plasma, UHF plasma, V
4. The method for producing a semiconductor thin film according to claim 1, wherein the method is performed by generating plasma by one of HF plasma and arc discharge plasma. 8. A discharge decomposition of a raw material containing a constituent element of a semiconductor thin film is performed by a high-frequency inductively coupled plasma, a helicon wave plasma,
Electron cyclotron resonance plasma, UHF plasma, V
5. The semiconductor thin film manufacturing apparatus according to claim 2, wherein plasma is generated by any one of HF plasma and arc discharge plasma. 9. A discharge decomposition of a raw material containing a constituent element of a semiconductor thin film is performed by a high-frequency inductively coupled plasma, a helicon wave plasma,
Electron cyclotron resonance plasma, UHF plasma, V
7. The semiconductor device according to claim 5, wherein plasma is generated by one of HF plasma and arc discharge plasma. 10. The method according to claim 1, wherein the raw material containing the constituent element of the semiconductor thin film contains silicon, and the constituent element of the crystalline semiconductor thin film contains silicon. A method for manufacturing a semiconductor thin film. 11. The method according to claim 2, wherein the raw material containing the constituent element of the semiconductor thin film contains silicon, and the constituent element of the crystalline semiconductor thin film contains silicon. Equipment for manufacturing semiconductor thin films. 12. The method according to claim 5, wherein the raw material containing the constituent element of the semiconductor thin film contains silicon, and the constituent element of the crystalline semiconductor thin film contains silicon. Semiconductor device. 13. The method for producing a semiconductor thin film according to claim 10, wherein the raw material containing the constituent elements of the semiconductor thin film is diluted with a hydrogen gas or an inert gas. 14. The semiconductor thin film manufacturing apparatus according to claim 11, wherein the raw material containing the constituent elements of the semiconductor thin film is diluted with hydrogen gas or an inert gas. 15. The semiconductor device according to claim 12, wherein the raw material containing the constituent elements of the semiconductor thin film is diluted with a hydrogen gas or an inert gas. 16. A method for forming a semiconductor thin film, comprising:
The method according to claim 10, wherein the temperature is 0 ° C. to 600 ° C. 11. 17. A method for forming a semiconductor thin film, comprising:
The apparatus for producing a semiconductor thin film according to claim 11, wherein the temperature is set to 0C to 600C. 18. The method according to claim 18, wherein the temperature of the substrate is set at 10 when forming the semiconductor thin film.
The semiconductor device according to claim 12, wherein the temperature is 0 ° C. to 600 ° C. 13. 19. The method according to claim 10, wherein the semiconductor thin film is microcrystalline silicon or polycrystalline silicon. 20. The apparatus according to claim 11, wherein the semiconductor thin film is microcrystalline silicon or polycrystalline silicon. 21. The semiconductor device according to claim 12, wherein the semiconductor thin film is microcrystalline silicon or polycrystalline silicon. 22. A semiconductor thin film having a hydrogen content of 10 atom
8. The method of manufacturing a semiconductor thin film according to claim 1, wherein the amount is not more than%. 23. A semiconductor thin film having a hydrogen content of 10 atom
%. The apparatus for manufacturing a semiconductor thin film according to claim 2, wherein the percentage is not more than%. 24. A semiconductor thin film having a hydrogen content of 10 atom
%. The semiconductor device according to claim 5, wherein the ratio is not more than%. 25. The method according to claim 10, wherein a light-transmitting substrate is used as the substrate. 26. The apparatus according to claim 11, wherein a light-transmitting substrate is used as said substrate. 27. The semiconductor device according to claim 12, wherein a light-transmitting substrate is used as said substrate. 28. A semiconductor device according to claim 28, wherein at least one kind of an insulating film and a conductive film is formed on a part or the whole surface of the substrate, and a crystalline semiconductor thin film is formed on the insulating film or the conductive film. The method for manufacturing a semiconductor thin film according to claim 10, wherein: 29. At least one of an insulating film and a conductive film is formed on a part or the whole surface of the substrate, and a crystalline semiconductor thin film is formed on the insulating film or the conductive film. The apparatus for manufacturing a semiconductor thin film according to claim 11, wherein: 30. An apparatus according to claim 30, wherein at least one kind of an insulating film and a conductive film is formed on a part or the whole surface of the substrate, and a crystalline semiconductor thin film is formed on the insulating film or the conductive film. The semiconductor device according to claim 12, wherein: 31. The semiconductor thin film having a thickness of 5 nm or more and 2
The method for producing a semiconductor thin film according to claim 10, wherein the thickness is not more than 00 nm. 32. The semiconductor thin film having a thickness of 5 nm or more and 2
The apparatus for manufacturing a semiconductor thin film according to claim 11, wherein the thickness is not more than 00 nm. 33. The semiconductor thin film having a thickness of 5 nm or more and 2
13. The semiconductor device according to claim 12, wherein the thickness is not more than 00 nm.