JP2001313257A - Method for producing high quality silicon based thin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a silicon based thin film and a method for forming a large grain size silicon based thin film having a high crystallization rate at a high rate on an inexpensive substrate of glass, ceramics, metal, or resin by a low temperature process of 450 deg.C or below. SOLUTION: In the method for forming a silicon based thin film, a substrate having a surface formed with at least one thin metal film of aluminum, tin, zinc, antimony, indium, gallium, silver, nickel, tellurium and germanium is placed in a vacuum chamber and material gas is supplied onto the surface of the heated substrate in order to form a silicon based thin film. The material gas is preferably supplied in the form of high density plasma excited by electron beam excited plasma method, high frequency parallel plate plasma method, high frequency plasma method employing rudder-like discharge electrodes, electron cyclotron resonance plasma method, induction coupling plasma method, or helicon wave plasma method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a silicon-based thin film, and more particularly to a method for forming a crystalline silicon-based thin film at a lower temperature, improved crystallinity, and reduced cost.

[0002]

2. Description of the Related Art Conventionally, in forming a silicon-based thin film used for a thin film transistor or a thin film solar cell, a high-frequency plasma chemical vapor deposition method (RF-PCVD method, VHF-PCVD method) such as a parallel plate type RF or VHF or the like has been known. Electron cyclotron resonance plasma chemical vapor deposition (ECR)
-PCVD method) and the like have been widely used. Furthermore, a method in which an amorphous film is once deposited on a substrate at a low temperature and then crystallized by performing thermal annealing or laser annealing, or a method in which a high-quality silicon-based thin film is formed on the substrate by a liquid phase epitaxy (LPE method). There is also. Further, a thin film of a metal having a low eutectic temperature with silicon (for example, aluminum, magnesium, calcium, tin, zinc, antimony, indium, gallium, silver or bismuth) is formed on a substrate, and a substrate temperature of 450 ° C. or more is formed. To form a polycrystalline silicon thin film by heating. (Appl.
Phys. Lett., V29, 600, (1976); Appl.Phys. Lett., V25,
583, (1977); Apll.Phys.Lett., V31, 125, (1977);
(JP-A-11-251611)

[0003]

SUMMARY OF THE INVENTION RF-PCVD method, V
In the film formation by the HF-PCVD method or the ECR-PCVD method, a substrate having low heat resistance such as an inexpensive glass substrate is used.
Although a silicon film can be formed at high speed, the crystallization rate of the formed film is low, the crystal grain size is about several hundreds of mm, and the mobility important as a semiconductor film is extremely small. On the other hand, in the RF-PCVD method, the VHF-PCVD method, the ECR-PCVD method, or the thermal CVD method, the crystallization rate of a silicon-based thin film formed by forming a film at a substrate temperature of 600 ° C. or higher is increased, Can be several hundred square meters or more. However, an inexpensive glass substrate or the like cannot be used, and the production cost increases. After the amorphous film is deposited on the substrate, thermal annealing or laser annealing is performed to increase the crystallization rate and increase the grain size, or a liquid phase growth method (LP
The method of forming a high-quality silicon-based thin film by the E method) requires a film-forming time and a crystallization time, thereby increasing the production cost. Also, a metal having a low eutectic temperature with silicon on the substrate (for example, aluminum, magnesium, calcium, tin, zinc, antimony, indium, gallium,
In the method of forming a polycrystalline silicon thin film by forming a thin film of (silver or bismuth) and heating at a substrate temperature of 450 ° C. or more, it is possible to form a highly crystalline silicon thin film at a relatively low temperature. Use of a low-melting substrate such as a glass substrate in terms of high-speed film formation and low-temperature film formation,
Or, it is not enough to prevent the influence of thermal stress generated in the crystal.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a high crystallization rate by a low-temperature process of 450 ° C. or less on an inexpensive substrate such as glass, ceramics, metal, and resin. An object of the present invention is to provide a silicon-based thin film capable of forming a silicon-based thin film having a large diameter at a high speed, and a film forming method.

[0005]

According to the method for manufacturing a silicon-based thin film of the present invention, at least one metal thin film of aluminum, tin, zinc, antimony, indium, gallium, silver, nickel, tellurium, and germanium is formed on the surface. The obtained substrate is placed in a vacuum chamber, and a raw material gas serving as a silicon supply source is supplied onto the heated surface of the substrate to form a silicon-based thin film. The raw material gas is preferably supplied in the form of plasma, and the plasma can be excited by an electron beam excitation plasma method, a high-frequency parallel plate plasma method, a high-frequency plasma method using a ladder-like discharge electrode,
A high-density plasma such as an electron cyclotron resonance plasma method, an inductively coupled plasma method, or a helicon wave plasma method is used. The substrate temperature during film formation is
Preferably, the temperature is in the range of 150 to 600 ° C or lower, and more preferably, the substrate temperature is in the range of 300 to 450 ° C. The raw material gas to be supplied at the time of film formation is preferably silane, silicon hydride gas such as disilane, silicon fluoride, halosilane such as dichlorosilane, or hydrogen gas or hydrocarbon gas such as methane gas contained in such a gas. Or a mixture of these gases containing a gas for adding impurities such as diborane, phosphine, or arsine, or a combination thereof.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The silicon-based thin film of the present invention means a polycrystalline silicon thin film and a microcrystalline silicon thin film formed by a vapor phase synthesis method. Also included are thin-film polycrystalline silicon and microcrystalline silicon thin films containing hydrogen atoms in the grain boundaries and in the grains. The silicon-based thin film also includes thin-film polycrystalline silicon and microcrystalline silicon containing an additional element such as a p-type or n-type dopant. Further, a silicon-based thin film includes a polycrystalline silicon thin film containing carbon and a microcrystalline silicon thin film. The thin film of the present invention has a thickness of 50 ° to 10 μm.
m.

Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows an electron-beam-excited plasma apparatus (hereinafter, referred to as a silicon-based thin film).
Device A. FIG. The apparatus A is of a type in which an electron beam is emitted in parallel to the substrate surface, and a discharge chamber 1a defining a discharge chamber 1 at one end and a process chamber 28A defining a film forming chamber 17 at the other end. And an intermediate chamber 2a and an electron acceleration chamber 3 defining an intermediate chamber 2 in the middle.
Is provided.

In the discharge chamber 1, a hot filament 4 and a hot electron emission plate 5 are provided to face each other. Hot filament 4
The circuit of the power supply 14 is connected to the thermoelectron emission plate 5 and the thermoelectron emission plate 5. When a discharge gas is introduced into the discharge chamber 1 through the gas supply path 10 and power is supplied from the power supply 14 between the hot filament 4 and the thermionic emission plate 5, a discharge plasma 13 is generated between the two. Has become.

An electrode 7 insulated by an insulator 6 is inserted between the discharge chamber 1 and the intermediate chamber 2, and the two chambers 1 and 2 communicate with each other via a central hole 12a of the electrode 7. Discharge plasma 13 by electrode 7
Are extracted from the inside, and the electrons are guided to the intermediate chamber 2 through the central hole 12a. Intermediate room 2 and acceleration room
An electrode 8 that is insulated by an insulator 6 is inserted between the two chambers 3, and the two chambers 2 and 3 communicate with each other via a central hole 12b of the electrode 8. Further, an electrode 9 insulated by the insulator 6 is inserted between the acceleration chamber 3 and the film forming chamber 17, and the two chambers 3, 17 are inserted through the central hole 12c of the electrode 9.
Are communicating. A power supply 15 is provided in a circuit between the thermionic emission plate 5 and the electrode 7, and a power supply 16 is provided in a circuit between the electrode 8 and the electrode 9. A differential exhaust path 11 is opened on the side surface of the acceleration chamber 3 so that the differential exhaust is performed so that the internal pressure of the acceleration chamber 3 becomes lower than the internal pressure of the intermediate chamber 2. Acceleration room 3
The entrance-side electrode 8 and the exit-side electrode 9 are respectively surrounded by a coil 23 so that a magnetic field for converging the accelerated electron beam is formed.

In the film forming chamber 17, a chuck heater 21 and
Two cusp magnetic field forming coils 24a and 24b are provided. The cusp magnetic field forming coils 24a and 24b are
May be provided outside. The chuck heater 21 is for holding and heating the substrate 20. A pair of coils 24a and 24b are arranged so as to sandwich the substrate 20 held by the chuck heater 21 from above and below. Main exhaust path 18
A and the source gas supply path 19 communicate with the film forming chamber 17, respectively. The main exhaust path 18A opens at the rear surface of the chamber 28A and communicates with a suction port of a vacuum exhaust pump (not shown). The source gas supply path 19 opens at the side surface of the chamber 28A, and communicates with a gas dozer (not shown) and a gas supply source (not shown). The gas dozer includes a rectifying plate for uniformly supplying the source gas to the substrate 20. The chamber 28A is connected to the ground 26.

When an electron beam is injected while supplying a raw material gas into the film forming chamber 17, a plasma 22 is generated, and a coil 22 is formed.
When power is supplied to 24a and 24b, a cusp magnetic field is formed as shown in FIG. The cusp magnetic field acts on the generated plasma 22 as shown by an arrow in FIG. 4 to confine the plasma 22 in the film forming chamber 17, promote the deposition of the active species in the plasma 22 on the substrate 20, and homogenize the plasma 22. .

Next, a method of forming a silicon-based thin film will be described. Electric power is supplied to the hot filament 4 provided in the discharge chamber 1 of the apparatus A by the filament power supply 14, and the thermoelectron emission plate 5 is supplied.
To emit electrons. The gas introduced from the gas supply port 10 is discharged as plasma 13 by the voltage applied to the discharge electrode 7 by the discharge power supply 15. The electron beam 12 drawn into the intermediate chamber 2 by the discharge electrode 15 applied to the discharge electrode 7 is accelerated by the intermediate electrode 8 and the accelerating electrode 9 to which a voltage is applied by the power supply 16 and introduced into the film forming chamber 17. At this time, the gas supplied to the discharge chamber 1 is evacuated via the differential evacuation path 11 to such an extent that it does not affect the film formation in the film formation chamber 17. Since the electron beam 12 introduced into the film forming chamber 17 has high energy, it excites the source gas, so that a high-density gas plasma 22 is generated in the film forming chamber 17.

A substrate 20 heated by a heater 21 is installed in a film forming chamber 17, and a silicon-based thin film is formed on the substrate 20 by a source gas plasma 22. The source gas is introduced from the source gas supply path 19 and is exhausted from the film forming chamber 17 via the main exhaust path 18A. Further, by providing the cusp magnetic field 24 inside or outside the film forming chamber 17, the source gas plasma 22 can be confined at a high density near the surface of the substrate 20.

The effect of the present invention is that the electron beam excited plasma apparatus (hereinafter referred to as apparatus B) of another embodiment shown in FIG.
Also, the present invention can be realized in another electron beam excited plasma apparatus (hereinafter, referred to as apparatus C) shown in FIG. The same elements as those in the apparatus shown in FIG. 1 are denoted by the same reference numerals. The device C is a device of a type in which the electron beam 12 is emitted in the vertical direction. The device C is configured to accelerate thermoelectrons from above and drive them into the film forming chamber 17 below. However, in the configuration of the device C, the surface of the substrate 20 is charged to a negative potential by the incident electron beam 12, and positive ions generated in the source gas plasma 22 excited by the electron beam 12 are incident on the surface of the substrate 20 with high energy. And may deteriorate the film quality. Furthermore, when the surface of the substrate 20 is placed upward, particles generated in the source gas plasma 22 may accumulate on the surface of the substrate 20 during film formation, thereby deteriorating the film quality. However, these are based on the fact that the incidence of positive ions is
Can be solved by using a device configuration that does not directly enter the surface of the substrate 20, and can be solved by using the shield plate 25 of the device B described below. The device B includes a shielding plate 25 which is mounted perpendicular to the incident axis of the electron beam 12 and is grounded to the earth 26. Such a shielding plate 25 prevents the electron beam 12 from being directly incident on the surface of the substrate 20 to prevent the positive ions from being incident at a high energy. Can be suppressed.

Further, the effect of the present invention can be realized also in a high-frequency parallel plate type plasma apparatus (hereinafter referred to as apparatus D) shown in FIG. As shown in FIG. 5, the apparatus D includes a film forming chamber 32, a gas mixing box 35, a heater 31, an electrode 38,
And a vacuum pump 34 and the like. The substrate 20 has a structure in which the film-forming surface is placed in close contact with the heater 31. The electrode 38 may be an ordinary parallel flat plate or a ladder electrode 38a shown in FIG.

The film forming chamber 32 communicates with a vacuum pump 34 via an exhaust passage 33 provided on a side surface of the vacuum vessel 30. The substrate 20 is placed in the vacuum vessel 30 evacuated by the vacuum pump 34 so as to be in close contact with the heater 31. Vacuum container
At the same time as supplying the source gas from the source gas supply source 37 into the inside 30, the high-frequency power is supplied from the high-frequency power supply 40 to the heater 31 and the electrode 38 installed so as to face the substrate 20. During that time, source gas plasma 22 is generated. In order to stably maintain the source gas plasma 22, the impedance for the supplied high frequency power is matched using the impedance matching unit 39. Thus, a silicon-based thin film is formed on the surface of the substrate 20.

FIG. 6 shows the ladder electrode 38a. Ladder electrode 3
8a is a structure in which metal wires having a diameter of 4 to 12 mm or less are combined in a ladder shape. The ladder electrode 38a is characterized in that it has both characteristics of the capacitively coupled discharge and the inductively coupled discharge. The ladder electrode 38a has a wider opening than the conventionally used parallel plate type electrode,
One of the features is that the controllability of the flow of the source gas is excellent.

Next, conditions for forming the silicon-based thin film of the present invention will be described. As a raw material gas to be introduced into the film forming chamber 17, a silicon hydride gas such as silane or disilane, a halosilane such as silicon fluoride or dichlorosilane, or a hydrogen gas or a hydrocarbon gas such as methane gas is contained in such a gas. Can be used. Further, a p-type or n-type film can be formed by using a gas containing a gas for adding impurities such as diborane, phosphine, or arsine in these gases. Further, when a substrate on which aluminum is formed is used, a p-type film can be formed by containing aluminum in the formed silicon-based thin film. As for the source gas, in the electron beam excited plasma method such as the apparatus A, the apparatus B or the apparatus C, it is desirable that the flow ratio of hydrogen to the flow rate of the gas containing silicon is 100 times or less. If the flow rate ratio of hydrogen exceeds 100 times, the film forming speed becomes extremely low, so that there is a possibility that the productivity may be significantly reduced for industrial use. The pressure is 0.5-200mT
Orr is desirable. If the pressure is less than 0.5 mTorr, the plasma density of the raw material gas decreases, and the film forming speed becomes extremely low. Therefore, there is a possibility that the productivity may be significantly reduced for industrial use. On the other hand, when the pressure exceeds 200 mTorr, the source gas pressure in the acceleration chamber 9 increases, and the amount of current of the electron beam 12 that can be incident on the film formation chamber 17 becomes small because plasma discharge starts in the acceleration chamber 9 and contributes to film formation. Since the plasma density of the raw material gas is reduced and the film forming speed is extremely reduced, the productivity may be significantly reduced for industrial use. Device D
In such a high-frequency parallel plate plasma method, the flow rate ratio of hydrogen to the flow rate of the gas containing silicon is desirably 5 to 100 times. When the flow rate ratio of hydrogen is less than 5 times, the amount of generated hydrogen radicals is reduced, so that the hydrogen termination of dangling bonds in the film becomes insufficient, and as a result, defects may be increased in the film. On the other hand, when the flow rate ratio of hydrogen exceeds 100 times, the film formation rate becomes extremely low, and therefore, the productivity may be significantly reduced for industrial use. The pressure is 0.1
Desirably, the pressure is in the range of Torr to 5 Torr. When the pressure is less than 0.1 Torr, the film forming speed becomes extremely low, and thus there is a possibility that the productivity may be significantly reduced for industrial use. On the other hand, when the pressure exceeds 5 Torr, there is a problem that powder is easily generated in a gas phase during film formation.

As the substrate 20, a substrate of glass, semiconductor, metal, resin or the like on which at least one metal thin film of aluminum, tin, zinc, antimony, indium, gallium, silver, nickel, tellurium, or germanium is formed is used. . By using these metal thin films, it becomes possible to form a silicon-based thin film having a high crystallization rate and a large grain size at a low temperature.

The substrate 20 is heated to a temperature range of preferably 150 to 600 ° C. by the heater 21 or the heater 31. In order to obtain a high crystallization ratio and a large particle size, and to use a substrate that can be used only at a low temperature, such as glass or resin, it is more preferable to heat the substrate to a temperature range of 300 to 450 ° C.

In the apparatus A, apparatus B or apparatus C, a refractory metal such as tungsten can be used as the hot filament 4 and a LaB ₆ plate or the like can be used as the thermoelectron emission plate 5. As a gas supplied from the gas supply path 10, a rare gas such as Ar or He or a hydrogen gas which hardly affects the film formation is supplied at a flow rate of 0.5 to 10 sccm or less and the pressure in the discharge chamber 1 is 1 × 10
^The plasma 13 is generated by supplying the plasma 13 at ^-3 Torr or less. The power supply 15 applied to the discharge electrode 7 has a discharge current of 5
It is set so that it is not less than A and not more than 100A. Acceleration electrode 9
The power supply 16 to be applied is 30 to 200V. That is, when the plasma generation method is the electron plasma method, the voltage at which the electron beam can be incident from the acceleration chamber 9 to the film forming chamber 17 is 30 volts.
V, and excitation of source gas such as silicon hydride gas.
It is preferable that the energy of the electron beam be in the range of 30 to 200 eV from the viewpoint of using an electron beam having a high dissociation efficiency of 200 eV or less. Power supply 16 applied to acceleration electrode 9
The electron beam 12 can be incident on the film forming chamber 17 at 5 to 100 A, which is almost equal to the discharge current, by setting the voltage to 30 to 200 V. At this time, it is more preferable that the power supply 16 is set to 50 V or more because the excitation efficiency of the source gas is improved and high-density plasma can be generated. Cusp magnetic field 24
The magnetic field generated by this is a cusp magnetic field, and the source gas plasma 22 can be spatially confined near the substrate 20 by generating a magnetic field as shown in FIG. In the device D, it is desirable to use a frequency of 10 to 300 MHz as the power supplied from the high frequency power supply 40 to the electrode 38. When the frequency is less than 10 MHz, the plasma density is low, the film formation rate is low, and the amount of generated hydrogen radicals is small. Therefore, the hydrogen termination of dangling bonds becomes insufficient, and defects in the film may increase. . on the other hand,
If the frequency exceeds 300 MHz, the voltage distribution in the electrode 38 becomes large, making uniform discharge difficult, and as a result, there is a problem that uniform film formation may become difficult.

In the production of the silicon thin film of the present invention, the plasma generation method is preferably the above-mentioned electron beam excitation plasma method, high-frequency parallel plate plasma method, or high-frequency plasma method using a ladder-shaped discharge electrode. It is not limited to these. Electron cyclotron resonance plasma method,
An inductively coupled plasma method, a helicon wave plasma method, or the like can also be used. FIG. 7 shows a cross-sectional view of the inside of the electron cyclotron resonance plasma film forming apparatus. In the electron cyclotron resonance plasma, a high frequency power of 2.45 GHz is supplied from the microwave waveguide 42 to the main electromagnetic coil 44.
The high frequency of the resonance frequency is applied to
By supplying a silicon hydride gas, a hydrogen-diluted silicon hydride gas, or the like, which is a raw material gas, from the 36, a high-density plasma of the raw material gas can be generated in the film forming chamber 17. The raw material gas supplied from the gas nozzle 36 is silicon hydride gas such as silane diluted to 0.5 to 20 mol% with hydrogen at 0.1 mTorr.
It is desirable to supply at a pressure of 1 Torr or less.

FIG. 8 is a cross-sectional view of the inside of the inductively coupled plasma film forming apparatus. In the inductively coupled plasma, the high frequency power supply 40 connected to the induction coil
At the same time as supplying high-frequency power with a frequency of 0 MHz or less,
By supplying a material gas such as silicon hydride gas or hydrogen-diluted silicon hydride gas from the gas nozzle 36, high frequency power inductively coupled to the material gas in the film forming chamber 17 through the dielectric 43 High-density plasma of the source gas can be generated in the film forming chamber 17. The source gas supplied from the gas nozzle 36 is desirably a silicon hydride gas such as silane diluted to 0.5 to 20 mol% with hydrogen at a pressure of 10 mTorr to 5 Torr.

FIG. 9 is a cross-sectional view of the inside of the helicon wave plasma film forming apparatus. In the helicon wave plasma, the high frequency power supply 40 connected to the helicon wave coil 45
At the same time as supplying high-frequency power having a frequency of 200 MHz or less, a gas hydride gas, such as a silicon hydride gas or a hydrogen-diluted silicon hydride gas, is supplied from a gas nozzle 36 to form a film forming chamber 17 through a dielectric 43. High-density plasma of the source gas can be generated in the film forming chamber 17 by high-frequency power coupled to the source gas in the chamber by a helicon wave. Gas nozzle
The source gas supplied from 36 is desirably a silicon hydride gas such as silane diluted to 0.5 to 20 mol% with hydrogen at a pressure of 10 mTorr to 5 Torr.

[0025]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. (Examples) Table 1 shows the film forming conditions of the examples and the comparative examples. Examples 1 to 6 are film forming conditions using a glass substrate having aluminum evaporated on the surface as a substrate in the apparatus A, and Examples 7 to 8 are films using a glass substrate having aluminum evaporated on the surface as the substrate in the apparatus B. For membrane conditions,
Examples 9 to 10 are film-forming conditions using a glass substrate having aluminum evaporated on the surface as a substrate in the device D, and Comparative Examples 1 to 3 are devices using a glass substrate as a substrate in the device A, device B or device D. Each corresponds to a film condition. In the apparatuses A and B, the source gas pressure is set to 16
mTorr, silane gas flow rate 0.5sccm or 3sccm
The hydrogen flow rate was set to 80 sccm, the electron acceleration voltage was set to 50 V or 80 V, and the substrate temperature was set to 300 ° C.
The test was carried out at 30 ° C., 370 ° C., and 400 ° C. Device D
In the above, the source gas pressure was set to 1 Torr, the silane gas flow rate was set to 3 sccm, the hydrogen flow rate was set to 300 sccm, and the discharge frequency was set to 10 sccm.
0 MHz and the substrate temperature was 350 ° C, 370 ° C,
The test was carried out with the temperature changed to 00 ° C.

[0026]

[Table 1]

Next, the film quality evaluation for Examples 1 to 10 and Comparative Examples 1 to 3 will be described with reference to FIGS. In FIG. 10, the horizontal axis indicates the substrate temperature (° C.), and the vertical axis indicates the Raman ratio (Ic / Ia).
The results of film formation in each of the devices A, B, and D when using a glass substrate on which aluminum was vapor-deposited, and the devices A, B, and D when using a glass substrate corresponding to a comparative example. 3 shows the results of film formation. Here, the "Raman ratio" refers to the ratio of the spectral intensity of 520 cm ^-1 and 480 cm ^-1 in the spectrum of the results of Raman spectroscopy of a film was formed, corresponding to the height of the crystallization of the film. As is clear from the figure, when a film is formed on a glass substrate at a substrate temperature of 370 ° C., the Raman ratio is low in any of the apparatuses A, B and D. On the other hand, when a film is formed on a glass substrate on which aluminum is deposited at a substrate temperature of 300 to 370 ° C., the Raman ratio sharply increases as the substrate temperature increases in any of the apparatuses A, B, and D, and the substrate temperature becomes 370 ° C.
In the above, the Raman ratio is improved to 30 or more.

FIG. 11 shows the substrate temperature (° C.) on the horizontal axis.
The crystal grain size (nm) is plotted on the vertical axis, and corresponds to the results of film formation in each of the apparatuses A, B, and D when a glass substrate on which aluminum corresponding to Examples 1 to 10 is deposited and a comparative example. The results of film formation in apparatuses A, B and D when a glass substrate is used are shown. As is apparent from the figure, when a film was formed on a glass substrate at a substrate temperature of 370 ° C., the apparatus A,
In both B and D, the crystal grain size is as very small as 0.1 μm or less. On the other hand, when a film is formed at a substrate temperature of 300 ° C. to 370 ° C. on a glass substrate on which aluminum is deposited, the crystal grain size increases with an increase in the substrate temperature in any of the apparatuses A, B, and D. At 350 ° C. or higher, the crystal grain size exceeds 1 μm.

FIGS. 12A and 12B show photographs of the silicon thin film formed in Example 8 observed by a surface electron microscope. It is clear that the silicon thin film formed by the method of the present invention is a polycrystalline silicon thin film having a particle size of 1 μm or more.

[0030]

[Table 2]

Further, as is clear from the results of the film evaluation shown in Table 2, the use of the present invention makes it possible to obtain 1.2 in Example 7
Å / sec or more, and the maximum value in Example 10 is 12.5 Å / sec.
Second film forming speed can be realized. These film forming speeds are reduced by reducing the distance between the electron beam incident position and the substrate 20 in the apparatuses A, B and C, and by the electrode D in the apparatus D.
This can be further improved by reducing the distance between 38 and substrate 20.

[0032]

According to the present invention, a high-quality silicon thin film can be formed on an inexpensive substrate made of glass, ceramics, metal, resin, or the like at a high speed by a low-temperature process of, for example, 450 ° C. or less.

[Brief description of the drawings]

FIG. 1 is an internal perspective sectional view of a manufacturing apparatus according to a first embodiment of the present invention.

FIG. 2 is an internal perspective sectional view of a manufacturing apparatus according to a second embodiment of the present invention.

FIG. 3 is an internal perspective sectional view of a manufacturing apparatus according to a third embodiment of the present invention.

FIG. 4 is a cutaway perspective view showing a pair of ring electrodes forming a cusp magnetic field.

FIG. 5 is an internal perspective sectional view of a manufacturing apparatus according to a fourth embodiment of the present invention.

FIG. 6 is a schematic plan view showing a part of the film forming apparatus of FIG.

FIG. 7 is an internal perspective sectional view of an electron cyclotron resonance plasma film forming apparatus.

FIG. 8 is an internal perspective sectional view of an inductively coupled plasma film forming apparatus.

FIG. 9 is an internal perspective sectional view of a helicon wave plasma film forming apparatus.

FIG. 10 is a characteristic diagram showing a correlation between a substrate temperature and a Raman ratio in each device.

FIG. 11 is a characteristic diagram showing a correlation between a substrate temperature and a crystal grain size in each device.

FIG. 12 is a surface electron micrograph of a silicon thin film formed according to the present invention, wherein (a) is 1,000 times, and (b) is.
It is 10,000 times.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Discharge chamber 1a Discharge chamber 2 Intermediate chamber 2a Intermediate chamber 3 Electron acceleration chamber 3a Acceleration chamber 4 Hot filament 5 Thermoelectron emission plate 6 Insulating plate 7 Discharge electrode 8 Intermediate electrode 9 Acceleration electrode 10 Gas supply path 11 Differential exhaust path 12 Electron Beam 12a Electron beam path 12b Electron beam path 12c Electron beam path 13 Plasma 14 Power supply 15 Power supply 16 Power supply 17 Film forming chamber 18 Main exhaust path 18A Main exhaust path 18B Main exhaust path 18C Main exhaust path 19 Source gas supply path 20 Substrate 21 Heater Reference Signs List 22 Plasma 23 Electron beam focusing magnetic field forming coil 24 Cusp magnetic field 24a Cusp magnetic field forming coil 24b Cusp magnetic field forming coil 25 Shielding plate 26 Earth 27 Cusp magnetic field 28 Process chamber 28A Process chamber 28B Process chamber 28C Process Chamber 30 Vacuum container 31 Heater 32 Film forming chamber 33 Exhaust path 34 Vacuum pump 35 Gas mixing box 36 Gas nozzle 37 Source gas supply source 38 Electrode 38a Ladder electrode 39 Impedance matching device 40 High frequency power supply 41 Coaxial cable 42 Microwave waveguide 43 Dielectric 44 Main electromagnetic coil 45 Induction coil 46 Helicon wave coil

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Katsuhiko Kondo, Inventor, 1-8-1, Koura, Kanazawa-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Heavy Industries, Ltd. Fundamental Technology Research Laboratories (72) Kengo Yamaguchi, Kengo Yamaguchi, Kanazawa-ku, Yokohama-shi, Kanagawa Prefecture 8th Street 1 F-term in Mitsubishi Heavy Industries, Ltd. Fundamental Research Laboratory 4K030 AA04 AA05 AA06 AA09 AA17 BA29 CA06 DA02 FA01 FA02 FA03 FA04 HA04 JA09 JA10 JA20 LA16 5F045 AA08 AA09 AA10 AA14 AB02 AC01 AC02 AC07 AD05 AD09 AD07 AD08 AE13 AE15 AE17 AE19 AE21 AF10 CA13 CA15 EH11 EH13 EH17 5F051 AA03 AA04 BA14 CB12 CB29 GA03 GA06

Claims (7)

[Claims] Claims: 1. An aluminum, tin, zinc, antimony, indium, gallium, silver, nickel, tellurium,
A substrate formed with one or more metal thin films selected from a group consisting of germanium and germanium is placed in a vacuum chamber, and a raw material gas serving as a silicon supply source is turned into plasma and supplied to the heated substrate surface. Method of manufacturing system thin film. 2. The method according to claim 1, wherein the substrate temperature is in a range of 150 to 600 ° C. 3. The method of generating plasma includes an electron beam excited plasma method, a high-frequency parallel plate plasma method, a high-frequency plasma method using a ladder-shaped discharge electrode, an electron cyclotron resonance plasma method, an inductively coupled plasma method, and a helicon. The method for producing a silicon-based thin film according to claim 1, wherein the method is selected from a microwave plasma method. 4. The method according to claim 1, wherein the raw material gas is silicon hydride gas, silicon fluoride, halosilane, a gas containing hydrogen gas or a hydrocarbon gas, or a gas for adding impurities. The method for producing a silicon-based thin film according to any one of claims 1 to 3, wherein the method is selected from the group consisting of: 5. The method according to claim 1, wherein the plasma is generated by an electron beam excitation plasma method.
The pressure is set in the range of 0 to 200 eV and the pressure of the raw material gas is set to 0.
The method for producing a silicon-based thin film according to any one of claims 1 to 4, wherein the pressure is in the range of 5 to 200 mTorr. 6. The plasma generation method according to claim 1, wherein the plasma generation method is a high-frequency parallel plate plasma method or a high-frequency plasma method using a ladder-shaped discharge electrode, wherein the discharge frequency is 10 to 300 MHz.
And the pressure of the raw material gas is 0.1 to 5 Torr.
The method for producing a silicon-based thin film according to any one of claims 1 to 4, wherein 7. The method according to claim 1, wherein the source gas is selected from silane, disilane, halosilane, and a mixture thereof diluted with hydrogen gas in a range of 0.5 to 20 mol%.
7. The method for producing a silicon-based thin film according to any one of 6.