JPH0459970A - Formation of amorphous silicon carbide film - Google Patents

Abstract

PURPOSE:To increase the energy gap in the silicon carbide film to be obtained to a greater extent by using a specific hydrocarbon gas as a gas containing carbon atoms at the time of forming an amorphous silicon carbide film by a magnetic field microwave plasma CVD method. CONSTITUTION:In a magnetic field microwave plasma CVD method where a silicon carbide film is formed by introducing a gas for excitation and microwaves into a plasma formation chamber 1 and applying a magnetic field to produce plasma, introducing the plasma into a specimen chamber 2 connected to the plasma formation chamber 1, introducing a gas containing silicon atoms and a gas containing carbon atoms into the resulting plasma stream, and irradiating a substrate 3 placed in the specimen chamber with the plasma, an amorphous silicon carbide film is formed by using H2, SiH4, and any of those selected from the group consisting of CH2=CH2, CHidenticalCH, CH2=CH-CH3, CH2=C=CH2, and CH3CidenticalCH as the gas for excitation, the gas containing silicon atoms, and the gas containing carbon atoms, respectively.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for efficiently forming an amorphous silicon carbide film with an increased energy gap by a magnetic field microwave plasma CVD method. .

[Prior Art] De-amorphous silicon carbide films are used as wide-gap materials for pr-n junction layers, which are very important for amorphous silicon-based devices, such as thin-film solar cells and image sensors.
It is an indispensable material for (1) improving the characteristics of light emitting/receiving devices such as thin-film LEDs. It is also used as a wide-gap emitter for silicon-based heterobipolar transistors.

The characteristics required of such an amorphous silicon carbide film are a wide gap and high electrical conductivity, but at present these characteristics have not yet been fully satisfied. This is mainly due to the fact that amorphous silicon carbide films have conventionally been produced by plasma CVD using high-frequency induced glow discharge. That is, in the plasma CVD method using high-frequency induced glow discharge, doping efficiency is poor and an amorphous silicon carbide film with high conductivity cannot be created.

Incidentally, by causing microcrystalline silicon or a microcrystalline silicon carbide phase to appear in the network of amorphous silicon carbide and achieving microcrystalization, it is possible to make the thin film thinner and have higher conductivity.

Microcrystallization of such a thin film can be performed by forming the film in a high temperature range, or it is desirable to perform it under low temperature conditions (300° C. or lower) from the viewpoint of device fabrication.

Hydrogen dilution is commonly used to microcrystallize amorphous silicon thin films at low temperatures. In this method, by terminating active dangling bonds on the growth surface with hydrogen radicals, the precursors for film deposition that reach the surface can easily diffuse into unstable sites on the growth surface, building the network structure of the film. At this time, a sufficient relaxation process results in the appearance of a stable microcrystalline phase.

However, conventional high frequency glow discharge plasma CVD
Even if an attempt is made to create a microcrystalline silicon carbide film under low-temperature conditions using this method, the density of the plasma formed is low and highly active hydrogen cannot be sufficiently supplied to the film surface, making it difficult to form a microcrystalline silicon carbide film. If the amount of hydrogen dilution is too large in order to achieve this, the deposition rate becomes extremely slow, making it practically unsuitable for device fabrication.

In recent years, by applying a magnetic field to plasma, electron cyclotron coupling (hereinafter referred to as ECR) has been developed, which causes resonance between microwaves guided by a waveguide and electron cyclotron coupling in the magnetic field, increasing the degree of ionization. .) Plasma CV
Method D has been developed.

Here, the ideal ECR conditions include a case where a magnetic field B is set in the plasma generation chamber that satisfies the condition of the following equation for the microwave frequency ω used.

(υ= e B / m e (In the formula, e represents the charge of electric f・, and me represents the mass of electric r.) The ECR magnetic field for the commonly used microwave frequency of 2.45 GHz is 875 G. It is.

Since the ECR plasma CVD method can generate high-density plasma at low pressure, it is advantageous for forming thin films at low temperatures and for high-speed deposition.

There have also been reports on the formation of microcrystalline silicon carbide films under low dJ conditions using such an ECR plasma CVD method (Tceh, Di, Int'l, P.
VSEC-3, pp. 171-174 (1987
) ;Y, ! Iattori at al). In this example, H2 was introduced into the plasma generation chamber as an excitation gas for 10 to 50 seconds, and the excited plasma using an electron cyclotron was introduced into the sample chamber as a plasma stream. i H4,C
H4, PH3, H2 are decomposed and the gas pressure is 10-4
The film is formed on the substrate -1- heated to 250 to 300°C in the region of -10-3. The deposited film has an energy gap of 2°0 eV or more and a conductivity of 102 S/cml.
: It is said that it exhibited good doping characteristics.

However, when depositing a silicon carbide film using the ECR plasma CVD method under the conditions described above, it is difficult to desire a further increase in the energy gap of the resulting deposited film, and the deposition rate during film formation is also satisfactory. What I could do was very limited. This is because, although the energy gap of an amorphous silicon carbide film generally increases as the amount of carbon in the film increases, depending on the above conditions, the generation of active carbon species in the plasma is sufficient. This is thought to be because it is difficult to form a large amount of carbon atoms in the film. Furthermore, it is thought that the deposition rate is not favorable because the supply of carbon atoms forming the film structure is not sufficient.

In addition, although there have been many studies on the ECR plasma CVD method, there are no other reports on microcrystalline silicon carbide films, such as the one described above, and it is believed that stable deposition conditions have not yet been established. cannot be said. moreover,
” - We actually manufactured 1m under the conditions described in the report below.
However, the reproducibility was poor and it was difficult to form a thin film with good properties.

[Problems to be Solved by the Invention] Therefore, an object of the present invention is to provide a method for efficiently forming an amorphous silicon carbide film having an increased energy gap by a magnetic field microwave plasma CVD method. be. Furthermore, it is an object of the present invention to provide a method for forming an amorphous silicon carbide film containing microcrystals that exhibits high electrical conductivity and further increases the energy gap under low temperature conditions. It is something to do.

[Means for solving the problem] - The purpose of notation is to generate plasma by introducing excitation gas and microwaves into a plasma generation chamber and applying a magnetic field, and to generate a sample connected to the plasma generation chamber. The plasma is introduced into the chamber, a silicon atom-containing gas and a carbon atom-containing gas are introduced into the plasma flow thus formed, and the plasma is irradiated onto a substrate placed in the sample chamber to form a silicon carbide film. In the magnetic field microwave plasma CVD method, B2 is used as the excitation gas, SiH4 is used as the silicon atom-containing gas, and CH2=CH2, CHmmCH1CH2 as the carbon 1 prince a# gas.
=CH≡CH3, CH2=C≡CH2 and CH3C≡
This is achieved by a method for forming an amorphous silicon carbide film characterized in that each one selected from the group consisting of CH is used.

The present invention further provides a hydrogen dilution ratio of 50 times (capacity ratio) or more, which is the amount of hydrogen gas used divided by the amount of silicon atom-containing gas and carbon atom-containing gas, and a gas pressure during discharge of 2.5X10- 3Torr~5.0XIO-2To
3 shows a method for forming an amorphous silicon carbide film characterized by r r. The present invention also provides a substrate temperature of 1
This shows a method of forming an amorphous silicon carbide film at a temperature of 50°C to 300°C. The present invention further provides silicon atoms A
SiH4 as u gas has P as doping gas.
This shows a method for forming an amorphous silicon carbide film in which H3 or B2 H6 is mixed in an amount of 0.1 to 5% by volume.

[Function] As mentioned above, the energy gap of an amorphous silicon carbide film increases as the carbon content in the film increases, and the deposition rate of the film also increases as the amount of carbon atoms supplied to the growth surface increases. it is conceivable that.

However, in the conventional plasma of a mixed gas system of SiH4 and CH4, the decomposition energy of CH4 is higher than that of 5i)(4), so the decomposed and excited species related to Si are
This amount is higher than that of related substances, and as long as CH4 is used as the carbon atom-containing gas, the composition of the film will inevitably have a high Si content.

In molecules that contain two or more C atoms and have unsaturated bonds, the bond energy of the π bond is lower than that of the C-π bond, so when electrons are bombarded in plasma, the electrons involved in the π bond are state more easily becomes an excited state, that is, the π bond is easier to break than the C-π bond.

Therefore, in the plasma of a mixed gas system with SiH4, C
When using an unsaturated hydrocarbon, the amount of C-related radicals in the decomposed excited state increases more than when using H4, so the amount of C atoms incorporated into the film increases.

As a result of considering the following points, the present inventors have developed a method using CH4 as carbon atoms pf1 gas in order to more efficiently obtain an amorphous silicon carbide film with a further increased energy gap using magnetic field microwave plasma CV D3A. Gases with lower decomposition energy than CH2=CH2, C
H=CH5CH2=CH≡CH3, CH2=C=CH2
, CH3C=CH, etc. That is, by using gases with lower decomposition energy, decomposition excitation occurs more efficiently in the plasma, and more carbon atoms are incorporated into the film, thereby increasing the energy gap and increasing the deposition rate. This will result in an increase in

Hereinafter, the present invention will be explained in more detail based on embodiments.

FIG. 1 schematically shows an example of the configuration of a plasma CVD processing apparatus used in the method of forming an amorphous silicon carbide film containing microcrystals according to the present invention.

As shown in FIG. 1, the plasma CVD processing apparatus used in the present invention includes a plasma generation chamber 1 that converts excitation gas into plasma by electron cyclotron resonance, and a plasma generation chamber 1 that generates a film-forming gas using the plasma generated in the plasma generation chamber 1. This plasma generation chamber 1 is separated from the sample chamber 2 in which a thin film is deposited on a substrate 3 by decomposition and excitation.
and the sample chamber 2 are in communication via a plasma extraction window 4. An excitation gas introducing means 5 for introducing an excitation gas is connected to the plasma generation chamber 1, and on a wall surface facing the plasma extraction window 4, microwaves propagated by a waveguide 6 are connected to the plasma generation chamber 1. A microwave introduction window 7 for introducing microwaves into the generation chamber 1 is provided. Further, a magnetic circuit 8 is arranged around the plasma generation chamber 1, so that a magnetic field can be formed within the plasma generation chamber 1. On the other hand, the sample chamber 2 is provided with a sample stage 9 for placing the substrate 3 therein, and further includes a film-forming gas for introducing a film-forming gas into a position close to the plasma extraction window 4. A gas blowing ring 1 serving as an outlet of the introducing means 10 is arranged. In addition, test Fl room 2 has exhaust system 1.
Connected to 2.

To give an overview of the ECR plasma CVD method using such an apparatus, first, microwaves, for example, a 2.45 GHz microwave, are introduced into the plasma generation chamber 1 by a waveguide 6 and passed through a microwave introduction window 7. Waves are introduced into the plasma generation chamber 1, and a magnetic circuit 8 generates an electron cyclotron resonance magnetic field (2,
875 G for 45 GHz), the excitation gas introduced into the plasma generation chamber 1 through the excitation gas introducing means 5 is decomposed and excited by electron cyclotron resonance, and plasma is generated. This plasma is turned into a plasma flow by the divergent magnetic field through the plasma extraction window 4, and is guided to the chamber 2, where the film-forming gas is introduced.
Upon contact with the film-forming gas introduced into the sample f-1 chamber 2 through the stage 10, the film-forming gas is decomposed and excited, and a film-forming precursor is generated in the plasma flow.
A film is formed by reaching the substrate 3 at -. In the present invention, an amorphous silicon carbide film is formed by the ECR plasma CVD method. It is desirable to cause a microcrystalline silicon or microcrystalline silicon carbide film to appear in the silicon network and to microcrystallize it, and furthermore, from the viewpoint of device formation, it is desirable to deposit the film under low temperature conditions. Plasma C
Hydrogen radicals play an important role in forming a -H silicon carbide film containing fine crystals under low temperature conditions by the VD method. That is, as mentioned above, i on the growth surface of the thin film
Terminate the J-type tank ring pond with hydrogen radicals
1. By doing so, the precursors for film deposition that reach the surface can easily diffuse into unstable sites on the growth surface, and during the delineation of the network structure of the film, a sufficient relaxation process can be carried out.
This is because a microcrystalline phase, which is a stable phase, appears as a result. For this reason, film deposition is performed at high hydrogen dilution rates.

In the method for forming an amorphous silicon carbide film of the present invention, H2 is used as the excitation gas excited by electron cyclotron resonance, partly because the film is deposited at a high hydrogen dilution ratio as described above. .

Therefore, in the method for forming an amorphous silicon carbide film of the present invention, the carbon atom-containing gas, which is one of the film-forming gases, is CH2=CH2, CHICH.

CH2=CH≡CH3, CH2=C=CH2 and CH
Either one of 3C≡CHCH4 is used alone or in combination. Note that among these carbon atom g6-gases, CH=CH is particularly preferred. All of the above-mentioned unsaturated hydrocarbons used as the carbon atom-containing gas in the present invention have lower decomposition energy than CH4, which has been conventionally used as the carbon atom hexagonal gas.

Further, SiH4 is used as another silicon atom-containing gas that is a film-forming gas. In addition, when trying to dope the silicon carbide film to be obtained, for example, PH3 or B2H6 is used as a doping gas.
It is mixed into SiH4 gas at a rate of 0.1 to 5% by volume.

The method for forming amorphous silicon carbide of the present invention is preferably carried out at a high hydrogen dilution rate as described above;
Specifically, the hydrogen dilution ratio, that is, the value obtained by dividing the amount of hydrogen gas used by the amount of film-forming gas (silicon whitening gas and carbon atom Nh gas), is 50 times (volume ratio). )
From 1-1 below, it is preferably about 75 to 90 times. In other words, when the hydrogen dilution ratio is 50 times or less, hydrogen radicals that act to cause microcrystalline silicon or microcrystalline silicon carbide films to appear within the grown film by terminating active dangling bonds on the growth surface of the thin film are generated. This is because it becomes difficult to supply the thin film growth surface within 1 minute. Note that the higher the hydrogen dilution rate, the easier microcrystallization becomes, but the etching effect of hydrogen ions or hydrogen radicals becomes stronger, and the film formation rate becomes slower. A ratio of up to about 100 times is usually appropriate.

Furthermore, in the method for forming an amorphous silicon carbide film of the present invention, in order to widen the gap and increase the electrical conductivity of the deposited film obtained as described above, microcrystalline silicon or microcrystalline silicon is added to the network of the amorphous silicon carbide. When a crystalline silicon carbide film appears and becomes microcrystalline, the gas pressure during discharge is also an extremely important parameter. That is, while hydrogen radicals in the plasma play an important role in microcrystallization of the deposited film as described above, hydrogen ions or hydrogen radicals in the hydrogen plasma excited by the h' magnetic field microwave are highly active. This has a strong etching effect on the plasma, which may cause 13;L to become trapped and inhibit the progress of film deposition or cause a decline in film quality. However, by keeping the gas pressure at an appropriate level, the plasma It is possible to control the mobility of particles and suppress the occurrence of these problems.

To explain this point in detail, first, plasma CVD equipment has a quartz window for introducing microwaves, but the highly active hydrogen plasma excited by the 0° magnetic field microwave etches this quartz window and contains oxygen. A white microcrystal.

An amorphous silicon carbide film cannot be produced if there is oxygen contamination at the growth interface. When the gas pressure during discharge is low, the mean free path is long, so there is a high probability that oxygen mixed into the plasma near the microwave introduction window will reach the substrate, increasing the oxygen content in the film and causing microcrystals to form. Unable to create silicon carbide film. On the other hand, when the gas pressure during discharge is high,
Although there is some oxygen mixed into the plasma, the average self-intensity becomes shorter, so the amount of oxygen reaching the substrate decreases, and the amount of oxygen in the film decreases. Therefore, if the gas pressure during discharge is set high, a microcrystalline silicon carbide film is likely to be deposited.

In addition, when the gas pressure is low, the density of the hydrogen ions or hydrogen radicals present in the hydrogen plasma excited by the white magnetic field microwaves that irradiates the substrate increases because the homogeneous process in step 1 is long. Therefore, at low gas pressure, even when the hydrogen dilution rate is relatively low, the etching action goes through the deposition process 11 times, so no film is formed.On the other hand, at high gas pressure, the density of hydrogen ions or hydrogen radicals decreases, so high hydrogen Film deposition occurs even at dilution rates.

Furthermore, active species such as hydrogen ions or hydrogen radicals present in the hydrogen plasma excited by the magnetic field microwave also affect the reproducibility of the film quality of the deposited film. This is related to the deposition history of residual deposits from previous film forming steps in the plasma generation chamber of the plasma CVD apparatus. If any remaining deposited film from the previous film forming process exists on the inner wall of the plasma generation chamber, it will be etched away by chemical sputtering using the highly active hydrogen plasma.

Then, the remaining deposited film components mix into the plasma, and some of them reach the substrate surface and mix into the deposited film. When the gas pressure during discharge is low, the probability that the etched residual adherent film components will reach the substrate increases because the etched process takes a long time.

In order to form a microcrystalline thin film, high dilution with hydrogen is performed and only a small amount of film-forming gas is supplied. For this reason,
Among the film-forming precursors that reach the substrate surface, the proportion of products from the residual film on the inner wall of the plasma production process can no longer be ignored compared to the decomposed and excited species caused by the film-forming gas, and the reproducibility of film properties is reduced. This makes it difficult to ensure that

It should be noted that these phenomena in CVD using plasma excited by magnetic field microwaves were discovered for the first time by the inventor of the present invention.

From this point of view, in the method for forming an amorphous silicon carbide film of the present invention, the gas pressure during discharge is 2.5XIO' to 5XIO'.
．． 0XIO-2Torr, more preferably 3. ox
lo-: Should it be 3 to 1.0XIO-2Torr?
(Preferably. That is, the gas pressure of discharge 11+t is 2.5X
If it is less than 1O' Torr, the mean free path in the formed plasma becomes longer, and the probability that oxygen mixed into the plasma near the microwave introduction window 7 reaches the substrate 3 increases, causing As the amount of oxygen S'r increases, microcrystalization becomes +sn'nier, and the density of hydrogen ions or hydrogen radicals in the plasma with which the substrate 3 is irradiated increases, so that the etching process due to these increases. The film is not deposited after passing through the JNILA culm -1, and the rate of residual adhesion components mixed in the plasma +1 and reaching the substrate 31- increases, resulting in a decrease in film quality. This is because both A and I become more shy. -h\The gas pressure of the discharges 11 and 4 is 5. ClXl0-2
If it exceeds Torr, electron cyclotron a>J
l: This is because the stability of the plasma formed by excitation and decomposition due to the noise phenomenon may deteriorate.

Note that the degree of vacuum referred to here is a value measured using a Baratron vacuum gauge. The reason for using the display using the Baratron vacuum gauge is as follows.

The gas pressure during discharge in the ECRCVD process is 10
Since it is in the range of -4 to 1O-3 Torr, it is the upper limit range of 4 (normally ionization vacuum gauge) and also the lower measurement limit range of Baratron vacuum gauge.For this reason, which vacuum = There will be a difference in the degree of vacuum measurement depending on whether B-
Comparing the indicated values in the A-cage and Baratron, the degree of vacuum in Baratron is 5 to 6 times higher, ranging from several mTorr to more than ten mTorr.
It becomes the value of r.

In this case, in the B-A gauge: 1) The amount of ion current flowing into the filament of the gauge bulb cannot be ignored.

2) Accurate measurements cannot be made in such a vacuum region because the frequency of ionization of electrons increases.

1-/-j, Baratron vacuum: 1. Since it measures mechanical displacement, it is more accurate than the B-A gauge in this vacuum range.

In addition, in the formation method of the amorphous silicon carbide film of the present invention, since the hydrogen dilution rate is high as described above, the flow rate of H2 as the excitation gas is lower than that of SiH4 as the film-forming gas.
and CH2≡CH2, CHmiCHSCH2=CH≡C
The flow rate is very large compared to the flow rates of H3, CH2=C=CH2, CH3C=CH, etc. For this purpose, the gas pressure within the plasma processing apparatus is substantially determined by the flow rate of H2, which is one gas.

Further, as described above, the method for forming an amorphous silicon carbide film of the present invention is preferably carried out under low temperature conditions from the viewpoint of device formation, but the temperature range is from 160°C to 30°C.
00°C is preferable. Note that by heating the substrate 3 to such a temperature during film deposition, it is possible to promote the network formation reaction of amorphous silicon carbide on the film growth surface and form a denser film.

Hereinafter, the present invention has been explained taking as an example the case where an amorphous silicon carbide film containing microcrystals is formed. However, the method for forming an amorphous silicon carbide film of the present invention +'
It is not particularly limited to the form of i-product conversion, and can be similarly applied to the formation of an amorphous silicon carbide film that does not contain microcrystals, and CH4 can be replaced as the carbon atom-containing gas with decomposition energy. By using a low unsaturated hydrocarbon as described above, it is possible to increase the energy gap and increase the deposition rate.

[Example code] EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples.

An SiC film was formed using an apparatus having a configuration as schematically shown in FIG. 1 under the conditions shown below. In addition, in the examples related to the present invention, C is used as the carbon atom-containing gas.
2H2 was used for comparison, while CH4 was used for comparison, and other conditions were the same in both cases.

Microwave frequency 2.45GHz Microwave output 300W Magnetic coil current 16A Plasma generation indoor magnetic field 875G Substrate temperature 300℃ H2 flow rate 19QsccmSiH4 (1
%PH3) Flow rate 1, 2 secmCy H
s or C, H + flow rate 1, 2 sec dilution rate 79 times gas pressure 5 mTorr 2 for substrate
Using a 0x20x0, 3mm quartz plate, the deposition time was approximately 3
The film was deposited for up to approximately 2000 hours.

The energy gap E and the dark conductivity σ were improved as the characteristics of the film thus obtained.

Also, the film deposition rate R6° during film formation. I also looked into it.

The 11 fruits obtained are shown in Table 1. The energy gap E1 is obtained by determining the absorption coefficient from the 71111 constant of the transmittance and using Taue's plot. The measurement of the dark conductivity σ was carried out by vacuum evaporating the deposited film in a comb-shape in which Aρ of about 600 was opposed to 1− of the deposited film, and using a C0-PLANER type electrode.

Table 1 As is clear from the results shown in Table 1, the deposited film obtained in the example of the present invention using C2H2 as the carbon atom-containing gas and the comparative example using CH4 as the carbon atom gas Both of the deposited films obtained in 1 and 2 showed good values for the dark conductivity σ, but the energy gap E.

Regarding the deposition rate Rde911, the deposited film of the example shows a better value. That is, it was shown that by using C2H2 instead of CH4 as the carbon atom-containing gas, the value of the energy gap and the deposition rate can be increased while maintaining high conductivity.

The reason why the energy cap of the deposited film of the example is larger is that C2H2 has a lower decomposition energy than CH4, so decomposition occurs more easily when C2H2 is used in the ECR plasma CVD method. More carbon atoms・ka11. ．． This is thought to be due to the fact that it was incorporated into 5. Furthermore, the deposition rate of the deposited film of the example is higher than that of the film using C2H2 because there are more decomposed species. S
It is thought that the number of carbon 1 princes who create structures has increased, making it the second f2f.

Furthermore, CH according to the present invention is used as a carbon source ff gas.
A microcrystalline silicon carbide film was separately formed using 2=CH2, CH2=C=CH2, etc., but in these deposited films, the energy gap value and the deposition rate could be increased as in the above example. I could see the direction.

[Effects of the Invention] As described in -1- above, the present invention uses CH2=CH2,
CHyoCH, CH2=CH≡CH3, CH2=C=CH
2 and 7! consisting of CH3C=CH! Since it is characterized by using any one selected from T, it is possible to further increase the energy key cap of the obtained silicon carbide film. Therefore, for example, when this silicon carbide film is applied to a window layer of a light receiving/emitting device, the device characteristics can be improved.

Further, by using the above gases, it is possible to increase the deposition rate during film formation, so that productivity can be expected to be improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing an example of the configuration of a plasma CVD processing apparatus used in the method of forming an amorphous silicon carbide film containing microcrystals according to the present invention. DESCRIPTION OF SYMBOLS 1... Plasma generation chamber, 2... Sample chamber, 3... Substrate, 4... Plasma extraction window, 5... Excitation gas introduction means, 6... Waveguide shield, 7... Microwave introduction window, 8
. . . Magnetic circuit, 9. 1 test fi unit, 10. Film forming gas introduction means, 11. Gas blowing link, 12. Exhaust system.

Claims (4)

[Claims] (1) Generate plasma by introducing excitation gas and microwaves into the plasma generation chamber and applying a magnetic field,
Introducing the plasma into a sample chamber connected to the plasma generation chamber, introducing a silicon atom-containing gas and a carbon atom-containing gas into the plasma flow thus formed,
Magnetic field microwave plasma CV for forming a silicon carbide film by irradiating plasma onto a substrate placed in the sample chamber.
In method D, H_2 is used as an excitation gas, SiH_4 is used as a silicon atom-containing gas, and CH_2=CH_2, CH≡CH, CH_2=C as a carbon atom-containing gas.
H-CH_3, CH_2=C=CH_2 and CH_3
A method for forming an amorphous silicon carbide film, characterized in that each one selected from the group consisting of C≡CH is used. (2) The hydrogen dilution ratio, which is the amount of hydrogen gas used divided by the amount of silicon atom-containing gas and carbon atom-containing gas, is 50 times or more (capacity ratio), and the gas pressure during discharge is 2.5 times
10^-^3 Torr ~ 5.0 x 10^-^2 Torr
2. The method for forming an amorphous silicon carbide film according to claim 1. (3) Claim 1 wherein the substrate temperature is 150°C to 300°C.
or 2. The method for forming an amorphous silicon carbide film according to 2. (4) SiH_4 as a silicon atom-containing gas has the following properties:
PH_3 or B_2H_6 as doping gas is 0
．． Claims 1 to 3 are a mixture of 1 to 5% by volume.
A method for forming an amorphous silicon carbide film containing microcrystals according to any one of the above.