JPH0941147A - Plasma cvd method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease the amt. of hydrogen in a film by controlling the flow rate of rare gas to a specified times or more as much as the flow rate of whole gas except for rare gas so that the electron temp. decreases and the electron density increases and that the hydrogen releasing reaction is promoted in the film forming process. SOLUTION: The flow rate of rare gas is controlled to 5 times or more, preferably 10 times or more, as much as the whole gas amt. except for the rare gas. If the vol. flow rate of the rare gas is less than five times, the electron density does not increase so much. The upper limit of the flow rate is not specified, however, if the exhaustion function is const., the flow rate of the film forming gas decreases with the increase in the flow rate of the rare gas, which decreases the deposition rate. The waveguide to introduce microwaves is an annular waveguide having a slot. When the substrate is an insulating substrate comprising a polymer, this method is significantly effective for a material which is durable at <=100 deg.C such as polycarbonate (durable at <=60 deg.C).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma CVD method, and more particularly to a plasma CVD method for forming a thin film with high performance at a low temperature and at a high speed. Applicable plasma C
It relates to the VD method.

[0002]

2. Description of the Related Art Film formation on polycarbonate by a microwave plasma CVD method, which is an example of a plasma CVD method, is performed as follows, for example. The raw material gas was introduced into the film forming chamber of the microwave plasma CVD apparatus, and at the same time, microwave energy was introduced to generate plasma in the film forming chamber to excite and decompose the gas, and the gas was placed in the film forming chamber. A deposited film is formed on the substrate. At this time, normally, the source gas does not contain Ar, or even if it does, it is less than a few percent of the total gas flow rate. However, in the above-mentioned conventional example, even if a thin film is formed by high-density plasma having a plasma density of about 5 × 10 ¹¹ / cm ^3, there is a problem that the hydrogen content in the film is not small. Although the hydrogen content is decreased by increasing the microwave power, the number of incident ions in the plasma is increased, so that the substrate temperature is increased, and there is a problem that the substrate is melted when a plastic substrate such as polycarbonate is used.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art and increase the plasma density while suppressing the temperature rise of the substrate to form a thin film at low temperature with high performance and high speed. It is to provide a plasma CVD method.

[0004]

The above object is achieved by the following means.

That is, according to the present invention, the plasma generating chamber and the film forming chamber communicating with the plasma generating chamber are decompressed by the exhaust means, and a rare gas and a gas other than the rare gas are supplied to the plasma generating chamber or the film forming chamber. A plasma CVD method for supplying electric energy into the plasma generation chamber and depositing a thin film on the surface of a substrate arranged in a film formation chamber communicating with the plasma generation chamber, the method being based on a flow rate of all gases except the rare gas. Plasma C characterized in that the flow rate of the rare gas is increased five times or more
A VD method is provided, wherein the flow rate of the rare gas is 10 times or more the flow rate of all gases other than the rare gas, the electric energy is a microwave introduced by an introduction pipe, The waveguide that introduces waves is an annular waveguide with a slot, and the heat-resistant temperature is 100 ° C
The following base is used, and the base is Fe, Al,
A conductive substrate made of a metal such as Mo, Au, Nb, Ta, V, Ti, Pt, Pb or an alloy thereof, and the substrate is polyethylene, polyester, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride. , Polystyrene, polyamide, polyimide, acrylic, gelatin, or a polymer containing them as a main component, the substrate is polycarbonate or a polymer containing it as a main component, and deposited by the plasma CVD method. The thin film is an insulating film such as a silicon nitride film, a silicon oxide film, a tantalum oxide film, a titanium oxide film, a titanium nitride film, an aluminum oxide film, an aluminum nitride film, or a magnesium fluoride film, and the thin film is aS
It includes a semiconductor film of i, poly-Si, SiC, GaAs, etc., the thin film is a metal film of Al, W, Mo, Ti, Ta, etc., and the rare gas is Ar. Further, the present invention is a plasma C characterized by being used in a method for manufacturing a substrate for magneto-optical disk and a CVD method characterized by being used in a method for manufacturing a substrate for liquid crystal display device.
It proposes a VD method.

According to the present invention, the electron temperature is lowered and the electron density is increased by increasing the volumetric flow rate of the rare gas to 5 times or more the flow rate of all the raw material gases except the rare gas, while suppressing the substrate temperature rise. , Precursor (intermediate activator: eg Si-
The degree of reactivity of (N—H) advances, the hydrogen desorption reaction is promoted in the film forming process, the hydrogen content in the film decreases, the film quality improves, and high-performance and high-speed film formation becomes possible.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1 is a sectional view of the microwave plasma CVD apparatus. Reference numeral 1 is a film forming chamber, 1'is a plasma generating chamber, 2 is a coated substrate, 3 is a support for the coated substrate 2, 4 is a heater for heating the coated substrate 2, 5 is an exhaust pipe, and 6 is a first source gas introduction. A tube, 7 is a second source gas introduction tube, 8 is a third source gas introduction tube, 9 is a microwave waveguide, and 10 is a quartz member. The device is an exhaust system, a gas introduction pipe, and a system that can input electric energy (in microwave, a power supply / waveguide,
DC and RF are equipped with a power source and electrodes.

To carry out the method of the present invention, the substrate 2 is placed on the support 3 in the film forming chamber 1 as shown in FIG. The substrate formed by the plasma treatment of the present invention may be conductive, electrically insulating, or semiconductor.

As the conductive substrate, Fe, Ni, Cr, A
Examples thereof include metals such as 1, Mo, Au, Nb, Ta, V, Ti, Pt, and Pb or alloys thereof, such as brass and stainless steel.

Examples of the insulating substrate include films and sheets of organic materials such as polyethylene, polyester, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene and polyamide.

Next, the film forming chamber is sufficiently evacuated by an exhaust means (not shown), gas is introduced, and a desired pressure is adjusted by a conductance valve (not shown) provided on the exhaust side.

In the plasma CVD method of the present invention, the pressure in the plasma generating chamber 1'or the film forming chamber 1 in the microwave plasma CVD apparatus is preferably 0.1 mTorr-1.
It can be selected from the range of Torr.

Further, a single probe is arranged so that it can be inserted into the plasma in order to measure the plasma density,
It is preferable to collect data so that the electron temperature and electron density can be obtained.

The substrate temperature when forming a film by the microwave plasma CVD apparatus according to the plasma CVD method of the present invention is somewhat different depending on the kind of the source gas used, the kind of the deposited film, and the use, but it is generally from room temperature to 400 ° C. However, a lower temperature of 200 ° C. or lower is particularly preferable for sufficiently exerting the effect of the present invention, and a heat resistant temperature of 100 ° C. or lower is preferable in the case of an insulating substrate made of the above polymer. .
For example, polycarbonate has a heat resistant temperature of 60 ° C,
When the substrate temperature was 60 ° C. or lower, a good quality film was obtained at high speed.

Next, the deposited film forming gas and the plasma generating gas are introduced through the first source gas introducing pipe 6, the second source gas introducing pipe 7 and the third source gas introducing pipe 8.

As the deposited film forming gas, a generally known gas can be used.

The gas which is easily decomposed by the action of plasma and can be deposited by itself is used, for example, in order to achieve a stoichiometric composition and prevent film adhesion in the plasma generation chamber, for example, the first and The film forming chamber 1 via the second source gas introduction pipes 6 and 7.
It is desirable to introduce Further, a gas that is not easily decomposed by the action of plasma and is difficult to deposit by itself is introduced into the plasma generation chamber 1'in the plasma generation chamber 1, for example, through the third source gas introduction pipe 8 for plasma generation. Is desirable.

S such as a-Si, poly-Si and SiC
Via a gas introduction tube for film formation when forming an i-based semiconductor film
As a raw material containing Si atoms to be introduced as SiH
_Four , Si₂ H₆ Inorganic silanes such as tetraethylsila
(TES), Tetramethylsilane (TMS), Dimethyl
Organic silanes such as rusilane (DMS), SiF_Four , S
i₂ F₆ , SiHF_Three , SiH₂ F₂ , SiCl_Four , S
i₂ Cl₆ , SiHCl _Three , SiH₂ Cl₂ , SiH_Three 
Cl, SiCl₂ F₂ Normal temperature and pressure such as halosilanes
That is in a gas state or that can be easily gasified
No. Also, in this case, a gas introduction tube for plasma generation
For example, a plasma introduced through the third source gas introduction pipe 8
H for gas₂ , He, Ne, Ar, Kr,
Examples include Xe and Rn.

As a raw material containing Si atoms, which is introduced through the gas introduction tube for film formation when forming a Si compound type thin film such as Si ₃ N ₄ or SiO ₂ , SiH ₄ and Si ₂ H
Inorganic silanes such as _{6 and} tetraethoxysilane (TEO
S), tetramethoxysilane (TMOS), organic silanes such as octamethylcyclotetrasilane (OMCTS), SiF ₄ , Si ₂ F ₆ , SiHF ₃ , SiH ₂ F
₂ , SiCl ₄ , Si ₂ Cl ₆ , SiHCl ₃ , SiH ₂
Examples thereof include halosilanes such as Cl ₂ , SiH ₃ Cl and SiCl ₂ F _{2 which} are in a gas state at room temperature and normal pressure or which can be easily gasified. Further, as the raw material introduced through the plasma generating gas introduction pipe in this case,
N ₂ , NH ₃ , N ₂ H ₄ , hexamethyldisilazane (H
MDS), O ₂ , O ₃ , H ₂ O, NO, N ₂ O, NO ₂
And the like.

As a raw material containing metal atoms introduced through a gas introduction tube for film formation when forming a metal thin film of Al, W, Mo, Ti, Ta or the like, trimethylaluminum (TMAl), triethylaluminum ( TEA
l), triisobutylaluminum (TIBAl), dimethylaluminum hydride (DMAlH), tungsten carbonyl (W (CO) ₆ ), molybdenum carbonyl (Mo (CO) ₆ ), trimethylgallium (TM)
Ga), organic metals such as triethylgallium (TEGa), and halogenated metals such as AlCl ₃ , WF ₆ , TiCl ₃ and TaCl ₅ . Further, as the plasma generating gas introduced through the plasma generating gas introducing pipe in this case, H ₂ , He, Ne, Ar, Kr, X
e and Rn are mentioned.

Al ₂ O ₃ , AlN, Ta ₂ O ₅ , TiO
_As a raw material containing a metal atom introduced through a gas introduction pipe for film formation when a metal compound thin film such as ₂ , TiN or WO ₃ is formed, trimethyl aluminum (TMA
l), triethyl aluminum (TEAl), triisobutyl aluminum (TIBAl), dimethyl aluminum hydride (DMAlH), tungsten carbonyl (W (CO) ₆ ), molybdenum carbonyl (Mo).
(CO) ₆ ), organic metals such as trimethylgallium (TMGa), triethylgallium (TEGa), AlCl
Examples thereof include metal halides such as ₃ , WF ₆ , TiCl ₃ , and TaCl ₅ . The plasma generating gas introduced through the plasma generating gas introducing pipe in this case includes N ₂ , NH ₃ , N ₂ H ₄ , hexamethyldisilazane (HMDS), O ₂ , O ₃ , and H _2. O, NO, N ₂ O,
NO _{2 and the} like.

The formation of the deposited film by the plasma treatment of the present invention is made possible by properly selecting the gas to be used, as is apparent from the above description, by the silicon nitride film, the silicon oxide film, the tantalum oxide film, the titanium oxide film, the nitride film. Insulating film such as titanium film, aluminum oxide film, aluminum nitride film, magnesium fluoride film, a-Si, poly-Si, Si
Semiconductor films such as C and GaAs, Al, W, Mo, Ti, T
It is possible to efficiently form various deposited films such as metal films such as a.

The plasma treatment of the present invention can also be applied to surface modification. For example, by appropriately selecting the gas to be used, the base or surface layer of Si, Al, Ti, Zn, Ta or the like may be subjected to an oxidation treatment or a nitriding treatment, or B or A.
Doping treatment of s, P, etc. is possible. Further, the plasma treatment of the present invention can be applied to a cleaning method. In that case, it can be used for cleaning oxides or organic substances or heavy metals. Oxidizing gas introduced through the gas introducing tube for plasma generation in the case of subjecting the substrate to the oxidative surface treatment includes O ₂ , O ₃ , H ₂ O, NO, N ₂ O and NO ₂
And the like. In addition, examples of the nitriding gas introduced through the plasma introduction gas introduction pipe when the substrate is subjected to the nitriding surface treatment include N ₂ , NH ₃ , N ₂ H ₄ , and hexamethyldisilazane (HMDS). In this case, since film formation is not performed, the raw material gas is not introduced through the film formation gas introduction pipe, or the same gas as the gas introduced through the plasma generation gas introduction pipe is introduced.

When cleaning organic substances on the substrate surface
Cleaning introduced from the plasma generation gas introduction tube
As the gas for use, O₂ , O_Three , H₂ O, NO, N₂ O,
NO ₂ And the like. In addition, the inorganic substances on the substrate surface should be removed.
Introduced from the gas introduction tube for plasma generation when turning
The cleaning gas used is F₂ , CF_Four , CH
₂ F₂ , C₂ F₆ , CF₂ Cl₂ , SF₆ , NF_Three Etc.
No. In this case, film formation is not performed, so gas for film formation introduction
The raw material gas is not introduced through the pipe. Or from plasma
A gas similar to the gas introduced through the raw gas introduction pipe is introduced.
Enter.

In the present invention, it is essential that the flow rate of the rare gas is 5 times or more, more preferably 10 times or more, the flow rate of all gases except the rare gas.

If the volumetric flow rate of the rare gas is less than 5 times, the electron density is not so high and there is no particular upper limit, but if the exhaust capacity is constant, the flow rate of the film forming gas decreases as the flow rate of the rare gas increases. There are problems such as a decrease in the deposition rate. The microwave power source for generating plasma is 50
0 MHz to 50 GHz is preferable. Power is 1-10kW
Is preferred. Thus, plasma is generated by the gas introduced into the plasma generation chamber 1 ′ from the plasma generation gas introduction pipe and the electric power introduced into the plasma generation chamber 1 ′ via the waveguide, and the plasma is generated in the film formation chamber 1. The introduced film forming gas reacts to form a deposited film having a thickness of about 10 to 1000 nm on the substrate 2.

[0027]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. (Embodiment 1) An embodiment in which the plasma CVD method of the present invention is applied to film formation of silicon nitride for a magneto-optical disk.
This will be described with reference to FIG. FIG. 1 is a sectional view of the microwave plasma CVD apparatus.

The substrate 2 is made of polycarbonate (P
C) A substrate [φ3.5 inch, heat resistant temperature 60 ° C.] was used. First, the substrate 2 was placed on the support 3, and the inside of the plasma generation chamber 1 ′ and the film formation chamber 1 was evacuated via an exhaust system (not shown) to reduce the pressure to 10 ⁻⁶ Torr. Next, SiH ₄ is supplied from the first source gas introduction pipe 6 at a flow rate of 100 sccm, and N ₂ is supplied from the second source gas introduction pipe 7 to 100 sccm.
Is introduced into the film formation chamber 1 at a flow rate of 1 s, Ar is introduced into the plasma generation chamber 1 ′ from the third source gas introduction pipe 8 at a flow rate of 1 s1 m, and the conductance valve (unset The pressure of 20 mTorr is maintained by the method shown in the figure. Further through the microwave power source (not shown) slotted annular waveguide 9 the power of 1kW oscillated from the 2.45 GHz _Z to generate introduced plasma in the plasma generation chamber 1 '. At this time, the nitrogen gas introduced through the second source gas introduction pipe 7 is excited and decomposed in the plasma generation chamber 1 ′ to be an active species, which is transported toward the PC substrate 2, and the first source gas introduction pipe 7 is introduced. A silicon nitride film was formed on the PC substrate 2 to a thickness of 100 nm by reacting with the monosilane gas introduced through the substrate 6.

Further, FIG. 2 shows the relationship when the flow rate of the third gas / the flow rate of the first / second gas is plotted on the horizontal axis and the electron density is plotted on the vertical axis. When the flow rate ratio is 5 times, the electron density is higher than when it is 3 times. As a result, the reaction of the precursor such as Si—N—H progresses, and a high-quality silicon nitride film with a low hydrogen content in the film is formed at a low temperature (since no deformation is observed on the PC substrate.
The film was formed at a high speed at 0 ° C. or lower). (Embodiment 2) An embodiment in which the plasma CVD method of the present invention is applied to film formation of silicon nitride for semiconductor device protection, with reference to FIGS.
This will be described with reference to FIG.

As the substrate 2, a P-type single crystal silicon substrate (plane orientation <100>, resistivity 10 Ω · cm) was used. First, the substrate 2 was placed on the support 3, and the inside of the plasma generation chamber 1 ′ and the film formation chamber 1 was evacuated via an exhaust system (not shown) to reduce the pressure to 10 ⁻⁶ Torr. Subsequently, the silicon substrate 2 was heated to 300 ° C. by using the heater 4, and the substrate was kept at this temperature. From the first source gas introduction pipe 6 to Si
H ₄ was introduced into the film forming chamber 1 at a flow rate of 100 sccm, N ₂ was introduced at a flow rate of 200 sccm from the second source gas introduction pipe 7, and Ar was introduced at a flow rate of 3 s1 m from the third source gas introduction pipe 8. It was introduced into the generation chamber 1 '. 30m due to the conductance valve (not shown) provided on the exhaust pipe 5 side
The pressure was maintained at Torr. Further power 2kW oscillated from a microwave power source (not shown) of 2.45 GHz _Z via a microwave waveguide 9 to generate introduced plasma in the plasma generation chamber 1 '. At this time, the second source gas introduction pipe 7
The nitrogen gas introduced through the plasma generation chamber 1 ′ is excited and decomposed in the plasma generation chamber 1 ′ to be an active species, which is transported toward the silicon substrate 2 and reacts with the monosilane gas introduced through the first source gas introduction pipe 6. A silicon nitride film was formed on the silicon substrate 2 to a thickness of 1.0 μm.

Further, FIG. 3 shows the relationship when the flow rate of the third gas / the flow rate of the first and second gases is plotted on the horizontal axis and the electron density is plotted on the vertical axis. When the flow rate ratio is 10 times, the electron density is higher than when it is 5. As a result, a high-quality silicon nitride film having a low hydrogen content in the film was deposited at a high speed because the reaction of a precursor such as Si—N—H proceeded. (Embodiment 3) An embodiment in which the plasma CVD method of the present invention is applied to the formation of a plastic lens antireflection silicon nitride film and a silicon oxide film will be described with reference to FIG.

As the base 2, a plastic convex lens having a diameter of 50 mm was used. First, the substrate 2 was placed on the support 3, and the inside of the plasma generation chamber 1'and the film forming chamber 1 was evacuated through an exhaust system (not shown) to reduce the pressure to 10 ^-6 Torr. Next, 100H of SiH ₄ is fed from the first source gas introduction pipe 6.
At a flow rate of sccm, N ₂ is introduced into the film forming chamber 1 from the second source gas introduction pipe 7 at a flow rate of 150 sccm, and Ar is introduced from the third source gas introduction pipe 8 at a flow rate of 2 s1 m to the plasma generation chamber 1. The pressure is maintained at 1 mTorr by a conductance valve (not shown) provided on the exhaust pipe 5 side. Further through the microwave power source (not shown) slotted annular waveguide 9 the power of 1kW oscillated from the 2.45 GHz _Z to generate introduced plasma in the plasma generation chamber 1 '. At this time, the nitrogen gas introduced through the second source gas introduction pipe 7 is excited and decomposed in the plasma generation chamber 1 ′ to become active species such as nitrogen atoms, which are transported toward the substrate 2 and The silicon nitride film reacts with the monosilane gas introduced through the source gas introduction pipe 6 to form a silicon nitride film on the substrate 2.
It was formed with a thickness of nm.

Next, from the first source gas introduction pipe 6, SiH
₄ at a flow rate of 100 sccm, the second source gas introduction pipe 7
To O ₂ at a flow rate of 200 sccm into the film forming chamber 1 and Ar at a flow rate of 2 slm into the plasma generating chamber 1 ′ from the third source gas introducing pipe 8 to be provided on the exhaust pipe 5 side. 1m Tor by conductance valve (not shown)
The pressure is maintained at r. Further to generate introduced plasma 1kW of power oscillated from a microwave power source (not shown) of 2.45 GHz _Z in the film forming chamber 1 through the slotted annular waveguide 9. At this time, the oxygen gas introduced through the second source gas introduction pipe 7 is excited and decomposed in the plasma generation chamber 1 ′ to become active species such as oxygen atoms, which is transported toward the substrate 2 and The silicon oxide film reacts with the monosilane gas introduced through the source gas introduction pipe 6 to form 86 n of silicon oxide film on the substrate 2.
It was formed with a thickness of m. The obtained silicon nitride film and silicon oxide film have a film formation rate of 300 nm / min, 360
It was confirmed that the optical quality was as good as nm / min, and the film quality had an extremely good optical characteristic with a reflectance of 0.3% near 500 nm. Moreover, the curvature of the lens surface was measured and compared with the reference lens by an interferometer, and no change due to film formation was observed.

[0034]

As described above, when the flow rate of the rare gas is 5 times or more the flow rate of all the source gases except the rare gas, the electron temperature is lowered and the electron density is increased, so that the substrate temperature is increased. While suppressing the reaction, the reactivity of the precursor (intermediate activator) progresses, the hydrogen desorption reaction is promoted in the film formation process, and the hydrogen content in the film decreases, which has the effect of enabling high-performance and high-speed film formation. .

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a plasma CVD apparatus used in the present invention.

FIG. 2 is a graph showing the relationship between the flow rate of the third gas / the flow rates of the first and second gases and the electron density when the electron density is measured by the plasma CVD apparatus according to the first embodiment of the present invention. .

FIG. 3 is a graph showing the relationship between the flow rate of the third gas / the flow rates of the first and second gases and the electron density when the electron density is measured by the plasma CVD apparatus according to the second embodiment of the present invention. .

[Explanation of symbols]

 1 film forming chamber 1'plasma generating chamber 2 substrate 3 support 4 heater 5 exhaust pipe 6 first raw material gas introduction pipe 7 second raw material gas introduction pipe 8 third raw material gas introduction pipe 9 microwave waveguide 10 quartz Member 11 Top plate member 12 Bottom plate member

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H01L 21/316 H01L 21/316 X 21/318 21/318 B H05H 1/46 9216-2G H05H 1 / 46 B

Claims (14)

[Claims] 1. A plasma generating chamber and a film forming chamber communicating with the plasma generating chamber are decompressed by exhaust means, and a rare gas and a gas other than the rare gas are supplied to the plasma generating chamber or the film forming chamber to generate the plasma. Supply electrical energy to the room,
A plasma CVD method for depositing a thin film on a surface of a substrate arranged in a film forming chamber communicating with the plasma generating chamber, wherein the flow rate of a rare gas is 5 times or more the flow rate of all gases except the rare gas. A characteristic plasma CVD method. 2. The plasma CVD method according to claim 1, wherein the flow rate of the rare gas is 10 times or more the flow rate of all gases except the rare gas. 3. The plasma CVD method according to claim 1, wherein the electric energy is microwave. 4. The plasma CVD method according to claim 3, wherein the waveguide for introducing the microwave is an annular waveguide with a slot. 5. The plasma CVD method according to claim 1, wherein a substrate having a heat resistant temperature of 100 ° C. or lower is used. 6. The substrate is Fe, Ni, Cr, Al, M
The plasma CVD method according to any one of claims 1 to 4, which is a conductive substrate made of a metal such as o, Au, Nb, Ta, V, Ti, Pt, or Pb or an alloy thereof. 7. The substrate is polyethylene, polyester,
The plasma CVD method according to any one of claims 1 to 4, which is cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, acrylic, gelatin, or a polymer containing these as the main components. . 8. The plasma CVD method according to claim 1, wherein the substrate is polycarbonate or a polymer mainly containing polycarbonate. 9. The thin film deposited by the plasma CVD method is a silicon nitride film, a silicon oxide film, a tantalum oxide film, a titanium oxide film, a titanium nitride film, an aluminum oxide film, an aluminum nitride film, a magnesium fluoride film, or the like. The plasma CVD method according to claim 1, wherein the plasma CVD method is an insulating film. 10. The thin film is a-Si, poly-Si, S.
9. The plasma CVD method according to claim 1, wherein the plasma CVD method is a semiconductor film made of iC, GaAs, or the like. 11. The plasma CVD method according to claim 1, wherein the thin film is a metal film of Al, W, Mo, Ti, Ta or the like. 12. The rare gas is Ar, according to any one of claims 1 to 11.
The plasma CVD method according to claim 1. 13. The plasma CVD method according to claim 1, which is used in a method for manufacturing a magneto-optical disk substrate. 14. The liquid crystal display device according to claim 1, which is used in a method for manufacturing a substrate for a liquid crystal display device.
The plasma CVD method according to item.