JP3116454B2 - Method for producing organic polysilane and / or silicon carbide thin film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an organic polysilane and / or an organic polysilane.
Alternatively, the present invention relates to a method for producing a silicon carbide thin film.

2. Description of the Related Art Conventionally, it has been known that silicon carbide useful for silicon-based electronic materials and the like can be obtained by heating organic polysilane, but it is mainly obtained in a fibrous or powdery form. Have been. Of these, the thin film
It is manufactured by methods such as plasma CVD (chemical vapor deposition), thermal CVD, and sputtering. In any of these methods, the growth rate of a thin film is as low as about 1 micron per hour, which makes industrialization difficult. In addition, since silane is used as a raw material particularly in the CVD method, there is a great risk of toxicity and fire. In addition, methylpolysilane and the like do not have a suitable organic solvent for coating by dissolving in a solvent. For these reasons, a production method sufficient for mass-producing an organic polysilane thin film has not been obtained.

[0002]

In order to solve such problems, the present inventor has performed heating deposition in a vacuum chamber. An organic polysilane thin film could be obtained at a high speed. By further heating the obtained thin film or heating the substrate in advance, an organic polysilane thin film having various compositions or a silicon carbide thin film can be obtained.

[0003] That is, the present invention resides in a method for producing an organic polysilane and / or silicon carbide thin film, comprising heating an organic polysilane raw material under reduced pressure and depositing it on a substrate. Hereinafter, the present invention will be described in detail. The material used in the present invention is, for example, permethylpolysilane ([Si (C
H ₃ ) ₂ ] n), polysilastyrene ([Si (CH ₃ )
(C ₆ H ₅ )] n), methylpropylpolysilane, etc.
Various organic polysilane powders obtained by substituting the methyl group of permethyl polysilane with a side chain such as a propyl group can be used.

[0004] These raw material powders are heated in a vacuum chamber. As the heating method, various methods may be employed depending on the case. In general, however, it is convenient to use a current-carrying heating element, for example, a method in which raw material powder is placed on a boat-type heater and current is applied. The temperature varies depending on the material, but it is sufficient that the powder is melted and becomes liquid. Since it is in a vacuum chamber, it liquefies in a relatively short time. Specifically, it liquefies in the order of several tens of amperes for several minutes.

The present invention is characterized in that the process is performed under reduced pressure. In this case, “under reduced pressure” is specifically 10 ⁻² To
If a reduced pressure of about rr, quickened greater growth rate than in the case of performing at normal pressure, if reduced to about 10 ^-4 Torr, almost no danger of contamination of the thin film of impurities in the residual gas, It is also very preferable from the viewpoint of film growth rate. If the deposition is carried out in a substantially vacuum state of 10 ^-6 Torr or less, the growth rate will be drastically increased. As described above, the present invention is most preferably performed in a vacuum state.

In vapor deposition, a substrate is placed in a vacuum chamber at a position close to a heater on which raw material powder is placed. Although the distance from the raw material powder is not particularly limited, it is usually 2
0 cm or less, more preferably 1 to 15 cm is appropriate. The type of the substrate is selected from a wide range depending on the application. For example, a quartz glass, a silicon wafer, or a slide glass can be used. In addition, any organic polysilane to be deposited can be used as long as it does not change such as deformation, alteration, and transformation at the heating temperature.

In addition, the composition of the thin film obtained by heating the substrate during the deposition can be changed. The higher the temperature, the more hydrogen atoms in the polymer are released. Therefore, by changing the substrate temperature at the time of vapor deposition, the emission wavelength of the thin film can be changed simultaneously with the composition of the thin film, which is convenient when manufacturing a light emitting device. . In addition to the method of heating the substrate at the time of vapor deposition, by further heating the already obtained thin film, thin films of various compositions can be obtained by the heating method.

In this case, by heating in an inert gas atmosphere, especially in an argon or helium atmosphere, introduction of oxygen atoms, nitrogen atoms, etc. into the thin film can be prevented.
By heating to 800 to 1000 ° C., a silicon carbide thin film can be obtained.

[0009]

EXAMPLES The present invention will be described in more detail with reference to Examples, but it should not be construed that the invention is limited thereto without departing from the gist of the invention.

Example 1 Permethylpolysilane ([Si (C
H ₃ ) ₂ ] _n , _n to 20,000) About 1 g (several cups of earpick) of powder is placed on a molybdenum boat type heater, and an oil diffusion pump equipped with a liquid nitrogen trap together with a quartz glass substrate and a single crystal silicon wafer substrate at a distance of 10 cm. And placed in a vacuum chamber that can be evacuated by an oil rotary pump and 10 ^-6 To
It exhausted to rr or less. 2 for molybdenum boat type heater
When a direct current of 0 to 30 A was passed for about 2 minutes to deposit permethylpolysilane on the substrate, a thin film of about 5 μm was obtained. (The actual film growth rate is several tens of μm / min since the material was vaporized in about 10 seconds after the material was liquefied.) Infrared absorption measurement (transmission type,
600-3500Cm ^-1), by X-ray diffraction and argon ion laser (488.0 and 514.5nm multiline), and the material obtained on the quartz glass substrate was measured by visible absorption (200-900Nm). FIG. 1 shows the obtained infrared absorption spectrum, FIG. 2 shows the X-ray diffraction pattern (the permethyl polysilane powder is shown in parentheses), and FIG.
The figure is a visible absorption spectrum. When the single crystal silicon wafer was irradiated with an argon ion laser, visible light emission (red) was observed at room temperature.

[0010]

According to the present invention, an organic light emitting device, an optical IC,
A thin film of organic polysilane and silicon carbide useful as an optical nonlinear material such as a switch, an insulating film, a sensor, and a photosensitive drum can be obtained at an extremely high speed.

[Brief description of the drawings]

FIG. 1 shows an infrared absorption spectrum of a thin film obtained in Example 1.

FIG. 2 shows an X-ray diffraction pattern.

FIG. 3 shows a visible absorption spectrum.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 77/00 C01B 31/36 C23C 14/12 C23C 20/08 H01L 21/316

Claims (2)

(57) [Claims] 1. A method for producing an organic polysilane, comprising heating an organic silane raw material under reduced pressure to deposit the organic silane on a substrate. 2. A method for producing a silicon carbide thin film, comprising heating an organic silane raw material under reduced pressure to further heat an organic polysilane thin film obtained by vapor deposition on a substrate.