JPH0237087B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention aims to coat glass, metal or ceramics with a carbon film to reinforce its mechanical strength.
By introducing a hydrocarbon gas such as methane into a plasma atmosphere and allowing it to decompose, it creates C-C bonds that produce optical energy rather than creating conductive or poorly conductive carbons such as graphite. It is characterized by the formation of insulating carbon similar to diamond having a band width (referred to as Eg) of 2.0 eV or more, preferably 2.6 to 4.5 eV. Furthermore, the carbon of the present invention has a hardness of 4500
It has a hardness similar to diamond, at Kg/mm ² or more, typically 6500 Kg/mm ² . And its crystallographic structure is amorphous or 5-200 Å
It has microcrystallinity with a size of . Further, this carbon simultaneously contains hydrogen and halogen elements in an amount of 25 mol% or less.

Such carbon is extremely thermally and chemically stable and therefore cannot be selectively etched as is generally known. Therefore, the present invention aims to selectively remove this chemically stable carbon film and leave carbon on the substrate or substrate. The present invention
This is a method for selectively removing such a carbon film.

The present invention provides a composite body in which these carbons (hereinafter simply referred to as carbon in the present invention) are provided on glass, metal, or ceramics.

In the present invention, the temperature applied to the substrate when forming this carbon is 150 to 450 degrees Celsius, which is different from conventionally known methods.
500° compared to the substrate temperature used in CVD method.
Another feature is that it was formed at temperatures as low as ~1500℃.

Another feature of the present invention is that a carbon film is selectively provided on a glass substrate and used as a photomask for an electron beam exposure device or an ultraviolet exposure device.

Furthermore, the composite of the present invention can be used as a valve, wear-resistant material,
Alternatively, it can be applied to a device as a semiconductor having a PIN type, such as a light receiving or light emitting device.

The composite used in the present invention and the method for producing the composite will be described below according to the drawings.

Example 1 FIG. 1 shows an outline of a plasma CVD apparatus for forming carbon according to the present invention.

hydrocarbon gas, which is a reactive gas in the drawing;
For example, acetylene 8 is introduced into the excitation chamber 4 in the reaction system through a valve and a flow meter 5. Further, if necessary, the carrier gas is supplied with hydrogen or helium from 7 through a valve and a flow meter 6 to reach the excitation chamber in the same manner. If a valent or valent impurity, such as diborane or phosphin, is to be introduced, it may be added to the system in the same manner.

These reactive gases are activated, decomposed, or reacted in an excitation chamber by applying 0.1 to 5 Kw of electromagnetic energy using 2.45 GHz microwaves. Furthermore, this reactive gas is heated to 150 to 450°C in the heating furnace 9 in the reactor 1, and then
It is reacted and polymerized by high frequency energy 2 of 13.56 MHz to produce carbon having many C--C bonds. At this time, if the applied electromagnetic energy is small, carbon with an amorphous structure is produced. On the other hand, if this electromagnetic energy is strongly applied, diamond-shaped microcrystalline carbon with a size of 5 to 200 Å can be produced. This reaction is carried out by heating the heater 11 with the power supply 13 and further heating the substrate 10 thereon. Then, a carbon film of the reaction product is formed as a film on the upper surface of this substrate. Unwanted substances after the reaction are exhausted from the exhaust port 12 via a rotary pump. Reaction chamber 1 is typically 0.001 to 10 torr.
It is maintained at 0.1 to 0.5 torr, and microwave 3,
A plasma state is generated within the reaction chamber 1 by the energy of the high frequency wave 2 . Particularly at frequencies above 1GHz, hydrogen is separated from the C-H bond, and 0.1~
At a frequency of 50 MHz, C≡C bonds and C=C bonds are decomposed to create C-C bonds or -C-C- bonds, and the unpaired bonds of carbon collide with each other to form covalent bonds. It has a stable diamond structure.

Thus, carbon, especially carbon containing 25 mol% or less of hydrogen, P, I or N, is applied onto a substrate having a surface made of glass, metal or ceramics.
Carbon having a conductivity type of the type was formed.

Embodiment 2 FIG. 2 shows a structure in which a photomask is provided. That is, in FIG. 2A, a coating 2 is selectively etched on glass, particularly quartz glass 20.
9 was provided, and a carbon film was formed on the upper surface thereof to a thickness of 0.1 to 1 μm by the method of Example 1. Thereafter, lift-off was performed to selectively remove the coating 29 and the carbon coating on its upper surface, and as a result, the carbon coating 21 layer was left on the substrate 20. This is super
It is an extremely excellent mask for semiconductors such as LSIs, has a masking effect against electron beams or far ultraviolet light, has excellent wear resistance, and can be used semi-permanently.

When producing such a carbon film for a photomask, it is effective to give it a slight color tone to make it easier to identify. For this purpose, it is also possible to use a plasma CVD method in which coloring impurities are added at the same time as the carbon film is created.

As a method for selectively removing the carbon film, laser light is selectively applied to the carbon provided on the entire surface of the substrate in an oxide atmosphere under computer control.
Unnecessary carbon is oxidized and released as carbon dioxide gas to be removed. As a result, we were able to create a mask as shown in Figure 2 (B).

As is clear from the above description, the present invention provides a film coated with carbon or a film mainly composed of carbon on the surface or inside of glass, metal, or ceramic. As seen in many other examples, the applications of this composite are immeasurable, especially since this carbon is formed at a low temperature of 450°C or less, and its hardness and adhesion to substrates are extremely excellent. It is characterized by

The ceramic used in the present invention may be alumina, zirconia, or any material to which a rare earth element such as carbon or lanthanum is added. For metals, stainless steel, molybdenum, tungsten, etc., at least 300 to 450℃.
It can be applied to any material that can withstand this temperature. Further, glass can be coated not only on quartz but also on soda glass, etc., and its applications are extremely wide.

[Brief explanation of drawings]

FIG. 1 shows an outline of a manufacturing apparatus for manufacturing carbon of the present invention on a surface to be formed. FIG. 2 shows an example of a composite according to the invention.

Claims (1)

[Claims] 1. A step of forming carbon having a diamond structure having an optical energy band width of 2.0 eV or more on a substrate, and irradiating the carbon with laser light in an oxidizing atmosphere to form the diamond structure of the unnecessary material. 1. A method for producing a composite having a carbon film, comprising a step of oxidizing carbon to release and remove carbon as carbon gas.