JPH0780720B2 - Patterning method for vapor-phase synthetic diamond film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] A metal in which carbon such as nickel, iron, and cobalt is solid-dissolved is deposited on a region of a substrate to be patterned (removed),
When this is used as a patterning mask and a diamond film is then deposited, the diamond film is selectively deposited only in the regions where the metal such as nickel, iron, and cobalt that dissolves in carbon is not deposited, resulting in patterning. It is a method for patterning a vapor phase synthetic diamond film, which is characterized by being realized.

[Industrial application field]

The present invention relates to an improvement in a method for patterning a vapor phase synthetic diamond film.

[Conventional technology]

Hydrogen gas containing methane gas is used as the source gas and 50 Torr
It is known that a diamond film can be formed on the above-mentioned silicon carbide substrate etc. by using the microwave plasma method in which the silicon carbide substrate etc. is kept at a high temperature of about 850 ° C. under a pressure of about There is.

Since the diamond film has high dielectric strength and high thermal conductivity, it is an excellent electronic material used for circuit boards, heat sinks, and the like.

[Problems to be solved by the invention]

When using a diamond film as a material for electronic devices,
In many cases, it is necessary to apply fine patterning to this.
The fine processing method that can be used for the diamond film includes a physical etching method by irradiating a laser beam, a physical etching method by irradiating an ion beam, and an ion beam assisted method in which ion irradiation is performed in a nitrogen dioxide atmosphere. Etching methods and the like are known, but not only it is necessary to use a laser beam drawing apparatus, an ion beam drawing apparatus, etc., but none of them is sufficiently satisfactory in various respects. Improvement was desired.

An object of the present invention is to meet this demand, and to provide a method capable of patterning a diamond film with a small number of steps and without fear of causing damage.

[Means for solving problems]

The above-mentioned purpose is to deposit a film of nickel, iron, or cobalt on a partial region (removed region) on the substrate (2) and use this as a patterning mask (3). 3) is used to form a diamond film (4) on a region of the substrate (2) which is not covered by the patterning mask (3), and the patterning mask (3) is removed, This is achieved by a method of patterning a vapor phase synthetic diamond film, characterized in that the diamond film (4) is left in a region other than the partial region (region to be removed) on the substrate (2).

[Action]

INDUSTRIAL APPLICABILITY The present invention positively utilizes the property that a diamond film generally undergoes vapor phase growth regardless of the material of the substrate, but does not grow on a metal in which carbon such as nickel, iron, and cobalt is dissolved as a solid solution. If these metals are deposited in the area to be patterned (removed) and then the diamond film is deposited, the diamond is selectively deposited only in the area where the metal that dissolves carbon such as nickel, iron, and cobalt is not deposited. The film is deposited, resulting in patterning.

〔Example〕

Hereinafter, with reference to the drawings, a manufacturing process of a diamond circuit board using a method for patterning a vapor phase synthetic diamond film according to an embodiment of the present invention will be described.

See FIG. 2. A diamond film 2 having a thickness of 10 μm is formed on a silicon carbide substrate 1 having a high thermal conductivity of 20 mm × 20 mm × 1 mm. This process uses 100 SCCM of hydrogen gas containing about 2% methane gas.
If a microwave plasma method is used in which the substrate 1 is supplied at a flow rate of about 50 Torr and the substrate 1 is kept at a high temperature of about 850 ° C., it can be performed in about 4 hours.

See FIG. 3. A nickel film having a thickness of about 1 mm and a line width of 10 μm is deposited in a region where wiring is formed, and this is used as a patterning mask 3. This step can be performed by using a sputtering method and a photolithography method.

See FIG. 1a In the same manner as above, a diamond film 4 having a thickness of 10 μm is formed. At this time, the diamond film hardly grows on the patterning mask 3.

See FIG. 1b. The patterning mask 3 is dissolved and removed. This process is
This can easily be done using nitric acid as an etchant.

See FIG. 4. Refractory metal such as tungsten is deposited by using the sputtering method, and is then polished to form metal wiring 5 in the recessed region formed by dissolving and removing the patterning mask 3.

See FIG. 6. By repeating the above steps, a multilayer wiring can be formed.

〔The invention's effect〕

As described above, according to the present invention, it is not necessary to use a laser beam drawing apparatus, an ion beam drawing apparatus, or the like, and a diamond film is selectively grown using a mask having a property that a diamond film is not deposited on the device. So
The number of steps has also decreased, and of course there is no risk of damage due to etching, which is an excellent win.

[Brief description of drawings]

1a and 1b are diagrams showing steps involved in the gist of the method for patterning a vapor phase synthetic diamond film according to an embodiment of the present invention. 2, 3, 4, and 5 are process drawings of a vapor-phase synthetic diamond film according to an embodiment of the present invention. 1 ... Silicon carbide substrate, 2 ... Diamond film, 3 ...
... Patterning mask, 4 ... Diamond film, 5 ...
… Metal wiring.

Claims (1)

[Claims] 1. Nickel, in a partial area on a substrate (2),
A film of iron or cobalt is deposited and used as a patterning mask (3), and the patterning mask (3) is used to cover the substrate (2) with the patterning mask (3). A diamond film (4) is formed in a region which is not formed, the patterning mask (3) is removed, and the diamond film (4) is left in a region other than the partial region on the substrate (2). A method for patterning a vapor phase synthetic diamond film, comprising: