JPS63190798A - Production of diamond-like thin film - Google Patents

Abstract

PURPOSE:To enhance the synthesizing velocity of a diamond-like thin film by performing sputtering vapor deposition while keeping carbon as a target under the existence of hydrocarbon having cyano radical. CONSTITUTION:Hydrocarbon contg. cyano group and an unsaturated C-C bond such as cyanoacetylene, dicyanoacetylene, acrylonitrile and methacrylonitrile is prepared. Sputtering vapor deposition is performed while keeping carbon as a target under the existence of hydrocarbon having one or more cyano group selected from among these. Thereby a diamond-like carbon thin film is quickly formed on a substrate.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is directed to the synthesis of diamond and diamond-like carbon films that are used in a wide range of fields such as heat sinks for microelectronics such as LSIs and lasers, ICW boards, and IC packaging. Regarding the method.

[Prior art] Diamond has excellent properties such as being the hardest solid, having high electrical resistance and thermal conductivity, being transparent over a wide range, having a wide band gap, and being roughly chemically stable. are doing.

Diamond, which has excellent properties as an industrial material, has been synthesized in the form of a thin film by chemical vapor deposition (CVD) using hydrocarbons such as methane consisting only of carbon and hydrogen, and hydrogen as raw materials. This technology was developed in Japanese Unexamined Patent Publication No. 59
This can be seen in Japanese Patent Application Laid-Open No. 60-54995, Japanese Patent Application Laid-Open No. 59-63732, etc.

It is also synthesized by sputtering using carbon as a target in an inert atmosphere. This technology was developed in Japanese Unexamined Patent Publication No. 53-10
This can be seen in JP-A No. 394, JP-A-60-131896, and the like.

[Problems to be solved by the invention] However, the existing methods for this, namely the CVD method using hydrocarbons and hydrogen as raw materials, and the sputtering method using carbon as a target in an inert atmosphere, both have a slow synthesis rate. The problem is that the diamond-like R9 film is expensive, and it has been desired to improve the synthesis rate.

[Means for Solving the Problems] In order to solve the drawbacks of the prior art, the present invention has the following configuration.

That is, the present invention relates to a method for producing a diamond-like carbon thin film on a substrate, which comprises sputtering deposition using carbon as a target in the presence of a hydrocarbon having a cyano group.

The diamond-like carbon in the present invention is a composition in which 70% or more of carbon-carbon bonds are Sp3 bonds, and components other than carbon and hydrogen are 20% by weight or less,
Further, the diamond-like carbon in the present invention does not necessarily need to be crystalline. Furthermore, the diamond-like carbon in the present invention contains nitrogen in a range of 20 mol% or less. This nitrogen may exist in the form of a so-called dopant, replacing carbon in the diamond (in this case, it becomes an N-type diamond), or it may exist in an amorphous portion.

Hydrocarbons having cyano-13 that are particularly preferably used in the present invention include cyanoacetylene, dicyanoacetylene,
)7 Acrylonitrile, methacrylonitrile, vinylidene cyanide, etc. Volatile compounds that have a triple bond or double bond with a cyano group other than these can also be used, and in particular, compounds that have 6 or less carbon atoms and have a triple bond and/or a triple bond with a cyano group are used. Ru. Even if the number of carbon atoms is 6 or more, it can be used as long as it has the volatility required in the sputtering method. Roughly volatile saturated nitrites such as acetonitrile and propionitrile can also be used. These compounds may be used alone or in combination of two or more. Sputtering is performed in the presence of a commonly used inert gas such as argon or hydrogen in addition to these hydrocarbons. Although the concentration of the hydrocarbon having a cyano group to be added to the reaction system can be selected within a wide range, it is sufficient that the hydrocarbon having a cyano group accounts for 10 mol% or less of the gaseous molecules present in the system.

The optimal value for sputtering pressure varies depending on the sputtering method, so it cannot be said with certainty, but it is usually 10-3↑or
It is selected from r in the range of 5 to 61 orr. However, pressures outside this range are also possible.

The sputtering method can also be selected using a scale rod; examples include two-, three-, and four-pole DC and RF sputtering methods, magnetron sputtering methods, methods that apply a bias potential to the substrate, and methods of countermeasures. can be mentioned.

During sputtering, it is usually preferable to cool the substrate and maintain it at a temperature of about room temperature to about 150° C. in order to produce a good diamond-like thin film.

A variety of substrates are used for diamond-like thin films, including diamond, livedenum, tungsten, tantalum, copper, gold, silicon, graphite, carbon, glass, saphire, boron nitride, aluminum nitride, and cermet. span. The shape of the substrate can also be selected as required, such as film, fiber, or bulk. When using a fibrous or film-like substrate, it is also possible to produce a diamond-like thin film by continuously supplying the fiber or film to the reaction section. By polishing the surfaces of these substrates with diamond-on-board paste and its similar abrasives, the rate of diamond nucleus generation can be improved.

[Example] The present invention will be described in more detail in the following examples, but the present invention is not limited thereto.

Example 1 Targeter 1 of an RF magnetron sputtering device consisting of a stainless steel chamber with a diameter of 3 Q cm and a height of 3 Q cm, a vacuum system, a magnet I~, a 13.5 MHz, 500 W RF power source, and a water-cooled substrate with 2 inches of graphite in the holder. Place a 1 inch silicon wafer (001) in the holder.
(p-type) was attached. After reducing the pressure in the system to 10-7 torr, hydrogen saturated with 7crylonitrile was flowed at 40°C so that the system pressure became 1 tOrr, and the RF input was increased to 1
Sputtering was performed at 0 W/cm2 for 60 minutes. The temperature of the substrate was cooled to 100'C or less. After the reaction, the thin film formed on the surface was evaluated. The Raman spectrum of the sample showed a Raman line characteristic of diamond at 1334 cm-1. The ESCA spectrum also showed the presence of Sp3 carbon. The thickness of the produced wJ film was 1.5μ.

Comparative Example 1 Sputtering was performed in the same manner as in Example 1, except that only hydrogen was used instead of hydrogen saturated with acrylonitrile at 40°C.

After the reaction, the a and film formed on the surface were evaluated. The Raman spectrum of the sample showed a Raman line characteristic of diamond at 1334 Cm-1. Also, the spectrum to ESC is Sp3
It showed the presence of carbon. The thickness of the produced thin film was 0.3μ.

The thickness of the young pigs produced showed that the presence of acrinitrile significantly improved the rate of thin film production.

Example 2 Using the same equipment as in Example 1, a 2-inch carbon plate was used as a target holder, and a 1-inch silicon wafer (001 plane, p-type ) was installed. system to 1O-7to
Shun reduced the pressure to rr, then poured hydrogen saturated with cyanoacerene at room temperature so that the pressure of the system was Q, 5 torr.
RF large input 20W/Cm2, eomr n spa'
) L/ Ta. The temperature of the substrate was cooled to 150° C. or less.

After the reaction, the thin film formed on the surface was evaluated. The Raman spectrum of the sample showed a Raman line characteristic of diamond at 1334 cm-1. The ESCA spectrum also showed the presence of Sp3 carbon. The thickness of the produced thin film was 0.8μ.

Comparative Example 2 Sputtering was carried out in the same manner as in Example 2, except that only hydrogen was used instead of hydrogen saturated with cyanacetylene at room temperature. After the reaction, the thin film formed on the surface was evaluated. The Raman spectrum of the sample showed a Raman line characteristic of diamond at 1334 Cm'. The ESCA spegetol also showed the presence of Sp3 carbon.

The thickness of the produced thin film was 0.2μ.

From the abrasion of the eight films produced, it was found that the presence of cyanacetylene significantly improved the rate of thin film formation.

[Effects of the Invention] According to the present invention, it is possible to provide a method for producing a diamond-like thin film at a faster rate than conventional methods.

Claims (3)

[Claims] (1) A method for producing a diamond-like carbon thin film on a substrate, the method comprising sputtering deposition using carbon as a target in the presence of a hydrocarbon having a cyano group. (2) A hydrocarbon having a cyano group has a cyano group and a carbon-
A method for producing a diamond-like thin film according to claim 1, characterized in that the diamond-like thin film contains carbon unsaturated bonds. (3) A diamond-like thin film according to claim (1), wherein the hydrocarbon having a cyano group is at least one selected from cyanoacetylene, dicyanoacetylene, acrylonitrile, and methacrylonitrile. Production method.