The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 24, 1994
Filed:
Mar. 23, 1992
Satoshi Nakamura, Aichi, JP;
Minoru Yamamoto, Kariya, JP;
Nobuei Ito, Chiryu, JP;
Tadasi Hattori, Okazaki, JP;
Nippondenso Co., Ltd., Kariya, JP;
Abstract
Apparatus and process for synthesizing a diamond film of high purity at a high rate. Mixture gas of hydrocarbon gas and hydrogen gas is introduced into an arc discharge to produce a gas plasma. This gas plasma is blown against a substrate to deposit diamond. A plasma current power supply is connected with a third electrode disposed above the substrate to place the third electrode at a positive potential. An electrical current is supplied into the gas plasma from the third electrode. Flow of the electrical current through the plasma promotes the decomposition of the hydrogen and hydrocarbon. A diamond film of high purity can be deposited at a high rate. The invention is characterized in that the substrate is placed at a lower potential than the third electrode or the direction of the electrical current intersects the flow of the gas plasma although the electrical current is passed through the plasma. Therefore, it is unlikely that the accelerated electrons reach the substrate, elevating its temperature. Hence, diamond of high quality can be synthesized.