Accession Number:

ADD018788

Title:

Metal Initiated Nucleation of Diamond

Descriptive Note:

Patent, Filed 3 Aug 95, patented 11 Nov 97

Corporate Author:

PATENT OFFICE WASHINGTON DC

Report Date:

1997-11-11

Pagination or Media Count:

11.0

Abstract:

Nucleation of diamond crystallites is initiated on electrically nonconducting substrates and on semiconducting substrates at a temperatures of 650 deg C. or lower by providing atoms of a metal in a plasma formed by activation, as by microwave energy in a vacuum chamber, of a mixture of hydrogen and a carbon containing vapor. A continuous, adhering film of polycrystalline diamond is then grown on the substrate from the nucleated crystallites. The nucleation is effective when the substrate has a positive electric potential relative to a wall of the chamber. Positive and negative dopants may be provided in the vapor to give a semiconducting film. The nucleation and film growth are effective at the relatively low substrate temperatures so that dopant diffusion and substrate damage occurring at the usual, higher diamond film deposition temperatures are avoided. Atoms of chromium, titanium, and nickel are particularly effective and may be provided by a metalorganic compound in the vapor or by a solid material which is etched by the plasma and may be the pure metal or its oxide, nitride, or alloy. The solid may be provided as an open vessel or on a ring within which the substrate is placed or as a coating deposited on the substrate. A partial coating of the solid material results in the diamond film being selectively deposited only on the uncoated portion.

Subject Categories:

  • Laminates and Composite Materials
  • Crystallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE