Process for forming diamond coating using a silent discharge plasma jet process

Abstract

A novel process is disclosed for forming diamond coatings whereby a silent discharge, such as a DC glow discharge, is used to form a plasma containing activated species. The plasma is then expanded through a nozzle to form a low temperature plasma jet which contacts a substrate to form the diamond coating. The plasma initially contains a mixture of hydrogen and carbon based gases such as methane. In a preferred embodiment, hydrogen is initially present in the plasma and the carbon containing gas (carbon containing molecules e.g. methane, carbon monoxide) is subsequently mixed into the plasma jet downstream of the nozzle throat and allowed to react with the activated hydrogen, prior to the plasma jet contacting the substrate.

Dependencies are inferred from the claim text.