Methods for manufacturing substrates to form monocrystalline diamond films by chemical vapor deposition

摘要

A method is presented to manufacture substrates for growing monocrystalline diamond films by chemical vapor deposition (CVD) on large area at low cost. The substrate materials are either Pt or its alloys, which have been subject to a single or multiple cycle of cleaning, roller press, and high temperature annealing processes to make the thickness of the substrate materials to 0.5 mm or less, or most preferably to 0.2 mm or less, so that either (111) crystal surfaces or inclined crystal surfaces with angular deviations within .+-.10 degrees from (111), or both, appear on the entire surfaces or at least part of the surfaces of the substrates. The annealing is carried out at a temperature above 800. degree. C. The present invention will make it possible to markedly improve various characteristics of diamond films, and hence put them into practical use.