TRANSPARENT DIAMOND THIN FILM AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To grow an independent and transparent polycrystalline diamond thin film having definite thickness and dimensions in lateral direction by introducing a specific hydrogen-methane mixed gas into a thermal reaction area adjacent to a substrate. SOLUTION: A heating filament 20 is arranged at a distance of about 0.3-1cm from the surface of substrates (preferably molybdenum substrate) 18 and 19 in a bell jar made of quartz to form a thermal reaction area. A hydrogen- methane mixed gas containing about 1.5-2vol.% methane based on total volume of hydrogen and methane is introduced from a gas inlet 12 into the thermal reaction area under conditions at about 600-1000 deg.C and about 3-24Torr enough to produce active carbon-hydrogen chemical seeds to grow the objective non- adhesive and substantially transparent polycrystalline diamond thin film having 50-5000 micron thickness and >=10mm dimensions in lateral direction on the substrate.