PROCESS FOR PRODUCING EXTREMELY FLAT MICROCRYSTALLINE DIAMOND THIN FILM BY LASER ABLATION METHOD

摘要

With respect to the conventional diamond thin film grown by the PLD method, the size of diamond crystal grains is on the order of 1 .mu.m and the film surface is uneven. There is provided a process for producing a diamond thin film by a laser ablation method, comprising heating a substrate at 450 to 650~C, creating a hydrogen atmosphere in a reaction chamber, setting laser energy for 100 mJ or more and providing a spacing of 15 to 25 mm between a target and the substrate so as to form a supersaturation of atomic hydrogen and carbon between the target and the substrate, and further comprising realizing a hydrogen atmosphere pressure sufficient to completely selectivel y etch off sp2 bond component (graphite component) from the sp2 bond component and sp3 bond component deposited on the substrate so as to effect growth of a single-phase superflat microcrystalline diamond thin film substantially not containing any non-diamond components.