H atom impact induced chemical erosion reaction at C:H film surfaces

Abstract

C:H film surfaces which are subjected to a flux of thermal H atoms erode chemically via hydrocarbon, probably methyl, production. At the present H flux the erosion reaction is effective above 400 K and below 700 K, with a maximum around 600 K. The erosion efficiency at this temperature is ≈ 0.01 C atom per incoming H. A kinetic analysis of the erosion reaction and competing hydrogenation and dehydrogenation surface reactions under impact ofH reveals an activation energy of ≈37 kcal mol for the H atom impact induced erosion. As the efficiency of the erosion reaction depends on the incoming H flux, it may contribute as an important reaction in low-pressure diamond synthesis. © 1994.