Hydrogen detection in CVD diamond films by elastic recoil detection analysis

The hydrogen concentration in diamond films deposited by the microwave plasma CVD method was evaluated by elastic recoil detection analysis (ERDA) using He ion beam. Diamond films with ~500 μm thickness were peeled off Si substrates and the hydrogen concentration was measured for both growth surface and backside. The hydrogen concentration of the growth surface was approximately 1.9% against the number of carbon atoms, while that of the backside was 6.5%. By grinding both surfaces, the hydrogen concentration of the growth surface became approximately 2.6%, and that of the backside 4.2%. These results show that the hydrogen measurement by ERDA depends strongly on the surface roughness. In this paper, we also discuss the growth mechanism at the initial stage of diamond deposition, comparing the hydrogen concentration of the growth surface and backside of films.