High quality heteroepitaxial diamond films on silicon

This paper reports the progresses made recently on the nucleation and growth of high-quality, [001]-oriented diamond films and discusses the problems to be resolved. The interface structure of diamond on silicon has further been investigated by transmission electron microscopy (TEM). Heteroepitaxial diamond films with increased lateral grain size and reduced grain boundary density were prepared in both microwave plasma chemical vapour deposition (MW-CVD) and hot filament chemical vapour deposition (HF-CVD) processes. Using a growth process combining a bias-assisted H+ etching an a [001]-textured growth smooth diamond films with large lateral grain size up to 10 mu m can be obtained at a film thickness of approximately 10 mu m. By controlling the [001]-textured growth process thick diamond films with a lateral grain size up to 30 mu m has been achieved in HF-CVD.