HIGHLY TRANSPARENT NANO-CRYSTALLINE DIAMOND FILMS GROWN BY MICROWAVE CVD

We report here the growth of highly transparent nano-crystalline diamo nd films on quartz substrates by microwave plasma enhanced CVD. Optica l transmittance of greater than 73% beyond 700 nm has been obtained fo r films as thick as 1 mu m, while for 0.6 mu m thick films it is 80%. Such high optical transparency of these films is primarily attributed to the smoothness of their surface (average roughness of about 100-130 Angstrom) as well as the high content of sp(3) bonded carbon. A growt h model for explaining the dependence of optical transparency on vario us deposition parameters is also proposed. (C) 1998 Elsevier Science L td. All rights reserved.