Versatile microwave PECVD technique for deposition of DLC and other ordered carbon nanostructures

A remote microwave plasma enhanced chemical vapour deposition system was op timized to deposit different types of diamond like carbon films, as well as , some ordered carbon structures like carbon nanotubes (CNTs) and nanodiamo nds. These films were obtained at room temperature using C2H2 + Ar as the f eedstock and at different sets of parameter space. While some DLC films had the required optical parameters to provide an anti-reflection coating on S i solar cells (1.9% enhancement of efficiency), others were transparent in the visible region. CNTs and nanodiamond structures were obtained simply by varying the applied RF bias at an optimized microwave power of 25 W. Hardn ess and stress of these films were in the range of 9-20 GPa and < I GPa, re spectively. The root mean square roughness in DLC films varied from 0.06 to 0.12 nm. Raman spectroscopy was performed to identify different phases pre sent in the films. The grain size of nanocrystalline diamonds varied from 4 0 to 120 nm. The CNTs were found to be multiwalled with their diameters var ying from 23 to 30 nm. (C) 2001 Elsevier Science Ltd. All rights reserved.