CHARACTERIZATION OF THE EFFECT OF GROWTH-CONDITIONS ON A-SIC-H FILMS

The effects of dissipated power and gas dwell lime in SiH4+CH4 plasmas on the properties of a-SiC:H films deposited by plasma-enhanced chemi cal-vapor deposition have been investigated for different methane frac tions in plasmas operating in the low-power regime. Optical, structura l, and electrical characterizations have been performed in order to in vestigate the influence of dissipated power and molecule dwell time on the physical properties of a-SiC:H films. It was found that both the investigated deposition parameters can have a remarkable influence on carbon incorporation and on optical properties such as the energy gap. In particular an increase in the dissipated power or in the molecule dwell time leads to an increase in carbon incorporation and in energy gap. The electrical properties and defect density are still those of d evice quality films grown in standard deposition conditions and are: n ot influenced by variations in dissipated power or gas dwell time. Fro m these results Some conclusions regarding the growth mechanisms are d rawn. (C) 1996 American Institute of Physics.