Growth of microcrystalline β-SiC films on silicon by ECR plasma CVD

Abstract

We have investigated the growth of microcrystalline β-SiC films grown by ECR plasma CVD for application as a solar cell window material. The main reactant gases used were silane and methane. Hydrogen has been employed as the plasma gas with phosphine as the dopant gas. Film growth and properties have been investigated over a wide range of process parameters. This paper presents results on the structural and compositional properties of the films as a function of these process parameters, particularly growth temperature, ECR microwave power and reactant gas composition. The primary analysis techniques employed have been Rutherford Backscattering using the Simulated Annealing algorithm and X-ray diffractometry. We have found the grain size in our films to be limited to values less than 10 nm. Both growth rate and crystallite size increase with sample temperature. In addition, the growth rate increases with power while crystallite size reaches a maximum between 800 and 900 W. Small amounts of argon added to the reactant gases have a significant effect on the deposition kinetics and have produced the largest grain size in our material. An analysis of these findings is presented.