CONTROL OF SIH4/O-2 CHEMICAL-VAPOR-DEPOSITION USING THE GAS-PHASE ADDITIVE C2H4

The effects of adding C2H4 on the chemical vapor deposition (CVD) of SiO2 films from SiH4/O2 were studied at temperatures ranging from 673 to 1073 K using a hot-wall-type tubular reactor. Adding C2H4 improved the step coverage of the films while effectively suppressing the gas-phase formation of particles. Because C2H4 is a well-known radical scavenger, the control of gas-phase chain reactions by consuming atom and/or radical species is responsible for the suppression of particle formation. Comparison of the sticking probability of growth species in SiH4/O2 systems with and without added C2H4 shows that high deposition temperatures are responsible for the improvement in step coverage. The analysis of the carbon content in the films by x-ray photoelectron spectroscopy (XPS) shows no difference in carbon impurity levels between the SiH4/O2/C2H4 and SiH4/O2 chemical systems.© 1995 American Institute of Physics.