Effects of temperature and bias on the microstructure of plasma-deposited amorphous silicon carbide

We report a new method of depositing amorphous hydrogenated silicon carbide (a-SiC:H) at low substrate temperature in a plasma-enhanced chemical vapor deposition reactor. By applying an external dc voltage to the rf-excited powered electrode, we can shift the optimal deposition temperature from 250 °C to as low as 100 °C. We find that a-SiC:H films deposited at positive powered-electrode potential and low substrate temperature exhibit less microstructure, wider optical band gaps, and faster deposition rates than films deposited at conventional conditions.