Frequency and duty cycle dependence on the pulsed bias-enhanced nucleationof highly oriented diamond on (100) silicon

Pulsed bias-enhanced nucleation of highly oriented diamond on (100) silicon is reported. A square waveform substrate bias was implemented in this inve stigation employing a pulse ON bias voltage of -250 V and a pulse OFF bias voltage of 0 V. An evaluation of the pulse ON fractions of 0.17 and 0.50 re vealed a duty cycle dependence on the bias time required for forming a diam ond film as well as the highly oriented diamond percentage. Oriented crysta llite percentages of nearly 50% and 20% were observed for the 0.17 and 0,50 pulse ON fractions, respectively. Pulse biasing from 10 to 100 Hz (again i mplementing a square waveform bias and a pulse ON fraction of 0.17) did not influence the process of forming the epitaxial diamond. Throughout this fr equency range the onset of diamond film formation was approximately 60 min and a nominal highly oriented diamond percentage of 50% was observed.