Pulsed laser deposition of wide-bandgap semiconductor thin films

Thin films of ZnO and GaN have been deposited by pulsed laser deposition in atmospheres of oxygen and nitrgoen respectively. A time-of-flight ion probe and optical spectroscopy were used to study the interaction of the ablation plasma with the background gas. The deposition rate was measured using in situ optical reflectivity, and the thin film quality was assessed using x-ray diffraction and photoluminescence. By correlating the plasma measurements and the thin film characterization it was possible to identify the plasma regime required for the deposition of good quality films.