Deposition of Aluminum Nitride Films Using RF Reactive Sputtering

Abstract

AbstractRF reactive sputtering of aluminum in argon-nitrogen mixture has been used to deposit basal oriented aluminum nitride films at temperatures lower than 200°C.X-ray diffraction studies of films deposited in 40–60% nitrogen show very high degree of crystallinity.A characteristic step-like decrease in target induced dc bias and the deposition rate (at a constant rf power level) is observed when the nitrogen content is increased above about 20%.The plot of target bias vs.nitrogen content shows a typical hysteresis loop which decreases in size at higher power levels, thus indicating nitride formation at the target surface.Glow discharge mass spectrometry was used to monitor the ions arriving at the substrate.There is a dramatic decrease in Al+ ion current when the nitrogen percentage in the gas mixture is increased above 20%.