Field-induced surface passivation of p-type silicon by using AlON films

摘要

In the present work, we report on the evidence for a high negative charge density in aluminum oxinitride (AlON) coating on silicon. A comparative study was carried out on the composition and electrical properties of A1ON and aluminum nitride (A1N). A10N films were deposited on p-type Si (1 00) substrate by RF magnetron sputtering using a mixture of argon and oxygen gases at substrate temperature of 300 ℃. The electrical properties of the A1ON, A1N films were studied through capacitance-voltage (C-V) characteristics of metal-insulator-semiconductor (MIS) using the films as insulating layers. The Hatband voltage shift KFB observed for A1ON is around 4.5 V, which is high as compared to the A1N thin film. Heat treatment caused the V_(FB) reduction to 3 V, but still the negative charge density was observed to be very high. In the A1N film, no fixed negative charge was observed at all. The XRD spectrum of AlON shows the major peaks of AlON (2 20) and A1N (002), located at 2θ value of 32.96° and 37.8°, respectively. The atomic percentage of Al, N in A1N film was found to be 42.5% and 57.5%, respectively. Atomic percentages of Al, N and O in EDS of AlON film are 20.21%, 27.31%, and 52.48%, respectively.