Investigation of oxygen impurity in pulsed laser deposited GaN film using 16O(α,α)16O resonance scattering

The well known O-16(alpha, alpha)O-16 scattering resonance near 3.034 MeV was used to investigate oxygen impurity in a GaN film deposited by a liquid target pulsed laser deposition (LTPLD) method. The depth distribution was obtained by changing the energy of the incident beam. By using the resonance scattering peak in the fused silica (FS) substrate as a standard, the obtained oxygen atomic concentration ranges from 4.5% to 9.5% in the GaN film. This relatively high level of oxygen impurity is attributed to the poor chamber vacuum before the deposition and to the H2O/O-2 contaminants in the ammonia used. (C) 1998 Elsevier Science B.V.