INVESTIGATION OF OXYGEN IMPURITY IN PULSED-LASER DEPOSITED GAN FILM USING O-16(ALPHA, ALPHA)O-16 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 dis tribution was obtained by changing the energy of the incident beam. By using the resonance scattering peak in the fused silica (FS) substrat e 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 imp urity is attributed to the poor chamber vacuum before the deposition a nd to the H2O/O-2 contaminants in the ammonia used. (C) 1998 Elsevier Science B.V.