Diffusion behavior of implanted Li ions in GaN thin films studied by secondary ion mass spectrometry

Lithium ions with dosages of 2.6×1012, 2.6×1013, 2.6×1014, and 2.6×1015 cm−2 have been implanted into a GaN thin film grown on sapphire substrates. The diffusion behavior of these implanted Li ions in GaN thin film at different temperature anneals was studied using secondary ion mass spectrometry. In general, the diffusion profiles show relatively little movement of Li in the GaN thin film for temperatures up to 700 °C. At low-temperature anneals (<500 °C), up-hill diffusion dominated the Li profiles and at high-temperature anneals (>800 °C), out-diffusion dominated the Li profiles.