Mechanism of H2 pre-annealing on the growth of GaN on sapphire by MOVPE
Pre-annealing of a sapphire substrate in hydrogen atmosphere strongly affects the growth of GaN by metalorganic vapor phase epitaxy using a low-temperature (LT) deposited AlN buffer layer. In order to grow high-quality GaN, the pre-annealing temperature should be higher than 900 °C. No annealing or low-temperature annealing results in the polycrystalline growth of GaN.
