Polarity inversion during halide VPE growth of GaN on GaAs(111)B-As surface at high temperatures

摘要

Halide Vapor Phase Epitaxy (HVPE) is a promising growth method of bulk GaN. Polarity of GaN grown on GaAs(111)B-As surface was investigated. Depending on whether the GaAs substrate was exposed to GaCl or NH{sub}3 ambient prior to growth. polarity of the low temperature buffer layer exhibited Ga polarity or N polarity. However, GaN layers grown on it at 850°C always showed Ga polarity independently of the polarity of the buffer layer, suggesting that HVPE prefers Ga polar growth at high temperatures.