GROWTH CONDITION DEPENDENCE OF GAN CRYSTAL-STRUCTURE ON (001)GAAS BY HYDRIDE VAPOR-PHASE EPITAXY

In order to understand growth feature of GaN on (0 0 1)GaAs, GaN layer s were grown by hydride vapor-phase epitaxy (HVPE) under various growt h conditions. Hexagonal GaN has dominantly grown even on (0 0 1)GaAs f or the substrate temperatures below 800 degrees C even though the buff er layer had an almost pure cubic structure. Hexagonal component of th e grown layer also greatly depends on the V/III ratio of the supplied gases as well as quality of buffer layer, and it was less than 1% for a good cubic buffer layer and an optimum V/III ratio. (C) 1998 Elsevie r Science B.V. All rights reserved.