GaAs(111)衬底上生长的GaN的极性与生长方法和生长条件的关系

摘要

Dependence of polarity of hexagonal GaN on that of GaAs (111 ) substrates was investirngated. GaN grown by MOVPE and MOMBE with a high V/Ⅲ ratio followed polarity of the rnGaAs substrate; a layer grown on the (111)A -Ga- surface showed Ga polarity and that on the rn(111)B -As-surface showed N polarity. However, GaN grown on GaAs (111 )B surface showed rnGa polarity when the layer was grown by HVPE, MOMBE with a low V/Ⅲ ratio, or with an rnAlN intermediate layer. The reason is not made clear yet, but these results suggest that HVPE rngrowth or an A1N high temperature buffer layer gives a better quality GaN.%研究了在GaAs(111)衬底上生长的六角相GaN的极性的相关关系.在高V/Ⅲ比的条件下用MOVPE和MOMBE方法生长的GaN的极性和GaAs衬底的极性一致;在(111)A-Ga表面上的生长层呈现Ga的极性,而在(n1)B-As表面上的生长层呈现N的极性.然而,在低的V/Ⅲ比,或采用一个～N中间层的条件下,用HVPE和MOMBE方法在GaAs(111)B表面上生长的GaN呈现出Ga的极性.目前,其原因尚不清楚,但是这些结果表明采用HVPE生长方法或用一高温AlN阻挡层可以得到高质量的GaN.