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 (英文)

Growth Method and Growth Condition Dependence of the Polarity of GaN Grown on the GaAs (111) Substrate

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（１１１）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ＡＩＮ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。

Dependence of polarity of hexagonal GaN on that of GaAs (111) substrates was investi- gated. GaN grown by MOVPE and MOMBE with a high Ⅴ /Ⅲ ratio followed polarity of the GaAs substrate; a layer grown on the (111) A -Ga- surface showed Ga polarity and that on the (111) B -As-surface showed N polarity. However, GaN grown on GaAs (111) B surface showed Ga polarity when the layer was grown by HVPE, MOMBE with a low Ⅴ /Ⅲ ratio, or with an AIN intermediate layer. The reason is not made clear yet, but these results suggest that HVPE growth or an MN high temperature buffer layer gives a better quality GaN.