Nature of the highly conducting interfacial layer in GaN films

被引:36
作者
Hsu, JWP [1 ]
Lang, DV
Richter, S
Kleiman, RN
Sergent, AM
Molnar, RJ
机构
[1] Lucent Technol, Bell Labs, Murray Hill, NJ 07974 USA
[2] MIT, Lincoln Lab, Lexington, MA 02420 USA
关键词
D O I
10.1063/1.1320853
中图分类号
O59 [应用物理学];
学科分类号
摘要
Using several scanning probe techniques to investigate local electronic properties, we show that the GaN/sapphire interfacial region contains greater than or equal to ten times higher electron density but with the Fermi level being 50-100 meV deeper in the band gap compared to the less-conducting bulk film. This anomalous behavior cannot be explained by transport in the intrinsic conduction band of GaN. Rather, it points to the existence of a partially filled donor impurity band. We relate the presence of this impurity band conduction to excess oxygen in the region and the defective microstructure at the GaN/sapphire interface. (C) 2000 American Institute of Physics. [S0003-6951(00)01144-X].
引用
收藏
页码:2873 / 2875
页数:3
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