Measurement of polarization charge and conduction-band offset at InxGa1−xN/GaN heterojunction interfaces
Measurement of polarization charge and conduction-band offset at InxGa1−xN/GaN heterojunction interfaces
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DOI：
10.1063/1.1759388
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发表时间：
2004-05
影响因子：
4
通讯作者：
H. Zhang;E. J. Miller;E. Yu;C. Poblenz;J. Speck
中科院分区：
文献类型：
--
作者：
H. Zhang;E. J. Miller;E. Yu;C. Poblenz;J. Speck
iii族氮化物半导体中的自发极化场和压电极化场导致氮化物半导体异质结界面处存在较大的静电片电荷密度。因此，在氮化物半导体器件的设计和分析中，对这些极化引起的电荷密度和氮化物异质结界面的带边不连续的精确定量知识是必不可少的。在x=0.054和x=0.09的情况下，我们利用电容电压谱测量了InxGa1−xN/GaN异质结界面上的导带偏移和极化电荷密度。我们得到x=0.054时导带偏移ΔEC=0.09±0.07 eV, x=0.09时ΔEC=0.22±0.05 eV，对应于平均导价带偏移比ΔEC：ΔEV为58:42。我们的测量结果显示，x=0.054时极化电荷密度为（1.80±0.32）×1012 e/cm2, x=0.09时极化电荷密度为（4.38±0.36）×1012 e/cm2。这些值比最近的理论计算预测的值要小，但在……
The spontaneous and piezoelectric polarization fields in group-III nitride semiconductors lead to the presence of large electrostatic sheet charge densities at nitride semiconductor heterojunction interfaces. Precise quantitative knowledge of these polarization-induced charge densities and of the band-edge discontinuities at nitride heterojunction interfaces is therefore essential in nitride semiconductor device design and analysis. We have used capacitance–voltage profiling to measure the conduction-band offset and polarization charge density at InxGa1−xN/GaN heterojunction interfaces with x=0.054 and x=0.09. We obtain conduction-band offsets ΔEC=0.09±0.07 eV for x=0.054 and ΔEC=0.22±0.05 eV for x=0.09, corresponding to an averaged conduction-to-valence-band offset ratio ΔEC:ΔEV of 58:42. Our measurements yield polarization charge densities of (1.80±0.32)×1012 e/cm2 for x=0.054 and (4.38±0.36)×1012 e/cm2 for x=0.09. These values are smaller than those predicted by recent theoretical calculations, but in ...