Investigation of the electronic properties of nitrogen vacancies in AlGaN
Investigation of the electronic properties of nitrogen vacancies in AlGaN
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DOI：
10.1063/1.3089239
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发表时间：
2009-03
影响因子：
3.2
通讯作者：
Xian-an Cao;A. Syed;H. Piao
中科院分区：
文献类型：
--
作者：
Xian-an Cao;A. Syed;H. Piao
研究了预金属化退火对GaN和AlxGa 1 −xN（x=0.25和0.5）肖特基二极管电学特性的影响。在Ar气氛中高于800 °C的退火导致显著的优先N损失，并且在1000 °C下的退火导致局部表面分解。退火GaN上的Pt/Au肖特基接触变得更漏电，而热损伤AlGaN上的肖特基接触则表现出更多的整流特性。延长退火产生更多的导电AlGaN表面缺乏N和Al，所揭示的X射线光电子能谱。这些发现表明，与GaN中的施主空位相反，Al摩尔分数≥25%的AlGaN中的N空位表现为深能级态，补偿了近表面区域。因此，必须注意防止在高Al含量AlGaN的热处理期间N的损失。
The effects of premetallization annealing on the electrical characteristics of GaN and AlxGa1−xN (x=0.25 and 0.5) Schottky diodes have been studied. Annealing above 800 °C in an Ar ambient led to a significant preferential N loss, and annealing at 1000 °C caused localized surface decomposition. The Pt/Au Schottky contacts on the annealed GaN became leakier, whereas those on the thermally damaged AlGaN exhibited more rectifying characteristics. Prolonged annealing produced more conductive AlGaN surfaces deficient in both N and Al, as revealed by x-ray photoelectron spectroscopy. These findings suggest that, as opposed to donorlike vacancies in GaN, N vacancies in AlGaN with an Al mole fraction ≥25% behave as deep-level states, compensating the near-surface region. Care must therefore be taken to prevent the loss of N during thermal processing of high-Al content AlGaN.