Mechanism of anomalous current transport in n-type GaN Schottky contacts
Mechanism of anomalous current transport in n-type GaN Schottky contacts
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DOI：
10.1116/1.1491539
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发表时间：
2002-08
影响因子：
1.4
通讯作者：
H. Hasegawa;Susumu Oyama
中科院分区：
文献类型：
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作者：
H. Hasegawa;Susumu Oyama
详细测量了Ni和Pt/n-GaN肖特基接触的电流-电压（I-V）特性的温度T依赖性，并从不同角度对结果进行了分析。在I-V-T行为中观察到与电子发射输运的大偏差，反向漏电流非常大。正向特性可以用经典的场致发射（TFE）/场致发射（FE）模型来拟合。然而，一个异常高的掺杂浓度，必须假设，和反向特性是远离测量数据。提出了一种新的薄表面势垒（TSB）模型，其中肖特基势垒的宽度由于无意的表面施主的存在而减小。通过TSB区的TFE/TE过程的分析导致了一组I-V-T曲线，这些曲线几乎完美地再现了所观察到的具有正确数量级的电流的正向和反向I-V-T行为。与氮空位有关的深施主可能是表面缺陷的来源。
Temperature T dependences of the current–voltage (I–V) characteristics of Ni and Pt/n-GaN Schottky contacts were measured in detail, and the results were analyzed from various viewpoints. Large deviations from the thermionic emission transport were observed in the I–V–T behavior with anomalously large reverse leakage currents. Forward characteristics could be fitted into the classical thermionic-field emission (TFE)/field emission (FE) model. However, an unusually high doping density had to be assumed, and the reverse characteristics were far away from measured data. A new thin surface barrier (TSB) model was proposed in which the width of the Schottky barrier is reduced due to the presence of unintentional surface donors. Analysis of TFE/TE process through the TSB region has led to sets of I–V–T curves that reproduce almost perfectly the observed forward and reverse I–V–T behavior with correct orders of magnitude of currents. Deep donors related to nitrogen vacancy are suggested to be the origin of surfa...