Al-I(102?)-nGaAs势垒二极管中载流子的输运

在金属-高掺杂nGaAs之间加入薄氧化层(约10²?)后,器件的I-V特性不再能用经典的金属-半导体接触理论来描述,而必须计入如下修正:电子由量子力学中的隧道效应穿过界面层势垒,由此引进透射系数P;反向偏置时,有效势垒高度因界面层及界面态的存在而有所改变,并且随外加电压而变化;正向偏置时,界面层的影响可以用理想因子n来描述。经过上述修正后推得的理论I-V,I-1/T关系式(表1)与实测曲线符合较好。文中讨论了透射系数与有效势垒高度提高的关系。关键词：

CARRIER TRANSPORT IN METAL-THIN INSULATOR n GaAs BARRIER DIODES

The current-voltage (I-V) characteristics of heavily doped n-GaAs metal-thin insulator (10²?)-semiconductor barrier diodes can not be described by classical theory of metal-semiconductor contacts. It is necessary to modify the theory by assuming: (1) the electrons pass through the barrier of interface layer by tunnelling, resulting in transmission coefficient P; (2) at reverse bias, the effective barrier height alters due to the presence of interface layer and states and changes with variation of voltage; (3) at forward bias, the effects of interface layer are embodied in ideality factor n. The I-V and I-1/T expressions (table 1) derived from the modified theory are in good agreement with experimental results. The relationship between transmission coefficient and effective barrier height increasing is also discussed.
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