Cryogenic Processing of Schottky Contacts to III-V Semiconductors

高势垒高度、低漏电流的III-V型半导体肖特基触点对于场效应晶体管、光学传感器和光伏变换器的应用具有重要意义。III-V半导体的肖特基触点将进行低温处理（CP），以大大增加势垒高度并减少泄漏电流。具体的半导体材料将包括n型InP、GaAs、InAlAs和IngaAs。二极管将在衬底冷却到77K的情况下制造，这一工艺已经给出了有希望的结果，其形式是增加势垒高度，在n-InP中达到0.96 eV，并将泄漏电流降低了几个数量级。金属Al， Cu, Au， Pd和Pt将被用来显示费米能级的解钉。该研究的一个重要方面是了解CP接触提供这种改进性能的原因。电学和光学数据将与高分辨率的结构和化学数据相关联。电学和光学数据将包括揭示传导机制的电流-电压-温度、深能级瞬态光谱、光反射光谱、光反射光谱和拉曼光谱。高分辨率透射电子显微镜和化学分析将与其他数据相关联。稍后的重点将是将CP技术应用于量子阱和超晶格结构，其中非常尖锐的界面非常重要。

High barrier height, low leakage current Schottky contacts to III-V semiconductors are important for application to field effect transistors, optical sensors and photovoltaic converters. Schottky contacts to III-V semiconductors will be cryogenically processed (CP) to greatly increase barrier height and reduce leakage current. Specific semiconductor materials will include n-type InP, GaAs, InAlAs and IngaAs. Diodes will be fabricated with the substrate cooled to 77K, a process which already has given promising results in the form of increased barrier height, to 0.96 eV in n-InP, and reduced leakage current by several orders of magnitude. The metals Al, Cu, Au, Pd and Pt will be utilized to show unpinning of the Fermi level. An important aspect of the study involves understanding the reason for CP contacts to give such improved performance. Electrical and optical data will be correlated with high resolution structural and chemical data. Electrical and optical data will include current-voltage-temperature to reveal conduction mechanisms, deep level transient spectroscopy, photoreflectance spectroscopy, photoreflectance spectroscopy, and Raman spectroscopy. High resolution transmission electron microscopy and chemical analysis will be correlated with other data. A later focus will be made to apply the CP technique to quantum well and superlattice structures, where extremely sharp interfaces are of great importance.