中文摘要：

研究了在Si基GaN外延材料上实现低温欧姆接触的技术途径。研究了外延层的刻蚀深度、合金温度以及不同金属体系对接触特性的影响，发现外延层刻蚀深度的优化可显著改善欧姆接触特性。采用Ti／AI（10／200nm）金属，在外延层刻蚀深度为20nm以及合金温度550℃时，得到接近传统高温合金条件下的接触电阻，最小值达到0·76Ω·mm，同时实现的欧姆接触电极具有良好的形貌。该技术有望应用于高频、高功率GaNHEMT的工艺。

英文摘要：

Low temperature GaN Ohmic contact technology was developed and the influences on the Ohmic contact property from the epilayer etching depth, alloying temperature, different metal structures were also investigated. It is found that contact resistance can be improved by op- timization of the epilayer etching. With Ti/AI（10/200 nm） metal structure and 20 nm epilayer etching, a minimum Ohmic contact resistance of 0.76 Ω · mm was obtained after 550 ℃ alloying. By using this method, Ohmic contact metal with smooth surface and sharp edge was obtained. The low temperature GaN Ohmic contact technology is prospective in high power and high fre- quency GaN HEMT devices fabrication.