中文摘要：

随着高压开关和高速射频电路的发展,增强型GaN基高电子迁移率晶体管（HEMT）成为该领域内的研究热点。增强型GaN基HEMT只有在加正栅压才有工作电流,可以大大拓展该器件在低功耗数字电路中的应用。近年来,国内外对增强型GaN基HEMT阈值电压的研究主要集中以下两个方面：在材料生长方面,通过生长薄势垒、降低Al组分、生长无极化电荷的AlGaN/GaN异质材料、生长InGaN或p-GaN盖帽层,来控制二维电子气浓度;在器件工艺方面,采用高功函数金属、MIS结构、刻蚀凹栅、F基等离子体处理,来控制表面电势,影响二维电子气浓度。从影响器件阈值电压的相关因素出发,探讨了实现和优化增强型GaN基HEMT的各种工艺方法和发展方向。

英文摘要：

With the development of high-voltage switches and high-speed RF circuits,the enhancement-mode（E-mode）AlGaN/GaN HEMTs become a research hotspot in those fields.The E-mode GaN-based HEMTs have channel current at the gate voltage higher than zero,greatly expanding the device in low power digital circuit applications.Recent years,research on the threshold voltage of the E-mode AlGaN/GaN HEMTs mainly focus on material growth and device structure process.The concentration of two-dimensional electron gas（2DEG）can be adjusted by growing a thin barrier,Al composition reduction,non-polar charge AlGaN/GaN heterostructure,InGaN or p-GaN cap layer.Device structure processes,such as high work function metals,MIS structure,the gate recess etching and F-based plasma treatment can further revise the surface potential to affect 2DEG.Variety of process methods optimizing the threshold voltage of the E-mode AlGaN/GaN HEMTs and further development are discussed.