摘要
氮化镓(GaN)作为第三代宽禁带半导体材料具有禁带宽度大、电子迁移率高和临界击穿电场高等优点,已经广泛应用于新型电力系统。基于Ti/Al/Ni/Au金属叠层制备了AlGNa/GaN异质结欧姆接触。通过传输线模型(TLM)测试其接触电阻率和方块电阻分别为1.01Ω·mm和304Ω/□。通过TLM结构的变温测试来研究AlGaN/GaN异质结欧姆接触的导通机理。实验结果表明,随着测试温度升高,接触电阻率仅从1.01Ω·mm增加到1.26Ω·mm,展现出良好的温度稳定性。比接触电阻率与温度的拟合曲线表明,场发射是AlGaN/GaN异质结欧姆接触电流传输的主导机制。透射电子显微镜的结果表明,在高温退火中,金属Ti扩散至AlGaN中与之发生反应并产生大量的N空位,在AlGaN势垒层中形成重掺杂,从而减小了势垒宽度,促进了欧姆接触的形成。
Gallium nitride(GaN),as a third-generation wide-bandgap semiconductor material,has advantages such as a wide bandgap,high electron mobility and high critical breakdown electric field.It has been widely applied in new power systems.An AlGaN/GaN heterojunction ohmic contact was fabricated based on a Ti/Al/Ni/Au metal stack.The contact resistivity and sheet resistance were measured by the transmission line model(TLM)to be 1.01Ω·mm and 304Ω/□,respectively.The conduction mechanism of the AlGaN/GaN heterojunction ohmic contact was investigated by TLM variable temperature test.The experimental results show that as the test temperature increases,the contact resistivity rises only slightly from 1.01Ω·mm to 1.26Ω·mm,demonstrating good temperature stability.The fitting curve of the specific contact resistivity and temperature indicates that field emission is the dominant mechanism for current transport in the AlGaN/GaN heterojunction ohmic contact.Transmission electron microscope results reveal that during high-temperature annealing,metal Ti diffuses into AlGaN,reacts with it,and generates a large number of nitrogen vacancies.This creates heavy doping in the AlGaN barrier layer,reducing the barrier width and facilitating the formation of ohmic contact.
作者
王强
曹京津
曲莹
范晶晶
李飞扬
Wang Qiang;Cao Jingjin;Qu Ying;Fan Jingjing;Li Feiyang(Electric Power Research Institute,State Grid Shanxi Electric Power Co.,Ltd.,Taiyuan 030001,China;College of Electrical and Information Engineering,Hunan University,Changsha 410000,China)
出处
《微纳电子技术》
2026年第1期87-93,共7页
Micronanoelectronic Technology
