摘要
研究了在高温工作环境下Ti/Al/Ni/Au(15nm/220nm/40nm/50nm)四层复合金属层与n-GaN的欧姆接触的高温工作特性.退火后样品在500℃高温下工作仍能显示出良好的欧姆接触特性;接触电阻率随测量温度的增加而增大,且增加幅度与掺杂浓度有密切关系.掺杂浓度越高,其接触电阻率随测量温度的升高而增加越缓慢;重掺杂样品的Ti/Al/Ni/Au-n-GaN欧姆接触具有更佳的高温可靠性;当样品被施加500℃,1h的热应力后,其接触电阻率表现出不可恢复性增加.
The high temperature characteristics of the ohmic contact of Ti/AI/Ni/Au （15nm/220nm/40nm/50nm） multilayer contacts to n-type GaN（Nd =3.7×10^17cm^-3 , Nd=3.0×10^18cm^-3） are studied. The annealed samples still show excellent ohmic contact characteristics at 500℃. Contact resistivity increases with the rise of temperature. Furthermore, the tendency of increase is related to doping concentration：The higher the doping concentration, the slower the increase of the contact re-sistivity with the temperature. Ti/AI/Ni/Au ohmic contact to heavy doping n-GaN has better high temperature reliability. The contact resistivity shows unrecoverable characteristics after the samples are placed under the thermal stress.
基金
国家高技术研究发展计划资助项目(批准号:2006AA03A112)~~
关键词
欧姆接触
接触电阻率
退火
高温
ohmic contact： specific contact resistivity
annealing
high temperature
