Study of contact resistivity, mechanical integrity, and thermal stability of Ti/Al and Ta/Al ohmic contacts to n-type GaN
Study of contact resistivity, mechanical integrity, and thermal stability of Ti/Al and Ta/Al ohmic contacts to n-type GaN
复制标题
研究 Ti/Al 和 Ta/Al 欧姆接触与 n 型 GaN 的接触电阻率、机械完整性和热稳定性
DOI：
10.1007/s11664-998-0386-7
复制
发表时间：
1998
影响因子：
2.1
通讯作者：
R. Karlicek
中科院分区：
文献类型：
--
作者：
B. P. Luther;S. Mohney;J. Delucca;R. Karlicek
首次报道了Ta/Al欧姆接触n型GaN的退火条件和接触电阻率。研究了Ti/Al和Ta/Al触头的高温稳定性和机械完整性。Ta/Al(35 nm/115 nm)与n型GaN的接触在500℃退火3min或在600℃退火15 S后形成欧姆效应，测量了接触电阻率为5×10−6Ωcm2，用铝层重新图案化接触以减少高金属片阻的影响。真空封装在石英管中的Ti/Al和Ta/Al触头在600℃下老化5天后，接触电阻率显著增加。在时效样品的金属/GaN界面上观察到了微小的反应。
The annealing conditions and contact resistivities of Ta/Al ohmic contacts to n-type GaN are reported for the first time. The high temperature stability and mechanical integrity of Ti/Al and Ta/Al contacts have been investigated. Ta/Al (35 nm/115 nm) contacts to n-type GaN became ohmic after annealing for 3 min at 500°C or for 15 s at 600°C. A minimum contact resistivity of 5×10−6Ω cm2was measured after contacts were repatterned with an Al layer to reduce the effect of a high metal sheet resistance. Ti/Al and Ta/Al contacts encapsulated under vacuum in quartz tubes showed a significant increase in contact resistivity after aging for five days at 600°C. Cross section transmission electron microscopy micrographs and electrical measurements of aged samples indicate that the increased contact resistivity is primarily the result of degradation of the metal layers. Minimal reactions at the metal/GaN interface of aged samples were observed.