Improved Ohmic contacts to plasma etched n-Al0.5Ga0.5N by annealing under nitrogen ambient before metal deposition
Improved Ohmic contacts to plasma etched n-Al0.5Ga0.5N by annealing under nitrogen ambient before metal deposition
复制标题
通过金属沉积前在氮气环境下退火，改善等离子蚀刻 n-Al0.5Ga0.5N 的欧姆接触
DOI：
10.1063/1.4794099
复制
发表时间：
2013-03-07
影响因子：
3.2
通讯作者：
Fang, Yanyan
中科院分区：
文献类型：
--
作者：
Zhang, Wei;Zhang, Jianbao;Fang, Yanyan
比较了Ti/Al和Ti/Al/Ni/Au在N-2 n-Al0.5Ga0.5N薄膜中生长、等离子体刻蚀和等离子体刻蚀+退火时的接触特性。经过快速热退火后，Ti/Al和Ti/Al/Ni/Au触点生长和在N-2 n-Al0.5Ga0.5N中等离子蚀刻+退火后都变成了真正的欧姆，而等离子蚀刻样品的触点仍然保持整流状态。表面原子浓度分析表明，等离子体处理产生的N空位更像深能级态而不是浅能级供体。然而，通过在N-2环境下对等离子体刻蚀的n-Al0.5Ga0.5N进行退火，可以有效去除这些深能级态，使费米能级向导带边缘升高，有利于欧姆触点的形成。(C) 2013年美国物理研究所。[http://dx.doi.org/10.1063/1.4794099]
The contact characteristics of Ti/Al and Ti/Al/Ni/Au contacts to as-grown, plasma etched and plasma etched + annealed in N-2 n-Al0.5Ga0.5N epilayers were compared. After a rapid thermal annealing, both Ti/Al and Ti/Al/Ni/Au contacts to as-grown and plasma etched + annealed in N-2 n-Al0.5Ga0.5N became truly Ohmic, whereas the contacts to plasma etched samples still remained rectifying. Surface atomic concentration analysis indicates the N vacancies resulting from plasma treatment act more as deep-level states rather than shallow donors. However, these deep-level states could be effectively removed by annealing the plasma etched n-Al0.5Ga0.5N under N-2 ambient, and as a result, the Fermi level was elevated toward conduction band edge, facilitating the formation of Ohmic contacts. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4794099]