Analysis of a thin AlN interfacial layer in Ti/Al and Pd/Al ohmic contacts to n-type GaN
Analysis of a thin AlN interfacial layer in Ti/Al and Pd/Al ohmic contacts to n-type GaN
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DOI：
10.1063/1.120526
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发表时间：
1997-12
影响因子：
4
通讯作者：
B. P. Luther;J. Delucca;S. Mohney;R. Karlicek
中科院分区：
文献类型：
--
作者：
B. P. Luther;J. Delucca;S. Mohney;R. Karlicek
使用高分辨率透射电子显微镜，在Ti/Al（35/115 nm）和Pd/Al（25/125 nm）欧姆接触的金属/GaN界面处观察到薄的假晶AlN层（2-3 nm），所述金属/GaN欧姆接触与n型GaN在600 °C下分别退火15和30 s。界面层具有2.48±.03 A的c-平面（002）晶格间距和与GaN（2.76 A）匹配的a-平面（100）间距，并且将该层鉴定为AlN与通过能量色散X射线光谱的化学分析一致。该界面AlN层的形成与在600 °C退火的Ti/Al和Pd/Al接触中欧姆行为的开始一致，并且可能是原因。
Using high resolution transmission electron microscopy, a thin pseudomorphic AlN layer (2–3 nm) has been observed at the metal/GaN interfaces of Ti/Al (35/115 nm) and Pd/Al (25/125 nm) ohmic contacts to n-type GaN annealed in Ar at 600 °C for 15 and 30 s, respectively. The interfacial layer has a c-plane (002) lattice spacing of 2.48±.03 A and an a-plane (100) spacing matching that of GaN (2.76 A), and the identification of this layer as AlN is consistent with chemical analysis by energy dispersive x-ray spectroscopy. The formation of this interfacial AlN layer coincides with the onset of ohmic behavior in Ti/Al and Pd/Al contacts annealed at 600 °C and may be the cause.