High Mg effective incorporation in Al-rich AlxGa1 - xN by periodic repetition of ultimate V/III ratio conditions.
According to first-principles calculations, the solubility of Mg as a substitute for Ga or Al in AlxGa1 - xN bulk is limited by large, positive formation enthalpies. In contrast to the bulk case, the formation enthalpies become negative on AlxGa1 - xN surface. In addition, the N-rich growth atmosphere can also be favorable to Mg incorporation on the surface by changing the chemical potentials. On the basis of these special features, we proposed a modified surface engineering technique that applies periodical interruptions under an ultimate V/III ratio condition (extremely N-rich), to enhance Mg effective incorporation. By optimizing the interruption conditions (2 nm interruption interval with 2 s interruption time), the enhancement ratio can be up to about 5 in the Al0.99Ga0.01N epilayer.
Tongchang
T
Zheng
Department of Physics, Fujian Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen 361005, People's Republic of China. linwei@xmu.edu.cn.
Wei
W
Lin
Duanjun
D
Cai
Weihuang
W
Yang
Wei
W
Jiang
Hangyang
H
Chen
Jinchai
J
Li
Shuping
S
Li
Junyong
J
Kang