Band alignment of HfAlO/GaN (0 0 0 1) determined by X-ray photoelectron spectroscopy: Effect of in situ SiH4 passivation

The energy band alignment between HfAlO and GaN (0001) was characterized using high-resolution X-ray photoelectron spectroscopy (XPS). The HfAlO was deposited using a metal–organic chemical vapor deposition (MOCVD) gate cluster. A valence band offset of 0.38eV and a conduction band offset of 2.22eV...

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Bibliographic Details
Published in:Journal of alloys and compounds 2015-07, Vol.636, p.191-195
Main Authors: Liu, Xinke, Liu, Zhihong, Pannirselvam, Somasuntharam, Pan, Jishen, Liu, Wei, Jia, Fang, Lu, Youming, Liu, Chang, Yu, Wenjie, He, Jin, Tan, Leng Seow
Format: Article
Language:English
Subjects:
Band alignment
Gallium nitride
High-k
X-ray photoelectron spectroscopy
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Summary:The energy band alignment between HfAlO and GaN (0001) was characterized using high-resolution X-ray photoelectron spectroscopy (XPS). The HfAlO was deposited using a metal–organic chemical vapor deposition (MOCVD) gate cluster. A valence band offset of 0.38eV and a conduction band offset of 2.22eV were obtained across the HfAlO/GaN heterointerface without any passivation. With in situ SiH4 passivation (vacuum anneal+SiH4 treatment) on the GaN surface right before HfAlO deposition, the valence band offset and the conduction band offset across the HfAlO/GaN heterointerface were found to be 0.51eV and 2.09eV, respectively. The difference in the band alignment is believed to be dominated by the core level up-shift or chemical shift in the GaN substrate as a result of different interlayers (ILs) formed by the two surface preparations.
ISSN:0925-8388
1873-4669
DOI:10.1016/j.jallcom.2015.02.139