Band alignment of HfAlO/GaN (0001) determined by X-ray photoelectron spectroscopy: Effect of in situ SiH4 passivation

JOURNAL OF ALLOYS AND COMPOUNDS

卷:636

Article

Liu, Xinke¹  Liu, Zhihong²  Pannirselvam, Somasuntharam²  Pan, Jishen³  Liu, Wei⁴  Jia, Fang¹  Lu, Youming¹  Liu, Chang⁵  Yu, Wenjie⁵  He, Jin^6,7  Tan, Leng Seow² 

[1] Shenzhen Univ, Coll Mat Sci & Engn, Shenzhen Key Lab Special Funct Mat, Shenzhen 518060, Peoples R China

[2] Natl Univ Singapore, Dept Elect & Comp Engn, Singapore 117576, Singapore

[3] Agcy Sci Technol & Res, Inst Mat Res & Engn, Singapore 117602, Singapore

[4] Nanyang Technol Univ, Luminous Ctr Excellence Semicond Lighting & Displ, Singapore 639785, Singapore

[5] Chinese Acad Sci, Shanghai Inst Microsyst & Informat Technol, State Key Lab Funct Mat Informat, Shanghai, Peoples R China

[6] Peking Univ, PKU Shenzhen Inst, Shenzhen SOC Key Lab, Shenzhen 518057, Peoples R China

[7] PKU, HKUST, Shenzhen Hongkong Inst, Shenzhen 518057, Peoples R China

关键词: Gallium nitride;    High-k;    Band alignment;    X-ray photoelectron spectroscopy;   

DOI  :  10.1016/j.jallcom.2015.02.139

来源: Elsevier

【 摘 要 】

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 0.38 eV and a conduction band offset of 2.22 eV 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 0.51 eV and 2.09 eV, 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. (C) 2015 Elsevier B.V. All rights reserved.

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