A comparative study of atomic layer deposition of Al2O3 and HfO2 on AlGaN/GaN

作者：Qin Xiaoye; Cheng Lanxia; McDonnell Stephen; Azcatl Angelica; Zhu Hui; Kim Jiyoung; Wallace Robert M^*

来源：Journal of Materials Science: Materials in Electronics , 2015, 26(7): 4638-4643.

DOI：10.1007/s10854-015-2926-2

The atomic layer depositions of Al2O3 and HfO2 on AlGaN/GaN were systematically studied. The band alignments of Al2O3/AlGaN and HfO2/AlGaN were investigated using in situ X-ray photoelectron spectroscopy. A conduction band offset of 1.8 and 1.1 eV were observed for Al2O3/AlGaN and HfO2/AlGaN, respectively. The Al2O3 and HfO2 dielectric layers were found to reduce the leakage current as expected with respect to metal/AlGaN/GaN Schottky diodes, but neither changes the surface states of AlGaN. The positive ionized surface donor states density and average interface state density (D-it) below the AlGaN conduction band edge (0.34 < E-C - E-T < 0.50 eV), extracted from capacitance voltage (C-V) curves, were similar to 5 x 10(13) cm(-2) and 1.1 x 10(14) cm(-2) eV(-1), respectively.

• 出版日期2015-7