Effects of annealing on the interfacial properties and energy-band alignment of AlN dielectric on 4H-SiC
Author(s): Shen, ZW (Shen, Zhanwei); Zhang, F (Zhang, Feng); Chen, J (Chen, Jun); Fu, Z (Fu, Zhao); Liu, XF (Liu, Xingfang); Yan, GG (Yan, Guoguo); Lv, BW (Lv, Bowen); Wang, YS (Wang, Yinshu); Wang, L (Wang, Lei); Zhao, WS (Zhao, Wanshun); Sun, GS (Sun, Guosheng); Zeng, YP (Zeng, Yiping)
Source: APPLIED PHYSICS LETTERS Volume: 117 Issue: 10 Article Number: 102105 DOI: 10.1063/5.0018330 Published: SEP 8 2020
Abstract: Interfacial properties and energy-band alignment of annealed AlN dielectric films on Si-face 4 degrees off-axis 4H-SiC substrates were characterized and demonstrated by x-ray photoelectron spectroscopy (XPS) and current-electric field (I-E) measurements. The XPS results reveal that the Al-O bonds and the silicon suboxides can convert into more stable Al-N bonds and Al-O-Si bonds at the AlN/4H-SiC interface under 1000 degrees C annealing. The variations in both oxygen-rich composition and the crystallinity in AlN make annealing-dependent conduction band offsets of as-deposited and annealed AlN/4H-SiC to be 1.36eV and 1.20eV, respectively. Meanwhile, I-E measurements separately yield the occurrence of the Fowler-Nordheim (FN) tunneling and space-charge-limited conduction in as-deposited and annealed metal-insulator-semiconductor capacitors, corresponding to lower barrier heights of 0.92eV and 0.54eV, respectively. The reason for the energy-band shift between I-E derivations and the XPS results was analyzed and demonstrated together. These results can provide considerable insight into the energy-band alignment of AlN as gate dielectric or passivation layers on 4H-SiC based devices.
Accession Number: WOS:000571939200002
Author Identifiers:
Author Web of Science ResearcherID ORCID Number
Zhang, Feng A-6644-2012 0000-0002-1163-2498
ISSN: 0003-6951
eISSN: 1077-3118
