TY - JOUR
T1 - Insights into the effects of Al-ion implantation temperature on material properties of 4H-SiC
AU - Wu, Fanzhengshu
AU - Zhang, Jie
AU - Xi, Wei
AU - Chi, Yan Qing
AU - Liu, Qi Bin
AU - Yang, Lei
AU - Ma, Hong Ping
AU - Zhang, Qing Chun
N1 - Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2023/3/15
Y1 - 2023/3/15
N2 - In this study, Al implantation in 4H-SiC at the dose of 1 × 1014 cm−2 was investigated. The impacts of implantation temperature on the lattice quality, microstructure, surface composition, and band structure were all studied experimentally and theoretically. Atomic force microscope (AFM) images showed the difference in surface morphology between high-temperature and low-temperature implantation. Transmission electron microscopy (TEM) characterization indicated the lattice damage induced by implantation was recovered after the post-annealing at 1750 °C, except for the samples implanted at room temperature. X-ray photoelectron spectroscopy (XPS) analysis suggested an oxidation effect during and after the implantation process, and it was more serious at lower implantation temperatures. As the implantation temperature incremented, the ratio of Si-C composition with high binding energy increased, the element valence became closer to that of ideal Al-doped 4H-SiC calculated by density functional theory (DFT); and the Fermi level shifted toward the valence band maximum (VBM), demonstrating the formation of efficient p-type doping. A more obvious asymmetric broadening in Raman spectroscopy was observed at higher implantation temperature. The theoretically obtained band structures and bond lengths from DFT calculations corroborated the experimental results, providing physical insights into the possible effect mechanism. In sum, correlations between the implantation process, external material properties, and internal crystal structure were recorded, paving the way for further research and future applications.
AB - In this study, Al implantation in 4H-SiC at the dose of 1 × 1014 cm−2 was investigated. The impacts of implantation temperature on the lattice quality, microstructure, surface composition, and band structure were all studied experimentally and theoretically. Atomic force microscope (AFM) images showed the difference in surface morphology between high-temperature and low-temperature implantation. Transmission electron microscopy (TEM) characterization indicated the lattice damage induced by implantation was recovered after the post-annealing at 1750 °C, except for the samples implanted at room temperature. X-ray photoelectron spectroscopy (XPS) analysis suggested an oxidation effect during and after the implantation process, and it was more serious at lower implantation temperatures. As the implantation temperature incremented, the ratio of Si-C composition with high binding energy increased, the element valence became closer to that of ideal Al-doped 4H-SiC calculated by density functional theory (DFT); and the Fermi level shifted toward the valence band maximum (VBM), demonstrating the formation of efficient p-type doping. A more obvious asymmetric broadening in Raman spectroscopy was observed at higher implantation temperature. The theoretically obtained band structures and bond lengths from DFT calculations corroborated the experimental results, providing physical insights into the possible effect mechanism. In sum, correlations between the implantation process, external material properties, and internal crystal structure were recorded, paving the way for further research and future applications.
KW - DFT
KW - Energy band alignment
KW - Implantation temperature
KW - Raman
KW - Silicon carbide
KW - X-ray photoelectron spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=85144088825&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2022.156014
DO - 10.1016/j.apsusc.2022.156014
M3 - Article
AN - SCOPUS:85144088825
SN - 0169-4332
VL - 613
JO - Applied Surface Science
JF - Applied Surface Science
M1 - 156014
ER -