1Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 2University of Chinese Academy of Sciences, Beijing 100049 3School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000
Abstract：Radiation-induced defect annealing in He$^{+}$ ion-implanted 4H-SiC via H$^{+}$ ion irradiation is investigated by Raman spectroscopy. There are 4H-SiC wafers irradiated with 230 keV He$^{+}$ ions with fluences ranging from $5.0\times10^{15}$ cm$^{-2}$ to $2.0\times10^{16}$ cm$^{-2}$ at room temperature. The post-implantation samples are irradiated by 260 keV H$^{+}$ ions at a fluence of $5.0\times10^{15}$ cm$^{-2}$ at room temperature. The intensities of Raman lines decrease after He implantation, while they increase after H irradiation. The experimental results present that the magnitude of Raman line increment is related to the concentration of pre-existing defects formed by He implantation. A strong new peak located near 966 cm$^{-1}$, which is assigned to 3C-SiC LO (${\it \Gamma}$) phonon, is found in the He-implanted sample with a fluence of $5.0\times10^{15}$ cm$^{-2}$ followed by H irradiation. However, for the He-implanted sample with a fluence of $2.0\times10^{16}$ cm$^{-2}$ followed by H irradiation, no 3C-SiC phonon vibrations are found. The detailed reason for H irradiation-induced phase transformation in the He-implanted 4H-SiC is discussed.
Fu S N, Chen H S, Chi Y L, Fang S X, Ma L, Pan W M, Tang J Y, Zhang C, He Y and Zhao H W 2011 15th International Conference on RF Superconductivity (Chicago, USA 25–29 July 2011) p 977
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2017, Vol. 34 
