Penetration depth profiling of proton-irradiated 4H-SiC at 6 MeV and 8 MeV by micro-Raman spectroscopy

4H-SiC samples irradiated with high energy protons were probed by low temperature photoluminescence (PL) and room temperature micro-Raman scattering spectroscopies. The quench of the near band-edge emission and the presence of a number of new sharp lines in the luminescence spectra of the proton-irradiated samples confirm the formation of various new defects. The changes of the line-shape and peak position of the longitudinal optical phonon-plasmon coupled (LOPC) mode in 4H-SiC are consistent with the decrease in the free carrier concentrations due to the introduction of carrier traps induced by the high energy proton irradiation. The estimated penetration depths for 6 and 8 MeV energy proton were 180 μm and 300 μm, respectively, which are in good agreement with the Monte Carlo numerical simulation results. At the 180 μm and 300 μm depths, the carrier concentrations were reduced by approximately 34% and 21%, respectively.