Xu, ZongweiZongweiXuSong, YingYingSongRommel, MathiasMathiasRommelLiu, T.T.LiuKocher, MatthiasMatthiasKocherHe, Z.D.Z.D.HeWang, H.H.WangYao, B.T.B.T.YaoLiu, L.L.LiuFang, FengzhouFengzhouFang2022-03-142022-03-142019https://publica.fraunhofer.de/handle/publica/40498910.4028/www.scientific.net/MSF.963.424Raman spectroscopy and sheet resistance measurements were used to study the preparation processes of low-resistance p-type 4H-SiC by Al ion implantation with ion doses of 2.45×1012 - 9.0×1014 cm-2 and annealing treatment with temperatures of 1700 - 1900 °C. Greatly different from the LOPC (longitudinal optical phonon-plasmon coupled) Raman mode found from the sample of doping 4H-SiC during epitaxial growth, no significant influence on the surface concentration could be found for the longitudinal optical (LO) mode of Al-implanted 4H-SiC samples. When the Al surface concentration is larger than around 1018 cm-3, it was found that the intensity of the LO+ Raman peak (~ 980 - 1000 cm-1) increases and its full width at half maximum (FWHM) drops with the increase of surface concentration after annealing treatment. Moreover, for surface concentrations above 1018 cm-3, the LO+ Raman peak showed a left shift towards the LO peak, which could be related to the increase of free carrier concentration in the Al-implanted 4H-SiC samples. After higher annealing temperatures of 1800 °C and 1900 °C, the crystallinity of Al-implanted 4H-SiC was found to be improved compared to annealing at 1700 °C for surface concentrations larger than 1018 cm-3, which is consistent with the results of sheet resistance measurements.en4H-SiCion implantationraman spectroscopy670620530conference paper