【摘要】 在4H-SiC(0001)衬底上,使用CVD法生长不同掺杂浓度的外延层。将不同掺杂浓度的4H-SiC外延层,用拉曼散射光谱进行了研究。使用Matlab拟合了LOPC模的线型,并从理论上计算出载流子浓度,载流子浓度的理论计算值与SIMS测量的结果符合良好。随着掺杂浓度的变大,载流子浓度变大,LOPC峰发生蓝移,频移变大,散射强度变小,峰宽变宽。分析认为,LOPC峰发生蓝移主要和晶格振动有关,浓度越大,使得原子之间和晶胞之间的相互作用越强,致使出现蓝移现象。随着掺杂浓度的增大,声子增加,进而散射概率增加,散射概率降低了声子寿命,声子寿命和峰宽成反比,随着掺杂浓度增大,峰宽变宽。随着掺杂浓度的增大,散射强度越来越小。更多还原

【Abstract】 Using CVD grown epitaxial layers of different doping concentrations on the 4H-SiC. This article,using Raman scattering spectra,is to study 4H-SiC epitaxial layer of different doping concentrations. MATLAB was used fitting the LOPC mode linear and theoretically calculated the carrier concentration,the theoretical calculations results of the carrier concentration were in good agreement with SIMS measurement. As the doping concentration increases,the carrier concentration increases,the peak of LOPC blue shifts,frequency shift becomes large,the scattering intensity is small,the peak width is widened. Analysis shows that the peak of LOPC mode shift is related to the lattice vibrations,with greater concentration the interaction between the atom and the cell,resulting in a blue-shift phenomenon. As the doping concentration increases,the phonon increases,thereby increasing the probability of scattering,lifetime and phonon peak width is inversely proportional with the doping concentration,the peak width is widened. As the doping concentration increases,the scattering intensity reduces.更多还原