Micro-Raman imaging on 4H-SiC in contact with the electrode at room temperature

Raman images of a 4H-SiC wafer in contact with a Ni/Au electrode film 100-nm/200-nm thick have been measured by micro-Raman spectroscopy at room temperature. As the imaging area approached the interface between SiC and electrode, the center frequency of the E2(TO) mode showed an immediate downturn, and in Raman imaging showed relative distribution of compressive residual stress around residual tensile stress. For the LOPC mode, the center frequency varied immediately near the interface, while linewidth decreased slowly as the imaging area approached the interface.123