Lattice defects distribution of H+ implanted 4H-SiC investigated by deep-ultraviolet Raman spectroscopy

Abstract

The defects distribution of ion-implanted SiC is a key to understanding changes in the electronic, optical, and mechanical properties of SiC devices. However, accessing the defect distribution within the sample primarily relies on simulation, yet a number of factors remain unaccounted for in the simulation results, ultimately resulting in numerous inaccuracies. To address this issue, a defect distribution investigation method based on the combination of argon ion etching and deep-ultraviolet (DUV) Raman spectroscopy has been established. The defects at different depths were exposed to the surface by etching, and the crystal quality of the surface layer was assessed using Raman spectra with a 266 nm DUV laser. The spectra for the H+ implanted 4H-SiC showed that the full width at half maximum of the transverse optical mode at 781 cm−1 and the longitudinal optical mode at 965 cm−1 exhibited an increasing and then decreasing trend, approximate to a Gaussian distribution. These results were confirmed with the transmission electron microscopy cross-sectional image and SRIM-2013 simulation. The establishment of this analytical investigation method can be widely applied to other semiconductor materials, without the need for electrodes and sample contamination.