Atomic-scale revealing defects in ion irradiated 4H-SiC

Abstract

Here we identified atomic-scale defects in ion irradiated 4H-SiC, by integrated differential phase contrast technique equipped on aberration-corrected transmission electron microscopy and Raman scattering spectrometer. In 21 MeV Ni+ ions irradiated 4H-SiC, in which electronic energy loss is dominant almost at the whole penetration depth, Si- and C-related vacancies and interstitials are successfully imaged. In 900 keV Si+ ions irradiated 4H-SiC, however, the electronic energy loss plays the key role near the surface, and the nuclear and electronic energy loss are comparable at the depth of the peak damaged zone. As a result, 900 keV Si+ ions produce more point defects, atomic-scale in-plane and out-of-plane lattice distortions, and plenty of dislocations at the depth of damage peak. Meantime, these imaged point defects may provide direct detailed information for the vibration modes of defects in the Raman spectrum of the damaged 4H-SiC. This study illustrates the compelling intrinsic nature of point defects induced by energetic ions, providing important fundamental information for nuclear and electronic applications.