Study on annealing behavior of Xe-irradiated 6H-SiC

Abstract

This paper investigated the microstructure evolution of 6H-SiC irradiated by Xe²⁰⁺ ions at room temperature, combined with Raman spectroscopy and transmission electron microscopy (TEM). Specifically, Xe²⁰⁺ ions with an energy of 5 MeV were selected to irradiate 6H-SiC at a fluence of 5 × 10¹⁵ Xe²⁰⁺/cm² at room temperature, and then subsequently placed in a vacuum annealing treatment at temperatures of 900 °C, 1200 °C, and 1500 °C, respectively, with a heat preservation of 30 min. After irradiation, Raman characteristic peaks of 6H-SiC weaken or disappear, replaced by C-C peaks. TEM reveals Xe bubbles nucleate and grow along stacking faults. With the gradual increase of annealing temperature, lattice defects are absorbed by layer dislocations, causing bubble growth and coalescence. In this process, the modified power-law formula can more accurately fit the change of bubble size with annealing temperature, which is accurately fitted by a modified power-law formula. Dislocation loops show depth-dependent size and density, concentrated in the damage zone. Basal and prismatic dislocation loops formed during annealing correlate with damage depth, with mixed dislocations (Burgers vector: 1/6<2–201>) observed between {0001} basal and {11–20} prismatic planes. At 1500 °C, partial dislocation loop annihilation and stacking faults appear in heavily damaged regions.