Influence of radiation damage on krypton diffusion in silicon carbide

Abstract

Diffusion of krypton in poly and single crystalline silicon carbide is investigated and compared with the previously obtained results for xenon, which pointed to a different diffusion mechanism than observed for chemically active elements. For this purpose 360 keV krypton ions were implanted in commercial 6H-SiC and CVD-SiC wafers at room temperature, 350 °C and 600 °C. Width broadening of the implantation profiles and krypton retention during isochronal and isothermal annealing up to temperatures of 1400 °C was determined by RBS-analysis, whilst in the case of 6H-SiC damage profiles were simultaneously obtained by α-particle channelling. Little diffusion and no krypton loss was detected in the initially amorphized and eventually recrystallized surface layer of cold implanted 6H-SiC during annealing up to 1200 °C. Above that temperature thermal etching of the implanted surface became increasingly important. No diffusion or krypton loss is detected in the hot implanted 6H-SiC samples during annealing up to 1400 °C. Radiation damage dependent grain boundary diffusion is observed at 1300 C in CVD-SiC. The results seem to indicate, that the chemically inert noble gas atoms do not form defect-impurity complexes, which strongly influence the diffusion behaviour of other diffusors in silicon carbide.

Effect of Xe ion (167 MeV) irradiation on polycrystalline SiC implanted with Kr and Xe at room temperature

“…Kr implantation into SiC at room temperature amorphized the SiC up to a depth of 186 nm. This is in agreement with the published RBS combined with channelling result of Kr (360 KeV) implanted into 6H-SiC at room temperature [11]. SHI irradiation of the Kr implanted SiC caused a reduction of the amorphous layer thickness from 186 to 159 nm.…”

“…We have concentrated on aspects such as the diffusion of several fission products implanted in SiC, carbon, and the effects of vacuum annealing on radiation damage introduced by the relatively low energy implantation ions [2][3][4][5][6][7][8][9][10][11][12].…”

Migration behaviour of Europium implanted into single crystalline 6H-SiC

“…The lack of amorphization is due to the availability of thermal energy to the displaced atoms that increase the probability of recombination. Similar results have been reported for other implanted FPs surrogates at the same implantation temperature [8][9][10][11][12][13][14].…”