Investigations on ion irradiation induced strain and structural modifications in 3C–SiC

• Published in: Materials science in semiconductor processing 2024-04, Vol.173, p.108170, Article 108170
• Main Authors: Sreelakshmi, N., Gupta, Pooja, Gupta, Mukul, Reddy, V.R., Rai, S.K., David, C., Amirthapandian, S.
• Format: Article
• Language: English
• Subjects: Diffuse reflectance; High-resolution XRD; Ion irradiation; Ionization induced defect recovery; Reciprocal space mapping; X-ray absorption spectroscopy
• ISSN: 1369-8001; 1873-4081
• DOI: 10.1016/j.mssp.2024.108170

Ion irradiation induced recovery of defects in 3C–SiC caused by electronic energy loss (Se) in the intermediate energy regime (a few 100s of keV to a few 10s of MeV) is less explored. Towards this, separate and sequential ion irradiation of 200 keV Si+ ions and 14 MeV Si+ ions in 3C–SiC were carried out. In our earlier work, RBS/C findings demonstrated that 14 MeV Si+ ion irradiation (Se- 4.9 keV/nm) resulted in defect recovery in 3C–SiC pre-damaged with 200 keV Si+ ions [1]. The present work investigates the strain and structural evolution using High-resolution X-ray diffraction (HRXRD), Reciprocal space mapping (RSM), X-ray absorption near edge spectroscopy (XANES) and Diffuse reflectance spectroscopy (DRS), in the 3C–SiC layer as a result of ion irradiation induced defect production and recovery. HRXRD results revealed that 200 keV Si+ ion results in 4 % of strain at the projected range of ions and strain relaxation as a result of ionization-induced annealing is observed after subsequent 14 MeV Si+ ion irradiation. RSM measurements showed evidence for the formation of extended defects in sequentially ion irradiated samples. Optical characterization using DRS measurements indicates a reduction of refractive index in the ion-irradiated layer, however, for the amorphous SiC layer (ion dose: 0.6 dpa, 200 keV Si+ ion), the refractive index increased due to a reduction in mass density. Modification of refractive index in the ion irradiated layer is a result of the combination of negative change in volume effect and positive change in electronic polarizability. [Display omitted]