Swift heavy ion irradiation of polycrystalline SiC pre-implanted with silver ions at room temperature: Effects of swift heavy ion fluence

Abstract

This study investigates the effects of SHIs irradiation fluence on the recrystallization and structural evolution of amorphous SiC layer induced by ion implantation. Polycrystalline SiC wafers were implanted with 360 keV Ag ions to a fluence of 2 × 10¹⁶ cm⁻² at room temperature. Some of the pre-implanted samples were then irradiated at room temperature with 167 MeV Xe ions to fluences of 1 × 10¹³ cm⁻², 1 × 10¹⁴ cm⁻², 3.4 × 10¹⁴ cm⁻² and 8.4 × 10¹⁴ cm⁻². The samples were then characterized using Transmission Electron Microscopy (TEM), Raman Spectroscopy, and Rutherford Backscattering Spectrometry (RBS). Ag implantation resulted in the amorphization of SiC from the surface to a depth of 270 nm. SHIs irradiation at a fluence of 1 × 10¹³ cm⁻² reduced the amorphous layer thickness to 230 nm, which represents a 15 % reduction. This was accompanied with a partial recrystallization in the amorphous layer. A similar reduction of approximately 15 % was observed at fluences of 1 × 10¹⁴ cm⁻² and 3.4 × 10¹⁴ cm⁻². While, irradiation at 8.4 × 10¹⁴ cm⁻² reduced the amorphous layer to 220 nm, which represents a 19 % reduction. The results showed that the degree of crystallization within the amorphous layer gradually increased with irradiation fluences of SHIs, indicating that recrystallization is fluence-dependent. No migration of pre-implanted Ag was observed after SHIs irradiation.