Ion irradiation induced blister formation and exfoliation in 3C-SiC

Abstract

AbstractInvestigation of surface blistering and exfoliation in silicon carbide (SiC) by H+ ion irradiation can be utilized for the smart cut or ion cut process, which will overcome the major challenges impeding the technological development of SiC. Blister formation and exfoliation in cubic 3CSiC were studied by carrying out 50 keV H+ ion irradiations. Both formation and exfoliation of blisters were observed in post-annealed (at 600 °C and 800 °C) samples (ion fluence: 7 × 1016 ions/cm2), where the disorder level is 0.95, which is close to the amorphization dose. The samples were characterized using optical microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), and Raman scattering techniques. AFM measurements indicate that blisters exfoliate at a depth of around 289 nm, where H ions result in maximum damage. Raman scattering results reveal the presence of vacancy-hydrogenated complex in the post-annealed samples. Raman mapping around blisters suggests that there is more internal stress around the periphery of blisters than at its centre. Internal pressure and stress inside the blisters are estimated using Föppl-von Karman’s (FvK) theory of thin plates. The internal pressure decreases with the diameter of the blisters. FvK theory of thin plates has enabled the determination of a threshold stress of 0.06 GPa, describing the change from a tensile to a compressive stress state in the buckles, which leads to the exfoliation of blisters.