Strain engineering 4H-SiC with ion beams

Abstract

Single crystals of 4H-SiC irradiated with 900 keV Si and 21 MeV Ni ions separately and sequentially were studied by Rutherford backscattering spectrometry in channeling geometry, single crystal X-ray diffraction, and Raman scattering. SiC irradiated with 900 keV Si ions to a fluence of 6.3 × 1014 ions/cm2 experiences 7.3% strain over the depth of 650 nm. Strain relaxation from ionization-induced annealing was directly observed due to subsequent irradiation with 21 MeV Ni ions to a fluence of 2 × 1014 ions/cm2. These competitive processes suggest the use of ion irradiation to create a specific strain state in 4H-SiC, particularly in films.