Scanning electron microscopy of the surfaces of ion implanted SiC
Malherbe, Johan B.; Van der Berg, Nic (Nicolaas George); Kuhudzai, Remeredzai Joseph; Hlatshwayo, Thulani Thokozani; Thabethe, Thabsile Theodora; Odutemowo, Opeyemi Shakirah; Theron, C.C. (Chris); Friedland, Erich Karl Helmuth; Botha, A.J.; Wendler, E.
This paper gives a brief review of radiation damage caused by particle (ions and neutrons) bombardment
in SiC at different temperatures, and its annealing, with an expanded discussion on the effects occurring
on the surface. The surface effects were observed using SEM (scanning electron microscopy) with an inlens
detector and EBSD (electron backscatter diffraction). Two substrates were used, viz. single crystalline
6H-SiC wafers and polycrystalline SiC, where the majority of the crystallites were 3C-SiC. The surface
modification of the SiC samples by 360 keV ion bombardment was studied at temperatures below (i.e.
room temperature), just at (i.e. 350 C), or above (i.e. 600 C) the critical temperature for amorphization
of SiC. For bombardment at a temperature at about the critical temperature an extra step, viz. postbombardment
annealing, was needed to ascertain the microstructure of bombarded layer. Another aspect
investigated was the effect of annealing of samples with an ion bombardment-induced amorphous layer
on a 6H-SiC substrate. SEM could detect that this layer started to crystalize at 900 C. The resulting
topography exhibited a dependence on the ion species. EBSD showed that the crystallites forming in
the amorphized layer were 3C-SiC and not 6H-SiC as the substrate. The investigations also pointed out
the behaviour of the epitaxial regrowth of the amorphous layer from the 6H-SiC interface.