Microstructural study of He + -implanted and thermally annealed silicon-on-sapphire layers

The effect of He + ion implantation and subsequent annealing on the silicon-on-sapphire microstructure is studied by transmission electron microscopy and X-ray diffraction analysis. It is established that He + ion implantation leads to the formation of defects in the Si layer and α-Al 2 O 3 , while subsequent annealing causes dissociation of radiation defects in Si and formation of nanopores in α-Al 2 O 3 . The effect of implanted-ion dose and annealing temperature on the parameters of the porous α-Al 2 O 3 layer and structural quality of the Si layer is investigated.