Generation and recovery of strain in 28Si-implanted pseudomorphic GeSi films on Si(100)

Effects of ion implantation of 320 keV “Si at room temperature in pseudomorphic metastable Ge$i,-, (x-0.04, 0.09, 0.13) layers 170 nm thick grown on Si( 100) wafers were characterized by x-ray double-crystal diffractometry and MeV 4He channeling spectrometry. The damage induced by implantation produces additional compressive strain in the Ge$i, _ x layers, superimposed on the intrinsic compressive strain of the heterostructures. This strain rises with the dose proportionally for doses below several times lOI 28Si/cm2. Furthermore, for a given dose, the strain increases with the Ge content in the layer. Upon thermal processing, the damage anneals out and the strain recovers to the value before implantation. Amorphized samples (doses of greater than 2 x lOI 28Si/cm2) regrow poorly.