The <100> wafers of p-type Si were implanted with Ge (150keV, 3.6 x 1016, 6.7 x 1016, or 9.0 x 1016/cm2), and were studied using Rutherford back-scattering spectrometry and channelling techniques. It was found that, after moderate or high doses and before annealing, more than 90% of the Ge atoms were in interstitial sites. After annealing (1000C), more than 50% of the Ge atoms were in substitutional sites. In low-dose samples, less than 70% of the Ge atoms were in interstitial sites before annealing and about 80% of them became substitutional after annealing at 1000C. The electron spin resonance spectra of these samples were Lorentzian in shape, with a g-value of about 2.007 and a spin density of about 6 x 1016/cm3. The electron spin resonance signals of these samples were suggested to be due mainly to Si dangling-bonds in a GeSi alloy layer. They could be eliminated by annealing at 1000C for 120s. Spreading resistance profiling of the GeSi layer showed that the implantation damage extended deep into the substrate before annealing. After annealing at 1000C, these defects were removed but the spreading resistance of the surface GeSi layer remained higher than that of the substrate.

W.Y.Cheung, S.P.Wong, I.H.Wilson, T.H.Zhang: Nuclear Instruments and Methods in Physics Research B, 1995, 101[3], 243-6