High energy high dose Si implantation into Ge and the effect of subsequentthermal annealing

A mirror polished (lll)-oriented Ge single crystal substrate was implanted with 1.0 MeV Si+ ions to a dose of similar to 8.5 x 10(17) cm(-2) at room t emperature. Rutherford backscattering spectrometry (RES) together with ion channeling analysis with H+ and He+ beams have been used to study the Si di stribution and radiation damage after implantation and subsequent vacuum an nealing in the temperature range of 500-850 degrees C. A non-RES (resonance ) measurement with an H+ beam of specified energy is used to study the Si a toms distribution in Ge. The experiments reveal the existence of an extensi ve damage (possibly an amorphous layer) buried at a depth corresponding to the peak Si concentration. Annealing up to 850 degrees C for 30 min does no t result in the complete recovery of the lattice order. The annealing tempe rature dependence of the damage depth distributions in Ge has been evaluate d using the multiple scattering model of Feldman and Rodgers. The compositi on of the alloy layer was measured by RES followed by computer-simulated sp ectrum analyses. A tentative explanation of the results is presented.