초록
Metastable pseudomorphic Ge0.06Si0.94 layers grown by molecular-beam-epitaxy on Si(100) were implanted at room temperature with 70 keV BF2+ ions to deses of 3${\times}$1013, 1${\times}$1014, and 2.5${\times}$1014cm-2. The samples were subsequently annealed in a vacuum furnace for 30 min periods at 700, 800, and 900$^{\circ}C$. crystalline degradation of the GeSi samples, observed by MeV 4He channeling spectrometry, is pronounced by increasing the dose even though the samples implanted to a low-dose of 3${\times}$1013cm-2 do not visibly degrade after annealing. For samples implanted to doses higher than 1${\times}$1014cm-2, strain conservation is not achieved after the thermal annealing observed by double crystal x-ray diffractometry, whereas the samples implanted to a low-dose of 3${\times}$1013cm-2 show strain conservation up to an anneal of 800$^{\circ}C$ for 30 min. We conclude that at the doping of 70keV BF2+ ions into metastable pseudomorphic Ge0.06Si0.94 layers the strain relaxation is enhanced by the implantation-induced damage, and that the strain conservation is only limited to a low-dose range of ∼1013cm-2.