TY - JOUR
T1 - Effects of BF+2 implantation on the strain-relaxation of pseudomorphic metastable Ge0.06Si0.94 alloy layers
AU - Oh, M. S.
AU - Joo, M. H.
AU - Im, S.
AU - Kim, H. B.
AU - Kim, H. K.
AU - Song, J. H.
PY - 1999/1/1
Y1 - 1999/1/1
N2 - Metastable pseudomorphic Ge0.06Si0.94 alloy layers grown by molecular beam epitaxy (MBE) on Si (100) substrates were implanted at room temperature by 70 keV BF2+ ions with three different doses of 3×1013, 1×1014, and 2.5×1014 cm-2. The implanted samples were subsequently annealed at 800 °C and 900 °C for 30 min in a vacuum tube furnace. Observed by MeV 4He channeling spectrometry, the sample implanted at a dose of 2.5×1014 BF2+ cm-2 is amorphized from surface to a depth of about 90 nm among all as-implanted samples. Crystalline degradation and strain-relaxation of post-annealed Ge0.06Si0.94 samples become pronounced as the dose increases. Only the samples implanted at 3×1013 cm-2 do not visibly degrade nor relax during anneal at 800 °C. In the leakage current measurements, no serious leakage is found in most of the samples except for one which is annealed at 8000 °C for 30 min after implantation to a dose of 2.5×1014 cm-2. It is concluded that such a low dose of 3×1013 BF2+ cm-2 can be doped by implantation to conserve intrinsic strain of the pseudomorphic GeSi, while for high dose regime to meet the strain-relaxation, annealing at high temperatures over 900 °C is necessary to prevent serious leakages from occuring near relaxed GeSi/Si interfaces.
AB - Metastable pseudomorphic Ge0.06Si0.94 alloy layers grown by molecular beam epitaxy (MBE) on Si (100) substrates were implanted at room temperature by 70 keV BF2+ ions with three different doses of 3×1013, 1×1014, and 2.5×1014 cm-2. The implanted samples were subsequently annealed at 800 °C and 900 °C for 30 min in a vacuum tube furnace. Observed by MeV 4He channeling spectrometry, the sample implanted at a dose of 2.5×1014 BF2+ cm-2 is amorphized from surface to a depth of about 90 nm among all as-implanted samples. Crystalline degradation and strain-relaxation of post-annealed Ge0.06Si0.94 samples become pronounced as the dose increases. Only the samples implanted at 3×1013 cm-2 do not visibly degrade nor relax during anneal at 800 °C. In the leakage current measurements, no serious leakage is found in most of the samples except for one which is annealed at 8000 °C for 30 min after implantation to a dose of 2.5×1014 cm-2. It is concluded that such a low dose of 3×1013 BF2+ cm-2 can be doped by implantation to conserve intrinsic strain of the pseudomorphic GeSi, while for high dose regime to meet the strain-relaxation, annealing at high temperatures over 900 °C is necessary to prevent serious leakages from occuring near relaxed GeSi/Si interfaces.
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U2 - 10.1016/S0168-583X(98)90559-6
DO - 10.1016/S0168-583X(98)90559-6
M3 - Article
AN - SCOPUS:0032756665
VL - 147
SP - 49
EP - 55
JO - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
JF - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
SN - 0168-583X
IS - 1-4
ER -