Slow positron implantation spectroscopy was used to investigate point defects which were formed during the synthesis of buried SiGe alloy layers via high-dose Ge implantation and post-amorphization using Si+. It was noted that omitting the post-amorphization stage before annealing left a damaged layer which contained open-volume defects and extended beyond the Ge+-implanted over-layer. It was found that, provided the Ge dose was low enough to permit planar crystal re-growth, post-amorphization tended to inhibit defect formation. Samples which were implanted to higher doses contained unidentified defects.

S.A.E.Kuna, P.G.Coleman, A.Nejim, F.Cristiano, P.L.F.Hemment: Semiconductor Science and Technology, 1998, 13[4], 394-8