High-quality Ge epilayers on Si substrates with low threading-dislocation densities were prepared by using a 2-step ultra-high vacuum/chemical vapour deposition process, followed by cyclic thermal annealing. In the case of large wafers, Ge on Si with a threading-dislocation density of 2.3 x 107/cm2 was obtained. The combination of selective-area growth, with cyclic thermal annealing, produced an average threading-dislocation density of 2.3 x 106/cm2. Small mesas of Ge on Si with no threading dislocations could also be obtained.

High-Quality Ge Epilayers on Si with Low Threading-Dislocation Densities H.C.Luan, D.R.Lim, K.K.Lee, K.M.Chen, J.G.Sandland, K.Wada, L.C.Kimerling: Applied Physics Letters, 1999, 75[19], 2909-11