Ex-situ doping of epitaxially grown Ge on Si by ion-implantation and pulsed laser melting

The integration in Si technology of highly doped of Ge layers with a controlled amount of strain is crucial for nanoelectronic and photonic applications. N-type doping of Ge layers epitaxially grown on Si by P ion-implantation and pulsed laser melting is reported. In particular, samples with or without a post-growth annealing cycle in order to reduce the amount of threading dislocations (TDs) have been studied, in comparison with bulk Ge. Samples have been characterized by Secondary Ion Mass Spectrometry, Van der Paw-Hall and High-Resolution X-ray Diffraction. A very low out-diffusion, 1 × 1020 cm−3 carrier concentration with 100% P activation, as well as an increase of the tensile strain together with an improvement of the crystalline quality is reported, regardless of the as-grown TD density.