Molecular beam epitaxy of highly antimony doped germanium on silicon

We investigated the antimony incorporation in germanium at high concentration regime above the maximum equilibrium solid solubility of 1.2×1019 cm−3. As growth method molecular beam epitaxy at temperatures between 160 and 330 °C was used. Electrical active Sb incorporation up to 2×1020 cm−3 was obtained. At higher chemical Sb concentrations up to 6×1020 cm−3 only a fraction of the dopants is electrically active at room temperatures.