Phosphorus Dopant Distribution in Highly N-Doped Ge Film on Si(001) Substrate Using Specific GaP Solid Source

摘要

Germanium (Ge) is a pseudo indirect band gap material due to a tiny difference (~140 meV) between the direct and indirect band gap. However, Ge could have greatly enhanced photoluminescence at room temperature by inducing a tensile strain and a heavy n-doping level. In this study, Ge growth on Si(100) wafer using molecular beam epitaxial (MBE) method and a high n-doping level in Ge was achieved owning to using GaP decomposition source. Phosphorus dopant distribution in Ge film is investigated by Atomic Probe Tomographic (APT) reconstruction. The dependence of optical property on Ge film thickness is also studied. An activated phosphorus concentration can be obtained up to more than 2 × 1019 atoms?cm?3confirmed by Hall effect measurement. This result opens a new perspective of realization of semiconductor optoelectronic devices based on silicon technology.