Growth and characterization of germanium epitaxial film on silicon (001) with germane precursor in metal organic chemical vapour deposition (MOCVD) chamber

The quality of germanium (Ge) epitaxial film grown directly on a silicon (Si) (001) substrate with 6° off-cut using conventional germane precursor in a metal organic chemical vapour deposition (MOCVD) system is studied. The growth sequence consists of several steps at low temperature (LT) at 400 °C, intermediate temperature ramp (LT-HT) of ∼10 °C/min and high temperature (HT) at 600 °C. This is followed by post-growth annealing in hydrogen at temperature ranging from 650 to 825 °C. The Ge epitaxial film of thickness ∼ 1 μm experiences thermally induced tensile strain of 0.11 % with a treading dislocation density (TDD) of ∼107/cm2 and the root-mean-square (RMS) roughness of ∼ 0.75 nm. The benefit of growing Ge epitaxial film using MOCVD is that the subsequent III-V materials can be grown in-situ without the need of breaking the vacuum hence it is manufacturing worthy.