High-quality Ge epilayers grown on a Si substrate in one step process via hot wire chemical vapor deposition

High-quality Ge epilayers on Si with a low threading-dislocation density (TDD) were grown by a one step hot wire chemical vapor deposition process at 350°C without cyclic thermal annealing. The Ge layers with threading dislocation density (TDD) of 1-105 cm-2 for a 1.4 μm thick Ge layer were obtained on Si wafers of a diameter O = 5 cm. Root mean square of roughness (RMS) of ~ 0.37 nm is achieved. The Ge layers produced are of high optical quality.