Low-temperature Ge and GeSn Chemical Vapor Deposition using Ge2H6

In this work, digermane (Ge2H6) is investigated as low temperature Ge precursor for Chemical Vapor Deposition. High quality Ge epitaxial growth on Si substrates is reported at temperatures as low as 275 °C and a specific Ge2H6 surface reaction is proposed to explain the growth mechanism at those very low temperatures. In addition, we highlight that Ge2H6 provides solutions, not covered by conventional GeH4, for various original Ge-based materials: direct deposition of amorphous Ge layers directly on dielectric or metallic surfaces, as well as the epitaxial growth of smooth, fully strained, monocrystalline GeSn layers on Ge substrates.