A Novel Layer-By-Layer Hetero-Epitaxy Of Germanium On Silicon (100) Surface

Layer-by-layer hetero-epitaxy of Ge has been successfully demonstrated on the Si(100) surface by combining the initial IML-Ge film growth on the Si surface and the successive Ge atomic-layer-epitxy (ALE), for the first time. The former was achieved using the substrate temperature modulation with alternate exposures of GeCL4 and atomic H, and the later was established by cyclic exposures of (CH 3)2GeH2 and atomic H under isothermal conditions. XPS measurements confirmed a discrete and uniform increase in the grown Ge film thickness with one monolayer/cycle step up to the critical Ge thickness, and no C contamination at the Ge/Si interface. Critical exposure for the saturated Ge adsorption was different from that for the homo-ALE on the bulk Ge surface.