Atomically controlled CVD processing of group IV semiconductors for strain engineering and doping in ultralarge scale integration

By atomic layer growth of C, Ge and B on Si (100) surface and subsequent Si cap layer growth, heavy atomic-layer doping is achieved at temperatures below 500°C. Sub-atomic layer of C, Ge or B is confined within an about 1 nm-thick region. It is confirmed that the incorporation of C atoms at substitutional site in Si is influenced by substrate surface strain and is larger than that of in-situ doping. Atomic layer doping of Ge is enhanced by the tensile strain in the substrate, comparing with those of C and B. In the nm-thick region of atomic layer doping, strain generation is not observed. It is also confirmed that growth characteristics as well as electrical activity of impurity in the strained layer are influenced by the substrate surface strain before the layer growth. These results demonstrate the capability of atomically controlled CVD technology of group IV semiconductors for strain engineering and doping in ultralarge scale integration.