Atomically controlled plasma processing for epitaxial growth of group IV semiconductors

By utilizing an electron-cyclotron-resonance plasma enhanced chemical vapor deposition (CVD) for low-temperature epitaxial growth of group IV semiconductors, atomically controlled plasma processing has been developed to achieve atomic-layer doping and heterostructure formation with nanometer-order thickness control as well as smooth and abrupt interfaces. In this paper, recent typical achievements in the plasma processing are reviewed: (1) By N and B atomic-layer formation and Si epitaxial growth on Si(100), heavy atomic-layer doping was demonstrated. Most of the incorporated N or B atoms can be confined in an about 2 nm-thick region. (2) Using a 84% relaxed Ge buffer layer formed on Si(100) by the plasma CVD, formation of a B-doped highly strained Si film with nanometer-order thickness with typical hole mobility enhancement as high as about 3 was achieved.