Carrier Transport in (110) nMOSFETs: Subband Structures, Non-Parabolicity, Mobility Characteristics, and Uniaxial Stress Engineering

(110) surface orientation have attracted great interests, since pFETs on (110) substrates show much superior mobility to (100) pFETs (Sun, et. al., 2005 and Sato, et, al, 1969). In addition, (110) surface orientation is widely utilized in advanced FET structures such as FinFETs (Liow, 2005) and Tri-gate FETs (Kavalieros, 2005). Thus, there are growing interests in whether, how, and how far the electron mobility, mu_e, of (110) nFETs can be improved. A few reports have been made on carrier transports in (110) nFETs (Irie, et. al., 2004) its physical mechanisms and stress dependence have not been fully investigated nor understood yet. In this paper, mu_e of (110) nFETs is studied in terms of channel direction, Ns, and temperature dependences to clarify the carrier transport mechanisms in (110) nFETs. In addition, the impact of stress engineering is investigated in terms of mu_e enhancements to provide the guidance to boost (110) nFETs performance