Dependence of hole mobility on channel surface of ultrathin-body silicon-on-insulator pMOSFETs

We investigated the characteristics of ultrathin-body (UTB) silicon-on-insulator (SOI) p-type metal–oxide–semiconductor field-effect transistors pMOSFETs with channel thickness less than 10 nm regime. At the same time, the dependence of electrical characteristics on the silicon surface orientations with (100) or (110) were also investigated. As a result, it is found that the electrical characteristics of (100)-surface UTB-SOI pMOSFETs were superior to those of (110)-surface. Moreover, the SOI thickness from 3 to 5 nm, the increase of effective hole mobility at the effective field of 0.3 MV/cm was observed for both (100) and (110) surfaces. The mobility enhancement ratio of (110) surface was larger than that of (100) surface.