Electron transport in ultrathin-body fully depleted n-MOSFETS fabricated on strained silicon directly on insulator with body thickness ranging from 22nm to 25 nm

Abstract

The electron effective mobility in ultrathin-body (UTB) n-MOSFETs fabricated on Ge-free 30% strained-Si directly on insulator (SSDOI) is mapped as the body thickness is scaled. Effective mobility and device body thickness were extracted using current-voltage and gate-to-channel capacitance-voltage measurements as well as cross section transmission electron microscopy. Devices with body thicknesses ranging from 2 nm to 25 nm are studied. Significant electron mobility enhancements ([approx] 1.8x) are observed in SSDOI compared to unstrained SOI for body thicknesses above 3.5 nm. The mobility exhibits a sharp drop as the body thickness is scaled below 3.5 nm.