Design for scaled thin film strained-SOI CMOS devices with higher carrier mobility

Physical mechanisms responsible for the reduction in both electron and hole mobility in thin strained-Si structures of strained-SOI CMOS devices are examined in detail. The slight decrease in electron mobility with thinning strained-Si layers is attributable to the quantum-mechanical confinement effect in strained-Si layers. Also, diffusion of Ge atoms into SiO₂/strained Si interface is found to cause the generation of interface states near valence band edge, leading to the reduction in hole mobility in lower E_eff region through Coulomb scattering. Based on considerations of these factors affecting mobility, the strained-Si thickness and the Ge content are designed to realize high-speed strained-SOI CMOS under the 65 nm technology and beyond.