Two-dimensional analytical models for the symmetrical triple-material double-gate strained Si MOSFETs

A novel double-gate strained Si metal-oxide-semiconductor field-effect transistor (MOSFET), in which the top and bottom gates consist of three laterally contacting materials with different work functions, is proposed in this paper. The two-dimensional (2D) analytical models for the surface potential, surface electric field and threshold voltage are presented. The effects of Ge fraction on surface potential, surface electric field and threshold voltage are investigated. The effects of the triple-material length ratio on threshold voltage and drain induced barrier lowering are discussed. The characteristics of the device are studied by comparing with those of the single-material double-gate MOSFETs. The results show that the structure can increase the carrier transport speed and suppress the drain induced barrier lowering effect. The three-material gate length ratio is optimized to minimize short-channel effect and drain induced barrier lowering effect.