Thin body silicon-on-insulator N-MOSFET with silicon-carbon source/drain regions for performance enhancement

Abstract

We report a novel strained n-channel transistor structure featuring silicon-carbon (SiC) source and drain (S/D) regions formed on thin body SOI substrate. The SiC material is pseudomorphically grown by selective epitaxy and the carbon mole fraction incorporated is 1%. Lattice mismatch between SiC and Si results in uniaxial tensile strain in the Si channel region which contributes favorably to electron mobility enhancement. Drive current IDsat enhancement of 25% was observed for 90 nm gate length LG transistors, and IDsat enhancement of up to 35% was observed at LG of 70 nm. In addition, drive current enhancement shows dependence on device width and channel orientation. All transistors were formed on (001) SOI substrates. The largest IDsat enhancement is observed for transistors with the [010] channel orientation. © 2005 IEEE.