Effects of uniaxial mechanical stress on drive current of 0.13 /spl mu/m MOSFETs

We study the effects of both external mechanical stress and intrinsic stress due to trench isolation on drive currents of 0.13 /spl mu/m-node MOSFETs. The drive current, I/sub dsat/, of PMOS is enhanced by about 13% while that of NMOS is reduced by about 9% upon applying a uniaxial compressive stress along the channel of L/sub physical/=85 nm. The shifts in linear drive current, I/sub dlin/, are larger. By applying the external stress, we have simultaneously reproduced, for both PMOS and NMOS, the I/sub dsat/ and I/sub dlin/ shifts due to different gate-trench-isolation distances. We find that the shifts by the applied stress, /spl Delta/I/sub dsat//I/sub dsat0/ and /spl Delta/I/sub dlin//I/sub dlin0/, decrease with decreasing gate length. The change in total resistance, /spl Delta/(V/sub ds//I/sub dlin/), is a linear function of gate length. Because of the mobility dependence on external stress, we have also been able to extract source-drain series resistance, R/sub sd/, by simply bending the wafer.