Strain-induced I-V characteristics modulation of p-n junctions and MOS capacitors in Si CMOS devices

In this paper, we review the recent progresses about the effect of the uniaxial tensile strain on the electrical properties of the Si p-n junctions and MOS capacitors. We found that the uniaxial tensile stress could increase the junction current in the large-forward-bias region significantly. However, only a slight current increase has been observed in the diffusion-current-dominant region. In nMOSFETs the uniaxial tensile strain could enhance Isub significantly, while decreasing Ig slightly. Furthermore, in pMOSFETs, the uniaxial tensile strain could enhance both Ig and Isub. All these results have been explained by taking the strain induced subband structure modulation, current components variation and the piezoresistance effect into consideration.