Abstract
The tensile strained Si, based on the lattice misfit between Si and SiGe, gives higher speed and higher drive current for the metal oxide silicon field effect transistors. Based on the strained Si technology, a tri-gate CMOS transistor is further applied in the current leakage control and chip performance enhancement. Moreover, the "highly-tensile" silicon nitride capping layer is also applied for the strained Si applications. The stress from the silicon nitride capping layer is uniaxially transferred to the NMOS channel through the source-drain region to create tensile strain in NMOS channel. This paper proposes a finite element method analysis to study the strain distribution of small island size (<200nm) of Si/SiGe strained silicon based tri-gate CMOS transistor and the "highly-tensile" SiN <sub>x</sub> /Si stacking devices. In the trigate CMOS transistor case, the simulation results show that the bending effect from the edge can significantly affect the strain on the surface of the Si channel layer, and a compressive strain or reduced tensile strain occurs at the edge of the Si channel layer. Moreover, the results also indicate that the length of the Si/SiGe channel and the thickness of the Si/SiGe stack layers show significant effects of the strain distribution on the surface of the Si channel layer. In terms of the "highly-tensile" SiN <sub>x</sub> /Si analysis, the results show that the "highly-tensile" silicon nitride could provide beneficial tensile strain for the channel of the NMOS transistor to enhance the device speed.