Impact of non uniform strain configuration on transport properties for FD14+ devices

Abstract

As device dimensions are scaled down, the use of non-geometrical performance boosters becomes of special relevance. In this sense, strained channels are proposed for the 14 nm FDSOI node.However this option may introduce a new source of variability since strain distribution inside the channel is not uniform at such scales. In this work, a MS-EMC study of different strain configurations including non-uniformities is presented showing drain current degradation because of the increase of intervalley phonon scattering and the subsequent variations of transport effective mass and drift velocity. This effect, which has an intrinsic statistical origin, will make necessary further optimizations to keep the expected boosting capabilities of strained channels.

Impact of Strain on S/D tunneling in FinFETs: a MS-EMC study

“…The system is coupled by solving the Poisson equation in the whole 2D simulation domain. On the one side, arbitrary strain conditions can be considered locally in this code by tailoring the energy minima of each valley in order to reproduce uniaxial, biaxial, a combination of both, or non-uniform analytical strain mapping [8]. On the other side, the additional modules needed for taking into account the quantum effects are included as separated transport mechanisms without increasing the computational time, which is a noteworthy advantage of our code in comparison to purely quantum transport simulations.…”

“…The numerical tool is can include molar fraction dependent biaxial strain induced by SiGe substrates, uniaxial strain (tensile and compressive) induced by technological stressors and a combination of both. As anticipated before, in order to reproduce real strain distributions in state-of-the-art devices, arbitrary strain conditions can be locally considered tailoring the energy minima of each valley obtained from both experimental and TCAD strain mapping results [8].…”