Impact of cross-section of 10.4 nm gate length Ino.53Gao.47As FinFETs on metal grain variability

Abstract

The sub-threshold region variability due to TiN metal grain work-function induced fluctuations in a 10.4 nm gate length In <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.53</inf> Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.47</inf> As FinFET is analysed for three different cross-section shapes (rectangular, triangular and bullet-like), using an in-house 3D Finite-Element Density-Gradient Quantum-Corrected Drift-Diffusion device simulation tool. The I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</inf> -V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</inf> characteristics in the sub-threshold region have been compared for the three cross-section shapes. The device with more triangular cross-section results in lower off-current, drain-induced-barrier-lowering (DIBL) and sub-threshold slope values. However, the cross-section shape has a very small influence on a metal grain work-function induced variability in the threshold voltage with differences of only 4% between the different device shapes. We also present a new approach, based on the creation of Gate Sensitivity Region Maps, to evaluate the sensitivity of the different regions of a semiconductor device to the metal grain work-function induced variability.