Study of the Impact of RDF on n-Type SOI Nanowire FET via Quantum-Corrected Monte Carlo Device Simulations

This article investigates the impact of random dopant fluctuation (RDF) on the current of a n-type nanowire silicon on insulator (SOI) triple-gate transistor. This study was performed employing a quantum-corrected Monte Carlo (MC) device simulator that was successfully assessed by comparing the simulation characteristics curves with experimental data. The results demonstrate that the impact of a single dopant atom on the transistor’s current depends on the dopant position along the channel length, fin height, and width. A random dopant in the channel affects the electrostatics, the electron density, and the electron mobility, thus degrading the transistor current. The study was performed for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {GS}} = {0.5}$ </tex-math></inline-formula> V, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {DS}} = {0.2}$ </tex-math></inline-formula> V, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {DS}} = {0.5}$ </tex-math></inline-formula> V, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {DS}} = {0.7}$ </tex-math></inline-formula> V. For <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {DS}} = {0.2}$ </tex-math></inline-formula> V, the maximum current variation was observed when the single dopant is placed in the middle of the channel length and the middle of fin height and width. For this case, the variation is 19.47% with respect to the nominal current. For <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {DS}} = {0.5}$ </tex-math></inline-formula> V and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {DS}} = {0.7}$ </tex-math></inline-formula> V, the maximum current variation was observed when the dopant is closer to the source region, and the current variation is, respectively, 20.60% and 21.48%.