Effects of Quantum Confinement on Electrical Characteristics of 12-nm Silicon-on-lnsulator Fin Field-Effect Transistors by Quantum Transport Analysis

摘要

Quantum confinement in nanoscale silicon-on-insulator (SOI) fin field-effect transistors (FinFETs) is significant and will affect their electrical characteristics. In this paper, we investigate this phenomenon by an in-house quantum transport simulator, Schrodinger equation Monte Carlo in three dimensions (SEMC-3D), which can provide the quantum transport simulation of nanoscale 3D metal-oxide-semiconductor field-effect transistor (MOSFET) geometries such as FinFETs as well as take various scattering processes into account. Our simulation results indicate that the degradation of the drain current and transconductance due to scattering is still significant even at 12 nm gate length. Under the ballistic limit, the drain currents per unit periphery of different fin height are almost the same. However, when scattering is considered, reducing the fin height, i.e., increasing the quantum confinement, will degrade the drain current per unit periphery because of increasing the scattering rate around the barrier top of the channel. The square fin cross section should be avoided since the degenerate subbands will increase the scattering rate and degrade the drain current per unit periphery.