Electron Substrate and Gate Current Modeling for Single-Drain Buried-Channel p-Type Metal–Oxide–Semiconductor Field-Effect Transistors Including Tunneling Mechanisms

Abstract

A model of nonlocal electron substrate and gate currents is presented for single-drain (SD) buried-channel (BC) p-type metaloxide-semiconductor field-effect transistors (pMOSFETs). A nonlocal impact ionization coefficient with characteristic length dependence both in the exponential term and the pre-exponential factor is used in the electron substrate current model. The gate current model is developed by originating a modified lucky electron concept that includes quantum-mechanical tunneling effects in parallel. The channel electric field is first calculated by using an analytical pseudo-two-dimensional MOSFET model, and the spatial distribution of electron temperature along the channel is then derived using a simplified energy balance equation. Having calculated the nonlocal impact ionization coefficient and electron temperature, and modified the lucky electron concept, the nonlocal electron substrate and gate currents can be derived. This model is a time-saving computeraided-design (CAD) model and is physics transparent for SD BC pMOSFETs.