Analytical Model for the Surrounded Field Plate in Folded Lateral MOSFET Structure

Abstract

A novel unified analytical model concerning the surrounded plate field is proposed for extended drain MOSFETs (EDMOS) in this article for the first time. The SFP analytical model demonstrates the edge-assisted depletion (AD) effect and the multidimensional AD effect through the dielectric-layer (DL) potential function and 3-D Poisson equation. The closed-form solutions of the electric field and potential distributions are derived to predict the breakdown voltage (BV) for different SFP lengths and dielectric parameters. The 3-D electric field modulation effect brought on by SFP is presented. The impact of SFP parameters on BV is explained using the effective doping concentration ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textit{N}_{\text{deff}}\text{)}$</tex-math> </inline-formula> . The analytical model takes into account the multidimensional conduction path and the electron accumulation effect while determining the specific ON-resistance ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textit{R}_{\text{on},\textit{sp}}\text{)}$</tex-math> </inline-formula> of SFP EDMOS. The proposed model is useful for the trade-off between mobility and doping concentration. It can also analyze the impact of the strain on BV and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textit{R}_{\text{on},\textit{sp}}$</tex-math> </inline-formula> . The analytical model is validated by the good agreement between the modeling results and simulation results.