Quasi-2-Dimensional Compact Resistor Model for the Drift Region in High-Voltage LDMOS Devices

摘要

High-voltage (HV) metal–oxide–semiconductor field-effect transistors (MOSFETs) of the laterally diffused metal–oxide–semiconductor (LDMOS) type enable applications over a wide range of bias voltages by optimizing the combined structure of MOSFET and drift region at its drain side. We report a physically accurate compact resistor model of the LDMOS drift region, adapted to the special requirements of the combined structure with a MOSFET. In particular, the reported resistor model captures the effects of the 2-D current flow in the drift region with its complicated bias dependence. The resistor model considers two device-structure-dependent potentials, namely, the internal node potential within the highly resistive drift region and the potential underneath the gate overlap region. The consistent potential-based description over the complete LDMOS device is the key modeling technology for enabling the accurate reproduction of the bias-dependent 2-D current flow and the resulting $I$–$V$ characteristics for a wide range of structure variations with a small number of only six fitting parameters. The reported quasi-2-D resistor model is implemented in the second-generation Hiroshima-university STARC IGFET Model-High Voltage (HiSIM-HV) compact models for HV MOSFETs and is expected to be useful for both, optimization of LDMOS circuits and devices.