TCAD simulation of hot-carrier stress degradation in split-gate n-channel STI-LDMOS transistors. (June 2020) - Giuliano, Federico
Abstract: A combined experimental and simulation analysis of the degradation mechanisms induced by hot carriers in a silicon-based split-gate n-channel LDMOS transistor featuring an STI structure is reported. In this regime, electrons can gain sufficient kinetic energy necessary to create charged traps at the silicon/oxide interface, thus inducing device degradation and causing the shift of the electrical parameters of the device. In particular, the on-resistance degradation in linear regime has been experimentally characterized at different stress conditions and at room temperature. The hot-carrier degradation has been reproduced in the frame of TCAD simulations by using physical-based models aimed at reproducing the degradation kinetics. An investigation of the electron distribution function at different stress conditions and its dependence on the split-gate bias is carried out achieving a quantitative understanding of the role played by hot electrons in the hot-carrier degradation mechanisms of the device under test. Highlights: Investigation of LDMOS with STI structure and split gate TCAD simulations of hot electrons degradation mechanisms by using the Boltzmann Transport Equation (BTE) solution TCAD has been proved to be a useful tool to quantitatively describe the degradation mechanisms and their localization The device has been proved having an electric field peak almost independent on the split-gate bias.