Compact SPICE Modeling of Total Ionizing Dose for Shield Gate Trench MOSFET

This paper develops a compact SPICE model of total ionizing dose (TID) for shield gate trench (SGT) MOSFETs, including a channel current, a drift region current and three external capacitances. The channel current is modeled by the simplified BSIM4, while the drift region current including velocity saturation describes the depletion caused by shield gate. The external capacitances adopt behavior models to facilitate the fitting of the
$Q_{\mathrm{G}}$
curves. In order to build the TID degradation model for the device, this paper explores the relationship between the oxide trap density in the channel and the drift region and the TID dose, external biases. Based on this relationship, the functions of various model parameters with respect to TID dose and external biases are proposed, enabling the proposed compact SPICE model to accurately capture the I-V and
$Q_{\mathrm{G}}$
characteristics under different TID doses. The experimental data demonstrate that the proposed model has ability to characterize the TID degradation of SGT MOSFETs.