Evidence of Hot-Hole Induced Degradation in Lateral NDRIFT MOSFET: Characterization and TCAD Analysis

The role of secondary hot holes in the degradation of n-channel lateral drift MOSFETs, possibly leading to gate oxide breakdown, is discussed. Trapping of positive charges in the gate and field oxides and the formation of interface states under hot-carrier stress (HCS) have been successfully monitored by means of direct current current-voltage (DCIV) measurements and through gate-drain capacitance measurements. Experimental data have been complemented with Technology Computer Aided Design (TCAD) analysis. A degradation model including both hot-electrons and secondary hot-holes induced degradation capable of interpreting and reproducing measured data is proposed. Simulations allow to gain insights in the kinetics laws governing charge trapping and interface states generation along the silicon/oxide interface. The drift kinetics of the ON-state resistance have been also characterized and reproduced by simulations.