Modeling of time dependent breakdown voltage degradation in Trench Field Plate Power MOSFET

Hydrogen diffusion physics of breakdown voltage instability in Trench Field Plate Power MOSFET was simulated. We developed TCAD model which incorporated transient hot hole-injected Si-H bond dissociation and hydrogen diffusion. This model indicated that generated hot holes near trench bottom increase trapped hole density in Si/Field Plate oxide interface. In addition, hydrogen diffusion limits hydrogen depassivation process. Proposed model qualitatively agreed with experimental time and avalanche current dependent breakdown voltage shifts. Furthermore, the model explained that optimizing drift layer doping concentration and trench depth prevent breakdown voltage decrease.