Impact of Field-Plate Insulating Layer on Junction Breakdown Instability in OFT-Pw.MOSFET Devices

In this article, we investigate the junction breakdown instability in oxide-filled trench power MOSFETs, as a function of field-plate oxide characteristics. We compare the junction breakdown instability in devices adopting field-plate insulating layers thermally grown and low-pressure chemical vapor deposition process (LPCVD) deposited. We experimentally observe a different junction breakdown walk-out, depending on the field-plate insulating material. We found out that, by applying an electrical stress, besides the junction breakdown instability, a damage of the channel region is observed in the case of thermally grown field-plate oxide layer.