Floating Island Structure With Metal Bridge to Resolve the Turn-On Recovery Problem

The floating Island (FI) device has a severe turn-on recovery problem. In this brief, a new “metal bridge” that connects the Island and the N+ buffer through ohmic contact is proposed. The objective of the new structure is to resolve the turn-on recovery problem. Simulations are conducted to validate the efficacy of the structure. The proposed FI junction barrier Schottky with the proposed metal bridge (MB-FIJBS) shows no voltage overshoot and has significantly reduced the recovered on-state voltage compared to the conventional junction barrier Schottky (Conv. JBS). The recovered on-state voltage of the MB-FIJBS is the same as its static On-state voltage, proving a complete recovery. The mechanism of the turn-on process of the MB-FIJBS is elucidated. The MB-FIJBS achieves rapid recovery by completely removing any additional potential barrier in the current flow path. The MB-FIJBS is well designed, so that it does not degrade the breakdown voltage (BV). The 3-D implementation of the MB-FIJBS is proposed to provide a practically feasible structure that is compatible with the current manufacturing process. A simulation of the 3-D structure has been conducted to validate its effectiveness.