A breakdown mechanism of polarized semiconductors represented by GaN-based materials is presented, based on the concept of a natural super junction, which is established by the inherent material polarization. In this concept, owing to the precise matching of positive and negative polarizations of both sides of GaN and AlGaN materials, average charge concentration in the material becomes nearly zero under reverse bias condition, which realizes extremely high breakdown voltage. This model is confirmed by device simulation taking all polarization charges of GaN-based materials into account. Furthermore, experimentally fabricated GaN-based Schottky barrier diodes showed a linear increase of breakdown voltage along the anode-cathode spacing, achieving a record breakdown voltage over 9000 V.
- Breakdown voltage
- Heterojunction fieldeffect transistor (HFET)
- Schottky barrier diode (SBD)
- Super junction