Evaluation of a 3 kV Polarization Superjunction GaN HEMT

Abstract:
Gallium Nitride (GaN) offers unique material properties making it more suitable for high frequency, high voltage, power dense applications. Our GaN devices benefit from high density polarization charges of 2DEG and 2DHG, which coexist in respective heterojunctions of a double heterostructure to form a charge balanced, polarization based super junction (PSJ). This capability enables design of area efficient, scalable, high performance transistors and diodes. This paper demonstrates a large area, 3 kV PSJ GaN high electron mobility transistor (HEMT) fabricated on sapphire. The device characteristics, working principle and switching performance are experimentally investigated. The device shows a low on-state resistance of 210 mOmega at 25 °C. At elevated operating temperatures, it can be observed that the turn-off switching losses are not affected while the turn-on losses show a small increase. Also, a wide range of dV/dt controllability can be achieved through intelligent control of gate without significant increase in losses to meet various application requirements.