High Voltage InAlN/GaN HFETs Achieved by Schottky-Contact Technology for Power Applications

Abstract

In this paper, a novel approach of Schottky-contact technology for high voltage InAlN/GaN power transistors is demonstrated. The improved breakdown voltage (BV) attributes to the effectively suppressed source carrier injection achieved by the Schottky source metallization featuring excellent metal morphology. Without using field-plate structure and buffer engineering technique, the record three-terminal off-state BV of 650 V is obtained for InAlN/GaN HFET featuring a Schottky source. The corresponding specific on-resistance is as low as 3.4 mΩ·cm 2 . Moreover, the proposed Schottky-contact technology enables the removal of conventional alloyed Ohmic contact which is beneficial to device scaling. The BV of 58 V is measured in an InAlN/GaN HFET with L GD of 250 nm, which is the highest BV reported on GaN-based HFETs with such a short drift region. With simple fabrication process as well as the device structure while achieving a significant breakdown voltage enhancement, the proposed technology opens up new perspectives for designing high voltage InAlN/GaN HFET for power applications.