A Normally-off AlGaN/GaN Transistor with RonA=2.6mΩcm2 and BVds=640V Using Conductivity Modulation

We report a normally-off GaN-based transistor using conductivity modulation, which we call GIT (gate injection transistor). This new device principle utilizes hole-injection from p-AlGaN to AlGaN/GaN heterojunction, which increases electron density in the depleted channel resulting in dramatic increase of the drain current owing to the conductivity modulation. The fabricated GIT exhibits the threshold voltage of 1.0V with high maximum drain current of 200mA/mm. The obtained on-state resistance (R_on·A) and off-state breakdown voltage (BV_ds) are 2.6mΩ·cm² and 640V, respectively. These values are the best ones ever reported for GaN-based normally-off transistors