Fabrication and characterization of vertical GaN Schottky barrier diodes with boron-implanted termination

The vertical GaN-on-GaN Schottky barrier diode with boron-implanted termination was fabricated and characterized. Compared with the Schottky barrier diode (SBD) without boron-implanted termination, this SBD effectively improved the breakdown voltage from 189 V to 585 V and significantly reduced the reverse leakage current by 10⁵ times. In addition, a high I_on/I_off ratio of ～10⁸ was achieved by the boron-implanted technology. We used Technology Computer Aided Design (TCAD) to analyze reasons for the improved performance of the SBD with boron-implanted termination. The improved performance of diodes may be attributed to that B⁺ could confine free carriers to suppress electron field crowding at the edge of the diode, which could improve the breakdown voltage and suppress the reverse leakage current.