Design of PAMBE-based selective-area growth compliant ultra-low leakage GaN mixed-conduction vertical diodes for high-power applications * *This work was supported by the Office of Naval Research (ONR) under the ONR Award N00014-17-1-2681 (Program Manager: Lynn J Petersen).

Abstract

Modern high-speed power applications require diodes with high-current capacity, larger reverse blocking voltage, lower reverse recovery transients, and lower leakage. GaN mixed-conduction vertical diodes are an attractive option for these operations. Experimentally reported GaN diodes have two major shortcomings, namely, higher leakage due to non-optimum design and conventional processing methods (e.g. ion implantation and dry etching), introducing huge leakage components. In this work, we design ultra-low leakage GaN buried p-base merged p–i–n Schottky and buried p-base merged p–i–n junction barrier controlled Schottky diodes, capable of reducing leakage current by more than five orders of magnitude by virtue of strong reduced surface field effect. Moreover, these designs are fully compliant with our earlier reported silicon nitride shadowed selective-area growth (SNS-SAG) methodology, capable of reducing the leakage by at least four orders of magnitude. In combination with SNS-SAG and highly efficient dielectric vertical sidewall edge termination scheme, these designs provide attractive options for higher performance.