Anomalous Decrease of Off-State Drain Leakage Current in GaN/AlGaN HEMTs With Dual Optical Excitation

    Authors

    A. Das; D. H. Ko; R. M. Lin; L. B. Chang;L. Chow

    Comments

    Authors: contact us about adding a copy of your work at STARS@ucf.edu

    Abbreviated Journal Title

    IEEE Electron Device Lett.

    Keywords

    Deep traps; GaN; HEMTs; optical excitation; off-state current; YELLOW LUMINESCENCE; GAN; PHOTOCONDUCTIVITY; Engineering, Electrical & Electronic

    Abstract

    We report an anomalous decrease of off-state drain leakage current (I-Off-state) of GaN/AlGaN HEMTs upon dual optical excitation. The phenomenon was observed accidentally during dc characterization of devices when both fluorescent white room light and incandescent optical microscope light were turned on. A similar phenomenon was observed and verified through simultaneous optical excitation of both ultraviolet (UV similar to 350 nm) light and 532-nm green light. A spectrally resolved measurement revealed broad trap level centered similar to 2.27 eV. The decrease of I-Off-state during dual excitation is owing to the optical quenching of photoconductivity in GaN buffer layer. This quenching effect is originated from enhanced light-defect interaction, where sub-band gap light reduces photoconductivity induced by above bandgap light. Observation of this phenomenon would provide us an alternative way to characterize GaN buffer layer quality for the development of GaN HEMTs.

    Journal Title

    Ieee Electron Device Letters

    Volume

    35

    Issue/Number

    8

    Publication Date

    1-1-2014

    Document Type

    Article

    Language

    English

    First Page

    820

    Last Page

    822

    WOS Identifier

    WOS:000341573000004

    ISSN

    0741-3106

    Share

    COinS