Josephine Chang

Northrop Grumman
  • Formation of Diamond Superjunctions to Enable GaN-Based Super-Lattice Power Amplifiers with Diamond Enhanced Superjunctions (SPADES)

    Geoffrey Foster, Jacobs Inc., Washington DC
    Tatyana Feygelson, U. S. Naval Research Laboratory
    James Gallagher, ASEE Postdoctoral Fellow Residing at NRL
    Josephine Chang, Northrop Grumman
    Shamima Afroz, Northrop Grumman
    Ken Nagamatsu, Northrop Grumman
    Robert Howell, Northrop Grumman
    Fritz Kub, Naval Research Laboratory

    The super-lattice power amplifier with diamond enhanced superjunctions (SPADES) is a device that incorporates nanocrystalline diamond superjunctions into the super-lattice castellated field effect transistor (SLCFET), to improve breakdown voltage. A diamond superjunction is formed with p-type nanocrystalline diamond to balance mutual depletion between the two-dimensional electron gas superlattices and the doped diamond in order to reduce the peak electric field in the drain access region.  Formation of the diamond superjunction presents several challenges, such as managing diamond conformality, strain, and control over p-type doping.  Optimization of diamond growth led to conformal films, with low stress, and linear dependence hole concentration from p-type doping, suitable for the SPADES device.

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