It is well known that vertical GaN devices could surpass current lateral GaN switch technology due to higher critical electric fields and higher breakdown voltages from its different geometry, and lower impurity concentration from the superior quality of homoepitaxial films. However, the inconsistency of GaN substrate properties, both within wafer and vendor-to-vendor, makes reliable device fabrication difficult. Here we implement long-range spectroscopic studies of GaN substrates and epitaxial wafers using Raman, photoluminescence, and optical profilometry to assess incoming material and correlate to electrical performance of vertical diodes. We have classified incoming wafers into two general types, and determined that inhomogeneities in the wafers can negatively affect the reverse leakage current of PiN diodes.
Andrew Koehler
Naval Research Laboratory
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Predicting Vertical GaN Diode Quality using Long Range Optical tests on Substrates
Francis Kub, U.S. Naval Research LaboratoryJames Gallagher, U.S. Naval Research LaboratoryAndrew Koehler, Naval Research LaboratoryMona Ebrish, NRC Postdoc Fellow Residing at the U.S. Naval Research LaboratoryMichael Mastro, U.S. Naval Research LaboratoryJennifer Hite, U.S. Naval Research LaboratoryKarl Holbart, U.S. Naval Research LaboratoryDownload Paper -
16.3 Evaluation of GaN Device Structures on 150 mm GaN on Engineered Substrates
Download PaperKarl D. Hobart, U.S. Naval Research LaboratoryAndrew Koehler, Naval Research LaboratoryAnindya Nath, George Mason UniversityJennifer Hite, U.S. Naval Research LaboratoryN. Mahadik, U.S. Naval Research LaboratoryFritz Kub, Naval Research LaboratoryOzgur Aktas, QROMIS, USAVladimir Odnoblyudov, QROMIS, USACem Basceri, QROMIS, USA -
18.2 Engineering PECVD SiN Passivation Layers to Enable AlGaN/GaN HEMTs with Low Leakage, Low Current Collapse and High Breakdown Voltage
Download PaperAndrew Koehler, Naval Research LaboratoryMarko Tadjer, U.S. Naval Research LaboratoryKarl D. Hobart, U.S. Naval Research LaboratoryFritz Kub, Naval Research Laboratory -
18.3 Threshold Voltage Control by Tuning Charge in ZrO2 Gate Dielectrics for Normally-off AlGaN/GaN MOS-HEMTs
Download PaperVirginia Wheeler, U.S. Naval Research LaboratoryDavid Shahin, University of MarylandMarko Tadjer, U.S. Naval Research LaboratoryLunet Luna, U.S. Naval Research LaboratoryAndrew Koehler, Naval Research LaboratoryKarl D. Hobart, U.S. Naval Research LaboratoryFrancis Kub, U.S. Naval Research LaboratoryCharles Eddy, US Naval Research LaboratoryJr., Naval Research Laboratory -
20.5 Characterization of ALD High-k Dielectrics in GaN and Ga2O3 Metal-Oxide-Semiconductor Systems
Download PaperDavid Shahin, University of MarylandVirginia Wheeler, U.S. Naval Research LaboratoryMarko Tadjer, U.S. Naval Research LaboratoryLunet Luna, U.S. Naval Research LaboratoryAndrew Koehler, Naval Research LaboratoryKarl D. Hobart, U.S. Naval Research LaboratoryCharles Eddy, US Naval Research LaboratoryJr., Naval Research LaboratoryFritz Kub, Naval Research LaboratoryAris Christou, University of Maryland-College Park -
5.3 Influence of Substrate Removal on the Electrothermal Characteristics of AlGaN/GaN Membrane High Electron Mobility Transistors
Download PaperMarko Tadjer, U.S. Naval Research LaboratoryPeter Raad, TMX Scientific and Southern Methodist UniversityTatyana Feygelson, Naval Research LaboratoryAndrew Koehler, Naval Research LaboratoryBradford Pate, Naval Research LaboratoryKarl D. Hobart, U.S. Naval Research LaboratoryFritz Kub, Naval Research Laboratory -
10b.4 Reliability Assessment of Thermally-Stable Gate Materials for AlGaN/GaN HEMTs
Download PaperDavid Shahin, University of MarylandJordan Greenlee, NRC Postdoctoral Fellow Residing at the Naval Research LaboratoryAndrew Koehler, Naval Research LaboratoryVirginia Wheeler, U.S. Naval Research LaboratoryMarko Tadjer, U.S. Naval Research LaboratoryTatyana Feygelson, Naval Research LaboratoryBradford Pate, Naval Research LaboratoryJennifer Hite, U.S. Naval Research LaboratoryKarl D. Hobart, U.S. Naval Research LaboratoryCharles Eddy, US Naval Research LaboratoryJr., Naval Research LaboratoryFrancis Kub, U.S. Naval Research LaboratoryAris Christou, University of Maryland-College Park -
11.2 Effect of Surface Passivation on Current Collapse of Proton-Irradiated AlGaN/GaN HEMTs
Download PaperAndrew Koehler, Naval Research LaboratoryMarko Tadjer, U.S. Naval Research LaboratoryBradley Weaver, U.S. Naval Research LaboratoryJordan Greenlee, NRC Postdoctoral Fellow Residing at the Naval Research LaboratoryDavid Shahin, University of MarylandKarl D. Hobart, U.S. Naval Research LaboratoryFrancis Kub, U.S. Naval Research Laboratory -
11.5 Optimization of AlGaN/GaN HEMT SiN Passivation by Mixed Frequency PECVD
Download PaperMarko Tadjer, U.S. Naval Research LaboratoryAndrew Koehler, Naval Research LaboratoryCharles Eddy, US Naval Research LaboratoryJr., Naval Research LaboratoryKarl D. Hobart, U.S. Naval Research LaboratoryFritz Kub, Naval Research Laboratory -
14.9 Fabrication of True Vertical GaN Schottky Diodes from 150 mm Engineered Substrates
Download PaperLunet E. Luna, NRC Postdoctoral Fellow Residing at NRLMarko J. Tadjer, U.S. Naval Research LaboratoryOzgur Aktas, QROMIS, USAFritz J. Kub, U.S. Naval Research Laboratory -
9.3.2023 Drift Region Epitaxy Development and Characterization for High Blocking Strength and Low Specific Resistance in Vertical GaN Based Devices
Eldad Bahat Treidel, Ferdinand-Braun-Institut, Berlin, GermanyFrank Brunner, Ferdinand-Braun-Institut, Berlin, GermanyEnrico Brusaterra, Ferdinand-Braun-InstitutMihaela Wolf, Ferdinand-Braun-Institut, Berlin, GermanyAndreas Thies, Ferdinand-Braun-InstitutJ. Würfl, Ferdinand-Braun-InstitutOliver Hilt, Ferdinand-Braun-Institut, Berlin, Germany -
9.4.2023 Scalable Manufacturing of Planar, Large-Area 1.2kV and 3.3kV Vertical GaN PiN Diodes
Alan Jacobs, U.S. Naval Research Laboratory, Washington DCMona Ebrish, NRC Postdoc Fellow Residing at the U.S. Naval Research LaboratoryJames Gallagher, U.S. Naval Research LaboratoryMarko J. Tadjer, U.S. Naval Research LaboratoryJames Spencer Lundh, National Research Council Postdoctoral Fellow, Residing at NRLJennifer K. Hite, Naval Research LaboratoryN. Mahadik, U.S. Naval Research LaboratoryRobert Kaplar, Sandia National Labs, Albuquerque, NMO. Aktas, Sandia National Labs, Albuquerque, NM -
Formation of Diamond Superjunctions to Enable GaN-Based Super-Lattice Power Amplifiers with Diamond Enhanced Superjunctions (SPADES)
Geoffrey Foster, Jacobs Inc., Washington DCTatyana Feygelson, Naval Research LaboratoryJames Gallagher, ASEE Postdoctoral Fellow Residing at NRLJosephine Chang, Northrop GrummanShamima Afroz, Northrop GrummanKen Nagamatsu, Northrop GrummanRobert Howell, Northrop GrummanFritz Kub, Naval Research LaboratoryDownload PaperThe 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.