Accession Number : ADA332734

Title :   GaN Based Structures for NEA by MBE and Investigation of Nitrogen Species and Precursors for Optimum Layer Properties

Descriptive Note : Final rept. 21 May 89-31 Dec 97

Corporate Author : ILLINOIS UNIV AT URBANA COORDINATED SCIENCE LAB

Personal Author(s) : Morkoc, Hadis

PDF Url : ADA332734

Report Date : DEC 1997

Pagination or Media Count : 14

Abstract : We have obtained: ohmic contacts with resistivities below 10(exp -7) Ohm sq cm to n type (GaN which are stable at 500 deg C, Pt Schottky barriers with nearly a unity ideality factor which appear stable at operation temperatures of about 500 deg C, AlGaN/GaN MODFETs on sapphire substrates with 1.5 micron gate length exhibiting extrinsic transconductances of about 220 mS/mm, drain currents of about 600 mA/mm and breakdown voltages of over 100 V for a 1 micrometer gate-drain separation, Inverted MODFETs on sapphire with extrinsic transconductances of about 80 mS/mm with lesser output negative conductance due to carrier confinement reducing the current path in the buffer layer, AlGaN/GaN MODFETs on SiC with 1.5 micron gate length exhibiting extrinsic transconductances of about 180 mS/mm, drain currents of about 325 mA/mm with the negative output conductance prevalent on sapphire being absent.

Descriptors :   *LAYERS, *FIELD EFFECT TRANSISTORS, *NITRIDES, *NITROGEN, *GALLIUM COMPOUNDS, *MOLECULAR BEAM EPITAXY, BUFFERS, TEMPERATURE, STABILITY, ALUMINUM COMPOUNDS, MILITARY AIRCRAFT, CONDUCTIVITY, QUANTUM THEORY, VOLTAGE, SUBSTRATES, SAPPHIRE, DRAINAGE, ZINC OXIDES, MILITARY APPLICATIONS, LETHALITY, INVERSION, DOPING, N TYPE SEMICONDUCTORS, SCHOTTKY BARRIER DEVICES, MODULATION, ANTIREFLECTION COATINGS, CURRENTS, BREAKDOWN(ELECTRONIC THRESHOLD), TRANSCONDUCTANCE, ULTRAVIOLET DETECTORS, ELECTRIC CONTACTS, ANTIAIRCRAFT MISSILES, WARNING SYSTEMS, METAL CONTACTS.

Subject Categories : Inorganic Chemistry
      Electrical and Electronic Equipment
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE