USA As Represented by Secretary of the Navy

Jennifer K Hite

Francis J Kub

Charles R Eddy, Jr

Travis J Anderson

Michael Anthony Mastro

Boris N Feigelson

Nelson Garces

Karl D Hobart

James C Gallagher

A method for mapping and analyzing a GaN substrate to identify areas of the substrate suitable for fabrication of electronic devices thereon. Raman spectroscopy is performed over the surface of a GaN substrate to produce maps of the Eand Apeaks at a plurality of areas on the substrate surface, the Eand Apeaks being associated with known concentrations of defects and charge carriers, so that areas of the GaN substrate having relatively high resistivity or conductivity which make those areas suitable or unsuitable for fabrication of electronic devices can be identified. The devices can then be fabricated only on suitable areas of the substrate, or the size of the devices can be tailored to maximize the yield of devices fabricated thereon. Substrates not meeting a threshold level of defect and/or charge carrier concentration can be discarded without fabrication of poor-quality devices thereon.

Mapping and evaluating GaN wafers for vertical device applications

Disclosed herein is a method of: depositing a patterned mask layer on an N-polar GaN epitaxial layer of a sapphire, silicon, or silicon carbide substrate; depositing an AlN inversion layer on the open areas; removing any remaining mask; and depositing a III-N epitaxial layer to simultaneously produce N-polar material and III-polar material. Also disclosed herein is: depositing an AlN inversion layer on an N-polar bulk III-N substrate and depositing a III-N epitaxial layer to produce III-polar material. Also disclosed herein is: depositing an inversion layer on a III-polar bulk III-N substrate and depositing a III-N epitaxial layer to produce N-polar material. Also disclosed herein is a composition having: a bulk III-N substrate; an inversion layer on portions of the substrate; and a III-N epitaxial layer on the inversion layer. The III-N epitaxial layer is of the opposite polarity of the surface of the substrate.

Method for vertical and lateral control of III-N polarity

A device with N-Channel and P-Channel III-Nitride field effect transistors comprising a non-inverted P-channel III-Nitride field effect transistor on a first nitrogen-polar nitrogen face III-Nitride material, a non-inverted N-channel III-Nitride field effect transistor, epitaxially grown, a first III-Nitride barrier layer, two-dimensional hole gas, second III-Nitride barrier layer, and a two-dimensional hole gas. A method of making complementary non-inverted P-channel and non-inverted N-channel III-Nitride FET comprising growing epitaxial layers, depositing oxide, defining opening, growing epitaxially a first nitrogen-polar III-Nitride material, buffer, back barrier, channel, spacer, barrier, and cap layer, and carrier enhancement layer, depositing oxide, growing AlN nucleation layer/polarity inversion layer, growing gallium-polar III-Nitride, including epitaxial layers, depositing dielectric, fabricating P-channel III-Nitride FET, and fabricating N-channel III-Nitride FET.

Complementary field effect transistors using gallium polar and nitrogen polar III-nitride material

A device with complementary non-inverted N-channel and inverted P-channel field effect transistors comprising a layer grown epitaxially on a substrate, a barrier layer, a two-dimensional electron gas in the first III-Nitride epitaxial layer, a second III-Nitride material layer, and a two-dimensional hole gas in the second III-Nitride epitaxial layer. A device with complementary inverted N-channel and non-inverted P-channel field effect transistors comprising a nitrogen-polar III-Nitride layer grown epitaxially, a barrier material layer, a two-dimensional hole gas, and a two-dimensional electron gas in the second III-Nitride epitaxial layer. A method of making complementary inverted P-channel and non-inverted N-channel III-Nitride field effect transistors. A method of making a complementary non-inverted P-channel field effect transistor and inverted N-channel III-Nitride field effect transistor on a substrate.

Millimeter-scale GaN single crystals in filamentary form, also known as GaN whiskers, grown from solution and a process for preparing the same at moderate temperatures and near atmospheric pressures are provided. GaN whiskers can be grown from a GaN source in a reaction vessel subjected to a temperature gradient at nitrogen pressure. The GaN source can be formed in situ as part of an exchange reaction or can be preexisting GaN material. The GaN source is dissolved in a solvent and precipitates out of the solution as millimeter-scale single crystal filaments as a result of the applied temperature gradient.

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Arlington, VA, United States of America

Jennifer K Hite