Purdue Research Foundation

International Business Machines Corporation

USA As Represented by Secretary of the Navy

Michael R Melloch

Jerry M Woodall

Rodney T Hodgson

Paul Michael Solomon

Jeremy H Burroughes

James A Cooper, Jr

Alan C Warren

David T McInturff

Nobuo Otsuka

David D Nolte

James Albert Cooper, Jr

Peter Daniel Kirchner

John Lawrence Freeouf

Robert L Gunshor

Jayarama N Shenoy

Jan Spitz

Kipp J Schoen

Robert F Pierret

Jason P Henning

Theresa B Stellwag

An insulated gate field effect transistor is disclosed. The transistor includes a semi-insulating silicon carbide substrate, an epitaxial layer of silicon carbide layer adjacent the semi-insulating substrate for providing a drift region having a first conductivity type, and source and drain regions in the epitaxial layer having the same conductivity type as the drift region. A channel region is in the epitaxial layer, has portions between the source and the drain regions, and has the opposite conductivity type from the source and drain regions. The transistor includes contacts to the epitaxial layer for the source, drain and channel regions, an insulating layer over the channel region of the epitaxial layer, and a gate contact adjacent the insulating layer and the channel region.

Power devices in wide bandgap semiconductor

A dual-metal-trench silicon carbide Schottky pinch rectifier having a plurality of trenches formed in an n-type SiC substrate, with a Schottky contact having a relatively low barrier height on a mesa defined between adjacent ones of the trenches, and a Schottky contact having a relatively high barrier height at the bottom of each trench. The same metal used for the Schottky contact in each trench is deposited over the Schottky contact on the mesa. A simplified fabrication process is disclosed in which the high barrier height metal is deposited over the low barrier height metal and then used as an etch mask for reactive ion etching of the trenches to produce a self-aligned low barrier contact.

Dual-metal-trench silicon carbide Schottky pinch rectifier

A light responsive device (10) has a body (12) that includes a matrix comprised of Group III-V material, the matrix having inclusions (14) comprised of a Group V material contained therein. The body is responsive to a presence of a light beam that has a spatially varying intensity for modifying in a corresponding spatially varying manner a distribution of trapped photoexcited charge carriers within the body. The distribution of trapped charge carriers induces a corresponding spatial variation in at least one optical property of the Group III-V material, such as the index of refraction of the Group III-V material and/or an absorption coefficient of the Group III-V material. The Group III-V material is comprised of LTG GaAs:As or LTG AlGaAs:As. In an optical storage medium embodiment of the invention the spatial variation in the intensity of the light beam results from a simultaneous application of a first light beam (LB1) and a second light beam (LB2) to the body, and from interference fringes resulting from an intersection of said first and second light beams.

LTG AlGaAs non-linear optical material and devices fabricated therefrom

A doped or undoped photoresponsive material having metallic precipitates, and a PiN photodiode utilizing the material for detecting light having a wavelength of 1.3 micrometers. The PiN photodiode includes a substrate having a first compound semiconductor layer disposed thereon. The PiN photodiode further includes an optically responsive compound semiconductor layer disposed above the first compound semiconductor layer. The optically responsive layer includes a plurality of buried Schottky barriers, each of which is associated with an inclusion within a crystal lattice of a Group III-V material. The PiN device also includes a further compound semiconductor layer disposed above the optically responsive layer. For a transversely illuminated embodiment, waveguiding layers may also be disposed above and below the PiN structure. In one example the optically responsive layer is comprised of GaAs:As. The GaAs:As exhibits a very low room temperature dark current, even under forward bias conditions, and a responsivity to 1.3 micrometer radiation modulated at frequencies greater than 1 GHz.

Method of making a compound semiconductor having metallic inclusions

Compound semiconductor having metallic inclusions and devices fabricated

A vertically integrated DRAM cell having a storage time of at least 4.5 hours at room temperature, formed from a wide-bandgap semiconductor such as GaAs or AlGaAs, in which an n-p-n bipolar access transistor is merged with a p-n-p storage capacitor, with the middle p-n layers being common to both. Similarly, a p-n-p transistor can be merged with an n-p-n storage capacitor.

Dynamic random access memory device

A separate comb transducer is disclosed in a ZnO/Si SAW device to enable doubling of the possible operating frequency for a given photolithographic capability of the device. Frequency doubling is made possible by a single-phase structure having conductive and non-conductive surfaces equal to one-half of the SAW wavelength. By connection of two such structures in parallel, a balanced separate comb transducer is achieved for reducing signal levels due to direct coupling that otherwise occurs in the single-phase structure. Separate comb grating transducers are also disclosed to enable fabrication of higher frequency MZOS convolvers, with both the separate comb transducer and separate comb grating transducer being shown utilized in both the Rayleigh and Sezawa modes.

ZnO/Si SAW Device having separate comb transducer

Growing community of inventors

West Lafayette, IN, United States of America

Michael R Melloch