International Business Machines Corporation

Purdue Research Foundation

Other

Alan C Warren

Jerry M Woodall

Peter Daniel Kirchner

Paul Michael Solomon

Jeremy H Burroughes

Steven Lorenz Wright

Rodney T Hodgson

Michael R Melloch

David T McInturff

Nobuo Otsuka

John Lawrence Freeouf

George D Pettit

Alan B Fowler

Matthew F Chisholm

Eric R Fossum

Paul Filkoski

A wheelchair attachment for powering a wheelchair is described. An attachment for a conventional wheelchair converts a non-motorized wheelchair into a motorized wheelchair. The attachment may also act as an anti-tipping device.

Motorized anti-tipper device

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

Heterostructures having a large lattice mismatch between an upper epilayer and a substrate and a method of forming such structures having a thin intermediate layer are disclosed. The strain due to a lattice mismatch between the intermediate layer and the substrate is partially relieved by the formation of edge type dislocations which are localized and photoelectrically inactive. Growth of the intermediate layer is interrupted before it reaches the thickness at which the left over strain is relieved by 60 degree type threading dislocations. The upper epilayer is then grown in an unstrained and defect-free condition upon the intermediate layer where the unstrained lattice constant of the epilayer is about the same as the partially relieved strain lattice constant or the intermediate layer. An unstrained defect-free epilayer of InGaAs has been grown on a GaAs substrate with an intermediate layer 3-10 nm in thickness of InAs. Other large mismatch systems are disclosed, including, GaAs on Si with an intermediate layer of GaInAs.

Strained defect-free epitaxial mismatched heterostructures and method of

Control of the Fermi level pinning problem and the production of flat band surface performance in compound semiconductors is achieved by providing a cationic oxide free of anionic species on the surface of the semiconductor for flat band performance and with a localized inclusion of some anionic species for barrier performance so that oxide and metal work function responsiveness is available in structure and performance in MOSFET, MESFET and different work function metal FET structures. A cationic gallium oxide is produced on GaAs by oxide growth during illumination and while being rinsed with oxygenated water. The oxidation is used to produce both anionic and cationic species while the rinsing process selectively removes all the anionic species.

Compound semiconductor interface control using cationic ingredient oxide

Submicron structure fabrication is accomplished by providing vapor chemical erosion of a compound crystal by suppressing the more volatile elements so that the less volatile element is provided with an anti-agglomeration and erosion rate limiting capability which can be followed by subsequent regrowth in the same environment. The erosion is sensitive to crystallographic orientation.

Submicron dimension compound semiconductor fabrication using thermal

Compound semiconductor interface control

A surface termination of a compound semiconductor is provided wherein conditions are provided for a pristine surface to be retained in an unpinned condition and a surface layer of a non-metallic material is provided. A GaAs substrate is heated in an oxygen-free atmosphere at high temperature with hydrogen sulfide, producing a pristine surface with a coating of gallium sulfide covered with a 1,000 nanometer covering of low temperature plasma enhanced chemical vapor deposited silicon dioxide.

Compound semiconductor surface termination

Growing community of inventors

Peekskill, NY, United States of America

Alan C Warren