US Government As Represented by the Secretary of the Army

Herbert L Wilson

William A Gutierrez

Edward M Yee

William A Guiterrez

A process of high pressure close-space epitaxy in the semi-confined atmosre of a reusable demountable ampule in a furnace growth chamber. The ampule has a substrate and source materials placed therein whereupon the ampule is then loaded in the pressure furnace and the furnace is sealed air tight. Alternate steps of high pressure gas scrubbing and evacuating the interior of the furnace growth chamber including the interior of the ampule through small vents are first used to purify the growth environment. The source materials are then epitaxially grown on the substrate at a high pressure within the ampule. The ampule may be repeatedly used without having to be destroyed after each growth.

Close space epitaxy process

A high pressure furnace and reusable demountable containment means for setive in situ information of epitaxial layers on a semiconductor substrate while under gas overpressure. The containment means has vent means therein for allowing the inert and reducing or reactive gases in an inner chamber of the furnace to enter into the interior of the containment means to equalize pressures on each side of the housing and to semi-confine the vapor from the epitaxial growth source materials in the interior of the containment means. The containment means has a removable, i.e. demountable, form-fittedly sealed plug which is removed to insert the substrate and growth source elements, which are mounted in a close-space relationship on a support structure, therein. The support structure is inserted back into the containment means and the plug is form fittedly sealed thereto for performing the epitaxial layering.

Apparatus for producing high quality epitaxially grown semiconductors

A method of forming a variable sensitivity transmission mode negative eleon affinity (NEA) photocathode in which the sensitivity of the photocathode to white or monochromatic light can be varied by varying the backsurface recombination velocity of the photoemitting material with an electric field. The basic structure of the photocathode is comprised of a Group III-V element photoemitter on a larger bandgap Group III-V element window substrate.

Variable sensitivity transmission mode negative electron affinity

Method of forming variable sensitivity transmission mode negative

A method of forming a high sensitivity, large area, negative electron affty (NEA), infrared sensitive transmission mode, GaAs on AlGaAs photocathode structure with the GaAs layer being of controlled homogeneous thickness and having a blemish-free surface. The structure is formed by using a combination of liquid and vapor phase epitaxial techniques, i.e., hybrid epitaxy.

Method of forming GaAs on Al.sub.y Ga.sub.1-y As transmission mode

A method of making transmission mode glass-sealed negative electron affinity (NEA) gallium arsenide (GaAs) photocathodes, utilizing germanium (Ge) as the seed crystal and multilayers of GaAs and gallium aluminum arsenide (GaAlAs) grown by metal alkyl-hydride vapor-phase epitaxy. The GaAs serves as the photoemitting layer and the GaAlAs serves as the passivating layer. The Ge, GaAs,GaAlAs combination is sealed to a glass support substrate which serves as the input window for the device. Finally, the Ge is removed and the GaAs is activated.

Method of making negative electron affinity photocathode

A method of fabricating high performance transmission mode negative elect affinity III-V compound photocathodes which eliminates recurrent liquid phase epitaxial growth surface defects and solves the 'wipe-off' problem incurred during the termination of the growth cycle.

Method of fabricating III-V photocathodes

Transmission mode negative electron affinity gallium arsenide (GaAs) photthodes and dynodes with a technique for the fabrication thereof, utilizing multilayers of GaAs and gallium aluminum arsenide (GaAlAs) wherein the GaAs layers serve as the emitting layer and as intermediate construction layers and the GaAlAs layer serves as a passivating window.

Electron emitter and method of fabrication

Transmission mode negative electron affinity gallium arsenide (GaAs) photthodes and dynodes with a technique for the fabrication thereof, utilizing multilayers of GaAs and gallium aluminum arsenide (GaAlAs) wherein the GaAs layers serve as the emitting layer and as an intermediate construction layer, and the GaAlAs layers serve as a passivating window and as an etch stop layer.

Transmission mode negative electron affinity gallium arsenide (GaAs) photthodes and dynodes and techniques for the fabrication thereof, utilizing multilayers of GaAs and gallium alluminum arsenide (GaAlAs) wherein the GaAs layer serves as the emitting layer and the GaAlAs serves as an intermediate construction layer and/or as an integral part of the component.

A photon sensing device utilizing a III-V negative electron affinity photthode grown on a window substrate support which simultaneously serves as a support and growth surface for the epitaxial growth of suitable cathode layers as well as the input window for the device.

Growing community of inventors

Woodbridge, VA, United States of America

Herbert L Wilson