Stauffer Chemical Company

Other

Leland Stanford Junior University

Varian Associates, Inc.

Intevac, Inc.

William E Spicer

John A Baumann

Diego J Olego

Kenneth A Costello

Rozalie Schachter

Verle W Aebi

Paul M Raccah

Harvey B Serreze

David G Brock

Henry C Smallbrook

Pnictide thin films, particularly phosphorus, grown on III-V semiconductors, particularly InP, GaP, and GaAs, are amorphous and have a novel layer-like, puckered sheet-like local order. The thin films are typically 400 Angstroms thick and grown preferably by molecular beam deposition, although other processes such as vacuum evaporation, sputtering, chemical vapor deposition, and deposition from a liquid melt may be used. The layers are grown on the &lt;100&gt; &lt;110&gt;, and surfaces of the III-V crystals. The pnictide layer reduces the density of surface states, and allows the depletion layer to be modulated, the surface barrier reduced, the electron concentration at the surface increased, and there is a decrease in the surface recombination velocity and an increase in the photoluminescence intensity. The layers may be utilized in MIS and Metal-semiconductor (Schottky) devices for example to insulate and passivate MISFETS, to passivate MESFETS, to reduce the surface current component of the reverse bias dark current in P-I-N and avalanche diodes, and to improve performance of opto-electronic devices such as light emitting diodes, lasers, solar cells, photo cathodes and photo detectors. The pnictide layer may be applied to intermetallic and compound semiconductors having a pnictide component. The pnictides may be phosphorus, arsenic, antimony or bismuth, or combinations thereof.

Passivation and insulation of III-V devices with pnictides, particularly

An improved transferred electron III-V semiconductor photocathode comprising an aluminum contact pad and an aluminum grid structure that improves quantum efficiency by removing a major obstacle to electrons escaping into the vacuum and controls dark spot blooming caused by overly bright photon emission sources.

Transferred electron III-V semiconductor photocathode

Metal-insulator-semiconductor devices are formed on III-V semiconductors utilizing a pnictide rich insulating layer. The layer may be applied by vacuum evaporation, sputtering, chemical vapor deposition, and from a liquid melt. Gallium arsenide, indium phosphide, and gallium phosphide substrates are insulated with an alkali metal high pnictide polypnictide, preferably a polyphosphide, having the formula MP.sub.x where x is equal to or greater than 15, including new forms of phosphorus grown in the presence of an alkali metal where x is much greater than 15. A KP.sub.15 layer is preferred. They may also be insulated with a layer of a solid elemental pnictide, namely phosphorus, arsenic, antimony or bismuth applied by one of the above named processes. An elemental phosphorus layer is preferred. A silicon nitride, Si.sub.3 N.sub.4, layer may be added on top of the pnictide layer to increase the breakdown voltage of the insulating layer.

MIS Device employing elemental pnictide or polyphosphide insulating

Air brake adjustment and measurement tools where the adjustment tool includes a long handle portion having a gripper assembly attached to one end and a socket wrench drive attached to the other end. The gripper assembly has a pair of facing jaw members adapted to engage opposing edges of a vehicle's air brake slack adjustment. The measuring tool includes a scale, and a permanent magnet attached to one end of the scale. In use, the measuring tool is placed next to the clevis rod of the vehicle's air brake assembly, and the adjustment tool is used to move the air brake slack adjustment between a braking and a non-braking position. The stroke of the clevis rod is measured by the measuring tool, and is adjusted by a socket wrench attached to a socket drive of the adjustment tool.

Air brake slack adjustment and measurement tools

Schottky barrier diodes with engineered barrier heights in III-V semiconductor material are disclosed. By fabricating the diodes using a very clean and defect free surface, the barrier height can be controlled by introducing selected amounts of dopant in the surface prior to evaporation of a contact metal. By selecting a dopant having the same conductivity as the semiconductor material a reliable ohmic contact can be provided.

Method for making Schottky barrier diodes with engineered heights

The present invention relates in general to methods for making pick-up screens for X-ray image intensifier tubes and, more particularly, to an improved method wherein the X-ray fluorescent phosphor screen element is formed by evaporation of an alkali metal halide material in vacuum and condensing the evaporated material on an X-ray transparent portion of the X-ray intensifier tube, whereby a curved X-ray image pick-up screen is formed which has improved quantum efficiency and resolution. Such improved X-ray image intensifier tubes are especially useful for, but not limited in use to, X-ray systems and for intensifying gamma ray images obtained in applications of nuclear medicine.

Growing community of inventors

Stanford, CA, United States of America

William E Spicer