Philips Electronics North America Corporation

U.S. Philips Corporation

North American Philips Corporation

Kevin W Haberern

Sharon J Flamholtz

Rudolf P Tijburg

Ronald R Drenten

Mark Thomas Johnson

John Petruzzello

Nikhil R Taskar

Gerard Cnossen

James M Gaines

Piotr M Mensz

Adrianus A Van Der Put

Michael Buchel

Tom Marshall

Thomas M Marshall

Josephus P A Deeben

Paulette Kellawon

A light-emitting semiconductor device such as a laser or LED includes a light-emitting region interposed between two GaN contact layers of different conductivity types. A metal electrical contact is provided directly on one of the contact layers and is formed of an annealed, at least partly alloyed metal layer including hafnium and gold. The metal layer may also include platinum, or platinum and titanium. Light-emitting semiconductor devices such as light-emitting diodes and lasers having such annealed, at least partly alloyed metal layer are particularly suitable for high current-density applications which result in higher operating temperatures, such they are capable of operating at higher temperatures without shorting.

Metal electrical contact for high current density applications in LED and laser devices

In a display device comprising a first substrate having at least one transparent, first picture electrode of a first material, a second substrate comprising at least one second picture electrode of a second material which, jointly with the picture electrode on the first substrate and an intermediate opto-electronic material, defines a pixel, and means for supplying electric voltages to the picture electrodes, the work function between the two picture electrodes is decreased in that at least one of the picture electrodes is coated with at least one layer of conducting material, or a layer of a material comprising a dipole.

Display device in which one of the two electrodes of a pixel is coated with a dipole material to equalize the electrode work functions

A method for fracturing semiconductor crystal wafers or bars to form individual chips with active devices without the use of mechanical scribing of the crystal. The method involves forming where fracture is desired a shallow trench by etching in the semiconductor wafer or bar, preferably with sharp corners, or providing over where the fracture is desired the edges of a metallization layer, or both. Applying pressure will then cause the crystal to fracture as a result of strains formed in the crystal at the sharp corners or below the metallization edges. The method is particularly suitable for the fabrication of laser chips from compound semiconductors.

Semiconductor chip-making without scribing

An etching composition and method for its use in etching a semiconductor structure, the semiconductor structure comprising a substrate and one or more epitaxial layers. The etching composition comprises a solvent, an etchant, and first and second complexing agents, the etchant and complexing agents being soluble in the solvent. The etchant preferentially etches the substrate with respect to at least one epitaxial layer. The first complexing agent is reactive with the substrate so as to accelerate the rate at which the etchant etches the substrate. The second completing agent is reactive with a component of the at least one epitaxial layer so as to form a resulting compound with the component. This reaction establishes an equilibrium between the resulting compound, the second complexing agent and the component, the equilibrium precluding significant etching of the at least one epitaxial layer. The etching composition preferably comprises an agent which provides for adjusting the acidity of the solution, and thereby provides for adjusting the etch rate of the substrate while maintaining the composition's etching characteristics with respect to the at least one epitaxial layer.

Method of preferentially etching a semiconductor substrate with respect

A method for manufacturing a ridge in a channel laser diode in II-VI materials by etching grooves to form an active mesa flanked by support mesas. The method involves using certain etchants for certain compositions of the II-VI layers so that the grooves can be formed by wet chemical etching using only a single photolithographic process.

Method for fabricating a ridge-shaped laser in a channel

A blue, green or blue-green stripe-geometry II/VI semiconductor injection laser utilizing a Zn.sub.1-u Cd.sub.u Se active layer (quantum well) having Zn.sub.1-x Mg.sub.x S.sub.y Se.sub.1-y cladding layers and ZnS.sub.z Se.sub.1-z guiding layers is fabricated on a GaAs substrate. The stripe-geometry configuration is obtained by ion implanting a dopant such as Nitrogen or Oxygen into the structure to form blocking layer portions of higher resistivity in the second cladding layer and the second guiding layer. These blocking layer portions are positioned on both sides of, and thereby define, a stripe-shaped lateral confinement region of lower resistivity in the second cladding layer and the second cladding layer.

Method of making a stripe-geometry II/VI semiconductor gain-guided

A II-VI semiconductor diode laser has a strained layer disposed on top of the structure. This strained layer, having a thickness of between about 0.05 microns and 2 microns, is either a single film or a stack of films, preferably of metal. The strain field produced by this layer in the semiconductor layer structure produces a change in the refractive index of the structure, due to the photo-elastic effect. By virtue of this effect a strain-induced waveguide is provided in the diode laser, with a strained layer in an edge, stripe or window structure. Furthermore, a tensely-strained layer covering the entire structure is used to produce a strain field similar to that which occurs when the structure is bent. This strain field will produce strain-enhanced gain in the underlying structure, which allows for operation of the laser at a lower threshold current.

II-VI semiconductor diode laser having a strained layer

A blue-green II/VI semiconductor injection laser utilizing a Zn.sub.1-u Cd.sub.u Se active layer (quantum well) having Zn.sub.1-x Mg.sub.x S.sub.y Se.sub.1-y cladding layers and ZnS.sub.z Se.sub.1-z guiding layers on a GaAs substrate. These devices are operable in a pulse mode at room temperature.

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Hopewell Junction, NY, United States of America

Kevin W Haberern