Bell Telephone Laboratories

At&t Bell Laboratories

Western Electric Company, Inc.

American Telephone & Telegraph Co., At&t Bell Laboratories

Irfan Camlibel

Shobha Singh

George J Zydzik

LeGrand G Van Uitert

Aland K Chin

Legrand G Van Uitert

Theodore C Rich

Brymer H Chin

John R Zuber

Howard Joseph Guggenheim

Randolph H Burton

Douglas Arthur Pinnow

Robert H Saul

Christie Lewis Zipfel

Franklin Winston Dabby

Walter W Benson

Donald R Mackenzie

The area of a surface-emitting LED is reduced, and hence the number of LEDs which can be obtained from a single wafer is increased, by a chip design in which the light-emitting spot is positioned asymmetrically toward one corner of the chip. Preferably, an L-shaped contact is formed on the light output surface so that light-emitting spot emerges from between the legs of the L.

Asymmetric chip design for LEDS

Proposed is a method of fabricating III-V and II-VI compound semiconductors and a resulting product where there is formed on the surface a coating which can function as a diffusion mask and/or a passivation layer. The coating is a silicon layer deposited by a method which does not damage the semiconductor surface.

Coating of III-V and II-VI compound semiconductors

Presented is a dual wavelength structure wherein two edge-emitting devices are bonded with p-regions adjacent. The bonding medium is a conductive compound that forms a common electrode between the devices. Each device is separately addressable. Efficient coupling of emitted light into a single fiber is accomplished by restricting the vertical and horizontal separation of the light emitting stripes.

Multiple wavelength light emitting devices

Electrical contacts with low specific-contact resistance to In-based Group III-V compound semiconductors (e.g., p-InGaAsP) are formed by electron beam depositing a thin Pt layer directly on the semiconductor and sintering at about 450.degree.-525.degree. C. for about 5-30 minutes. Light emitting diodes without dark spot defects can be fabricated using this technique.

Forming platinum contacts to in-based group III-V compound devices

Disclosed is an indium-containing semiconductor device which includes an ohmic contact formed by application of successive layers of Au-Sn-Cr-Au. The combination of Sn and Cr layers provides an effective barrier to the diffusion of indium to the surface of the contact so that bonding to the contact is not impeded.

Ohmic contacts for semiconductor devices

A process is described for doping compound semiconductors using a metal fluoride (e.g., ZnF.sub.2) as the source of dopant. The anhydrous metal fluoride is put down on the surface of the compound semiconductor, capped with a suitable encapsulant and heat treated to promote the diffusion. The heat treatment can be carried out in air without danger of surface damage to the compound semiconductor. Also, the diffusion is better controlled as to depth of diffusion and boundary delineation.

Diffusion procedure for semiconductor compound

A process is described for fabricating various optical devices including photodiodes in which a protective dielectric layer is put down on the surface of the device prior to heating to temperatures over about 250-300 degrees C. Such devices have excellent performance characteristics including low dark current and low noise figures.

Preparation of photodiodes

A fabrication technique is described for making various devices in which a type of glass is used as a surface protection layer. The glass layers are put down by particle bombardment (generally sputtering) of a borosilicate glass target. Devices with such surface layers are also described. Such glass layers are highly advantageous as encapsulating material, diffusion barrier layers, etc., particularly for optical type devices and certain semiconductor devices. Particularly important is the preparation procedure for the glass target used in the bombardment process. The glass layers are moisture stable, act as excellent barriers against diffusion, and are usable up to quite high temperatures without cracking or peeling. The glass layers also provide long-term protection against atmosphere components including water vapor, oxygen, atmosphere pollution contaminants, etc.

Device fabrication procedure

Display devices are described which contain organic quinones or diones as active material. These devices exhibit high optical contrast, pleasing and striking colors and unusually low power consumption. Particularly advantageous is the fact that these display devices may exhibit non-linear behavior (sharp thresholds) which permit multiplexing. This is highly advantageous in display device applications.

Display devices

A process for hermetically sealing an optical fiber to a metal housing is described. An optical fiber 12 is threaded through a thick-walled metal tube 10 which has a bore 11 of slightly larger diameter than the fiber. The tube and fiber are inserted in a pneumatically operated collet and uniform radial pressure is applied to the tube to form a unitary hermetic assembly. Metal tube 10 is characterized in that it has or, prior to forming the assembly, is annealed to have a Rockwell hardness of less that 15 T 15. At this value the metal is soft and the pressure required to cause the metal to cold flow around the fiber is less than that required to break the fiber. The tube is then soldered or otherwise secured in a hole in the housing, thus completing the hermetic seal. Such a seal is useful in hermetic packaging of optical devices. It is advantageous over the prior art for its simplicity and inexpensiveness. The technique is suited to high yield mass production of reliable seals.

Optical fiber-to-metal hermetic seal

An electrodeposition display device is described which uses an electrolyte containing silver species and certain anion species including iodide and bromide. The electrolyte also contains an opacifier made up of solid semiconductor substance and solid insulator substance. Such display devices have high contrast, large viewing angle and a pleasing variety of colors including blue, red and brown.

Electrodeposition display device

An electrodeposition display device is described which uses an electrolyte containing silver species and certain anion species including iodide bromide or chloride. The electrolyte also contains a substituted ammonium halide such as tetrabutyl ammonium iodide. Such display devices have high contrast, large viewing angle and rapid redissolution of the display.

An optical fiber is hermetically sealed to a metal housing containing an optical device (e.g, a semiconductor junction laser or photodiode) by threading and centering the fiber through a thin walled metal tube, filling the tube with solder (e.g., a cylindrical preform) and allowing it to cool. The solder, upon solidifying and cooling, squeezes against the fiber and forms a hermetic seal. The tube-fiber assembly is inserted through an aperture in the housing wall, the fiber is aligned with the optical device and then the tube is soldered to the wall. The housing is out-gassed and then back-filled with a noncorrosive ambient such as nitrogen. Other aspects of the hermetic package, including a laser mount, are also described.

Package for optical devices including optical fiber-to-metal hermetic

A method is disclosed for fabricating an optical fiber by drawing a preform whose manufacture involves the deposition of a borosilicate layer. The method calls for borosilicate deposition by high temperature pyrolysis of two gases, with processing parameters chosen so as to cause an acicular structure in the deposited layer, a structure which contributes to the uniformity of the drawn fiber.

Growing community of inventors

Stirling, NJ, United States of America

Irfan Camlibel