Bell Telephone Laboratories

At&t Bell Laboratories

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

Bertram Schwartz

Louis A Koszi

Robert Louis Hartman

Richard C Miller

Richard W Dixon

Marlin W Focht

Albert T Macrander

Shobha Singh

Federico Capasso

George J Zydzik

William Baxter Joyce

Legrand G Van Uitert

Leonard C Feldman

Wilbur D Johnston, Jr

Philip J Anthony

Cyril J Mogab

Judith A Long

Chuan C Chang

Bernard Collins De Loach, Jr

William Henry Grodkiewicz

Paul H Citrin

Marc Ilegems

Gerard E Henein

Ralph T Hepplewhite

David T Ekholm

Epitaxial layers of semi-insulating InP grown by MOCVD on conducting InP wafers make excellent substrates for III-V semiconductor devices. Particularly appealing is the low defect density obtained because of the conducting InP wafers and excellent insulating characteristics of the semi-insulating InP layer. The invention is a procedure for doping the insulating layer by ion implantation. Such a procedure is unusually advantageous for fabricating a variety of devices including MISFETs, MESFETs and JFETs.

Method of making indium phosphide devices

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 or e-beam bombardment) of a phosphorus-containing silicate glass target. Devices with such 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.

Fabrication of devices using phosphorus glasses

Indium is used to bond semiconductor lasers to their heat-sinks without the presence of a corrosive liquid flux. Fluxless bonding is achieved in a vacuum chamber in reducing ambients of CO or H.sub.2. Low strain bonds are achieved at bonding temperatures of approximately 180.degree.-240.degree. C. in CO and 220.degree.-230.degree. C. in H.sub.2. Void-free bonds are achieved in CO at temperatures as low as about 205.degree. C. The technique is applicable to other microelectronic chips such as LEDs, for example.

Fluxless bonding of microelectronic chips

Helium-3 and helium-4 bombardment of InP over a fluence range of 10.sup.11 to 10.sup.16 ions/cm.sup.2 reproducibly forms highly resistive regions in both p-type and n-type single crystal material. Average peak resistivities are about 10.sup.9 ohm-cm for p-type InP and are about 10.sup.3 ohm-cm for n-type InP. High resistivity has also been produced in GaP, GaSb, GaAs, and InGaAs by helium bombardment. Stripe geometry lasers and planar photodiodes which incorporate helium-bombarded zones are described.

High resistivity group III-V compounds by helium bombardment

The property of materials in the GaAs/AlGaAs system, whereby at certain doses proton bombarded n-type material becomes highly resistive but p-type material remains highly conductive, is utilized to fabrication of integrated circuits which include buried semiconductor interconnections or bus bars between devices.

Method of making integrated circuits employing proton-bombarded AlGaAs

The property of materials in the InP system, whereby helium ion or deuteron bombarded p-type material becomes highly resistive but n-type material remains relatively conductive, is utilized to fabricate integrated circuits which include buried semiconductor interconnections or bus bars between devices.

Method of making integrated circuits employing ion-bombarded InP layers

The property of Group III-V compound materials, whereby ion bombarded material becomes highly resistive but recovers its original low resistivity by annealing at a temperature which is dopant and material dependant, is utilized to fabricate integrated circuits which include buried semiconductor interconnections or bus bars between devices.

Production of semiconductor structures with buried resistive or

Semiconductor light emitting devices, lasers and LEDs, are described in which the current flow channel is narrower near the top surface of the device and wider at its bottom near the active region. Also, described are several attenuation masks for fabricating the channels of these devices by particle bombardment.

Method of forming current confinement channels in semiconductor devices

A TJS light emitting diode (laser or LED) comprises an isotype double heterostructure (DH) and a V-groove which penetrates the intermediate layer of the DH. The groove is filled with a region of semiconductor material which enables carrier injection to occur from the region into the intermediate layer, or conversely, depending on the relative bandgaps of the layer and region. Real-refractive index guiding by the groove is described.

Stripe-guide TJS laser

Current confinement in semiconductor light emitting devices

A system (FIG. 1) for interrogating the ON-OFF status of an electrical switch (31) comprises a semiconductor body (4) containing a PN junction and means (5) for electrically connecting an auxiliary switch (32) coupled to the interrogated switch, or alternately (FIG. 2) the interrogated switch (32), across the PN junction. Light (7) of a first wavelength incident on the semiconductor body causes light of a second wavelength (11) to be emitted from the body when the switch is open (OFF), whereas no light is emitted from the body when the switch is closed (ON). Therefore, photoelectric detection of the emission vs. non-emission of light of the second wavelength from the semiconductor body indicates the OFF vs. ON status of the switch.

Optical system for interrogation of the status of a switch

Semiconductor lasers and LEDs are described in which the pumping current is constrained to flow from a relatively narrow upper channel formed by a V-groove, which extends to a depth short of the active region, through a relatively wider lower channel bounded by high resistivity regions, which extend from at least that depth into or through the active region. Also described are devices in which the V-groove is refilled with semiconductor material.

V-Groove semiconductor light emitting devices

This invention is a semiconductor junction laser which operates in a transverse mode, other than the fundamental mode, parallel to the p-n junction. An undesired transverse mode parallel to the p-n junction may be suppressed by introducing a lossy region within the laser where this mode has at least one of its maxima. The zero order transverse mode parallel to the p-n junction may be suppressed in a double heterostructure stripe geometry laser by introducing an optically or electrically lossy region in the current flow path of the laser where the zero order mode has its maximum. This double heterostructure stripe geometry laser operates linearly with respect to current in the first order transverse mode parallel to the p-n junction.

Semiconductor lasers with stable higher-order modes parallel to the

The tracking problems of prior art optical monitoring (e.g., feedback stabilization) schemes are substantially alleviated by positioning a photodiode (PD 130) directly in the light path of the optical source (100) to be stabilized. The active (light-absorbing) layer (104) of the PD samples (absorbs) only a small portion of the light beam (140) emanating from the source and converts that portion to a photocurrent used in a feedback loop (120, 101) to control the excitation supplied to the source. The remaining, major portion (140') of the beam is transmitted unabsorbed through the PD active layer to utilization means (e.g., through an optical fiber 108 to a remote receiver). Advantageously, in one embodiment the PD is a double heterostructure (DH) in which the photocurrent is linearly related to the beam intensity. The use of discrete or integrated lens means (110, 110', 164, 166) to enhance coupling from the source to PD is described. In addition, tandem DH-PDs (150, 152) are also described which perform both detection, for demodulating encoded information at one optical frequency, and sampling, for feedback stabilization at another optical frequency.

Optical monitoring photodiode system

Plasma etching is described as a selective etch for dielectric masks such as SiO.sub.2, Si.sub.3 N.sub.4 and certain photoresists in the presence of native oxides of Group III-V compound semiconductors. This process can be used in the fabrication of mesa junction lasers and Burrus light emitting diodes.

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Westfield, NJ, United States of America

Bertram Schwartz