Westinghouse Electric Corporation

Northrop Grumman Systems Corporation

Michael C Driver

Harvey C Nathanson

Michael W Cresswell

Ronald G Freitag

Donald K Alexander

Daniel F Yaw

He B Kim

Rowan L Messham

James G Oakes

John Xavier Przybysz

Rowland C Clarke

Maurice H Hanes

Bruce R McAvoy

Joseph C Kotvas

Regis J Betsch

John R Davis

Varley L Wrick

A heat tolerant, frequency responsive transistor for use in the microwave region includes a collector region, a base region overlying the collector region, and an emitter region including an AlGaN layer overlying at least part of said base region, forming a heterojunction between said base region and said emitter region. The emitter region may include two layers. The HBT may be mounted on a SiC or sapphire substrate. The HBT may include a buffer layer between the substrate and the collector region.

Aluminum gallium nitride heterojunction bipolar transistor

Aluminum gallium nitride based heterojunction bipolar transistor

A bonded structure is described consisting of a semiconductor wafer, preferably gallium arsenide, soldered to a substrate material. A method for forming the structure is also described. The structure provides mechanical support and thermal conductivity for the wafer, as well as a multitude of connections through the substrate material at predetermined locations on the wafer. The substrate material and the soldering process are selected to minimize the resulting stresses in the wafer. A pattern of pads consisting of a refractory metal covered by a solder material is formed on the substrate to maintain space for excess solder in order to avoid the shorting of the individual connections on the wafer, and to control the size and location of voids in the solder upon solidification.

Semiconductor wafer with circuits bonded to a substrate

A radio frequency transmitting shutter operable at low power and high speed for use in the protection of a radar or electronic warfare array comprising a multiplicity of individual conductive beam members interconnected by electrostatic switches formed using high yield, common photolithographic methods is disclosed. Further, a photosensitive embodiment of this device which would allow activation of the shutter wherever the light falls upon the shutter during radar protection, is disclosed and claimed.

High attenuation broadband high speed RF shutter and method of making

An improved phased-array active antenna transmit-receive means utilizing a multiplicity of individual transmit-receive cells positioned in an array format upon a common wafer of semiconductor material. Each transmit-receiver cell, comprises a multiplicity of redundant, integrated circuit, electronic devices implanted upon the common semiconductor substrate. The transmit-receive cells utilize novel mitered mechanical switches to permanently interconnect individual electronic devices into either transmit or receive circuits during the fabrication and test of the transmit-receive cells. Radio frequency and direct current input and output vias formed from a novel metal evaporation technique connect the devices upon the surface of the common semiconductor wafer to underlying, insulated direct current distribution circuits and a radio frequency manifold. This array of improved phased-array active antenna transmit-receive means comprised of transmit-receive cells sharing common central processing means, logic control and heat dissipation means results in a significant reduction in the size and weight of the standard phased-array active antenna system. This significant reduction in antenna system size and weight is very important in broad band electronic countermeasure systems or narrow band phased array active antenna radar systems as used in advanced tactical fighters, or space applications.

Mitered mechanical switches

An improved phased-array active antenna transmit-receive means utilizing a multiplicity of individual transmit-receive cells positioned in an array format upon a common wafer of semiconductor material. Each transmit-receive cell, comprises a multiplicity of redundant, integrated circuit, electronic devices implanted upon the common semiconductor substrate. The transmit-receive cells utilize novel mitered mechanical switches to permanently interconnect individual electronic devices into either transmit or receive circuits during the fabrication and test of the transmit-receive cells. Radio frequency and direct current input and output vias formed from a novel metal evaporation technique connect the devices upon the surface of the common semiconductor wafer to underlying, insulated direct current distribution circuits and a radio frequency manifold. This array of improved phased-array active antenna transmit-receive means comprised of transmit-receive cells sharing common central processing means, logic control and heat dissipation means results in a significant reduction in the size and weight of the standard phased-array active antenna system. This significant reduction in antenna system size and weight is very important in broad band electronic countermeasure systems or narrow band phased array active antenna radar systems as used in advanced tactical fighters, or space applications.

Process for producing vias in semiconductor

An improved phased-array active antenna transmit-receive means utilizing a multiplicity of individual transmit-receive cells positioned in an array format upon a common wafer of semiconductor material. Each transmit-receive cell, comprises a multiplicity of redundant, integrated circuit, electronic devices implanted upon the common semiconductor substrate. The transmit-receive cells utilize novel mitered mechanical switches to permanently interconnect individual electronic devices into either transmit or receive circuits during the fabrication and test of the transmit-receive cells. Radio frequency and direct current input and output vias formed from a novel metal evaportion technique connect the devices upon the surface of the common semiconductor wafer to underlying, insulated direct current distribution circuits and a radio frequency manifold. This array of improved phased-array active antenna transmit-receive means comprised of transmit-receive cells sharing common central processing means, logic control and heat dissipation means results in a significant reduction in the size and weight of the standard phased-array active antenna system. This significant reduction in antenna system size and weight is very important in broad band electronic countermeasure systems or narrow band phased array active antenna radar systems as used in advanced tactical fighters, or space applications.

Transmit-receive means for phased-array active antenna system using rf

A method of tuning a microwave integrated circuit by trimming desired film-type circuit patterns included therein by a cold-pressure bonding technique is disclosed. More specifically, intercoupled circuit patterns are formed on a semi-insulating substrate with some circuit patterns having impedance characteristics of a desired nominal value. Each circuit pattern may comprise a plurality of conductive paths of malleable metal. Gaps are provided at appropriately chosen places in the conductive paths of predetermined circuit patterns. Selected ones of the gaps of the conductive paths are bridged to adjust the impedance characteristics of the associated predetermined circuit pattern by wiping with a probe the malleable metal of the conductive path at one end of the gap, across the gap to make contact with the malleable metal of the conductive path at the other end of the gap. The method further includes steps for in-situ testing of the integrated circuit by energizing the microwave integrated circuit to effect operation thereof; testing selected parameters of the energized microwave integrated circuit for determining the operational response thereof; and performing the step of bridging selected gaps of the energized microwave integrated circuit with a probe of insulating material to adjust the impedance characteristics thereof to render a desired measure response therefrom as determined by the testing step.

Method for tuning a microwave integrated circuit

Electrical interconnection paths or vias are provided through relatively thick type III/V semiconductive substrates, such as gallium arsenide, to permit through the substrate electrical interconnection of planar transistor devices. The vias are etched in a two-step process which ensures that the via lateral dimensions are less than the transistor contacts with which they are aligned. The first step comprises selectively thinning the thick substrate from the back surface over an area which encompasses the transistor array formed in the front surface of the substrate. The second step is to etch the individual vias through this prior thinned substrate at areas aligned with the transistor contacts.

Two stage etching process for through the substrate contacts

A high peak power microwave generator is disclosed in which a plurality of transmission lines are connected to an output wave guide at predetermined intervals along the direction of propagation. Each transmission line is periodically charged, and this electromagnetic energy is released into the wave guide upon the actuation of a light activated silicon switch (LASS) diode connected to the transmission line. The LASS diodes are actuated simultaneously by a laser beam which traverses equal optical paths to each switch. The coincident switching of the transmission lines enables the power in each line to be additive in the wave guide, and much higher output pulses can be obtained. Further, the high speed switching capabilities afforded by the LASS diodes means that the resulting high power can be obtained at a much higher frequency.

High peak power microwave generator using light activated switches

A self-aligned gate field effect transistor is described which is capable of operating at high frequencies. A method for making the transistor is described which comprises plating metal partially over an oxide layer, then removing the oxide to produce an overlapping metal portion and then plating again to produce a gate contact between the overlapping metal portions.

Self-aligned gate field effect transistor and method for making same

A semiconductor device and particularly a self-aligned Schottky barrier gate field-effect transistor is made by epitaxial growth of facets corresponding to the source and drain regions on a surface of a semiconductor body through spaced apart preferably elongated windows in a masking layer and overgrowing edge portions of the masking layer at the windows to form overgrown portions on the facets. The channel region of the transistor is previously formed in the semiconductor body, preferably by epitaxial growth of a layer on a surface of a semiconductor body having a semi-insulating layer adjoining the surface. After removal of the masking layer, the Schottky barrier gate is self-aligned by deposition of metal on the unshielded portions of the planar surface between the facets.

Application of facet-growth to self-aligned Shottky barrier gate field

A high frequency, Schottky barrier gate, field-effect transistor is provided with a substantially constant impedance over a broadband of frequencies. The transistor is comprised of a thin dielectric layer providing an effective dielectric constant at gate and drain contacts greater than .sqroot.2. The dielectric layer is supported on the major surface of a conductor substrate, and is preferably 5 microns in thickness and has a dielectric constant greater than about 5. The transistor is also comprised of a thin semiconductor layer of less than about 2 microns in thickness at least at gate portions with an N-type concentration of between about 5 .times. 10.sup.14 and 5 .times. 10.sup.17 carriers/cm.sup.3. The gate contact of the transistor is an elongated Schottky barrier contact adjoining the semiconductor layer spaced between elongated source and drain contacts which make ohmic contact with the semiconductor layer. Means are also provided to maintain the source contact at substantially the same RF potential as the conductor substrate.

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McKeesport, PA, United States of America

Michael C Driver