Bae Systems Information and Electronic Systems Integration Inc.

Biogen Idec Ma Inc.

Pane-Chane Chao

Kanin Chu

Dong Xu

Wendell Kong

Gabriel R Cueva

Lee M Mohnkern

Phillip M Smith

Anthony A Immorlica

Xiaoping S Yang

Robert Actis

Robert J Lender, Jr

Kirby B Nichols

Bernard J Schmanski

Sue May Jessup

A field effect transistor and method for making such a transistor is provided, the field effect transistor comprising: a gate layer stack comprising a layer of a first metal is disposed proximate to at least one layer of a second metal, wherein the first metal alloys with the second metal to form a shape memory alloy. The shape metal allow may be NiTi, and at the contact plane between the layers, the alloy is formed when the transistor is heated to an elevated temperature.

Field effect transistors with gate electrodes having Ni and Ti metal layers

A high-power and high-gain ultra-short gate HEMT device has exceptional gain and an exceptionally high breakdown voltage provided by an increased width asymmetric recess for the gate electrode, by a composite channel layer including a thin indium arsenide layer embedded in the indium gallium arsenide channel layer and by double doping through the use of an additional silicon doping spike. The improved transistor has an exceptional 14 dB gain at 110 GHz and exhibits an exceptionally high 3.5-4 V breakdown voltage, thus to provide high gain, high-power and ultra-high frequency in an ultra-short gate device.

Asymmetrically recessed high-power and high-gain ultra-short gate HEMT device

In summary, a vertical metalized transition in the form of a via goes from the back side of a high thermal conductivity substrate and through any semiconductor layers thereon to a patterned metalized strip, with the substrate having a patterned metalized layer on the back side that is provided with a keep away zone dimensioned to provide impedance matching for RF energy coupled through the substrate to the semiconductor device while at the same time permitting the heat generated by the semiconductor device to flow through the high thermal conductivity substrate, through the back side of the substrate and to a beat sink.

Method and design of an RF thru-via interconnect

A method for fabrication of a field effect transistor gate, with or without field plates, includes the steps of defining a relatively thin Schottky metal layer by a lithography/metal liftoff or metal deposition/etch process on a semiconductor surface. This is followed by depositing a dielectric passivation layer over the entire wafer and defining a second lithographic pattern coincident with or slightly inset from the boundaries of the previously defined metal gate layer. This is followed by etching the dielectric using dry or wet etching techniques and stripping the resist, followed by exposing and developing a third resist pattern to define the thicker gate metal layers required for electrical conductivity and also for the field plate if one is utilized. The final step is depositing gate and/or field plate metal, resulting in a gate electrode and an integral field plate.

Structure and method for fabrication of field effect transistor gates with or without field plates

A method for fabricating ultra-short T-gates on heterojunction field effect transistors (HFETs) comprising the steps of (a) providing a coating of three layers of resists, with polymethylmethacrylate (PMMA) with high molecular weight on the bottom, polydimethylglutarimide (PMGI) in the middle, and PMMA with low molecular weight on the top; (b) in a first exposure, exposing and developing the layers with a dose of a developer that is high enough to allow the developer to break the top PMMA but low to avoid contributing significantly to the overall dose received in the bottom PMMA layer; and (c) in a second exposure, using an exposure and developing process to define 0.03-0.05 um openings in the bottom PMMA layer.

Reproducible, high yield method for fabricating ultra-short T-gates on HFETs

Growing community of inventors

Nashua, NH, United States of America

Pane-Chane Chao