Macom Technology Solutions Holdings, Inc.

Bae Systems Information and Electronic Systems Integration Inc.

Gabriel R Cueva

Wayne Mack Struble

Timothy Edward Boles

Pane-Chane Chao

Allen W Hanson

Kanin Chu

Kirby B Nichols

Yan Zhang

Dong Xu

Wendell Kong

Semiconductor structures with reduced parasitic capacitance between interconnects and ground, for example, are described. An example method for making a semiconductor structure includes forming a trench in an interconnect area of a substrate between first and second device areas in the semiconductor structure, forming a low dielectric constant material region in the trench, forming a III-nitride material layer over the substrate and over the low dielectric constant material region in the trench, forming a first device in the III-nitride material layer in the first device area, forming a second device in the III-nitride material layer in the second device area, and forming an interconnect over the low dielectric constant material region, the interconnect comprising a continuous conductive metal interconnect from the first device area, over the low dielectric constant material region, and to the second device area.

Parasitic capacitance reduction in GaN-on-silicon devices

An electrode structure for a device, such as a GaN or AlGaN device is described. In one example, a method to form the structure includes providing a substrate including gallium nitride material, forming an insulating layer over a surface of the substrate, forming an opening in the insulating layer to expose a surface region of the substrate, depositing a barrier metal layer over the insulating layer and onto the surface region of the substrate through the opening, and depositing a conducting metal layer over the barrier metal layer. In one case, the barrier metal layer includes a layer of tungsten nitride. The layer of tungsten nitride is deposited over the insulating layer and onto the surface region of the substrate using atomic layer deposition.

Atomic layer deposition of barrier metal layer for electrode of gallium nitride material device

Semiconductor structures with reduced parasitic capacitance between interconnects and ground, for example, are described. In one case, a semiconductor structure includes a substrate and a low dielectric constant material region in the substrate. The low dielectric constant material region is positioned between a first device area in the semiconductor structure and a second device area in the semiconductor structure. The semiconductor structure also includes a III-nitride material layer over the substrate. The III-nitride material layer extends over the substrate in the first device area, over the low dielectric constant material region, and over the substrate in the second device area. The semiconductor structure can also include a first device formed in the III-nitride material layer in the first device area, a second device in the III-nitride material layer in the second device area, and an interconnect formed over the low dielectric constant material region. The interconnect can provide a continuous conductive path of metal from the first device area, over the low dielectric constant material region, and to the second device area.

Parasitic capacitance reduction in GaN devices

A method for making a semiconductor structure includes defining one or more device areas and one or more interconnect areas on a silicon substrate, forming trenches in the interconnect areas of the silicon substrate, oxidizing the silicon substrate in the trenches to form silicon dioxide regions, forming a III-nitride material layer on the surface of the silicon substrate, forming devices in the device areas of the gallium nitride layer, and forming interconnects in the interconnect areas. The silicon dioxide regions reduce parasitic capacitance between the interconnects and ground.

An apparatus includes a channel layer, a first layer, a hole barrier layer and a second layer. The channel layer may be configured to carry a drain current in response to a voltage at a gate node. The first layer may be between the channel layer and the gate node. The first layer generally has a first bandgap. The hole barrier layer may be in contact with the first layer. The hole barrier layer generally has a second bandgap that (i) forms a valence band offset relative to the first bandgap and (ii) is configured to impede holes generated in one or more of the channel layer and the first layer from reaching the gate node. The gate node may be in contact with the second layer. The apparatus generally forms a field effect transistor.

Transistor with hole barrier layer

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 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.

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Bedford, NH, United States of America

Gabriel R Cueva