Abstract: An example field effect transistor includes a substrate, a first source metal over the substrate, a second source metal over the substrate, and a drain metal positioned between the first source metal and the second source metal over a channel of the field effect transistor. The drain metal includes a drain metal body having a notched region between the first source metal and the second source metal over the channel, and the notched region defines a first projecting portion and a second projecting portion of the drain metal body. In one aspect, the first projecting portion and the second projecting portion are positioned on respective sides of the notched region. The notched region is a triangular-shaped notched region in one example.

Abstract: A power amplifier has an amplifier cell with an input terminal receiving an input signal and an output terminal providing an output signal. A bias network is coupled to the output terminal of the amplifier cell to provide a bias signal to the amplifier cell. A shutdown circuit is coupled to the bias network to disable the bias network in response to the input signal. The shutdown circuit has a transistor with a first conduction terminal coupled to the bias network, a second conduction terminal coupled to a power supply terminal. The shutdown circuit further has a first resistor with a first terminal coupled to the input terminal, and a second resistor with a first terminal coupled to a second terminal of the first resistor at a node, and a second terminal coupled to the power supply terminal. The control terminal of the transistor is coupled to the node.

Abstract: 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.

Abstract: Extrinsic structures formed outside the active regions of active devices can influence aging characteristics and performance of the active devices. An example integrated device including such an extrinsic structure includes an active region of a semiconductor device in a plurality of layers of semiconductor materials over a substrate, an isolation region in at least one of the layers of semiconductor materials, the isolation region extending around the semiconductor device in an area outside of the active region, an insulating layer over at least a portion of the active region and over at least a portion of the isolation region, a via in the isolation region and outside the active region, the via extending through the insulating layer and down to a conduction layer among the layers of semiconductor materials in the isolation region, and an interconnect within the via and directly on the conduction layer in the isolation region.

Abstract: Various aspects of integrated amplifiers, layouts for the integrated amplifiers, and packaged arrangements of the amplifiers are described. An example integrated amplifier includes an amplifier cell and a stability capacitor. The amplifier cell includes a common source transistor and a common gate transistor in a cascode arrangement. The common gate transistor includes a plurality of contacts. The stability capacitor is coupled between an output for the integrated amplifier and a gate of the common gate transistor. The stability capacitor is formed among the plurality of contacts of the common gate transistor over the semiconductor die. In one example, the stability capacitor includes a plurality of stability capacitors distributed among the plurality of contacts of the common gate transistor. The stability capacitor can also be distributed along an interconnect feed finger that extends between the contacts of the common gate transistor.

Abstract: An electrode structure for a device, such as a GaN or AlGaN device is described. An example electrode structure includes a substrate with a gallium nitride material layer, an insulating layer formed on the substrate, the insulating layer including an opening that exposes a surface region of the gallium nitride material layer through the opening, a barrier metal layer on the surface region of the gallium nitride material layer and on a region of the insulating layer, and a conducting metal layer on the barrier metal layer. In other aspects, the electrode structure can also include a cap metal layer on the conducting metal layer, and a cap etch photoresist layer over the cap metal layer. The cap metal layer, the conducting metal layer, and the barrier metal layer can be etched down to the insulating layer over an area outside a width of the cap etch photoresist layer.

Abstract: 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.

Abstract: Various aspects of integrated amplifiers, layouts for the integrated amplifiers, and packaged arrangements of the amplifiers are described. In one example, an amplifier includes an amplifier cell, and a biasing network coupled to the common gate transistor in the amplifier cell. The amplifier cell includes a common source transistor and a common gate transistor in a cascode arrangement, where at least one of the common source transistor and the common gate transistor comprises a field plate. Among other advantages, the amplifiers described herein can be biased with relatively high voltages and still operate like a single a common source transistor, without sacrificing reliability, performance, or requiring additional off-chip components, such as biasing networks of resistors and inductors.

Abstract: Semiconductor structures including III-nitride materials are described herein, including semiconductor structures comprising III-nitride material regions (e.g., gallium nitride material regions). An example semiconductor structure includes a substrate, a III-nitride material region located over the substrate, a first-type electrode over the III-nitride material region, and a second-type electrode over the III-nitride material region. The first-type electrode defines a first electrode interfacial area with the III-nitride material region. The second-type electrode defines a second electrode interfacial area with the III-nitride material region. The first electrode interfacial area is less than 20 times the second electrode interfacial area in at least one example.

Abstract: Electrode structures and methods of manufacturing electrode structures for devices are described. An example electrode structure includes a gate metal formation including a nitride layer with an opening that exposes a surface region of a substrate, a gate metal layer on the surface region of the substrate, a barrier metal layer on the gate metal layer and on at least a portion of a step around the opening in the nitride layer, and a conductive metal layer on the barrier metal layer. The gate metal layer is on the surface region of the substrate and on at least another portion of the step around the opening in the nitride layer in one example. The gate metal layer includes first and second gate metal layers in one example, such as nickel and tungsten.

Abstract: Extrinsic structures formed outside the active regions of active devices can influence aging characteristics and performance of the active devices. An example integrated device including such an extrinsic structure includes an active region of a semiconductor device in a plurality of layers of semiconductor materials over a substrate, an isolation region in at least one of the layers of semiconductor materials, the isolation region extending around the semiconductor device in an area outside of the active region, an insulating layer over at least a portion of the active region and over at least a portion of the isolation region, a via in the isolation region and outside the active region, the via extending through the insulating layer and down to a conduction layer among the layers of semiconductor materials in the isolation region, and an interconnect within the via and directly on the conduction layer in the isolation region.

Abstract: An example field effect transistor includes a substrate, a first source metal over the substrate, a second source metal over the substrate, and a drain metal positioned between the first source metal and the second source metal over a channel of the field effect transistor. The drain metal includes a drain metal body having a notched region between the first source metal and the second source metal over the channel, and the notched region defines a first projecting portion and a second projecting portion of the drain metal body. In one aspect, the first projecting portion and the second projecting portion are positioned on respective sides of the notched region. The notched region is a triangular-shaped notched region in one example.

Abstract: 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.

Abstract: A method of manufacturing an electrode structure for a device, such as a GaN or AlGaN device is described. In one example, the method includes providing a substrate (212) of GaN or AlGaN with a surface region of the GaN or AlGaN exposed through an opening (216) in a layer of silicon nitride (214) formed on the substrate. The method further includes depositing layers of W (222), in one example, or Ni (220) and W (222), in another example, on the substrate and the layer of silicon nitride using reactive evaporation and photoresist layers (230) having an undercut profile for liftoff. The method further includes removing the photoresist layers having the undercut profile, and depositing layers of WN (224) and Al over the underlying layers of W or Ni and W by sputtering.

Abstract: Extrinsic structures formed outside the active regions of active devices can influence aging characteristics and performance of the active devices. An example integrated device including such an intrinsic structure includes a semiconductor device having an active region in a conduction layer, an isolation region in the conduction layer, an insulating layer formed over at least a portion of the active region and over at least a portion of the isolation region, a via outside the active region, and a conductive interconnect. The isolation region extends around the semiconductor device in an area outside the active region. The via extends through the insulating layer and down to the isolation region in the conduction layer, and the conductive interconnect is formed directly on the isolation region in the conduction layer.

Abstract: Semiconductor structures and devices in III-nitride materials are described herein, including material structures comprising III-nitride material regions (e.g., gallium nitride material regions). In certain cases, the material structures comprise substrates having relatively high electrical conductivities. In other cases, the material structures comprise substrates having relatively high resistivities. Certain embodiments include one or more features that reduce the degree to which thermal runaway occurs, which can enhance device performance including at elevated flange temperatures. Some embodiments include one or more features that reduce the degree of capacitive coupling exhibited during operation. For example, in some embodiments, relatively thick III-nitride material regions and/or relatively small ohmic contacts are employed.

Abstract: Various embodiments are disclosed for improved and structurally optimized transistors, such as RF power amplifier transistors. A transistor may include a drain metal portion raised from a surface of a substrate, a drain metal having a notched region, a gate manifold body with angled gate tabs extending from the gate manifold, and/or a source-connected shielding. The transistor may include a high-electron-mobility transistor (HEMT), a gallium nitride (GaN)-on-silicon transistor, a GaN-on-silicon-carbide transistor, or other type of transistor.

Abstract: 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.

Abstract: Apparatus and methods relating to heterolithic microwave integrated circuits HMICs are described. An HMIC can include different semiconductor devices formed from different semiconductor systems in different regions of a same substrate. An HMIC can also include bulk regions of low-loss electrically-insulating material extending through the substrate and located between the different semiconductor regions. Passive RF circuit elements can be formed on the low-loss electrically-insulating material.

Abstract: Various methods of forming integrated circuits formed using gallium nitride and other materials are described. An example method includes forming a first integrated device over a first semiconductor structure in a first region of the integrated circuit, forming a second integrated device over a second semiconductor structure in a second region of the integrated circuit, etching a cavity in a third region of the of the integrated circuit located between the first region and the second region, filling the cavity with an insulating material, and forming a passive component over the insulating material in the third region of the integrated circuit. In other aspects, the method can include grinding a back side of a semiconductor substrate of the integrated circuit to electrically isolate the first semiconductor structure from the second semiconductor structure and, after the grinding, forming a ground plane over the back side of the semiconductor substrate.