Abstract: A transistor includes an active region bounded by an outer periphery and formed in a substrate. The active region includes sets of input fingers, output fingers, and common fingers disposed within the substrate and oriented substantially parallel to one another. The transistor further includes an input port, an output port, a first via connection disposed at the outer periphery of the active region proximate the input port and a second via connection disposed at the outer periphery of the active region proximate the output port. The second via connection has a noncircular cross-section with a second major axis and a second minor axis, the second major axis having a second major axis length, the second minor axis having a second minor axis length that is less than the second major axis length. The second major axis is oriented parallel to a longitudinal dimension of the input, output, and common fingers.

Abstract: An embodiment of a semiconductor device includes a semiconductor substrate, a first dielectric layer disposed over a semiconductor substrate, a source electrode and a drain electrode formed over the semiconductor substrate within openings formed in the first dielectric layer, a gate electrode formed over the semiconductor substrate between the source electrode and the drain electrode, and a protection layer disposed on the source electrode, the drain electrode, and the first dielectric layer, wherein a first edge of the protection layer terminates the protection layer between the source electrode and the gate electrode, and a second edge of the protection layer terminates the protection layer between the gate electrode and the drain electrode. A method for fabricating the semiconductor devices includes forming a first dielectric layer over the semiconductor substrate, forming source and drain electrodes, depositing the protection layer over the source and drain electrodes, and forming the gate electrode.

Abstract: A transistor includes an active region bounded by an outer periphery and formed in a substrate. The active region includes sets of input fingers, output fingers, and common fingers disposed within the substrate and oriented substantially parallel to one another. The transistor further includes an input port, an output port, a first via connection disposed at the outer periphery of the active region proximate the input port and a second via connection disposed at the outer periphery of the active region proximate the output port. The second via connection has a noncircular cross-section with a second major axis and a second minor axis, the second major axis having a second major axis length, the second minor axis having a second minor axis length that is less than the second major axis length. The second major axis is oriented parallel to a longitudinal dimension of the input, output, and common fingers.

Abstract: A transistor includes an active region bounded by an outer periphery and formed in a substrate. The active region includes sets of input fingers, output fingers, and common fingers disposed within the substrate and oriented substantially parallel to one another. The transistor further includes an input port, an output port, a first via connection disposed at the outer periphery of the active region proximate the input port and a second via connection disposed at the outer periphery of the active region proximate the output port. The second via connection has a noncircular cross-section with a second major axis and a second minor axis, the second major axis having a second major axis length, the second minor axis having a second minor axis length that is less than the second major axis length. The second major axis is oriented parallel to a longitudinal dimension of the input, output, and common fingers.

Abstract: Power amplifiers such as multi-path power amplifiers, systems employing such amplifiers, and methods of implementing amplifiers and amplifier systems are disclosed herein. In one example embodiment, a multi-path power amplifier includes a first semiconductor die with an integrated first transistor having a first source-to-drain pitch, and a second semiconductor die with an integrated second transistor having a second source-to-drain pitch, where the second source-to-drain pitch is smaller than the first source-to-drain pitch by at least 30 percent. In another example embodiment, a Doherty amplifier system includes a first semiconductor die with a first physical die area to total gate periphery ratio, and a second semiconductor die with a second physical die area to total gate periphery ratio, where the second physical die area to total gate periphery ratio is smaller than the first physical die area to total gate periphery ratio by at least 30 percent.

Abstract: Power amplifiers such as multi-path power amplifiers, systems employing such amplifiers, and methods of implementing amplifiers and amplifier systems are disclosed herein. In one example embodiment, a multi-path power amplifier includes a first semiconductor die with an integrated first transistor having a first source-to-drain pitch, and a second semiconductor die with an integrated second transistor having a second source-to-drain pitch, where the second source-to-drain pitch is smaller than the first source-to-drain pitch by at least 30 percent. In another example embodiment, a Doherty amplifier system includes a first semiconductor die with a first physical die area to total gate periphery ratio, and a second semiconductor die with a second physical die area to total gate periphery ratio, where the second physical die area to total gate periphery ratio is smaller than the first physical die area to total gate periphery ratio by at least 30 percent.

Abstract: A device includes a transistor configured for depletion-mode operation, the transistor having a gate terminal and a drain terminal, and an electrostatic discharge (ESD) protection circuit coupling the gate terminal and the drain terminal. The ESD protection circuit includes a discharge path circuit and a trigger circuit coupled to, and configured to control, the discharge path circuit. The discharge path circuit and the trigger circuit are disposed between the gate terminal and the drain terminal.

Abstract: A semiconductor device includes a semiconductor substrate configured to include a channel, first and second ohmic contacts supported by the semiconductor substrate, in ohmic contact with a contact region formed within the semiconductor substrate, and spaced from one another for current flow between the first and second ohmic contacts through the channel, and first and second dielectric layers supported by the semiconductor substrate. At least one of the first and second ohmic contacts extends through respective openings in the first and second dielectric layers. The second dielectric layer is disposed between the first dielectric layer and a surface of the semiconductor substrate, and the second dielectric layer includes a wet etchable material having an etch selectivity to a dry etchant of the first dielectric layer.

Abstract: A device includes a transistor configured for depletion-mode operation, the transistor having a gate terminal and a drain terminal, and an electrostatic discharge (ESD) protection circuit coupling the gate terminal and the drain terminal. The ESD protection circuit includes a discharge path circuit and a trigger circuit coupled to, and configured to control, the discharge path circuit. The discharge path circuit and the trigger circuit are disposed between the gate terminal and the drain terminal.

Abstract: In one form of the invention, an emitter structure for a bipolar transistor is disclosed. The structure is comprised of an emitter layer 6 of Al.sub.x Ga.sub.1-x As, where x>0.4, abutting a base layer 8.

Abstract: This is a method of fabricating a heterojunction bipolar transistor on a wafer. The method can comprise: forming a doped subcollector layer 31 on a semiconducting substrate 30; forming a doped collector layer 32 on top of the collector layer, the collector layer doped same conductivity type as the subcollector layer; forming a doped base epilayer 34 on top of the collector layer, the base epilayer doped conductivity type opposite of the collector layer; forming a doped emitter epilayer 36, the emitter epilayer doped conductivity type opposite of the base layer to form the bipolar transistor; forming a doped emitter cap layer 37 on top of the emitter epilayer, the emitter cap layer doped same conductivity as the emitter epilayer; forming an emitter contact 38 on top of the emitter cap layer; forming a base contact on top of the base layer; forming a collector contact on top of the collector layer; and selective etching the collector layer to produce an undercut 45 beneath the base layer.