Skyworks Solutions, Inc.

Cristian Cismaru

Peter J Zampardi

Andre G Metzger

Kai Hay Kwok

Guoliang Zhou

This disclosure relates to bipolar transistors, such as heterojunction bipolar transistors, having increased collector thickness for improved ruggedness. In some embodiments, the collector thickness can be above 1.1 microns. The collector can have at least one doping concentration grading. The collector can have a high doping concentration at a junction between the collector and the sub-collector, such as at the high end of the grading. In some embodiments, the high doping concentration can be above about 9×10cm. The collector can include a region with high doping concentration adjacent the base. The collector can include a discontinuity in the doping concentration, such as at the low end of the grading. Such bipolar transistors can be implemented, for example, in power amplifiers.

Bipolar transistor having collector with doping concentration grading

Bipolar transistor having collector with doping concentration discontinuity

Disclosed are structures and methods related to metallization of a gallium arsenide (GaAs) layer. In some embodiments, a tantalum nitride (TaN) layer can be formed on a doped GaAs layer, and a metal layer can be formed on the TaN layer. Such a structure can be included in a Schottky diode. In some embodiments, such a Schottky diode can be fabricated utilizing heterojunction bipolar transistor (HBT) processes.

Methods related to a semiconductor structure with gallium arsenide and tantalum nitride

Disclosed are structures and methods related to a barrier layer for metallization of a selected semiconductor such as indium gallium phosphide (InGaP). In some embodiments, the barrier layer can include tantalum nitride (TaN). Such a barrier layer can provide desirable features such as barrier functionality, improved adhesion of a metal layer, reduced diffusion, reduced reactivity between the metal and InGaP, and stability during the fabrication process. In some embodiments, structures formed in such a manner can be configured as an emitter of a gallium arsenide (GaAs) heterojunction bipolar transistor (HBT) or an on-die high-value capacitance element.

Devices related to barrier for metallization of gallium based semiconductor

Disclosed are structures and methods related to metallization of a doped gallium arsenide (GaAs) layer. In some embodiments, such metallization can include a tantalum nitride (TaN) layer formed on the doped GaAs layer, and a metal layer formed on the TaN layer. Such a combination can yield a Schottky diode having a low turn-on voltage, with the metal layer acting as an anode and an electrical contact connected to the doped GaAs layer acting as a cathode. Such a Schottky diode can be utilized in applications such as radio-frequency (RF) power detection, reference-voltage generation using a clamp diode, and photoelectric conversion. In some embodiments, the low turn-on Schottky diode can be fabricated utilizing heterojunction bipolar transistor (HBT) processes.

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Newbury Park, CA, United States of America

Cristian Cismaru