A bipolar junction transistor has a collector over a substrate and a multi-layer base structure over the collector, and an emitter over the base structure. The multi-layer base structure includes a first layer having a first III-V semiconductor alloy and a second layer having a second III-V semiconductor alloy having a different composition of elements than the first III-V semiconductor alloy. The second layer has a narrower bandgap than the first layer. The first layer is positioned between the collector and the second layer.

The present invention discloses a semiconductor structure and a method for manufacturing the same, which comprises providing a substrate, and forming a stress layer, a buried oxide layer, and an SOI layer on the substrate; forming a doped region of the stress layer arranged in a specific position in the stress layer; forming an oxide layer and a nitride layer on the SOI layer, and forming a first trench that etches the nitride layer, the oxide layer, the SOI layer, and the buried oxide layer, and stops on the upper surface of the stress layer, and exposes at least part of the doped region of the stress layer; forming a cavity by wet etching through the first trench to remove the doped region of the stress layer; forming a polycrystalline silicon region of the stress layer and a second trench by filling the cavity with polycrystalline silicon and etching back; forming an isolation region by filling the second trench. The semiconductor structure and the method for manufacturing the same disclosed in the present invention provide a favorable stress for the channel of the semiconductor device by introducing a stress layer and a stress induced zone set at specific positions depending on device type to help improving the performance of the semiconductor device.

A SiGe HBT has an inverted heterojunction structure, where the emitter layer is formed prior to the base layer and the collector layer. The frequency performance of the SiGe HBT is significantly improved through a better thermal process budget for the base profile, essential for higher cut-off frequency (f.sub.T) and a minimal collector-base area for a reduced parasitic capacitance, essential for higher maximum oscillation frequency (f.sub.max). This inverted heterojunction structure can be fabricated by using ALE processes to form an emitter on a preformed epitaxial silicide, a base over the emitter and a collector over the base.

Device structures and fabrication methods for a bipolar junction transistor. A first semiconductor layer is formed on a substrate containing a first terminal. An etch stop layer is formed on the first semiconductor layer, and a second semiconductor layer is formed on the etch stop layer. The second semiconductor layer is etched to define a second terminal at a location of an etch mask on the second semiconductor layer. A first material comprising the etch stop layer and a second material comprising the second semiconductor layer are selected such that the second material of the second semiconductor layer etches at a greater etch rate than the first material of the etch stop layer. The first semiconductor layer may be a base layer that is used to form an intrinsic base and an extrinsic base of the bipolar junction transistor.

A method of making a semiconductor structure includes forming a trench through a shallow trench isolation (STI) structure and into a substrate, and forming a liner including an electrical insulator material on sidewalls of the trench. The method also includes forming a core including a high thermal conductivity material in the trench and on the liner, and forming a cap in the trench and on the core.

According to one embodiment, a semiconductor device includes an n-type semiconductor layer, a first electrode, and a nitride semiconductor layer. The n-type semiconductor layer includes diamond. The nitride semiconductor layer is provided between the n-type semiconductor layer and the first electrode. The nitride semiconductor layer includes Al.sub.xGa.sub.1xN (0x1) and is of n-type.

A semiconductor structure includes a heterojunction bipolar transistor (HBT) including a collector layer located over a substrate, the collector layer including a semiconductor material, and a field effect transistor (FET) located over the substrate, the FET having a channel formed in the semiconductor material that forms the collector layer of the HBT. In some implementations, a second FET can be provided so as to be located over the substrate and configured to include a channel formed in a semiconductor material that forms an emitter of the HBT. One or more of the foregoing features can be implemented in devices such as a die, a packaged module, and a wireless device.

Methods, devices, and systems for using and forming vertically base-connected bipolar transistors have been shown. The vertically base-connected bipolar transistors in the embodiments of the present disclosure are formed with a CMOS fabrication technique that decreases the transistor size while maintaining the high performance characteristics of a bipolar transistor.

The present disclosure relates to a system for biasing a power amplifier. The system can include a first die that includes a power amplifier circuit and a passive component having an electrical property that depends on one or more conditions of the first die. Further, the system can include a second die including a bias signal generating circuit that is configured to generate a bias signal based at least in part on measurement of the electrical property of the passive component of the first die.

Systems and methods are disclosed for integrating functional components of front-end modules for wireless radios. Front-end modules disclosed may be dual-band front-end modules for use in 802.11ac-compliant devices. In certain embodiments, integration of front-end module components on a single die is achieved by implementing a high-resistivity layer or substrate directly underneath, adjacent to, and/or supporting SiGe BiCMOS technology elements.