Abstract: In one embodiment, a semiconductor device (500) includes a buffer layer (504) formed over a substrate (502). An AlxGa1-xAs layer (506) is formed over the buffer layer (504) and has a first doped region (508) formed therein. An InxGa1-xAs channel layer (512) is formed over the AlxGa1-xAs layer (506). An AlxGa1-xAs layer (518) is formed over the InxGa1-xAs channel layer (512), and the AlxGa1-xAs layer (518) has a second doped region formed therein. A GaAs layer (520) having a first recess is formed over the AlxGa1-xAs layer (518). A control electrode (526) is formed over the AlxGa1-xAs layer (518). A doped GaAs layer (524) is formed over the undoped GaAs layer (520) and on opposite sides of the control electrode (526) and provides first and second current electrodes. When used to amplify a digital modulation signal, the semiconductor device (500) maintains linear operation over a wide temperature range.

Abstract: A radio frequency (“RF”) circuit configured in accordance with an embodiment of the invention is fabricated on a substrate using integrated passive device (“IPD”) process technology. The RF circuit (which may be, for example, a harmonic filter) includes at least one RF signal line section and an integrated RF coupler located proximate to the RF signal line section. The integrated RF coupler, its output and grounding contact pads, and its matching network are fabricated on the same substrate using the same IPD process technology. The integrated RF coupler provides efficient and reproducible RF coupling without increasing the die footprint of the RF circuit.

Abstract: An implant-free enhancement mode metal-oxide semiconductor field effect transistor (EMOSFET) is provided. The EMOSFET has a III-V compound semiconductor substrate and an epitaxial layer structure overlying the III-V compound semiconductor substrate. The epitaxial material layer has a channel layer and at least one doped layer. A gate oxide layer overlies the epitaxial layer structure. The EMOSFET further includes a metal gate electrode overlying the gate oxide layer and source and drain ohmic contacts overlying the epitaxial layer structure.

Abstract: A semiconductor component includes: a semiconductor substrate (110); an epitaxial semiconductor layer (120) above the semiconductor substrate; a bipolar transistor (770, 870) in the epitaxial semiconductor layer; and a field effect transistor (780, 880) in the epitaxial semiconductor layer. A portion of the epitaxial semiconductor layer forms a base of the bipolar transistor and a gate of the field effect transistor, and the portion of the epitaxial semiconductor layer has a substantially uniform doping concentration. In the same or another embodiment, a different portion of the epitaxial semiconductor layer forms an emitter of the bipolar transistor and a channel of the field effect transistor, and the different portion of the epitaxial semiconductor layer has a substantially uniform doping concentration that can be the same as or different from the substantially uniform doping concentration of the portion of the epitaxial semiconductor layer.

Abstract: A semiconductor component includes: a semiconductor substrate (110); an epitaxial semiconductor layer (120) above the semiconductor substrate; a bipolar transistor (770, 870) in the epitaxial semiconductor layer; and a field effect transistor (780, 880) in the epitaxial semiconductor layer. A portion of the epitaxial semiconductor layer forms a base of the bipolar transistor and a gate of the field effect transistor, and the portion of the epitaxial semiconductor layer has a substantially uniform doping concentration. In the same or another embodiment, a different portion of the epitaxial semiconductor layer forms an emitter of the bipolar transistor and a channel of the field effect transistor, and the different portion of the epitaxial semiconductor layer has a substantially uniform doping concentration that can be the same as or different from the substantially uniform doping concentration of the portion of the epitaxial semiconductor layer.

Abstract: An implant-free enhancement mode metal-oxide semiconductor field effect transistor (EMOSFET) is provided. The EMOSFET has a III-V compound semiconductor substrate and an epitaxial layer structure overlying the III-V compound semiconductor substrate. The epitaxial material layer has a channel layer and at least one doped layer. A gate oxide layer overlies the epitaxial layer structure. The EMOSFET further includes a metal gate electrode overlying the gate oxide layer and source and drain ohmic contacts overlying the epitaxial layer structure.