Abstract: Method and apparatus are described for semiconductor devices. The method (100) comprises, providing a partially completed semiconductor device (31-1) including a substrate (21), a semiconductor (22) on the substrate (21) and a passivation layer (25) on the semiconductor (22), and using a first mask (32), locally etching the passivation layer (25) to expose a portion (36) of the semiconductor (22), and without removing the first mask (32) forming a Schottky contact (42-1) of a first material on the exposed portion (36) of the semiconductor (22), then removing the first mask (32) and using a further mask (44), forming a step-gate conductor (48-1) of a second material electrically coupled to the Schottky contact (42-1) and overlying parts (25-1) of the passivation layer (25) adjacent to the Schottky contact (42-1).

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: In one example embodiment, a transistor (100) is provided. The transistor (100) comprises a source (10), a gate (30), a drain (20), and a field plate (40) located between the gate (30) and the drain (20). The field plate (40) comprises a plurality of connection locations (47) and a plurality of electrical connectors (45) connecting said plurality of connection locations (47) to a potential.

Abstract: A semiconductor structure includes a first semiconductor layer, a second semiconductor layer over the first semiconductor layer, a third semiconductor layer over the second semiconductor layer, and a fourth semiconductor layer over the third semiconductor layer. A first conductive portion is coupled to the first semiconductor layer, and a second conductive portion is formed over the first semiconductor layer.

Abstract: A microwave field effect transistor (10) has a high conductivity gate (44) overlying a double heterojunction structure (14, 18, 22) that has an undoped channel layer (18). The heterojunction structure overlies a substrate (12). A recess layer that is a not intentionally doped (NID) layer (24) overlies the heterojunction structure and is formed with a predetermined thickness that minimizes impact ionization effects at an interface of a drain contact of source/drain ohmic contacts (30) and permits significantly higher voltage operation than previous step gate transistors. Another recess layer (26) is used to define a gate dimension. A Schottky gate opening (42) is formed within a step gate opening (40) to create a step gate structure. A channel layer (18) material of InxGa1?xAs is used to provide a region of electron confinement with improved transport characteristics that result in higher frequency of operation, higher power density and improved power-added efficiency.

Abstract: In one example embodiment, a transistor (100) is provided. The transistor (100) comprises a source (10), a gate (30), a drain (20), and a field plate (40) located between the gate (30) and the drain (20). The field plate (40) comprises a plurality of connection locations (47) and a plurality of electrical connectors (45) connecting said plurality of connection locations (47) to a potential.

Abstract: A passivation layer of AlN is deposited on a GaN channel HFET using molecular beam epitaxy (MBE). Using MBE, many other surfaces may also be coated with AlN, including silicon devices, nitride devices, GaN based LEDs and lasers as well as other semiconductor systems. The deposition is performed at approximately 150° C. and uses alternating beams of aluminum and remote plasma RF nitrogen to produce an approximately 500 Å thick AlN layer.