Abstract: A new transistor structure is disclosed. This new structure has a dielectric stress layer in a three-dimensional structure outside of the gate region for modulation or the characteristics of the transistor. Additionally, trenches are created in the region between the source electrode and the drain electrode in such a manner so as to create ridges that traverse the gate region.

Abstract: An improved semiconductor structure includes a substrate, a buffer layer disposed on a top surface of the substrate, a channel layer disposed on a top surface of the buffer layer, a barrier layer disposed on a top surface of the channel layer, an etch-stop layer disposed on a top surface area of the barrier layer, a cap-layer disposed on a top surface area of the etch-stop layer, a source contact disposed on a first area of the barrier layer, a drain contact disposed on a second area of the barrier layer, a gate contact disposed on the cap layer between the source contact and the drain contact, and a dielectric layer disposed on areas of the etch-stop layer between the source contact and the gate contact and between the drain contact and the gate contact, respectively. The etch-stop layer is disposed on an area of the top surface of the barrier layer between the first area and the second area.

Abstract: A semiconductor device such as a transistor includes a source region, a drain region, a semiconductor region, at least one island region and at least one gate region. The semiconductor region is located between the source region and the drain region. The island region is located in the semiconductor region. Each of the island regions differs from the semiconductor region in one or more characteristics selected from the group including resistivity, doping type, doping concentration, strain and material composition. The gate region is located between the source region and the drain region covering at least a portion of the island regions.

Abstract: Field-plate structures are disclosed for electrical field management in semiconductor devices. A field-plate semiconductor structure includes a semiconductor substrate, a source ohmic contact, a drain ohmic contact, and a gate contact disposed over a gate region between the source ohmic contact and the drain ohmic contact, and a source field plate connected to the source ohmic contact. A field-plate dielectric is disposed over the semiconductor substrate. An encapsulating dielectric is disposed over the gate contact, wherein the encapsulating dielectric covers a top surface of the gate contact. The source field plate is disposed over the field-plate dielectric in a field plate region, from which the encapsulating dielectric is absent.

Abstract: Field-plate structures are disclosed for electrical field management in semiconductor devices. A field-plate semiconductor device comprises a semiconductor substrate, a first ohmic contact and a second ohmic contact disposed over the semiconductor substrate, one or more coupling capacitors, and one or more capacitively-coupled field plates disposed over the semiconductor substrate between the first ohmic contact and the second ohmic contact. Each of the capacitively-coupled field plates is capacitively coupled to the first ohmic contact through one of the coupling capacitors, the coupling capacitor having a first terminal electrically connected to the first ohmic contact and a second terminal electrically connected to the capacitively-coupled field plate.

Abstract: A hybrid transistor circuit is disclosed for use in III-Nitride (III-N) semiconductor devices, comprising a Silicon (Si)-based Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), a Group III-Nitride (III-N)-based Field-Effect Transistor (FET), and a driver unit. A source terminal of the III-N-based FET is connected to a drain terminal of the Si-based MOSFET. The driver unit has at least one input terminal, and two output terminals connected to the gate terminals of the transistors respectively. The hybrid transistor circuit is turned on through the driver unit by switching on the Silicon-based MOSFET first before switching on the III-N-based FET, and is turned off through the driver unit by switching off the III-N-based FET before switching off the Silicon-based MOSFET. Also disclosed are integrated circuit packages and semiconductor structures for forming such hybrid transistor circuits. The resulting hybrid circuit provides power-efficient and robust use of III-Nitride semiconductor devices.

Abstract: A multi-layer semiconductor structure is disclosed for use in III-Nitride semiconductor devices, including a channel layer comprising a first III-Nitride material, a barrier layer comprising a second III-Nitride material, a pair of ohmic electrodes disposed in ohmic recesses etched into the barrier layer, a gate electrode disposed in a gate recess etched into the barrier layer, and a filler element. The gate electrode is stepped to form a bottom stem and at least one bottom step within the gate recess. The filler element, comprising an insulating material, is disposed at least below the bottom step of the gate electrode within the gate recess. Also described are methods for fabricating such semiconductor structures. The performance of resulting devices is improved, while providing design flexibility to reduce production cost and circuit footprint.

Abstract: A multi-layer semiconductor structure is disclosed for use in III-Nitride semiconductor devices, including a channel layer, a band-offset layer having a wider bandgap than the channel layer, a spacer layer having a narrower bandgap than the band-offset layer, and a cap layer comprising at least two sublayers. Each sublayer is selectively etchable with respect to sublayers immediately below and above, each sublayer comprises a III-N material AlxInyGazN in which 0?x?1, 0?y?1, and 0?z?1, at least one sublayer has a non-zero Ga content, and a sublayer immediately above the spacer layer has a wider bandgap than the spacer layer. Also described are methods for fabricating such semiconductor structures, with gate and/or ohmic recesses formed by selectively removing adjacent layers or sublayers. The performance of resulting devices is improved, while providing design flexibility to reduce production cost and circuit footprint.

Abstract: Semiconductor structures are disclosed for monolithically integrating multiple III-N transistors with different threshold voltages on a common substrate. A semiconductor structure includes a cap layer comprising a plurality of selectively etchable sublayers, wherein each sublayer is selectively etchable with respect to the sublayer immediately below, wherein each sublayer comprises a material AlxInyGazN (0?x, y, z?1), and wherein at least one selectively etchable sublayer has a non-zero Ga content (0<z?1). A gate recess is disposed in a number of adjacent sublayers of the cap layer to achieve a desired threshold voltage for a transistor. Also described are methods for fabricating such semiconductor structures, where gate recesses and/or ohmic recesses are formed by selectively removing adjacent sublayers of the cap layer. The performance of the resulting integrated circuits is improved, while providing design flexibility to reduce production cost and circuit footprint.

Abstract: A semiconductor device includes a substrate, a first active layer, a second active layer, at least first and second electrodes, an E-field management layer, and at least one injection electrode. The first active layer is disposed over the substrate. The second active layer is disposed on the first active layer such that a laterally extending conductive channel arises which extends in a lateral direction. The laterally extending conductive channel is located between the first active layer and the second active layer. The first and second electrodes are electrically connected to the first active layer. The E-field management layer, which reduces the electric-field gradients arising in the first and second active layers, is disposed over the second active layer. The injection electrode is electrically connected to the E-field management layer.