The disclosure relates to power semiconductor devices in GaN technology. The disclosure proposes an integrated auxiliary gate terminal (15) and a pulldown network to achieve a normally-off (E-Mode) GaN transistor with threshold voltage higher than 2V, low gate leakage current and enhanced switching performance. The high threshold voltage GaN transistor has a high-voltage active GaN device (205) and a low-voltage auxiliary GaN device (210) wherein the high-voltage GaN device has the gate connected to the source of the integrated auxiliary low-voltage GaN transistor and the drain being the external high-voltage drain terminal and the source being the external source terminal, while the low-voltage auxiliary GaN transistor has the gate (first auxiliary electrode) connected to the drain (second auxiliary electrode) functioning as an external gate terminal. In other embodiments a pull-down network for the switching-off of the high threshold voltage GaN transistor is formed by a diode, a resistor, or a parallel connection of both connected in parallel with the low-voltage auxiliary GaN transistor.

A disclosed compound semiconductor device includes a channel layer configured to generate carriers; a spacer layer of Al.sub.y1Ga.sub.1-y1N (0.20<y10.70) formed on the channel layer; and a barrier layer of In.sub.x2Al.sub.y2 Ga.sub.1-x2-y2N (0x20.15 and 0.20y2<0.70) formed on the spacer layer, where y1 and y2 satisfy a relationship of y1>y2.

Systems and methods of the disclosed embodiments include reducing defects in a semiconductor layer. The defects may be reduced by forming the semiconductor layer on a substrate, removing at least a portion the substrate from an underside of the semiconductor layer, and annealing the semiconductor layer to reduce the defects in the layer. The annealing includes focusing energy at the layer.

A bonded substrate for epitaxial growth and a method for forming the same are disclosed. The method includes steps of providing a first substrate, which has a first dopant concentration; providing a second substrate, which has a second dopant concentration, wherein the second dopant concentration is lower than the first dopant concentration; directly bonding a first surface of the first substrate with a second surface of the second substrate to form a bonded substrate; annealing the bonded substrate to form a high impedance layer in the bonded substrate; and removing part of the second substrate to expose the high impedance layer depending on the requirements whereby, the bonded substrate formed by the method could have a heavily doped substrate which includes a stronger strength and the impedance layer formed thereon, which could effectively increase the substrate strength, reduce the leakage current, and sustains a higher breakdown voltage.

The present invention provides a nitride semiconductor device, including an insulating substrate, a substrate over the first surface of the insulating substrate, a first lateral transistor over a first region of the substrate, wherein the first lateral transistor includes a first nitride semiconductor layer formed over the substrate, and a first gate electrode, a first source electrode and a first drain electrode formed over the first nitride semiconductor layer, and a second lateral transistor over a second region of the substrate, wherein the second lateral transistor includes a second nitride semiconductor layer formed over the substrate, and a second gate electrode, a second source electrode and a second drain electrode formed over the second nitride semiconductor layer, and a separation trench formed over a third region, wherein the third region is between the first region and the second region.

The present disclosure, in some embodiments, relates to an integrated chip. The integrated chip has a channel layer disposed over a substrate and including a first material. An active layer is over the channel layer and includes a second material different than the first material. An isolation structure has a horizontally extending segment that is below the channel layer and one or more vertically extending segments that are directly over the horizontally extending segment. One or more contacts extend through the channel layer and the active layer to contact the one or more vertically extending segments.

A method of fabricating an electronic device includes providing a III-V substrate having a hexagonal crystal structure and a normal to a growth surface characterized by a misorientation from the <0001> direction of between 0.15 and 0.65. The method also includes growing a first III-V epitaxial layer coupled to the III-V substrate and growing a second III-V epitaxial layer coupled to the first III-V epitaxial layer. The method further includes forming a first contact in electrical contact with the III-V substrate and forming a second contact in electrical contact with the second III-V epitaxial layer.

An isolation structure for active devices is provided. In some embodiments, the isolation structure is used in a transistor. The transistor includes a substrate having a first doping type. The transistor also includes a channel layer positioned over the substrate and comprising a first section and a second section. The transistor further includes an active layer positioned over the channel layer. The isolation structure includes a horizontal segment, a first vertical segment, and a second vertical segment. The horizontal segment is arranged below the second section of the channel layer and continuously extends between the first vertical segment and the second vertical segment. The isolation structure has a second doping type that is different than the first doping type.

A transistor having an emitter, a base, and a collector, the transistor includes a substrate, a collector contact, a metallic sub-collector coupled to the collector contact, and the metallic sub-collector electrically and thermally coupled to the collector, and an adhesive layer between the substrate and the metallic sub-collector, the adhesive layer bonded to the substrate and in direct contact with the substrate and bonded to the metallic sub-collector and in direct contact with the metallic sub-collector, wherein the adhesive layer comprises an electrically conductive material.

A method of wafer scale packaging acoustic resonator devices and an apparatus therefor. The method including providing a partially completed semiconductor substrate comprising a plurality of single crystal acoustic resonator devices, each having a first electrode member, a second electrode member, and an overlying passivation material. At least one of the devices to be configured with an external connection, a repassivation material overlying the passivation material, an under metal material overlying the repassivation material. Copper pillar interconnect structures are then configured overlying the electrode members, and solder bump structures are form overlying the copper pillar interconnect structures.