A semiconductor rectifier device comprises: an epitaxial layer having a top surface and a bottom surface; a first trench comprising a first side wall, a second side wall, and a first bottom surface; a second trench adjacent to the first trench, the second trench comprising a third side wall, a fourth side wall, and a second bottom surface; a first doped region abutting against the first side wall and at least a part of the first bottom surface of the first trench; a second doped region adjacent to and separated from the first doped region, wherein the second doped region abuts against the third side wall, the fourth side wall and the second bottom surface of the second trench; a gate structure disposed on the top surface between the first trench and the second trench; and a contact metal layer disposed on the top surface of the epitaxial layer.

A gallium nitride (GaN) transistor which includes a multi-layer/multi-thickness barrier layer formed of segments of progressively increasing thickness between the gate and drain to progressively increase the 2DEG density in the channel from gate to drain. The GaN gate can be formed on the base barrier layer to produce an enhancement mode device with a positive threshold voltage. By forming the gate over a thicker segment of the barrier layer, a GaN transistor with a less positive threshold voltage, or a depletion mode transistor with a negative threshold voltage, can be produced.

A transistor comprises a top source/drain region, a bottom source/drain region, a channel region vertically between the top and bottom source/drain regions, and a gate operatively laterally-adjacent the channel region. The channel region is crystalline and comprises a plurality of vertically-elongated crystal grains that individually are directly against both of the top source/drain region and the bottom source/drain region. Other embodiments, including methods, are disclosed.

A semiconductor rectifier device comprises: an epitaxial layer having a top surface and a bottom surface; a first trench comprising a first side wall, a second side wall, and a first bottom surface; a second trench adjacent to the first trench, the second trench comprising a third side wall, a fourth side wall, and a second bottom surface; a first doped region abutting against the first side wall and at least a part of the first bottom surface of the first trench; a second doped region adjacent to and separated from the first doped region, wherein the second doped region abuts against the third side wall, the fourth side wall and the second bottom surface of the second trench; a gate structure disposed on the top surface between the first trench and the second trench; and a contact metal layer disposed on the top surface of the epitaxial layer.

A method of manufacturing a vertical silicon carbide semiconductor device having an electrode on each of two main surfaces of a semiconductor chip in which an n-type low concentration buffer layer and an epitaxial layer are grown by epitaxy on a silicon carbide substrate. Defects extending from the silicon carbide substrate to the epitaxial layer and defects generated in the epitaxial layer during epitaxial growth are detected by a PL image of the n-type low concentration buffer layer; the defects generated in the epitaxial layer during the epitaxy are detected by a PL image of the epitaxial layer; the defects extending from the silicon carbide substrate to the epitaxial layer are detected by the difference between detection results; and semiconductor chips free of the defects extending from the silicon carbide substrate to the epitaxial layer are identified.

A semiconductor device includes substrate, a first gate structure, a second gate structure, and an epitaxy layer. The first gate structure and the second gate structure are over the substrate, in which the first gate structure and the second gate structure each comprises a shielding electrode, a gate electrode over the shielding electrode, and a first gate dielectric layer vertically separating the shielding electrode from the gate electrode. The epitaxy layer is over the substrate and cups an underside of the first gate structure and the second gate structure, in which the epitaxy layer comprises a doped region laterally between the first gate dielectric layer of the first gate structure and the first gate dielectric layer of the second gate structure, a dopant concentration of the doped region being non-uniform along a lateral direction.

The present invention provides an AlGaN/GaN power HEMT device and a preparation method therefor. The device comprises: an n-type GaN substrate, a first p-type GaN layer, an AlGaN layer, a hole-injection-type PN junction layer and a gate structure, wherein the gate structure penetrates the hole-injection-type PN junction layer, the AlGaN layer and the first p-type GaN layer and stops in the n-type GaN substrate, and comprises a gate metal aluminum layer and a gate silicon dioxide layer; and the hole-injection-type PN junction layer comprises a second p-type GaN layer and a second n-type GaN layer, which are distributed in the horizontal direction, and the second n-type GaN layer is located on the side close to the gate structure.

The present disclosure relates to semiconductor devices. An example semiconductor device includes a first well region and a second well region isolated from each other by a first device isolation film; an NPN transistor provided by a first collector region formed in the first well region and including first conductivity-type impurities, and a first emitter region formed in the second well region and including the first conductivity-type impurities; a PNP transistor provided by a second emitter region formed in the first well region and including second conductivity-type impurities different from the first conductivity-type, and a second collector region formed in the second well region and including the second conductivity-type impurities; and an NMOS transistor including a source region and a drain region formed in the second well region and including the first conductivity-type impurities, and a gate structure disposed between the source region and the drain region.

A method for forming a high electron mobility transistor is disclosed. A mesa structure having a channel layer and a barrier layer is formed on a substrate. The mesa structure has two first edges extending along a first direction and two second edges extending along a second direction. A passivation layer is formed on the substrate and the mesa structure. A first opening and a plurality of second openings connected to a bottom surface of the first opening are formed and through the passivation layer, the barrier layer and a portion of the channel layer. In a top view, the first opening exposes the two first edges of the mesa structure without exposing the two second edges of the mesa structure. A metal layer is formed in the first opening and the second openings thereby forming a contact structure.

A power amplifier module includes a power amplifier including a GaAs bipolar transistor having a collector, a base abutting the collector, and an emitter, the collector having a doping concentration of at least about 310.sup.16 cm.sup.3 at a junction with the base, the collector also having at least a first grading in which doping concentration increases away from the base; and an RF transmission line driven by the power amplifier, the RF transmission line including a conductive layer and finish plating on the conductive layer, the finish plating including a gold layer, a palladium layer proximate the gold layer, and a diffusion barrier layer proximate the palladium layer, the diffusion barrier layer including nickel and having a thickness that is less than about the skin depth of nickel at 0.9 GHZ. Other embodiments of the module are provided along with related methods and components thereof.