The present disclosure provides a semiconductor device and a fabrication method thereof. The semiconductor device includes a first nitride semiconductor layer, a second nitride semiconductor layer, a gate structure, a first spacer and a second spacer. The second nitride semiconductor layer is formed on the first nitride semiconductor layer and having a greater bandgap than that of the first nitride semiconductor layer. The gate structure is disposed on the second nitride semiconductor layer. The first spacer is disposed on the second nitride semiconductor layer. The in second spacer is disposed on the second nitride semiconductor layer and spaced apart from the first spacer by the gate structure. The bottom of the first spacer has a first width, the bottom of the second spacer has a second width, and the first width is different from the second width.

An embodiment of a semiconductor device includes a semiconductor substrate, a first current-carrying electrode, and a second current-carrying electrode formed over the semiconductor, a control electrode formed over the semiconductor substrate between the first current carrying electrode and the second current carrying electrode, and a first dielectric layer disposed over the control electrode, and a second dielectric layer disposed over the first dielectric layer. A first opening is formed in the second dielectric layer, adjacent the control electrode and the second current-carrying electrode, having a first edge laterally adjacent to and nearer the second current-carrying electrode, and a second edge laterally adjacent to and nearer to the control electrode, and a conductive element formed over the first dielectric layer and within the first opening, wherein the portion of the conductive element formed within the first opening forms a first metal-insulator-semiconductor region within the first opening.

An apparatus configured to reduce lag includes a substrate; a group III-Nitride back barrier layer on the substrate; a group III-Nitride channel layer on the group III-Nitride back barrier layer; a group III-Nitride barrier layer on the group III-Nitride channel layer, the group III-Nitride barrier layer include a higher bandgap than a bandgap of the group III-Nitride channel layer; a source electrically coupled to the group III-Nitride barrier layer; a gate on the group III-Nitride barrier layer; a drain electrically coupled to the group III-Nitride barrier layer; and a p-region being arranged at or below the group III-Nitride barrier layer. Additionally, at least a portion of the p-region is arranged vertically below at least one of the following: the source, the gate, an area between the gate and the drain.

An apparatus for reducing lag includes a substrate; a group III-Nitride barrier layer; a source electrically coupled to the group III-Nitride barrier layer; a gate on the group III-Nitride barrier layer; a drain electrically coupled to the group III-Nitride barrier layer; a p-region being arranged at or below the group III-Nitride barrier layer; and a gate control circuit configured to control a gate voltage of the gate. Additionally, at least a portion of the p-region is arranged vertically below at least one of the following: the source, the gate, and an area between the gate and the drain.

The present application provides a semiconductor structure and a manufacturing method thereof. The semiconductor structure includes: a semiconductor substrate, a heterojunction structure, a cap layer, a first passivation layer and a second passivation layer disposed from bottom to up; a trench penetrating through the first passivation layer and the second passivation layer; and a P-type semiconductor layer located at least on an inner wall of the trench. After a part of the second passivation layer is dry etched to form the trench, the first passivation layer can be used for etching endpoint detection to avoid over etching. A part of the first passivation layer exposed by the trench of the second passivation layer can be removed by wet etching. When the exposed part of the first passivation layer is removed by the wet etching, due to the cap layer has extremely high stability, after the exposed part of the first passivation layer is removed by the wet etching, the cap layer will not be damaged. The non-damaged cap layer can effectively reduce surface defects of the heterojunction structure to decrease a probability of electrons being trapped by the defects, thereby weakening a current collapse effect and reducing a dynamic on-resistance.

A method for fabricating high electron mobility transistor (HEMT) includes the steps of: forming a buffer layer on a substrate; forming a patterned mask on the buffer layer; using the patterned mask to remove the buffer layer for forming ridges and a damaged layer on the ridges; removing the damaged layer; forming a barrier layer on the ridges; and forming a p-type semiconductor layer on the barrier layer.

A buffer layer formed on a substrate, a base layer formed on the buffer layer, and a channel layer formed on the base layer are provided. The base layer includes Al.sub.xGa.sub.1-xN(0<x≤1) and the composition x of Al decreases in accordance with increasing approach of the composition x to the channel layer in a thickness direction. The channel layer includes Al.sub.yGa.sub.1-yN(0<y≤1) and the composition y of Al decreases in accordance with increasing approach of the composition y to the base layer in a thickness direction.

A distributed inductance integrated field effect transistor (FET) structure, comprising a plurality of FETs. Each FET comprises a plurality of source regions, a gate region having a plurality of gate fingers extending from a gate bus bar, a drain region having a plurality of drain finger extending from a drain bus bar between the plurality of gate fingers, wherein the gate region controls current flow in a conductive channel between the drain region and source region. A first distributed inductor connects the gate regions of adjacent ones of the plurality of FETs; and a second distributed inductor connects the drain regions of adjacent ones of the plurality of FETs.

Gate-all-around integrated circuit structures having confined epitaxial source or drain structures, are described. For example, an integrated circuit structure includes a plurality of nanowires above a sub-fin. A gate stack is over the plurality of nanowires and the sub-fin. Epitaxial source or drain structures are on opposite ends of the plurality of nanowires. The epitaxial source or drain structures comprise germanium and boron, and a protective layer comprises silicon, and germanium that at least partially covers the epitaxial source or drain structures. A conductive contact comprising titanium silicide is on the epitaxial source or drain structures.

A semiconductor device includes a transistor. The transistor includes a gate electrode, a channel layer, a gate dielectric layer, a first source/drain region and a second source/drain region and a dielectric pattern. The channel layer is disposed on the gate electrode. The gate dielectric layer is located between the channel layer and the gate electrode. The first source/drain region and the second source/drain region are disposed on the channel layer at opposite sides of the gate electrode. The dielectric pattern is disposed on the channel layer. The first source/drain region covers a first sidewall and a first surface of the dielectric pattern, and a second sidewall opposite to the first sidewall of the dielectric pattern is protruded from a sidewall of the first source/drain region.