A method of regrowing material includes providing a III-nitride structure including a masking layer and patterning the masking layer to form an etch mask. The method also includes removing, using an in-situ etch, a portion of the III-nitride structure to expose a regrowth region and regrowing a III-nitride material in the regrowth region.

A method includes forming a gate on a first fin, a second fin, and a third fin arranged on a substrate. The method includes depositing a semiconductor material on the first fin, the second fin, and the third fin. The method further includes depositing an interlayer dielectric (ILD) on the first fin, the second fin, and the third fin. The method further includes forming a first trench and a second trench through the ILD on a first side of the gate, and a third trench and a fourth trench through the ILD on a second side of the gate, the second trench coupling the second fin to the third fin, and the third trench coupling the first fin to the second fin. The method includes depositing a metal in the first trench, the second trench, the third trench, and the fourth trench.

A method for producing a semiconductor power device includes forming a gate trench from a surface of the semiconductor layer toward an inside thereof. A first insulation film is formed on the inner surface of the gate trench. The method also includes removing a part on a bottom surface of the gate trench in the first insulation film. A second insulation film having a dielectric constant higher than SiO2 is formed in such a way as to cover the bottom surface of the gate trench exposed by removing the first insulation film.

A field-effect transistor having a transconductance (gm) that remains within 65% of a maximum gm value over at least 85% of a gate voltage range that transitions the field-effect transistor between an on-state that allows substantial current flow through the channel layer and an off-state that prevents substantial current flow through the channel layer is disclosed. The field-effect transistor includes a substrate and a channel layer having a proximal boundary relative to the substrate and a distal boundary relative to the substrate. The channel layer is disposed over the substrate and comprises a compound semiconductor material that includes at least one element having a concentration that is graded between the proximal boundary and the distal boundary.

The present invention makes it possible to improve the characteristic of a semiconductor device using a nitride semiconductor. An electrically-conductive film is formed above a gate electrode above a substrate with an interlayer insulation film interposed and a source electrode coupled to a barrier layer on one side of the gate electrode and a drain electrode coupled to the barrier layer on the other side of the gate electrode are formed by etching the electrically-conductive film. On this occasion, the source electrode is etched so as to have a shape extending beyond above the gate electrode to the side of the drain electrode and having a gap (opening) above the gate electrode. Successively, hydrogen annealing is applied to the substrate. In this way, by forming the gap at a source field plate section of the source electrode, it is possible to efficiently supply hydrogen in the region where a channel is formed in the hydrogen annealing process.

According to one embodiment, a semiconductor device includes a first semiconductor layer including a nitride semiconductor, a first electrode separated from the first semiconductor layer in a first direction, and a first insulating film including silicon and oxygen and being provided between the first semiconductor layer and the first electrode. The first insulating film has a first thickness in the first direction. The first insulating film includes a first position, and a distance between the first position and the first semiconductor layer is of the first thickness. A first hydrogen concentration of hydrogen at the first position is 2.510.sup.19 atoms/cm.sup.3 or less.

A compound semiconductor field effect transistor (FET) may include a channel layer. The semiconductor FET may also include an oxide layer, partially surrounded by a passivation layer, on the channel layer. The semiconductor FET may also include a first dielectric layer on the oxide layer. The semiconductor FET may also include a second dielectric layer on the first dielectric layer. The semiconductor FET may further include a gate, comprising a base gate through the oxide layer and the first dielectric layer, and a head gate in the second dielectric layer and electrically coupled to the base gate.

One aspect of the disclosure relates to a method of forming a semiconductor structure. The method may include: forming a set of openings within a substrate; forming an insulator layer within each opening in the set of openings; recessing the substrate between adjacent openings containing the insulator layer in the set of openings to form a set of insulator pillars on the substrate; forming sigma cavities within the recessed substrate between adjacent insulator pillars in the set of insulator pillars; and filling the sigma cavities with a semiconductor material over the recessed substrate between adjacent insulator pillars.

A field-effect transistor having a transconductance (gm) that remains within 65% of a maximum gm value over at least 85% of a gate voltage range that transitions the field-effect transistor between an on-state that allows substantial current flow through the channel layer and an off-state that prevents substantial current flow through the channel layer is disclosed. The field-effect transistor includes a substrate and a channel layer having a proximal boundary relative to the substrate and a distal boundary relative to the substrate. The channel layer is disposed over the substrate and comprises a compound semiconductor material that includes at least one element having a concentration that is graded between the proximal boundary and the distal boundary.

A semiconductor device and a manufacturing method thereof are provided. The semiconductor device includes a first stacked structure, a second stacked structure, an isolation layer and a gate. The first stacked structure is disposed on a substrate, and includes a first GaN channel layer disposed on the substrate and having an N crystal phase and a first barrier layer disposed on the first GaN channel layer. The second stacked structure is disposed on the substrate, and includes a second GaN channel layer disposed on the substrate and having a Ga crystal phase and a second barrier layer disposed on the second GaN channel layer. The isolation layer is disposed between the first stacked structure and the second stacked structure. The gate is disposed on the first stacked structure, the isolation layer and the second stacked structure.