A nitride semiconductor device includes: a substrate; a first nitride semiconductor layer of a first conductivity type; a second nitride semiconductor layer of a second conductivity type; an electron transport layer and an electron supply layer provided, in that order from a side on which the substrate is located, above the second nitride semiconductor layer and on an inner surface of a first opening; a gate electrode provided above the electron supply layer and covering the first opening; a source electrode provided in a second opening and connected to the second nitride semiconductor layer; a drain electrode; a third opening at an outermost edge part in a plan view of the substrate; and a potential fixing electrode provided in the third opening, the potential fixing electrode being connected to the second nitride semiconductor layer and in contact with neither the electron transport layer nor the electron supply layer.

An integrated circuit structure comprises a relaxed buffer stack that includes a channel region, wherein the relaxed buffer stack and the channel region include a group III-N semiconductor material, wherein the relaxed buffer stack comprises a plurality of AlGaN material layers and a buffer stack is located over over the plurality of AlGaN material layers, wherein the buffer stack comprises the group III-N semiconductor material and has a thickness of less than approximately 25 nm. A back barrier is in the relaxed buffer stack between the plurality of AlGaN material layers and the buffer stack, wherein the back barrier comprises an AlGaN material of approximately 2-10% Al. A polarization stack over the relaxed buffer stack.

An integrated circuit structure comprises a relaxed buffer stack that includes a channel region, wherein the relaxed buffer stack and the channel region include a group III-N semiconductor material, wherein the relaxed buffer stack comprises a plurality of AlGaN material layers and a buffer stack is located over over the plurality of AlGaN material layers, wherein the buffer stack comprises the group III-N semiconductor material and has a thickness of less than approximately 25 nm. A back barrier is in the relaxed buffer stack between the plurality of AlGaN material layers and the buffer stack, wherein the back barrier comprises an AlGaN material of approximately 2-10% Al. A polarization stack over the relaxed buffer stack.

Embodiments of the present application disclose a semiconductor device and a manufacturing method thereof. The semiconductor device includes a semiconductor layer, a first doped nitride semiconductor layer disposed on the semiconductor layer, and a second doped nitride semiconductor layer disposed on the first doped nitride semiconductor layer. The semiconductor device further includes an undoped nitride semiconductor layer between the semiconductor layer and the first doped nitride semiconductor layer. The undoped nitride semiconductor layer has a first surface in contact with the semiconductor layer and a second surface in contact with the first doped nitride semiconductor layer.

Embodiments of the present application disclose a semiconductor device and a manufacturing method thereof. The semiconductor device includes a semiconductor layer, a first doped nitride semiconductor layer disposed on the semiconductor layer, and a second doped nitride semiconductor layer disposed on the first doped nitride semiconductor layer. The semiconductor device further includes an undoped nitride semiconductor layer between the semiconductor layer and the first doped nitride semiconductor layer. The undoped nitride semiconductor layer has a first surface in contact with the semiconductor layer and a second surface in contact with the first doped nitride semiconductor layer.

Some embodiments of the disclosure provide a semiconductor device. The semiconductor device comprises: a substrate; a first nitride semiconductor layer on the substrate; a second nitride semiconductor layer on the first nitride semiconductor layer and having a band gap greater than a band gap of the first nitride semiconductor layer; a group III-V dielectric layer disposed on the second nitride semiconductor layer; a gate electrode disposed on the second nitride semiconductor layer; and a first passivation layer disposed on the group III-V dielectric layer, wherein the group III-V dielectric layer is separated from the gate electrode by the first passivation layer.

Some embodiments of the disclosure provide a semiconductor device. The semiconductor device comprises: a substrate; a first nitride semiconductor layer on the substrate; a second nitride semiconductor layer on the first nitride semiconductor layer and having a band gap greater than a band gap of the first nitride semiconductor layer; a group III-V dielectric layer disposed on the second nitride semiconductor layer; a gate electrode disposed on the second nitride semiconductor layer; and a first passivation layer disposed on the group III-V dielectric layer, wherein the group III-V dielectric layer is separated from the gate electrode by the first passivation layer.

Some embodiments of the disclosure provide a semiconductor device. The semiconductor device comprises: a substrate; a first nitride semiconductor layer disposed on the substrate; a second nitride semiconductor layer disposed on the first nitride semiconductor layer and having a bandgap greater than that of the first nitride semiconductor layer; an ohmic contact disposed on the first nitride semiconductor layer; and a spacer disposed adjacent to a sidewall of the ohmic contact.

Some embodiments of the disclosure provide a semiconductor device. The semiconductor device comprises: a substrate; a first nitride semiconductor layer disposed on the substrate; a second nitride semiconductor layer disposed on the first nitride semiconductor layer and having a bandgap greater than that of the first nitride semiconductor layer; an ohmic contact disposed on the first nitride semiconductor layer; and a spacer disposed adjacent to a sidewall of the ohmic contact.

The present disclosure relates to a semiconductor device and a fabrication method thereof. The semiconductor device includes a substrate, a first nitride semiconductor layer disposed on the substrate, a second nitride semiconductor layer disposed on the first nitride semiconductor layer and having a bandgap greater than that of the first nitride semiconductor layer. The semiconductor device further includes a first gate conductor disposed on a first region of the second nitride semiconductor layer, a passivation layer covering the first gate conductor, and a second gate conductor disposed on the passivation layer and on a second region of the second nitride semiconductor layer, wherein the first region is laterally spaced apart from the second region.