A semiconductor device and a semiconductor structure are disclosed. The semiconductor device includes a substrate, a first III-V compound layer, a second III-V compound layer, a source, a drain and a gate stack structure. The first III-V compound layer is disposed on the substrate. The second III-V compound layer is disposed on the first III-V compound layer. The source and the drain are disposed on opposite sidewall boundaries of the second III-V compound layer. The gate stack structure is disposed on the second III-V compound layer. The gate stack structure includes a first gate and a second gate. The first gate is disposed on the second III-V compound layer. The second gate is disposed on and electrically isolated from the first gate. The second gate is electrically coupled to the source.

A semiconductor device is provided. The semiconductor device includes a channel layer disposed on a substrate, a barrier layer disposed on the channel layer, and a nitride layer disposed on the barrier layer. The semiconductor device also includes a compound semiconductor layer that includes an upper portion and a lower portion, wherein the lower portion penetrates through the nitride layer and a portion of the barrier layer. The semiconductor device also includes a spacer layer conformally disposed on a portion of the barrier layer and extending onto the nitride layer. The semiconductor device further includes a gate electrode disposed on the compound semiconductor layer, and a pair of source/drain electrodes disposed on opposite sides of the gate electrode. The pair of source/drain electrodes extends through the spacer layer, the nitride layer, and at least a portion of the barrier layer.

A transistor includes a substrate having a first surface and a second surface opposite the first surface, a drift region having a doped region on the first surface of the substrate and a graded doping region on the doped region, a semiconductor fin protruding from the graded doping region and comprising a metal compound layer at an upper portion of the semiconductor fin, a source metal contact on the metal compound layer, a gate layer having a bottom portion directly contacting the graded doping region; and a drain metal contact on the second surface of the substrate.

A method of fabricating a vertical fin-based field effect transistor (FET) includes providing a semiconductor substrate having a first surface and a second surface, the semiconductor substrate having a first conductivity type, epitaxially growing a first semiconductor layer on the first surface of the semiconductor substrate, the first semiconductor layer having the first conductivity type and including a drift layer and a graded doping layer on the drift layer, and epitaxially growing a second semiconductor layer having the first conductivity type on the graded doping layer. The method also includes forming a metal compound layer on the second semiconductor layer, forming a patterned hard mask layer on the metal compound layer, and etching the metal compound layer and the second semiconductor layer using the patterned hard mask layer as a mask exposing a surface of the graded doping layer to form a plurality of fins surrounded by a trench.

An electronic device can include a gate structure. In an embodiment, the gate structure can include a gate electrode including a doped semiconductor material, a metal-containing member, a pair of conductive sidewall spacers. The first metal-containing member can overlie the gate electrode. The conductive sidewall spacers can overlie the gate electrode and along opposite sides of the first metal-containing member. In another embodiment, the gate structure can include a gate electrode, a first metal-containing member overlying the gate electrode, and a second metal-containing member overlying the first metal-containing member. The first metal-containing member can have a length that is greater than the length of the second metal-containing member and substantially the same length as the gate electrode.

Provided is a nitride semiconductor device 3 including a GaN electron transit layer 13, an AlGaN electron supply layer 14 in contact with the electron transit layer 13, a gate layer 15, formed selectively on the electron supply layer 14 and constituted of a nitride semiconductor composition effectively not containing an acceptor type impurity, and a gate electrode 16, formed on the gate layer 15, and satisfying the following formula (1): $\begin{array}{cc}{d}_g\sqrt{\frac{2E_{F}q\left(N_{\mathrm{DA}}+N_A-N_{\mathrm{DD}}-N_D\right)}{{\epsilon }_0{\epsilon }_C}}+{\Phi }_B-\frac{d_{B}P}{{\epsilon }_0{\epsilon }_C}>0.& \left(1\right)\end{array}$

Provided is a nitride semiconductor device 3 including a GaN electron transit layer 13, an AlGaN electron supply layer 14 in contact with the electron transit layer 13, a gate layer 15, formed selectively on the electron supply layer 14 and constituted of a nitride semiconductor composition effectively not containing an acceptor type impurity, and a gate electrode 16, formed on the gate lever 15, and satisfying the following formula (1): $\begin{array}{c}{d}_G\sqrt{\frac{2E_{F}q\left(N_{\mathrm{DA}}+N_A-N_{\mathrm{DD}}-N_D\right)}{{\mathrm{.Math.}}_0{\mathrm{.Math.}}_C}}+{\Phi }_B-\frac{d_{B}P}{{\mathrm{.Math.}}_0}\end{array}$

A semiconductor device having a substrate, a pair of Group III-Nitride layers on the substrate forming: a heterojunction with a 2 Dimensional Electron Gas (2DEG) channel in a lower one of the pair of Group III-Nitride layers, a cap beryllium doped Group III-Nitride layer on the upper one of the pair of Group III-Nitride layers; and an electrical contact in Schottky contact with a portion of the cap beryllium doped, Group III-Nitride layer.

A semiconductor device comprising an N-type metal oxide semiconductor (NMOS) gate-all-around (GAA) transistor and a P-type metal oxide semiconductor (PMOS) GAA transistor with high charge mobility channel materials is disclosed. The semiconductor device may include a substrate. The semiconductor device may also include an NMOS GAA transistor on the substrate, wherein the NMOS GAA transistor comprises a first channel material. The semiconductor device may further include a PMOS GAA transistor on the substrate, wherein the PMOS GAA transistor comprises a second channel material. The first channel material may have an electron mobility greater than an electron mobility of Silicon (Si) and the second channel material may have a hole mobility greater than a hole mobility of Si.

A semiconductor device includes first and second nitride semiconductor layers, a source, a drain, a gate structure, first and second p-type doped nitride semiconductor compound islands. The second nitride semiconductor layer is disposed on the first nitride semiconductor layer and has a bandgap greater than that of the first nitride semiconductor layer. The source, the drain, and the gate structure are disposed on the second nitride semiconductor layer. The drain viewed in a direction normal to the second nitride semiconductor layer extends longitudinally in an extending direction. The gate structure is between the source and the drain. The first p-type doped nitride semiconductor compound islands are disposed on the second nitride semiconductor layer and arranged adjacent to the drain along the extending direction. The second p-type doped nitride semiconductor compound island is disposed between the gate structure and the second nitride semiconductor layer.