An epitaxial structure of a GaN-based radio frequency device based on a Si substrate and a manufacturing method thereof are provided. The epitaxial structure is composed of a Si substrate (1), an AlN nucleation layer (2), AlGaN buffer layers (3, 4, 5), a GaN:Fe/GaN high-resistance layer (6), a GaN superlattice layer (7), a GaN channel layer (8), an AlGaN barrier layer (9) and a GaN cap layer (10) which are stacked in turn from bottom to top, wherein the GaN:Fe/GaN high-resistance layer (6) is composed of an intentional Fe-doped GaN layer and an unintentional doped GaN layer which are alternately connected; the GaN superlattice layer (7) is composed of a low-pressure/low V/III ratio GaN layer and a high-pressure/high V/III ratio GaN layer which are periodically and alternately connected.

An epitaxial structure of a GaN-based radio frequency device based on a Si substrate and a manufacturing method thereof are provided. The epitaxial structure is composed of a Si substrate (1), an AlN nucleation layer (2), AlGaN buffer layers (3, 4, 5), a GaN:Fe/GaN high-resistance layer (6), a GaN superlattice layer (7), a GaN channel layer (8), an AlGaN barrier layer (9) and a GaN cap layer (10) which are stacked in turn from bottom to top, wherein the GaN:Fe/GaN high-resistance layer (6) is composed of an intentional Fe-doped GaN layer and an unintentional doped GaN layer which are alternately connected; the GaN superlattice layer (7) is composed of a low-pressure/low V/III ratio GaN layer and a high-pressure/high V/III ratio GaN layer which are periodically and alternately connected.

The present disclosure provides a semiconductor device and a fabrication method thereof. The semiconductor device includes a first III-nitride layer, a second III-nitride layer, a first contact layer, a second contact layer, a structure, and a gate layer. The second III-nitride layer is in direct contact with the first III-nitride layer. The first contact layer and the second contact layer are disposed over the second III-nitride layer. The structure is adjacent to an interface of the first III-nitride layer and the second III-nitride layer, and a material of the structure is different from a material of the first III-nitride layer or a material of the second III-nitride layer. The gate layer is disposed between the first contact layer and the second contact layer.

A device includes a substrate; a buffer layer on the substrate; a barrier layer on the buffer layer, a source electrically coupled to the barrier layer; a gate electrically coupled to the barrier layer; and a drain electrically coupled to the barrier layer. The device further includes an electron concentration reduction structure arranged with at least one of the following: in the barrier layer and on the barrier layer. The electron concentration reduction structure is configured to at least one of the following: reduce electron concentration around the gate, reduce electron concentration around an edge of the gate, reduce electron concentration, increase power gain, increase efficiency, decouple the gate from the drain, decouple the gate from the source, and reduce capacitance.

According to one embodiment, a semiconductor device includes first, second and third electrodes, first and second semiconductor layers, and a first compound member. A position of the third electrode is between a position of the second electrode and a position of the first electrode. The first semiconductor layer includes first, second, third, fourth, and fifth partial regions. The fourth partial region is between the third and first partial regions. The fifth partial region is between the second and third partial regions. The second semiconductor layer includes first, second, and third semiconductor regions. The third semiconductor region is between the first partial region and the first electrode. The first compound member includes first compound portions between the third semiconductor region and the first electrode. A portion of the first electrode is between one of the first compound portions and an other one of the first compound portions.

According to one embodiment, a semiconductor device includes first, second and third electrodes, first and second semiconductor layers, and a first compound member. A position of the third electrode is between a position of the second electrode and a position of the first electrode. The first semiconductor layer includes first, second, third, fourth, and fifth partial regions. The fourth partial region is between the third and first partial regions. The fifth partial region is between the second and third partial regions. The second semiconductor layer includes first, second, and third semiconductor regions. The third semiconductor region is between the first partial region and the first electrode. The first compound member includes first compound portions between the third semiconductor region and the first electrode. A portion of the first electrode is between one of the first compound portions and an other one of the first compound portions.

In a described example, an integrated circuit (IC) is disclosed that includes a transistor. The transistor includes a substrate, and a buffer structure overlying the substrate. The buffer structure has a first buffer layer, a second buffer layer overlying the first buffer layer, and a third buffer layer overlying the second buffer layer. The first buffer layer has a first carbon concentration, the second buffer layer has a second carbon concentration lower than the first carbon concentration, and the third buffer layer has a third carbon concentration higher than the second carbon concentration. An active structure overlies the buffer structure.

In a described example, an integrated circuit (IC) is disclosed that includes a transistor. The transistor includes a substrate, and a buffer structure overlying the substrate. The buffer structure has a first buffer layer, a second buffer layer overlying the first buffer layer, and a third buffer layer overlying the second buffer layer. The first buffer layer has a first carbon concentration, the second buffer layer has a second carbon concentration lower than the first carbon concentration, and the third buffer layer has a third carbon concentration higher than the second carbon concentration. An active structure overlies the buffer structure.

The present disclosure relates to semiconductor structures and, more particularly, to a semiconductor device with a dual isolation structure and methods of manufacture. The structure includes: a dual isolation structure including semiconductor material; and an active device region including a channel material and a gate metal material over the channel material. The channel material is between the dual isolation structure and the gate metal material includes a bottom surface not extending beyond a sidewall of the dual isolation structure.

A semiconductor structure includes a superlattice structure, an electrical isolation layer, a channel layer, and a composition gradient layer. The superlattice structure is disposed on a substrate, the electrical isolation layer is disposed on the superlattice structure, the channel layer is disposed on the electrical isolation layer, and the composition gradient layer is disposed between the electrical isolation layer and the superlattice structure. The composition gradient layer and the superlattice structure include a same group III element, and the atomic percentage of the same group III element in the composition gradient layer is gradually decreased in the direction from the superlattice structure to the electrical isolation layer. In addition, a high electron mobility transistor including the semiconductor structure is also provided.