A semiconductor device includes a GaN device provided with: a substrate made of a semi-insulating material or a semiconductor; a channel-forming layer including a GaN layer arranged on the substrate; a gate structure in which a gate-insulating film in contact with the GaN layer is arranged on the channel-forming layer, the gate structure having a gate electrode arranged across the gate-insulating film; and a source electrode and a drain electrode that are arranged on the channel-forming layer and on opposite sides interposing the gate structure. The donor element concentration at the interface between the gate-insulating film and the GaN layer and at the lattice position on the GaN layer side with respect to the interface is set to be less than or equal to 5.010.sup.17 cm.sup.3.

Embodiments include high electron mobility transistors (HEMT). In embodiments, a gate electrode is spaced apart by different distances from a source and drain semiconductor region to provide high breakdown voltage and low on-state resistance. In embodiments, self-alignment techniques are applied to form a dielectric liner in trenches and over an intervening mandrel to independently define a gate length, gate-source length, and gate-drain length with a single masking operation. In embodiments, III-N HEMTs include fluorine doped semiconductor barrier layers for threshold voltage tuning and/or enhancement mode operation.

A method of optical signal amplification. Incident photons are received at a photodetector including a doped semiconductor biased by a power source. The photons generate a change in a reflective property, refractive index, or electrical conductivity of the doped semiconductor. For the change in reflective property or refractive index, a first optical signal is reflected off the photodetector to provide a reflected beam, or the photodetector includes a reverse biased semiconductor junction including the doped semiconductor within a laser resonator including a laser medium, wherein a second optical signal is emitted. For the change in electrical conductivity the photodetector includes a reversed biased semiconductor junction that is within an electrical circuit along with an electrically driven light emitting device, where a drive current provided to the light emitting device increases as the electrical conductivity of the photodetector decreases, and the light emitting device emits a third optical signal.

A method and apparatus is disclosed for doping a semiconductor substrate with a dopant concentration greater than 10.sup.20 atoms per cubic centimeter. The method is suitable for producing an improved doped wide bandgap wafer for power electronic devices, photo conductive semiconductor switch, or a semiconductor catalyst.

Embodiments include high electron mobility transistors (HEMT). In embodiments, a gate electrode is spaced apart by different distances from a source and drain semiconductor region to provide high breakdown voltage and low on-state resistance. In embodiments, self-alignment techniques are applied to form a dielectric liner in trenches and over an intervening mandrel to independently define a gate length, gate-source length, and gate-drain length with a single masking operation. In embodiments, III-N HEMTs include fluorine doped semiconductor barrier layers for threshold voltage tuning and/or enhancement mode operation.

Methods for processing of a workpiece are disclosed. A fluid that contains a desired dopant is prepared. The workpiece is immersed in this fluid, such that the dopant is able to contact all surfaces of the workpiece. The fluid is then evacuated, leaving behind the dopant on the workpiece. The dopant is then subjected to a thermal treatment to drive the dopant into the surfaces of the workpiece. In certain embodiments, a selective doping process may be performed by applying a mask to certain surfaces prior to immersing the workpiece in the fluid. In certain embodiments, the fluid may be in a super-critical state to maximize the contact between the dopant and the workpiece.

Depositing gallium nitride and carbon (GaN:C) (e.g., in the form of composite layers) when forming a gallium nitride drain of a transistor provides a buffer between the gallium nitride of the drain and silicon of a substrate in which the drain is formed. As a result, gaps and other defects caused by lattice mismatch are reduced, which improves electrical performance of the drain. Additionally, current leakage into the substrate is reduced, which further improves electrical performance of the drain. Additionally, or alternatively, implanting silicon in an aluminum nitride (AlN) liner for a gallium nitride drain reduces contact resistance at an interface between the gallium nitride and the silicon. As a result, electrical performance of the transistor is improved.

According to some embodiments of the present disclosure, methods of forming a semiconductor device on a semiconductor layer having opposing first and second surfaces are disclosed. An n-type doped region including an n-type dopant may be formed at the first surface of the semiconductor layer. A p-type dopant source layer including a p-type dopant may be formed on the n-type doped region. The p-type dopant may be diffused from the p-type dopant source layer through the n-type doped region into the semiconductor layer to form a p-type doped region of the semiconductor layer, and the p-type doped region of the semiconductor layer may be between the n-type doped region and the second surface of the semiconductor layer. After diffusing the p-type dopant, the p-type dopant source layer may be removed.

Depositing gallium nitride and carbon (GaN:C) (e.g., in the form of composite layers) when forming a gallium nitride drain of a transistor provides a buffer between the gallium nitride of the drain and silicon of a substrate in which the drain is formed. As a result, gaps and other defects caused by lattice mismatch are reduced, which improves electrical performance of the drain. Additionally, current leakage into the substrate is reduced, which further improves electrical performance of the drain. Additionally, or alternatively, implanting silicon in an aluminum nitride (AlN) liner for a gallium nitride drain reduces contact resistance at an interface between the gallium nitride and the silicon. As a result, electrical performance of the transistor is improved.

Provided are a semi-conductor structure and a manufacturing method thereof. The semi-conductor structure includes: a substrate, a heterojunction, a P-type ion doped layer and a gate insulation layer disposed from bottom to top, wherein the heterojunction includes a source region, a drain region and a gate region; the P-type ion doped layer in the gate region includes an activated region and non-activated regions, P-type doping ions in the activated region are activated, and P-type doping ions in the non-activated regions are passivated; the non-activated regions include at least two regions which are spaced apart in a direction perpendicular to a connection line of the source region and the drain region; the gate insulation layer is located on the non-activated region to expose the activated region.