Vias, along with methods for fabricating vias, are disclosed that exhibit reduced capacitance and resistance. An exemplary interconnect structure includes a first source/drain contact and a second source/drain contact disposed in a dielectric layer. The first source/drain contact physically contacts a first source/drain feature and the second source/drain contact physically contacts a second source/drain feature. A first via having a first via layer configuration, a second via having a second via layer configuration, and a third via having a third via layer configuration are disposed in the dielectric layer. The first via and the second via extend into and physically contact the first source/drain contact and the second source/drain contact, respectively. A first thickness of the first via and a second thickness of the second via are the same. The third via physically contacts a gate structure, which is disposed between the first source/drain contact and the second source/drain contact.

Gate-all-around (GAA) devices and methods of manufacturing such devices are described herein. A method includes forming a multi-layer structure over a substrate and forming a plurality of source/drain regions in the multi-layer structure. Fins are then patterned into the multi-layer structure through adjacent source/drain regions. A wire release process is performed to remove materials of one or more of the layers in the multi-layer stack. The remaining layers of the multi-layer stack form a stack of nanostructures connecting adjacent source/drain regions of the fins.

A semiconductor device including source/drain contacts extending into source/drain regions, below topmost surfaces of the source/drain regions, and methods of forming the same are disclosed. In an embodiment, a semiconductor device includes a semiconductor substrate; a first channel region over the semiconductor substrate; a first gate stack over the semiconductor substrate and surrounding four sides of the first channel region; a first epitaxial source/drain region adjacent the first gate stack and the first channel region; and a first source/drain contact coupled to the first epitaxial source/drain region, a bottommost surface of the first source/drain contact extending below a topmost surface of the first channel region.

In some embodiments, the present disclosure relates to a method of forming a transistor device. The method includes forming a source contact over a substrate, forming a drain contact over the substrate, and forming a gate contact material over the substrate. The gate contact material is patterned to define a gate structure that wraps around the source contact along a continuous and unbroken path.

A semiconductor device includes a substrate including an active pattern, a channel pattern and a source/drain pattern on the active pattern, a gate electrode provided on the channel pattern and extended in a first direction, and an active contact coupled to the source/drain pattern. The active contact includes a buried portion buried in the source/drain pattern and a contact portion on the buried portion. The buried portion includes an expansion portion provided in a lower portion of the source/drain pattern and a vertical extension portion connecting the contact portion to the expansion portion.

A high electron mobility transistor includes a substrate. A channel layer is disposed on the substrate. An active layer is disposed on the channel layer. The active layer includes a P-type aluminum gallium nitride layer. A P-type gallium nitride gate is disposed on the active layer. A source electrode and a drain electrode are disposed on the active layer.

Methods of forming a nanosheet field effect transistor (FET) device with reduced source/drain contact resistance are provided herein. In some embodiments, a method of forming an FET device includes: etching a nanosheet stack of the nanosheet FET device to form a plurality of first source/drain regions and a plurality of second source/drain regions, the nanosheet stack comprising alternating layers of nanosheet channel layers and sacrificial nanosheet layers; depositing a silicide layer in the plurality of first source/drain regions at ends of the nanosheet channel layers via a selective silicidation process to control a length of the nanosheet channel layers between the first source/drain regions; and performing a metal fill process to fill the plurality of first source/drain regions, wherein the metal fill extends from a lowermost nanosheet channel layer to above an uppermost nanosheet channel layer to facilitate the reduced source/drain contact resistance.

A wide band gap semiconductor device includes a semiconductor layer, a trench formed in the semiconductor layer, first, second, and third regions having particular conductivity types and defining sides of the trench, and a first electrode embedded inside an insulating film in the trench. The second region integrally includes a first portion arranged closer to a first surface of the semiconductor layer than to a bottom surface of the trench, and a second portion projecting from the first portion toward a second surface of the semiconductor layer to a depth below a bottom surface of the trench. The second portion of the second region defines a boundary surface with the third region, the boundary region being at an incline with respect to the first surface of the semiconductor layer.

A switched-mode neutral forming device is provided herein and comprises one or more windings coupled to (i) a plurality of line terminals via a plurality of switches and (ii) a neutral terminal, wherein each switch of the plurality of switches is a native four quadrant bi-directional switch and a controller, coupled to the plurality of switches, for driving the switches at a frequency orders or magnitude greater than an AC mains frequency.

A nitride semiconductor device is disclosed. The semiconductor device is formed by a process that first deposits a silicon nitride (SiN) film on a semiconductor layer by the lower pressure chemical vapor deposition (LPCVD) technique at a temperature, then, forming an opening in the SiN film for an ohmic electrode. Preparing a photoresist on the SiN film, where the photoresist provides an opening that fully covers the opening in the SiN film, the process exposes a peripheral area around the opening of the SiN film to chlorine (Cl) plasma that may etch the semiconductor layer to form a recess therein. Metals for the ohmic electrode are filled within the recess in the semiconductor layer and the peripheral area of the SiN film. Finally, the metals are alloyed at a temperature lower than the deposition temperature of the SiN film.