A method includes depositing a first dielectric layer over and along sidewalls of a first semiconductor fin and a second semiconductor fin, depositing a second dielectric layer over the first dielectric layer, recessing the first dielectric layer to define a dummy fin between the first semiconductor fin and the second semiconductor fin, forming a cap layer over top surfaces and sidewalls of the first semiconductor fin and the second semiconductor fin, wherein the forming the cap layer comprises depositing the cap layer in a furnace at process temperatures higher than a first temperature, and lowering the temperature of the furnace, wherein during the lowering the temperature of the furnace, the pressure in the furnace is raised to and maintained at 10 torr or higher until the temperature of the furnace drops below the first temperature.

A semiconductor device including an insulating layer on a substrate; channel semiconductor patterns stacked on the insulating layer and vertically spaced apart from each other; a gate electrode crossing the channel semiconductor patterns; source/drain regions respectively at both sides of the gate electrode and connected to each other through the channel semiconductor patterns, the source/drain regions having concave bottom surfaces; and air gaps between the insulating layer and the bottom surfaces of the source/drain regions.

A method of forming a semiconductor device includes depositing a film over a dielectric layer. The dielectric layer is over a first fin, a second fin, and within a trench between the first fin and the second fin. The method further includes etching top portions of the film, performing a treatment on the dielectric layer to remove impurities after etching the top portions of the film, and filling the trench over the remaining portions of the film. The treatment includes bombarding the dielectric layer with radicals.

A semiconductor device and a forming method thereof, the semiconductor device includes a first and a second wells, a source region, a drain region, two gate structures and at least one doping region. The first well with a first conductive type is disposed in a substrate, and the source region is disposed in the first well. The second well with a second conductive type is disposed adjacent to the first well in a substrate, and the drain region is disposed in the second well. Two gate structures are disposed on the substrate between the source region and the drain region. At least one doping region with the first conductive type is disposed in the second well between the two gate structures.

Semiconductor devices and method of forming the same are provided. In one embodiment, a semiconductor device includes a first transistor and a second transistor. The first transistor includes two first source/drain features and a first number of nanostructures that are stacked vertically one over another and extend lengthwise between the two first source/drain features. The second transistor includes two second source/drain features and a second number of nanostructures that are stacked vertically one over another and extend lengthwise between the two second source/drain features.

Various embodiments of the present disclosure are directed towards a method for forming a bipolar junction transistor (BJT). A dielectric film is deposited over a substrate and comprises a lower dielectric layer, an upper dielectric layer, and an intermediate dielectric layer between the lower and upper dielectric layers. A first semiconductor layer is deposited over the dielectric film and is subsequently patterned to form an opening exposing the dielectric film. A first etch is performed into the upper dielectric layer through the opening to extend the opening to the intermediate dielectric layer. Further, the first etch stops on the intermediate dielectric layer and laterally undercuts the first semiconductor layer. Additional etches are performed to extend the opening to the substrate. A lower base structure and an emitter are formed stacked in and filling the opening, and the first semiconductor layer is patterned to form an upper base structure.

Various embodiments of the present disclosure are directed towards a method for forming a bipolar junction transistor (BJT). A dielectric film is deposited over a substrate and comprises a lower dielectric layer, an upper dielectric layer, and an intermediate dielectric layer between the lower and upper dielectric layers. A first semiconductor layer is deposited over the dielectric film and is subsequently patterned to form an opening exposing the dielectric film. A first etch is performed into the upper dielectric layer through the opening to extend the opening to the intermediate dielectric layer. Further, the first etch stops on the intermediate dielectric layer and laterally undercuts the first semiconductor layer. Additional etches are performed to extend the opening to the substrate. A lower base structure and an emitter are formed stacked in and filling the opening, and the first semiconductor layer is patterned to form an upper base structure.

A semiconductor device includes a first transistor in a first region of a substrate and a second transistor in a second region of the substrate. The first transistor includes multiple first semiconductor patterns; a first gate electrode; a first gate dielectric layer; a first source/drain region; and an inner-insulating spacer. The second transistor includes multiple second semiconductor patterns; a second gate electrode; a second gate dielectric layer; and a second source/drain region. The second gate dielectric layer extends between the second gate electrode and the second source/drain region and is in contact with the second source/drain region. The first source/drain region is not in contact with the first gate dielectric layer.

Methods of forming a strained channel device utilizing dislocations disposed in source/drain structures are described. Those methods and structures may include forming a thin silicon germanium material in a source/drain opening of a device comprising silicon, wherein multiple dislocations are formed in the silicon germanium material. A source/drain material may be formed on the thin silicon germanium material, wherein the dislocations induce a tensile strain in a channel region of the device.

A semiconductor device and a method of forming the same are provided. In an embodiment, an exemplary semiconductor device includes two stacks of channel members; a source/drain feature extending between the two stacks of channel members along a direction; a source/drain contact disposed under and electrically coupled to the source/drain feature; two gate structures over and interleaved with the two stacks of channel members; a low-k spacer horizontally surrounding the source/drain contact; and a dielectric layer horizontally surrounding the low-k spacer.