A semiconductor device may include active patterns extended in a first direction and spaced apart from each other in the first direction, a device isolation layer defining the active patterns, an insulating structure provided between the active patterns and between the device isolation layer, and a gate structure disposed on the insulating structure and extended in a second direction crossing the first direction. The gate structure may include an upper portion and a lower portion. The lower portion of the gate structure may be enclosed by the insulating 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 laterally diffused metal oxide semiconductor device can include: a base layer; a source region and a drain region located in the base layer; a first dielectric layer located on a top surface of the base layer and adjacent to the source region; a voltage withstanding layer located on the top surface of the base layer and located between the first dielectric layer and the drain region; a first conductor at least partially located on the first dielectric layer; a second conductor at least partially located on the voltage withstanding layer; and a source electrode electrically connected to the source region, where the first and second conductors are spatially isolated, and the source electrode at least covers a space between the first and second conductors.

A bipolar transistor includes a stack of an emitter, a base, and a collector. The base is structured to have a comb shape including fingers oriented in a plane orthogonal to a stacking direction of the stack.

A semiconductor device includes a base, a first FET that includes at least two channel structure portions laminated, the channel structure portions each including a channel portion having a nanowire structure, a gate insulation film, and a gate electrode, and a second FET that includes a channel forming layer, a gate insulation layer, and a gate electrode. The first FET and the second FET are provided above the base. The channel portions of the first FET are disposed apart from each other in a laminating direction of the channel structure portions. Assuming that each of a distance between the channel portions of the first FET is a distance L1 and that a thickness of the gate insulation layer of the second FET is a thickness T2, T2≥(L1/2) is satisfied.

A preparation method of a semiconductor structure includes: a substrate including a groove structure is provided; a first isolation layer, a second isolation layer and a third isolation layer are sequentially formed on a bottom and sidewalls of the groove structure, where an upper surface of the first isolation layer is lower than an upper surface of the second isolation layer and an upper surface of the substrate to form a side trench; the third isolation layer is etched to enable an upper surface of the third isolation layer to be lower than the upper surface of the second isolation layer so that a top of the second isolation layer protrudes with respect to the first isolation layer and the third isolation layer to form a convex structure; and the second isolation layer is etched to remove the convex structure.

A semiconductor structure and a manufacturing method thereof are provided in the present disclosure. The semiconductor structure includes a semiconductor substrate; a plurality of stacked structures and a plurality of isolation structures on the semiconductor substrate, wherein the stacked structures are spaced apart each other, and each of the isolation structures are located between adjacent stacked structures; each of the stacked structures comprises a nucleation layer and a first epitaxial layer from bottom to top; and a heterojunction structure on the plurality of stacked structures, wherein the heterojunction structure is distributed over an entire surface, and an air gap is formed between the heterojunction structure and each of the isolation structures.

A semiconductor device includes a fin-shaped structure on a substrate, a gate structure on the fin-shaped structure and an interlayer dielectric (ILD) layer around the gate structure, and a single diffusion break (SDB) structure in the ILD layer and the fin-shaped structure. Preferably, the SDB structure includes a bottom portion and a top portion on the bottom portion, in which the top portion and the bottom portion include different widths.

A semiconductor device includes a source/drain diffusion area, a first doped region and a gate. The source/drain diffusion area, defined between a first isolation structure and a second isolation structure, includes a source region, a drain region and a device channel. The first doped region, disposed along a first junction between the device channel and the first isolation structure, is separated from at least one of the source region and the drain region. The first doped region has a dopant concentration higher than that of the device channel. The gate is disposed over the source/drain diffusion area. The first doped region is located within a projected area of the gate onto the source/drain diffusion area, the first isolation structure and the second isolation structure. A length of the first doped region is shorter than a length of the gate in a direction from the source region to the drain region.

A semiconductor device is provided in the disclosure, including a substrate, multiple parallel fins protruding from the substrate and isolated by trenches, and a device insulating layer on the trenches between two fins, wherein the trench is provided with a central first trench and two second trenches at both sides of the first trench, and a depth of the first trench is deeper than a depth of the second trench, and the device insulating layer is provided with a top plane, a first trench and a second trench, and the fins protrude from the top plane, and the bottom surface of the second trench is lower than the bottom surface of the first trench.