A semiconductor structure includes a substrate, first fins extending from the substrate with a first fin pitch, and second fins extending from the substrate with a second fin pitch smaller than the first fin pitch. The semiconductor structure also includes first gate structures engaging the first fins with a first gate pitch and second gate structures engaging the second fins with a second gate pitch smaller than the first gate pitch. The semiconductor structure also includes first epitaxial semiconductor features partially embedded in the first fins and adjacent the first gate structures and second epitaxial semiconductor features partially embedded in the second fins and adjacent the second gate structures. A bottom surface of the first epitaxial semiconductor features is lower than a bottom surface of the second epitaxial semiconductor features.

Various embodiments of the present application are directed towards a method to integrate NVM devices with a logic or BCD device. In some embodiments, an isolation structure is formed in a semiconductor substrate. The isolation structure demarcates a memory region of the semiconductor substrate, and further demarcates a peripheral region of the semiconductor substrate. The peripheral region may, for example, correspond to BCD device or a logic device. A doped well is formed in the peripheral region. A dielectric seal layer is formed covering the memory and peripheral regions, and further covering the doped well. The dielectric seal layer is removed from the memory region, but not the peripheral region. A memory cell structure is formed on the memory region using a thermal oxidation process. The dielectric seal layer is removed from the peripheral region, and a peripheral device structure including a gate electrode is formed on the peripheral region.

A method of forming matched PFET/NFET spacers with differential widths for SG and EG structures and a method of forming differential width nitride spacers for SG NFET and SG PFET structures and PFET/NFET EG structures and respective resulting devices are provided. Embodiments include providing PFET SG and EG structures and NFET SG and EG structures; forming a first nitride layer over the substrate; forming an oxide liner; forming a second nitride layer on sidewalls of the PFET and NFET EG structures; removing horizontal portions of the first nitride layer and the oxide liner over the PFET SG and EG structures; forming RSD structures on opposite sides of each of the PFET SG and EG structures; removing horizontal portions of the first nitride layer and the oxide liner over the NFET SG and EG structures; and forming RSD structures on opposite sides of each of the NFET SG and EG structures.

A method of forming a vertical fin field effect transistor (vertical finFET) with an increased surface area between a source/drain contact and a doped region, including forming a doped region on a substrate, forming one or more interfacial features on the doped region, and forming a source/drain contact on at least a portion of the doped region, wherein the one or more interfacial features increases the surface area of the interface between the source/drain contact and the doped region compared to a flat source/drain contact-doped region interface.

A semiconductor structure includes at least two field effect transistors. A gate strip including a plurality of gate dielectrics and a gate electrode strip can be formed over a plurality of semiconductor active regions. Source/drain implantation is conducted using the gate strip as a mask. The gate strip is divided into gate electrodes after the implantation.

Structures for a bipolar junction transistor and methods of forming a structure for a bipolar junction transistor. The structure includes an emitter having a raised portion, a collector having a raised portion, and a base having a base layer and an extrinsic base layer stacked with the base layer. The base layer and the extrinsic base layer are positioned in a lateral direction between the raised portion of the emitter and the raised portion of the collector, the base layer has a first width in the lateral direction, the extrinsic base layer has a second width in the lateral direction, and the second width is greater than the first width.

A semiconductor device capable of improving operation performance and reliability, may include a gate insulating support to isolate gate electrodes that are adjacent in a length direction. The semiconductor device includes a first gate structure on a substrate, the first gate structure extending lengthwise in a first direction to have two long sides and two short sides, relative to each other, and including a first gate spacer; a second gate structure on the substrate, the second gate structure extending lengthwise in the first direction to have two long sides and two short sides, relative to each other, and including a second gate spacer, wherein a first short side of the second gate structure faces a first short side of the first gate structure; and a gate insulating support disposed between the first short side of the first gate structure and the first short side of the second gate structure and extending lengthwise in a second direction different from the first direction, a length of the gate insulating support in the second direction being greater than a width of each of the first gate structure and the second gate structure in the second direction.

A method of fabricating a metal gate transistor includes providing a substrate. Then, a high-k dielectric layer is formed to cover the substrate. Later, an ion implantation process is performed to implant fluoride ions into the high-k dielectric layer. After the ion implantation process, a polysilicon gate is formed on the high-k dielectric layer. Next, an interlayer dielectric layer is formed to cover the substrate and the polysilicon gate. Finally, the polysilicon gate is replaced by a metal gate.

A semiconductor structure and a forming method therefor are provided. The forming method includes: providing a base, a gate structure, a source/drain doped area, and a bottom dielectric layer; forming a source/drain interconnect layer running through the bottom dielectric layer on a top of the source/drain doped area; forming a top dielectric layer on the bottom dielectric layer; forming a gate contact running through the top dielectric layer on a top of the gate structure and a source/drain contact running through the top dielectric layer on a top of the source/drain interconnect layer; forming a sacrificial side wall layer on side walls of the gate contact and the source/drain contact; forming a gate plug filling the gate contact and a source/drain plug filling the source/drain contact; removing the sacrificial side wall layer to form a first gap; and forming a sealing layer sealing the first gap.

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.