A semiconductor structure includes an isolation structure, a source or drain region over the isolation structure, a channel layer connecting to the source or drain region, a gate structure over the isolation structure and engaging the channel layer, an isolating layer below the channel layer and the gate structure, a dielectric cap below the isolating layer, and a contact structure having a first portion and a second portion. The first portion of the contact structure extends through the isolation structure, and the second portion of the contact structure extends from the first portion of the contact structure, through the dielectric cap and the isolating layer, and to the source or drain region. The first portion of the contact structure is below the second portion and wider than the second portion.

A method of forming fully aligned vias in a semiconductor device, the method including forming a first level interconnect line embedded in a first interlevel dielectric (ILD), selectively depositing a dielectric on the first interlevel dielectric, laterally etching the selectively deposited dielectric, depositing a dielectric cap layer and a second level interlevel dielectric on top of the first interlevel dielectric, and forming a via opening.

A semiconductor structure (MG) includes a metal gate structure disposed over a semiconductor substrate, a dielectric layer disposed adjacent to the MG, a source/drain (S/D) feature disposed adjacent to the dielectric layer, and a S/D contact disposed over the S/D feature. The S/D contact includes a first metal layer disposed over the S/D feature and a second metal layer disposed on the first metal layer.

A semiconductor device includes a substrate, a gate trench in the substrate, a gate insulating film in the gate trench, a titanium nitride (TiN)-lower gate electrode film on the gate insulating film, the titanium nitride (TiN)-lower gate electrode film including a top surface, a first side surface, and a second side surface opposite the first side surface, a polysilicon-upper gate electrode film on the titanium nitride (TiN)-lower gate electrode film, and a gate capping film on the polysilicon-upper gate electrode film. A center portion of the top surface of the titanium nitride (TiN)-lower gate electrode film overlaps a center portion of the polysilicon-upper gate electrode film in a direction that is perpendicular to a top surface of the substrate, and each of the first side surface and the second side surface of the titanium nitride (TiN)-lower gate electrode film is connected to the gate insulating film.

A reaction chamber includes a chamber body and a base. The base is arranged in the chamber body. The base includes a carrier member, a first block ring, and a second block ring. The carrier member is configured to carry a substrate and an edge member arranged around the carrier member. A height of an upper surface of the carrier member is greater than a height of an upper surface of the edge member. The first block ring is arranged on the upper surface of the edge member and around the carrier member. The upper surface of the carrier member is higher than an upper surface of the first block ring. The second block ring is on the upper surface of the first block ring. The second block ring includes a body member and a shield member.

Methods and apparatuses for performing spacer on spacer multiple patterning schemes using an exhumable first spacer material and a complementary second spacer material. Certain embodiments involve using a tin oxide spacer material for one of the spacer materials in spacer on spacer self aligned multiple patterning.

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.

A method of forming a semiconductor structure is provided. The method includes forming a gate structure over an active region of a substrate, forming an epitaxial layer comprising first dopants of a first conductivity type over portions of the active region on opposite sides of the gate structure, the epitaxial layer, applying a cleaning solution comprising ozone and deionized water to the epitaxial layer, thereby forming an oxide layer on the epitaxial layer, forming a patterned photoresist layer over the oxide layer and the gate structure to expose a portion of the oxide layer, forming a contact region second dopants of a second conductivity type opposite the first conductivity type in the portion of the epitaxial layer not covered by the patterned photoresist layer, and forming a contact overlying the contact region.

A semiconductor device includes a source/drain region, a source/drain silicide layer formed on the source/drain region, and a first contact disposed over the source/drain silicide layer. The first contact includes a first metal layer, an upper surface of the first metal layer is at least covered by a silicide layer, and the silicide layer includes a same metal element as the first metal layer.