A method for fabricating a semiconductor device includes the steps of: forming a fin-shaped structure on a substrate, forming a gate material layer on the fin-shaped structure, performing an etching process to pattern the gate material layer for forming a gate structure and a silicon residue, performing an ashing process on the silicon residue, and then performing a cleaning process to transform the silicon residue into a polymer stop layer on a top surface and sidewalls of the fin-shaped structure.

A semiconductor-on-insulator (SOI) substrate includes a handle substrate, a charge-trapping layer located over the handle substrate and including nitrogen-doped polysilicon, an insulating layer located over the charge-trapping layer, and a semiconductor material layer located over the insulating layer. The nitrogen atoms in the charge-trapping layer suppress grain growth during anneal processes used to form the SOI substrate and during subsequent high temperature processes used to form semiconductor devices on the semiconductor material layer. Reduction in grain growth reduces distortion of the SOI substrate, and facilitates overlay of lithographic patterns during fabrication of the semiconductor devices. The charge-trapping layer suppresses formation of a parasitic surface conduction layer, and reduces capacitive coupling of the semiconductor devices with the handle substrate during high frequency operation such as operations in gigahertz range.

A semiconductor device includes a P-type body region and an N-type drift region disposed in a substrate; a gate electrode, disposed on the P-type body region and the N-type drift region, including a high concentration doping region and a high resistance region, wherein a dopant concentration of the high concentration doping region is higher than a dopant concentration of the high resistance region; a spacer disposed on a side of the gate electrode; a highly doped source region disposed in the P-type body region; and a highly doped drain region disposed in the N-type body region. The high concentration doping region overlaps the P-type body region, and the high resistance region overlaps the N-type drift region.

A field effect device is provided. The field effect device includes a semiconductor nanosheet segment above a substrate, and a T-shaped inner spacer on the semiconductor nanosheet segment. The field effect device further includes a gate dielectric layer on the semiconductor nanosheet segment, and a first work function material plug on the gate dielectric layer. The field effect device further includes a second work function material layer on the first work function material plug and a center portion of the gate dielectric layer, wherein the second work function material layer is a different work function material from the first work function material plug.

The present disclosure provides a semiconductor device capable of improving element performance and reliability. The semiconductor device comprises a lower wiring structure, an upper interlayer insulating layer disposed on the lower wiring structure and including an upper wiring trench, the upper wiring trench exposing a portion of the lower wiring structure, and an upper wiring structure including an upper liner and an upper filling layer on the upper liner in the upper wiring trench, wherein the upper liner includes a sidewall portion extending along a sidewall of the upper wiring trench and a bottom portion extending along a bottom surface of the upper wiring trench, the sidewall portion of the upper liner includes cobalt (Co) and ruthenium (Ru), and the bottom portion of the upper liner is formed of cobalt (Co).

A device includes a semiconductor substrate and a first gate stack over the semiconductor substrate, the first gate stack being between a first gate spacer and a second gate spacer. The device further includes a second gate stack over the semiconductor substrate between the first gate spacer and the second gate spacer and a dielectric material separating the first gate stack from the second gate stack. The dielectric material is at least partially between the first gate spacer and the second gate spacer, a first width of an upper portion of the dielectric material is greater than a second width of a lower portion of the dielectric material, and a third width of an upper portion of the first gate spacer is less than a fourth width of a lower portion of the first gate spacer.

Techniques are disclosed for transistor gate trench engineering to decrease capacitance and resistance. Sidewall spacers, sometimes referred to as gate spacers, or more generally, spacers, may be formed on either side of a transistor gate to help lower the gate-source/drain capacitance. Such spacers can define a gate trench after dummy gate materials are removed from between the spacers to form the gate trench region during a replacement gate process, for example. In some cases, to reduce resistance inside the gate trench region, techniques can be performed to form a multilayer gate or gate electrode, where the multilayer gate includes a first metal and a second metal above the first metal, where the second metal includes lower electrical resistivity properties than the first metal. In some cases, to reduce capacitance inside a transistor gate trench, techniques can be performed to form low-k dielectric material on the gate trench sidewalls.

A method for fabricating a semiconductor device is provided. The method includes forming a fin structure extending along a first lateral direction; forming a dummy gate structure that is over a portion of the fin structure and extends along a second direction perpendicular to the first lateral direction; growing source/drain structures that are respectively coupled to ends of the portion of the fin structure; removing the dummy gate structure to form a gate trench; lining inner sidewalls of the gate trench with a gate spacer; and forming an active gate structure in the gate trench.

A semiconductor device structure is provided. The semiconductor device structure includes a substrate. The semiconductor device structure includes a gate stack formed over the substrate. The semiconductor device structure includes a spacer structure formed over a sidewall of the gate stack. The spacer structure includes a dielectric layer, a silicon rich layer, and a protection layer. The dielectric layer is formed between the gate stack and the silicon rich layer. The silicon rich layer is formed between the dielectric layer and the protection layer. A first atomic percentage of silicon in the silicon rich layer is greater than about 50%. The semiconductor device structure includes a source/drain structure formed over the substrate. The spacer structure is formed between the source/drain structure and the gate stack.

A semiconductor device structure is provided. The semiconductor device structure includes a substrate. The semiconductor device structure includes a gate stack formed over the substrate. The semiconductor device structure includes a spacer structure formed over a sidewall of the gate stack. The spacer structure includes a dielectric layer, a silicon rich layer, and a protection layer. The dielectric layer is formed between the gate stack and the silicon rich layer. The silicon rich layer is formed between the dielectric layer and the protection layer. A first atomic percentage of silicon in the silicon rich layer is greater than about 50%. The semiconductor device structure includes a source/drain structure formed over the substrate. The spacer structure is formed between the source/drain structure and the gate stack.