A device includes a substrate, a semiconductor channel over the substrate, and a gate structure over and laterally surrounding the semiconductor channel. The gate structure includes a first dielectric layer over the semiconductor channel, a first work function metal layer over the first dielectric layer, a first protection layer over the first work function metal layer, a second protection layer over the first protection layer, and a metal fill layer over the second protection layer.

A semiconductor device includes first transistor having a first gate stack and first source/drain regions on opposing sides of the first gate stack; a second transistor having a second gate stack and second source/drain regions on opposing sides of the second gate stack; and a gate isolation structure separating the first gate stack from the second gate stack. The gate isolation structure includes a dielectric liner having a varied thickness along sidewalls of the first gate stack and the second gate stack and a dielectric fill material over the dielectric liner, wherein the dielectric fill material comprises a seam.

According to the present disclosure, hybrid fins positioned between two different epitaxial source/drain features are recessed to prevent conductive material from entering interior air gaps of the hybrid fins, thus, preventing short circuit between source/drain contacts and gate electrodes. Recessing the hybrid fins may be achieved by enlarging mask during semiconductor fin etch back, therefore, without increasing production cost.

The present disclosure describes a method to form a semiconductor device with backside contact structures. The method includes forming a semiconductor device on a first side of a substrate. The semiconductor device includes a source/drain (S/D) region. The method further includes etching a portion of the S/D region on a second side of the substrate to form an opening and forming an epitaxial contact structure on the S/D region in the opening. The second side is opposite to the first side. The epitaxial contact structure includes a first portion in contact with the S/D region in the opening and a second portion on the first portion. A width of the second portion is larger than the first portion.

A semiconductor device with different configurations of contact structures and a method of fabricating the same are disclosed. The method includes forming first and second fin structures on a substrate, forming n- and p-type source/drain (S/D) regions on the first and second fin structures, respectively, forming first and second contact openings on the n- and p-type S/D regions, respectively, forming a carbon-based layer in the first and second contact openings, performing a remote plasma treatment with radicals on the carbon-based layer to form a remote plasma treated layer, selectively removing a portion of the remote plasma treated layer, forming a p-type work function metal (pWFM) silicide layer on the p-type S/D region, and forming an n-type work function metal (nWFM) silicide layer on the pWFM silicide layer and on the n-type S/D region.

A semiconductor device structure includes a first S/D feature over a first device region of a substrate, a plurality of first semiconductor layers over the first device region of the substrate, and each first semiconductor layer is in contact with the first source/drain feature, a first gate electrode layer surrounding a portion of each first semiconductor layer, and a first dielectric spacer contacting the first S/D feature, the first dielectric spacer disposed between and in contact with two first semiconductor layers of the plurality of the first semiconductor layers. The substrate comprises a first dopant region underneath the first S/D feature and a second dopant region underneath first gate electrode layer and radial outwardly of the first dopant region, the first dopant region comprising first dopants having a first conductivity type and a first dopant concentration and the second dopant region comprising the first dopants having a second dopant concentration less than the first dopant concentration.

A method includes depositing a silicon layer, which includes first portions over a plurality of strips, and second portions filled into trenches between the plurality of strips. The plurality of strips protrudes higher than a base structure. The method further includes performing an anneal to allow parts of the first portions of the silicon layer to migrate toward lower parts of the plurality of trenches, and performing an etching on the silicon layer to remove some portions of the silicon layer.

A semiconductor device includes a substrate having cell areas and power areas that are alternately arranged in a second direction. Gate structures extend in the second direction. The gate structures are spaced apart from each other in a first direction perpendicular to the second direction. Junction layers are arranged at both sides of each gate structure. The junction layers are arranged in the second direction such that each of the junction layer has a flat portion that is proximate to the power area. Cutting patterns are arranged in the power areas. The cutting patterns extend in the first direction such that each of the gate structures and each of the junction layers in neighboring cell areas are separated from each other by the cutting pattern.

A method of fabricating a semiconductor device includes forming a gate structure, a first edge structure and a second edge structure on a semiconductor strip. The method further includes forming a first source/drain feature between the gate structure and the first edge structure. The method further includes forming a second source/drain feature between the gate structure and the second edge structure, wherein a distance between the gate structure and the first source/drain feature is different from a distance between the gate structure and the second source/drain feature. The method further includes implanting a buried channel in the semiconductor strip, wherein the buried channel is entirely below a top-most surface of the semiconductor strip, a maximum depth of the buried channel is less than a maximum depth of the first source/drain feature, and a dopant concentration of the buried channel is highest under the gate structure.

A SEU tolerant structure has two logic sections that generate two output signals that are complementary such that a fault which affects one section cannot affect the other section. Adjacent NMOS regions or adjacent PMOS regions contain no logic inversions in the combinational logic or if logic inversions in the combinational logic are present where all gates following the inversion are SEU hard by design. The circuits can be realized using one of a Complex CMOS gate, pass transistor logic, Multiplexor logic, AND-OR logic or OR-AND logic. A SRL latch is formed of three NMOS and PMOS structures having a first latch with a first NMOS structure adjacent a first PMOS structure, a second latch with a second NMOS structure adjacent a second PMOS structure wherein the first and second NMOS structures are adjacent one another, and a third latch with a third NMOS structure adjacent a third PMOS structure wherein the second and third PMOS structures are adjacent one another, wherein the latch is adapted to have alternating logic with a state assignment of 010 and 101. A Single Event Upset Triple Modular Redundancy (TMR) tolerant circuit generates complementary output values 010 and 101 with layouts that are adjacent.