Abstract: Methods for etching metal, such as for processing a metal gate, are provided. A method includes forming a hard mask over the metal, wherein the hard mask includes a sidewall defining an opening; and performing a plasma etching process including cycles of depositing a carbon nitride film on the sidewall and etching the metal.

Abstract: A device includes a semiconductor substrate, and a plurality of semiconductor fins parallel to each other, wherein the plurality of semiconductor fins is a portion of the semiconductor substrate. A Shallow Trench Isolation (STI) region is on a side of the plurality of semiconductor fins. The STI region has a top surface and a non-flat bottom surface, wherein the plurality of semiconductor fins is over the top surface of the STI region.

Abstract: A method of forming a semiconductor device includes forming a first fin and a second fin protruding above a substrate; forming isolation regions on opposing sides of the first fin and the second fin; forming a metal gate over the first fin and over the second fin, the metal gate being surrounded by a first dielectric layer; and forming a recess in the metal gate between the first fin and the second fin, where the recess extends from an upper surface of the metal gate distal the substrate into the metal gate, where the recess has an upper portion distal the substrate and a lower portion between the upper portion and the substrate, where the upper portion has a first width, and the lower portion has a second width larger than the first width, the first width and the second width measured along a longitudinal direction of the metal gate.

Abstract: A method includes forming a gate stack for a short-channel device and a longer-channel device; forming a first metal cap layer over the gate stacks for the short-channel device and the longer-channel device, wherein the first metal cap layer of the longer-channel device has a metal-cap recess; forming a first dielectric cap layer in the metal-cap recess; selectively removing in parallel, a portion of the gate stacks and first metal cap layer for the short-channel device and the longer-channel device; forming a first channel recess between spacers in the short-channel device and a second channel recess between a spacer and the first dielectric cap layer in the longer-channel device by the selectively removing; wherein each of the first channel recess and the second channel recess has a width dimension and a difference between the width dimensions of the first channel recess and second channel recess is less than 3 nm.

Abstract: Provided are structures and methods for forming structures with surfaces having a W-shaped profile. An exemplary method includes differentially etching a gate material to a recessed surface including a first and second horn and a valley located therebetween including first and second sections and a middle section therebetween; depositing an etch-retarding layer over the recessed surface including first and second edge regions and a central region therebetween, wherein the first edge region is located over the first horn and the first section, the second edge region is located over the second horn and the second section, the central region is located over the middle region, and the central region is thicker than the first edge region and the second edge region; and performing an etch process to recess the horns to establish the gate material with a W-shaped profile.

Abstract: A method of forming a semiconductor device includes forming a first fin and a second fin protruding above a substrate; forming isolation regions on opposing sides of the first fin and the second fin; forming a metal gate over the first fin and over the second fin, the metal gate being surrounded by a first dielectric layer; and forming a recess in the metal gate between the first fin and the second fin, where the recess extends from an upper surface of the metal gate distal the substrate into the metal gate, where the recess has an upper portion distal the substrate and a lower portion between the upper portion and the substrate, where the upper portion has a first width, and the lower portion has a second width larger than the first width, the first width and the second width measured along a longitudinal direction of the metal gate.

Abstract: A method includes forming an opening in a first dielectric layer. A region underlying the first dielectric layer is exposed to the opening. The method further includes depositing a dummy silicon layer extending into the opening, and depositing an isolation layer. The isolation layer and the dummy layer include a dummy silicon ring and an isolation ring, respectively, in the opening. The opening is filled with a metallic region, and the metal region is encircled by the isolation ring. The dummy silicon layer is etched to form an air spacer. A second dielectric layer is formed to seal the air spacer.

Abstract: A method includes forming a patterned etching mask, which includes a plurality of strips, and etching a semiconductor substrate underlying the patterned etching mask to form a first plurality of semiconductor fins and a second plurality of semiconductor fins. The patterned etching mask is used as an etching mask in the etching. The method further includes etching the second plurality of semiconductor fins without etching the first plurality of semiconductor fins. An isolation region is then formed, and the first plurality of semiconductor fins has top portions protruding higher than a top surface of the isolation region.

Abstract: A method of forming an integrated circuit includes forming a patterned mask layer on a material layer, wherein the patterned mask layer has a plurality of first features, and a first distance between adjacent first features of the plurality of first features. The method further includes patterning the material layer to form the first features in the material layer. The method further includes increasing the first distance between adjacent first features of the plurality of first features to a second distance. The method further includes treating portions of the material layer exposed by the patterned mask layer. The method further includes removing the patterned mask layer; and removing non-treated portions of the material layer.

Abstract: A method includes forming an opening in a first dielectric layer. A region underlying the first dielectric layer is exposed to the opening. The method further includes depositing a dummy silicon layer extending into the opening, and depositing an isolation layer. The isolation layer and the dummy layer include a dummy silicon ring and an isolation ring, respectively, in the opening. The opening is filled with a metallic region, and the metal region is encircled by the isolation ring. The dummy silicon layer is etched to form an air spacer. A second dielectric layer is formed to seal the air spacer.

Abstract: A semiconductor device includes a semiconductor substrate, an isolation structure in the semiconductor substrate for isolating a first active region and a second active region, a first device formed in the first active region, and a second device formed in the second active region. The first device has a first gate dielectric layer and a first gate electrode over the first gate dielectric layer. The first gate electrode includes at least one of Ta and C, and has a first work function for a first conductivity. The second device has a second gate dielectric layer and a second gate electrode over the second gate dielectric layer. The second gate electrode includes at least one of Ta, C, and Al, and has a second work function for a second conductivity. The second conductivity is different from the first conductivity.

Abstract: A fin-type field-effect transistor (FinFET) device includes a plurality of fins formed over a substrate. The semiconductor device further includes a dielectric layer filled in a space between each fin and over a first portion of the plurality of fins and a dielectric trench formed in the dielectric layer. The dielectric trench has a vertical profile. The semiconductor device further includes a second portion of the plurality of fins recessed and exposed in the dielectric trench. The second portion of the plurality of fins have a rounded-convex-shape top profile.

Abstract: In one example aspect, a method for integrated circuit (IC) fabrication comprises providing a device structure including a substrate, a source/drain (S/D) feature on the substrate, a gate stack on the substrate, a contact hole over the S/D feature; and a dummy feature over the S/D feature and between the gate stack and the contact hole. The method further comprises forming in the contact hole a contact plug that is electrically coupled to the S/D feature, and, after forming the contact plug, selectively removing the dummy feature to form an air gap that extends higher than a top surface of the gate stack. The method further comprises forming over the contact plug a seal layer that covers the air gap.

Abstract: Provided are structures and methods for forming structures with sloping surfaces of a desired profile. An exemplary method includes performing a first etch process to differentially etch a gate material to a recessed surface, wherein the recessed surface includes a first horn at a first edge, a second horn at a second edge, and a valley located between the first horn and the second horn; depositing an etch-retarding layer over the recessed surface, wherein the etch-retarding layer has a central region over the valley and has edge regions over the horns, and wherein the central region of the etch-retarding layer is thicker than the edge regions of the etch-retarding layer; and performing a second etch process to recess the horns to establish the gate material with a desired profile.

Abstract: A method for manufacturing a semiconductor structure is provided. A substrate including a fin structure is received, provided or formed. A sacrificial gate layer is formed over the fin structure and a source/drain structure is formed adjacent to the sacrificial gate layer, wherein the sacrificial gate layer is surrounded by a dielectric structure. The sacrificial gate layer is removed, wherein a recess is defined by the dielectric structure. A work function layer is formed in the recess, wherein the work function layer includes an overhang portion at an opening of the recess. A thickness of the work function layer is reduced. A glue layer is formed over the work function layer. A semiconductor structure thereof is also provided.

Abstract: Disclosed is a semiconductor fabrication method. The method includes forming a gate stack in an area previously occupied by a dummy gate structure; forming a first metal cap layer over the gate stack; forming a first dielectric cap layer over the first metal cap layer; selectively removing a portion of the gate stack and the first metal cap layer while leaving a sidewall portion of the first metal cap layer that extends along a sidewall of the first dielectric cap layer; forming a second metal cap layer over the gate stack and the first metal cap layer wherein a sidewall portion of the second metal cap layer extends further along a sidewall of the first dielectric cap layer; forming a second dielectric cap layer over the second metal cap layer; and flattening a top layer of the first dielectric cap layer and the second dielectric cap layer using planarization operations.

Abstract: A semiconductor device is disclosed. The semiconductor device includes a semiconductor fin. The semiconductor device includes first spacers over the semiconductor fin. The semiconductor device includes a metal gate structure, over the semiconductor fin, that is sandwiched at least by the first spacers. The semiconductor device includes a gate electrode contacting the metal gate structure. An interface between the metal gate structure and the gate electrode has its side portions extending toward the semiconductor fin with a first distance and a central portion extending toward the semiconductor fin with a second distance, the first distance being substantially less than the second distance.

Abstract: A fin-type field-effect transistor (FinFET) device includes a plurality of fins formed over a substrate. The semiconductor device further includes a dielectric layer filled in a space between each fin and over a first portion of the plurality of fins and a dielectric trench formed in the dielectric layer. The dielectric trench has a vertical profile. The semiconductor device further includes a second portion of the plurality of fins recessed and exposed in the dielectric trench. The second portion of the plurality of fins have a rounded-convex-shape top profile.

Abstract: In one example aspect, a method for integrated circuit (IC) fabrication comprises providing a device structure including a substrate, a source/drain (S/D) feature on the substrate, a gate stack on the substrate, a contact hole over the S/D feature; and a dummy feature over the S/D feature and between the gate stack and the contact hole. The method further comprises forming in the contact hole a contact plug that is electrically coupled to the S/D feature, and, after forming the contact plug, selectively removing the dummy feature to form an air gap that extends higher than a top surface of the gate stack. The method further comprises forming over the contact plug a seal layer that covers the air gap.

Abstract: A semiconductor structure includes a semiconductor substrate, a gate electrode, a first spacer, and a first contact etch stop layer (CESL). The semiconductor substrate includes a fin structure. The gate electrode is over the fin structure. The first spacer is over the fin structure and on a lateral side of the gate electrode, wherein a top surface of the first spacer is inclined towards the gate electrode. The first CESL is over the fin structure and contacting the first spacer, wherein an angle between the top surface of the first spacer and a sidewall of the first CESL is less than about 140°.