Abstract: A method of forming a semiconductor device includes: forming a fin protruding above a substrate, where a top portion of the fin comprises a layer stack that includes alternating layers of a first semiconductor material and a second semiconductor material; forming a dummy gate structure over the fin; forming openings in the fin on opposing sides of the dummy gate structure; forming source/drain regions in the openings; removing the dummy gate structure to expose the first semiconductor material and the second semiconductor material under the dummy gate structure; performing a first etching process to selectively remove the exposed first semiconductor material, where after the first etching process, the exposed second semiconductor material form nanostructures, where each of the nanostructures has a first shape; and after the first etching process, performing a second etching process to reshape each of the nanostructures into a second shape different from the first shape.

Abstract: In an embodiment, a device includes: a first fin extending from a substrate; a gate stack disposed on the first fin; a source/drain region disposed in the first fin; a contact etch stop layer (CESL) disposed over the source/drain region; a gate spacer extending along a side of the gate stack; and a dielectric plug disposed between the CESL and the gate spacer, where the dielectric plug, the CESL, the gate spacer, and the source/drain region collectively define a void physically separating the gate stack from the source/drain region.

Abstract: In an embodiment, a device includes: a first fin extending from a substrate; a gate stack disposed on the first fin; a source/drain region disposed in the first fin; a contact etch stop layer (CESL) disposed over the source/drain region; a gate spacer extending along a side of the gate stack; and a dielectric plug disposed between the CESL and the gate spacer, where the dielectric plug, the CESL, the gate spacer, and the source/drain region collectively define a void physically separating the gate stack from the source/drain region.

Abstract: Some implementations described herein provide techniques and semiconductor devices in which a dielectric region is included in a nanostructure transistor. The dielectric region, which may correspond to an air gap, may be located between dielectric spacer layers located along a sidewall of a metal gate structure. Techniques to form the dielectric region may include using a temporary spacer layer between the dielectric spacer layers during manufacturing of the nanostructure transistor. The temporary spacer layer may include a silicon germanium material having a reaction mechanism that allows the temporary spacer layer to be selectively removed without causing damage to the dielectric spacer layers, the metal gate structure, or other portions of the nanostructure transistor.

Abstract: A method, for making a semiconductor device, includes forming a first fin over a substrate. The method includes forming a dummy gate stack on the first fin. The method includes forming a first gate spacer along a side of the dummy gate stack. The first gate spacer includes a first dielectric material. The method includes forming a second gate spacer along a side of the first gate spacer. The second gate spacer includes a semiconductor material. The method includes forming a source/drain region in the first fin adjacent the second gate spacer. The method includes removing at least a portion of the second gate spacer to form a void extending between the first gate spacer and the source/drain region.

Abstract: In an embodiment, a method of forming a semiconductor device includes forming a dummy gate stack over a substrate; forming a first spacer layer over the dummy gate stack; oxidizing a surface of the first spacer layer to form a sacrificial liner; forming one or more second spacer layers over the sacrificial liner; forming a third spacer layer over the one or more second spacer layers; forming an inter-layer dielectric (ILD) layer over the third spacer layer; etching at least a portion of the one or more second spacer layers to form an air gap, the air gap being interposed between the third spacer layer and the first spacer layer; and forming a refill layer to fill an upper portion of the air gap.

Abstract: A method, for making a semiconductor device, includes forming a first fin over a substrate. The method includes forming a dummy gate stack on the first fin. The method includes forming a first gate spacer along a side of the dummy gate stack. The first gate spacer includes a first dielectric material. The method includes forming a second gate spacer along a side of the first gate spacer. The second gate spacer includes a semiconductor material. The method includes forming a source/drain region in the first fin adjacent the second gate spacer. The method includes removing at least a portion of the second gate spacer to form a void extending between the first gate spacer and the source/drain region.

Abstract: In an embodiment, a method of forming a semiconductor device includes forming a dummy gate stack over a substrate; forming a first spacer layer over the dummy gate stack; oxidizing a surface of the first spacer layer to form a sacrificial liner; forming one or more second spacer layers over the sacrificial liner; forming a third spacer layer over the one or more second spacer layers; forming an inter-layer dielectric (ILD) layer over the third spacer layer; etching at least a portion of the one or more second spacer layers to form an air gap, the air gap being interposed between the third spacer layer and the first spacer layer; and forming a refill layer to fill an upper portion of the air gap.

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: In an embodiment, a method of forming a semiconductor device includes forming a dummy gate stack over a substrate; forming a first spacer layer over the dummy gate stack; oxidizing a surface of the first spacer layer to form a sacrificial liner; forming one or more second spacer layers over the sacrificial liner; forming a third spacer layer over the one or more second spacer layers; forming an inter-layer dielectric (ILD) layer over the third spacer layer; etching at least a portion of the one or more second spacer layers to form an air gap, the air gap being interposed between the third spacer layer and the first spacer layer; and forming a refill layer to fill an upper portion of the air gap.

Abstract: A method of forming a gas spacer in a semiconductor device and a semiconductor device including the same are disclosed. In accordance with an embodiment, a method includes forming a gate stack over a substrate; forming a first gate spacer on sidewalls of the gate stack; forming a second gate spacer on sidewalls of the first gate spacer; removing the second gate spacer using an etching process to form a first opening, the etching process being performed at a temperature less than 0° C., the etching process using an etching solution including hydrogen fluoride; and depositing a dielectric layer over the first gate spacer and the gate stack, the dielectric layer sealing a gas spacer in the first opening.

Abstract: A method of forming a semiconductor device includes: forming a fin protruding above a substrate, where a top portion of the fin comprises a layer stack that includes alternating layers of a first semiconductor material and a second semiconductor material; forming a dummy gate structure over the fin; forming openings in the fin on opposing sides of the dummy gate structure; forming source/drain regions in the openings; removing the dummy gate structure to expose the first semiconductor material and the second semiconductor material under the dummy gate structure; performing a first etching process to selectively remove the exposed first semiconductor material, where after the first etching process, the exposed second semiconductor material form nanostructures, where each of the nanostructures has a first shape; and after the first etching process, performing a second etching process to reshape each of the nanostructures into a second shape different from the first shape.

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: In an embodiment, a method of forming a semiconductor device includes forming a dummy gate stack over a substrate; forming a first spacer layer over the dummy gate stack; oxidizing a surface of the first spacer layer to form a sacrificial liner; forming one or more second spacer layers over the sacrificial liner; forming a third spacer layer over the one or more second spacer layers; forming an inter-layer dielectric (ILD) layer over the third spacer layer; etching at least a portion of the one or more second spacer layers to form an air gap, the air gap being interposed between the third spacer layer and the first spacer layer; and forming a refill layer to fill an upper portion of the air gap.

Abstract: A method of forming a gas spacer in a semiconductor device and a semiconductor device including the same are disclosed. In accordance with an embodiment, a method includes forming a gate stack over a substrate; forming a first gate spacer on sidewalls of the gate stack; forming a second gate spacer on sidewalls of the first gate spacer; removing the second gate spacer using an etching process to form a first opening, the etching process being performed at a temperature less than 0° C., the etching process using an etching solution including hydrogen fluoride; and depositing a dielectric layer over the first gate spacer and the gate stack, the dielectric layer sealing a gas spacer in the first opening.

Abstract: A method of forming a semiconductor device includes: forming a fin protruding above a substrate, where a top portion of the fin comprises a layer stack that includes alternating layers of a first semiconductor material and a second semiconductor material; forming a dummy gate structure over the fin; forming openings in the fin on opposing sides of the dummy gate structure; forming source/drain regions in the openings; removing the dummy gate structure to expose the first semiconductor material and the second semiconductor material under the dummy gate structure; performing a first etching process to selectively remove the exposed first semiconductor material, where after the first etching process, the exposed second semiconductor material form nanostructures, where each of the nanostructures has a first shape; and after the first etching process, performing a second etching process to reshape each of the nanostructures into a second shape different from the first shape.

Abstract: In an embodiment, a method of forming a semiconductor device includes forming a dummy gate stack over a substrate; forming a first spacer layer over the dummy gate stack; oxidizing a surface of the first spacer layer to form a sacrificial liner; forming one or more second spacer layers over the sacrificial liner; forming a third spacer layer over the one or more second spacer layers; forming an inter-layer dielectric (ILD) layer over the third spacer layer; etching at least a portion of the one or more second spacer layers to form an air gap, the air gap being interposed between the third spacer layer and the first spacer layer; and forming a refill layer to fill an upper portion of the air gap.

Abstract: A method, for making a semiconductor device, includes forming a first fin over a substrate. The method includes forming a dummy gate stack on the first fin. The method includes forming a first gate spacer along a side of the dummy gate stack. The first gate spacer includes a first dielectric material. The method includes forming a second gate spacer along a side of the first gate spacer. The second gate spacer includes a semiconductor material. The method includes forming a source/drain region in the first fin adjacent the second gate spacer. The method includes removing at least a portion of the second gate spacer to form a void extending between the first gate spacer and the source/drain region.

Abstract: In an embodiment, a device includes: a first fin extending from a substrate; a gate stack disposed on the first fin; a source/drain region disposed in the first fin; a contact etch stop layer (CESL) disposed over the source/drain region; a gate spacer extending along a side of the gate stack; and a dielectric plug disposed between the CESL and the gate spacer, where the dielectric plug, the CESL, the gate spacer, and the source/drain region collectively define a void physically separating the gate stack from the source/drain region.

Abstract: A method of forming a gas spacer in a semiconductor device and a semiconductor device including the same are disclosed. In accordance with an embodiment, a method includes forming a gate stack over a substrate; forming a first gate spacer on sidewalls of the gate stack; forming a second gate spacer on sidewalls of the first gate spacer; removing the second gate spacer using an etching process to form a first opening, the etching process being performed at a temperature less than 0° C., the etching process using an etching solution including hydrogen fluoride; and depositing a dielectric layer over the first gate spacer and the gate stack, the dielectric layer sealing a gas spacer in the first opening.