A method includes: providing a substrate including a planar portion and a mesa portion over the planar portion; depositing an oxide layer over the mesa portion; depositing a ferroelectric material strip over the oxide layer and aligned with the mesa portion; and depositing a gate strip crossing the ferroelectric material strip and over the oxide layer.

Gate-all-around integrated circuit structures having germanium-doped nanowire/nanoribbon channel structures, and methods of fabricating gate-all-around integrated circuit structures having germanium-doped nanowire/nanoribbon channel structures, are described. For example, an integrated circuit structure includes a vertical arrangement of nanowires above a substrate. Individual ones of the vertical arrangement of nanowires have a relatively higher germanium concentration at a lateral mid-point of the nanowire than at lateral ends of the nanowire.

In a method of manufacturing a semiconductor device, a fin structure, in which first semiconductor layers and second semiconductor layers are alternately stacked, is formed. A sacrificial gate structure is formed over the fin structure. The first semiconductor layers, the second semiconductor layer and an upper portion of the fin structure at a source/drain region of the fin structure, which is not covered by the sacrificial gate structure, are etched. A dielectric layer is formed over the etched upper portion of the fin structure. A source/drain epitaxial layer is formed. The source/drain epitaxial layer is connected to ends of the second semiconductor wires, and a bottom of the source/drain epitaxial layer is separated from the fin structure by the dielectric layer.

A FinFET including a gate stack, a semiconductor fin embedded in the gate stack, a source and a drain disposed is provided. The semiconductor fin extends along a widthwise direction of the gate stack and has a first concave and a second concave exposed at sidewalls of the gate stack respectively. The source and drain are disposed at two opposite sides of the gate stack. The source includes a first portion in contact with and embedded in the first concave. The drain includes a second portion in contact with and embedded in the second concave. The first portion and the second portion are covered by the gate stack.

A technique for forming a semiconductor device is provided. Sacrificial mandrels are formed over a hardmask layer on a semiconductor layer. Spacers are formed on sidewalls of the sacrificial mandrels. The sacrificial mandrels are removed to leave the spacers. A masking process leaves exposed a first set of spacers with a second set protected. In response to the masking process, a first fin etch process forms a first set of fins in the semiconductor layer via first set of spacers. The first set of fins has a vertical sidewall profile. Another masking process leaves exposed the second set of spacers with the first set of spacers and the first set of fins protected. In response to the other masking process, a second fin etch process forms a second set of fins in semiconductor layer using the second set of spacers. The second set of fins has a trapezoidal sidewall profile.

A semiconductor device including at least one fin disposed on a surface of a semiconductor substrate is provided. The fin includes a main portion extending along a first direction, and at least one secondary portion extending outward from the main portion along a second direction not collinear with the first direction.

A method of forming a semiconductor structure is provided. A substrate having a memory region is provided. A plurality of fin structures are provided and each fin structure stretching along a first direction. A plurality of gate structures are formed, and each gate structure stretches along a second direction. Next, a dielectric layer is formed on the gate structures. A first patterned mask layer is formed, wherein the first patterned mask layer has a plurality of first trenches stretching along the second direction. A second patterned mask layer on the first patterned mask layer, wherein the second patterned mask layer comprises a plurality of first patterns stretching along the first direction. Subsequently, the dielectric layer is patterned by using the first patterned mask layer and the second patterned mask layer as a mask to form a plurality of contact vias. The contact holes are filled with a conductive layer.

In one example, a method for fabricating a semiconductor device includes forming a mandrel comprising silicon. Sidewalls of the silicon are orientated normal to the <111> direction of the silicon. A nanowire is grown directly on at least one of the sidewalls of the silicon and is formed from a material selected from Groups III-V. Only one end of the nanowire directly contacts the silicon.

A method for manufacturing fins includes following steps. A substrate including a plurality of fins formed thereon is provided. At least an ion implantation is performed to the fins. A thermal process is performed after the ion implantation. An insulating layer is formed on the substrate, and the fins are embedded in the insulating layer. Thereafter, a portion of the insulating layer is removed to form an isolation structure on the substrate, and the fins are exposed from a top surface of the isolation structure. The insulating layer is formed after the ion implantation and the thermal process. Or, the isolation structure is formed before the ion implantation, or between the ion implantation and the thermal process.

The present disclosure describes a fin-like field-effect transistor (FinFET). The device includes one or more fin structures over a substrate, each with source/drain (S/D) features and a high-k/metal gate (HK/MG). A first HK/MG in a first gate region wraps over an upper portion of a first fin structure, the first fin structure including an epitaxial silicon (Si) layer as its upper portion and an epitaxial growth silicon germanium (SiGe), with a silicon germanium oxide (SiGeO) feature at its outer layer, as its middle portion, and the substrate as its bottom portion. A second HK/MG in a second gate region, wraps over an upper portion of a second fin structure, the second fin structure including an epitaxial SiGe layer as its upper portion, an epitaxial Si layer as it upper middle portion, an epitaxial SiGe layer as its lower middle portion, and the substrate as its bottom portion.