An integrated circuit (IC) device includes a stripe of material perpendicular to, and spanning between, semiconductor structures with multiple widths, and the stripe is between transistors with channel regions of differing widths in the semiconductor structures. The material stripes cover transition portions between different widths of the semiconductor structures. The semiconductor structures may be channel structures of different types, including groups of fins or nanoribbons. Channel regions of differing widths may include more or fewer fins or narrower or wider nanoribbons. The channel regions may have alternating conductivity types, n- and p-type.

A high voltage transistor may include a plurality of source/drain regions, a gate structure, and a gate oxide layer that enables the gate structure to selectively control a channel region between the source/drain regions. The gate oxide layer may extend laterally outward toward one or more of the plurality of source/drain regions such that at least a portion of the gate oxide layer is not under the gate structure. The gate oxide layer extending laterally outward from under the gate structure enables the gate oxide layer to be used as a self-aligned structure for forming the source/drain regions of the high voltage transistor. In particular, the gate oxide layer extending laterally outward from under the gate structure enables the gate oxide layer to be used to form the source/drain regions at a greater spacing from the gate structure without the use of additional implant masks when forming the source/drain regions.

An integrated circuit structure includes a first vertical stack of horizontal nanowires or a first fin having a first lateral width. A first gate electrode is over the first vertical stack of horizontal nanowires or the first fin, the first gate electrode having a second lateral width. A second vertical stack of horizontal nanowires or a second fin is laterally spaced apart from the first vertical stack of horizontal nanowires or the second fin, the second vertical stack of horizontal nanowires or the second fin having a third lateral width, the third lateral width less than the first lateral width. A second gate electrode is over the second vertical stack of horizontal nanowires or the second fin, the second gate electrode laterally spaced apart from the first gate electrode, and the second gate electrode having a fourth lateral width, the fourth lateral width less than the second lateral width.

In some implementations, an apparatus may include a substrate having silicon. In addition, the apparatus may include a first layer of a source or drain region of a p-type transistor, the first layer positioned above the substrate, the first layer having boron, silicon and germanium. The apparatus may include a second layer coupled to the source or drain region, the second layer having a metal contact for the source or drain region. Moreover, the apparatus may include a third layer positioned between the first layer and the second layer, the third layer having at least one monolayer having gallium, where the third layer is adjacent to the first layer.

Semiconductor structures and methods are provided. An exemplary method according to the present disclosure includes forming a first and a second fin-shaped active region over a substrate, the first and second fin-shaped active regions extending lengthwise along a first direction, forming a gate structure over channel regions of the first and second fin-shaped active regions, the gate structure extending lengthwise along a second direction substantially perpendicular to the first direction, forming a trench to separate the gate structure into two segments, the trench extending lengthwise along the first direction and being disposed between the first and second fin-shaped active regions, performing an etching process to enlarge an upper portion of the trench, and forming a gate isolation structure in the trench, and, in a cross-sectional view cut through both the first and second fin-shaped active regions and the gate structure, the gate isolation structure is a T-shape structure.

N-type gate-all-around (nanosheet, nanoribbon, nanowire) field-effect transistors (GAAFETs) vertically stacked on top of p-type GAAFETs in complementary FET (CFET) devices comprise non-crystalline silicon layers that form the n-type transistor source, drain, and channel regions. The non-crystalline silicon layers can be formed via deposition, which can provide for a simplified processing flow to form the middle dielectric layer between the n-type and p-type GAAFETs relative to processing flows where the silicon layers forming the n-type transistor source, drain, and channel regions are grown epitaxially.

An embodiment includes a method including forming an opening in a cut metal gate region of a metal gate structure of a semiconductor device, conformally depositing a first dielectric layer in the opening, conformally depositing a silicon layer over the first dielectric layer, performing an oxidation process on the silicon layer to form a first silicon oxide layer, filling the opening with a second silicon oxide layer, performing a chemical mechanical polishing on the second silicon oxide layer and the first dielectric layer to form a cut metal gate plug, the chemical mechanical polishing exposing the metal gate structure of the semiconductor device, and forming a first contact to a first portion of the metal gate structure and a second contact to a second portion of the metal gate structure, the first portion and the second portion of the metal gate structure being separated by the cut metal gate plug.

An embodiment is a structure including a first fin over a substrate, a second fin over the substrate, the second fin being adjacent the first fin, an isolation region surrounding the first fin and the second fin, a gate structure along sidewalls and over upper surfaces of the first fin and the second fin, the gate structure defining channel regions in the first fin and the second fin, a source/drain region on the first fin and the second fin adjacent the gate structure, and an air gap separating the source/drain region from a top surface of the substrate.

A semiconductor device a method of forming the same are provided. The method includes forming a fin extending from a substrate and forming a gate dielectric layer along a top surface and sidewalls of the fin. A first thickness of the gate dielectric layer along the top surface of the fin is greater than a second thickness of the gate dielectric layer along the sidewalls of the fin.

A semiconductor structure, a method for manufacturing a FinFET structure and a method for manufacturing a semiconductor structure are provided. The method for forming a FinFET structure includes: providing a FinFET precursor including a plurality of fins and a plurality of gate trenches between the fins; forming a first portion of the trench dummy of a dummy gate within the plurality of gate trenches; removing at least a part of the first portion of the trench dummy; forming a second portion of the trench dummy over the first portion of the trench dummy; performing a first thermal treatment to the first and second portions of the trench dummy; and forming a blanket dummy of the dummy gate over the second portion of the trench dummy. The present disclosure further provides a FinFET structure with an improved metal gate.