A method of forming a complementary field-effect transistor (CFET) device includes: forming a plurality of channel regions stacked vertically over a fin; forming an isolation structure between a first subset of the plurality of channel regions and a second subset of the plurality of channel regions; forming a gate dielectric material around the plurality of channel regions and the isolation structure; forming a work function material around the gate dielectric material; forming a silicon-containing passivation layer around the work function material; after forming the silicon-containing passivation layer, removing a first portion of the silicon-containing passivation layer disposed around the first subset of the plurality of channel regions and keeping a second portion of the silicon-containing passivation layer disposed around the second subset of the plurality of channel regions; and after removing the first portion of the silicon-containing passivation layer, forming a gate fill material around the plurality of channel regions.

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.

A device structure includes a substrate, a fin structure disposed on the substrate and elongated in an X direction, a gate structure formed on the fin structure and elongated in a Y direction transverse to the X direction to terminate at two opposite ends, at least one dielectric portion connected to at least one of the two opposite ends of the gate structure, and having two sides that are opposite to each other in the X direction, and a pair of gate spacers which are spaced apart from each other in the X direction and are respectively disposed on two lateral sides of the gate structure, and which are elongated in the Y direction to cover the two sides of the dielectric portion, respectively. A method for manufacturing the device structure is also disclosed.

An integrated circuit device includes a first semiconductor layer, a second semiconductor layer, a first source/drain epitaxial structure, a second source/drain epitaxial structure, and a first contact plug. The second semiconductor layer is above the first semiconductor layer. The first and second semiconductor layers are vertically spaced apart from each other. The first source/drain epitaxial structure is on a side of the first semiconductor layer. The second source/drain epitaxial structure is on a side of the second semiconductor layer and above the first source/drain epitaxial structure. The first source/drain epitaxial structure has a portion extending beyond a sidewall of the second source/drain epitaxial structure from a top view. The first contact plug is over a frontside of the first source/drain epitaxial structure. The first contact plug overlaps the portion of the first source/drain epitaxial structure from the top view.

A transistor device and method of fabrication are provided, where the transistor device may include a semiconductor substrate, a first dielectric layer disposed on a surface of the semiconductor substrate, a second dielectric layer disposed directly on the first dielectric layer, a gate structure disposed directly on the surface of the semiconductor substrate, and a spacer structure. A first opening through the first dielectric layer and the second dielectric layer may correspond to a gate channel. Portions of the first dielectric layer and the second dielectric layer may be interposed directly between portions of the gate structure and the surface of the semiconductor substrate. The spacer structure may be disposed in the gate channel and interposed between the gate structure and the semiconductor substrate. The spacer structure may contact respective side surfaces of the first dielectric layer and the second dielectric layer that at least partially define the gate channel.

An exemplary structure includes a semiconductor substrate; a plurality of first dielectric layers at a top side of the substrate; an active device layer at a top side of the first dielectric layers; a plurality of second dielectric layers at a top side of the active device layer; and a metal body. The body includes a first portion that is embedded in the plurality of first dielectric layers. The first portion comprises a first layer of first metal. The body further includes a second portion that is embedded in the plurality of second dielectric layers. The second portion comprises a first layer of second metal. A plurality of vias interconnect the first portion to the second portion through the active device layer. The first layer of the first portion mechanically connects the plurality of vias and the first layer of the second portion mechanically connects the plurality of vias.

Devices, transistor structures, systems, and techniques are described herein related to providing a backside passivation layer on a transistor semiconductor material. The semiconductor material is between source and drain structures, and a gate structure is adjacent a channel region of the semiconductor material. The passivation layer is formed as a conformal insulative layer on a backside of the semiconductor material and is then treated using an ozone/UV cure to remove trap charges from the semiconductor material.

Method to form low-contact-resistance contacts to source/drain features is provided. A method of the present disclosure includes receiving a workpiece including an opening that exposes a surface of an n-type source/drain feature and a surface of a p-type source/drain feature, lateral epitaxial structures etching on the n-type source/drain feature creating the offset from the sidewall of the dielectric layer, depositing a silicide layer and the offset between etched epitaxial structures and sidewall of the dielectric layer is eliminated. The lateral epitaxial structures etching includes a reactive-ion etching (RIE) process and an atomic layer etching (ALE) process.

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.

A semiconductor device includes a plurality of first nanosheet fin structures located in a dense array region of a substrate. The semiconductor device further includes a plurality of first isolation trenches between adjacent first nanosheet fin structures of the plurality of first nanosheet fin structures. The plurality of first isolation trenches include: a first trench isolation layer, a protective liner formed on top of the first trench isolation layer, and a second trench isolation layer located above the protective liner. The protective liner separates the first trench isolation layer from the second trench isolation layer and the first trench isolation layer is more dense than the second trench isolation layer.