Taiwan Semiconductor Manufacturing Comp. Ltd.

Chang-Miao Liu

Xusheng Wu

Huiling Shang

Bwo-Ning Chen

Wei-Lun Min

Ko-Cheng Liu

Ming-Lung Cheng

Xu-Sheng Wu

Huicheng Chang

Liang-Yin Chen

Shih-Hao Lin

Su-Hao Liu

Chia-Cheng Chen

Huai-Tei Yang

Kuo-Ju Chen

Chun-Hung Wu

Lun-Kuang Tan

Wei-Ming You

Kei-Wei Chen

Chun-Fai Cheng

Kuan-Chung Chen

Ying-Keung Leung

Ming-Shuan Li

Pin-Ju Liang

Youbo Lin

Hui-Ling Shang

Chien-Tai Chan

Yin-Pin Wang

Yuh-Sheng Jean

A semiconductor device includes a substrate, a gate stack over the substrate and a gate spacer on a sidewall of the gate stack. The gate spacer includes an outer spacer and an inner spacer between the gate stack and the outer spacer. The outer spacer and the inner spacer have same k-value reduction impurities, and a concentration of the k-value reduction impurities in the inner spacer is greater than a concentration of the k-value reduction impurities in the outer spacer.

Dielectric constant reduction of gate spacer

An exemplary device includes a stack of channel layers over a substrate extension, a gate, and an insulation layer. The stack of channel layers extends between a first epitaxial source/drain and a second epitaxial source/drain. The gate surrounds each channel layer of the stack of the channel layers. The insulation layer is over the substrate extension, the gate is between a bottommost channel layer of the stack of channel layers and the insulation layer, and the insulation layer is between the gate and the substrate extension. The insulation layer extends between the first epitaxial source/drain and the second epitaxial source/drain, each of which may include an undoped epitaxial layer. A top surface of the undoped epitaxial layer is below a bottom surface of the bottommost channel layer and/or above a top surface of the insulation layer. The insulation layer may wrap the substrate extension and/or have an air gap therein.

Isolation for multigate devices

A method includes forming a semiconductor fin protruding from a substrate, forming a cladding layer on sidewalls of the semiconductor fin, forming first and second dielectric fins sandwiching the semiconductor fin, and removing the cladding layer. The removal of the cladding layer forms trenches between the semiconductor fin and the first and second dielectric fins. After the removing of the cladding layer, a dummy gate structure is formed over the semiconductor fin and in the trenches. The method also includes recessing the semiconductor fin in a region proximal to the dummy gate structure, forming an epitaxial feature on the recessed semiconductor fin, and forming a metal gate stack replacing the dummy gate structure. A top surface of the recessed semiconductor fin in the region has a concave shape.

Multi-gate device including semiconductor fin between dielectric fins and method of fabrication thereof

Semiconductor devices and methods are provided. An exemplary method according to the present disclosure includes providing fin-shaped active regions protruding from a substrate, forming cladding layers extending along sidewalls of the fin-shaped active regions, forming a dielectric feature over the substrate to fill space between two adjacent cladding layers, forming a gate structure over channel regions of the fin-shaped active regions and over a first portion of the cladding layers, performing an etching process to remove a second portion of the cladding layers not covered by the gate structure to form sidewall spacer trenches, forming a dielectric spacer in each of the sidewall spacer trenches, and after the forming of the dielectric spacers, forming source/drain features.

Semiconductor devices and methods of fabricating the same

A semiconductor device includes a substrate, two source/drain features disposed on the substrate, a stack of channel layers disposed over the substrate and between the two source/drain features, and a gate structure disposed over and wrapping around the stack of channel layers. Each channel layer of the stack of channel layers has a dog-bone shape in a cross-sectional view including the two source/drain features and the stack of channel layers. The gate structure includes a seam.

Methods for forming multi-gate transistors

A dummy gate is formed over a substrate. A sacrificial layer is formed over the dummy gate. An interlayer dielectric (ILD) is formed over the dummy gate and over the sacrificial layer. The dummy gate is replaced with a metal-containing gate. The sacrificial layer is removed. A removal of the sacrificial layer leaves air gaps around the metal-containing gate. The air gaps are then sealed.

Air spacer formation for semiconductor devices

A method includes performing a first etching process on a backside of a substrate to expose a dummy contact structure, performing a first deposition process to deposit a first portion of an oxide layer around the dummy contact structure, performing a second etching process to at least partially remove the first portion of oxide layer, forming a spacer layer around the dummy contact structure, performing a second deposition process to form a second portion of the oxide layer around the spacer layer, removing the spacer layer and the dummy contract structure to leave an opening, and filling the opening with a conductive material to form a conductive plug.

Enlarged backside contact

A semiconductor structure includes a substrate, an oxide layer disposed over the substrate, a stack of semiconductor layers disposed over the oxide layer, and an epitaxial source/drain (S/D) feature disposed adjacent to the stack of semiconductor layers. A portion of the epitaxial S/D feature is horizontally surrounded by the oxide layer.

Isolation structures in multi-gate semiconductor devices and methods of fabricating the same

A method includes providing a semiconductor structure including a device fin protruding from a substrate, forming a dummy gate stack over the device fin, forming a first spacer over the device fin and the dummy gate stack, forming a second spacer over the first spacer, forming a dielectric feature adjacent to the second spacer, and replacing the dummy gate stack with a metal gate stack. Thereafter, the method removes the second spacer, thereby forming an air gap between the first spacer and the dielectric feature and wrapping around the device fin. The method then forms a sealing layer over the first spacer and the dielectric feature, thereby sealing the air gap.

Semiconductor devices with air gaps and the method thereof

Semiconductor device and the manufacturing method thereof are disclosed. An exemplary semiconductor device comprises a semiconductor stack including semiconductor layers over a substrate, wherein the semiconductor layers are separated from each other and are stacked up along a direction substantially perpendicular to a top surface of the substrate; an isolation structure around a bottom portion of the semiconductor stack and separating active regions; a metal gate structure over a channel region of the semiconductor stack and wrapping each of the semiconductor layers; a gate spacer over a source/drain (S/D) region of the semiconductor stack and along sidewalls of a top portion of the metal gate structure; and an inner spacer over the S/D region of the semiconductor stack and along sidewalls of lower portions of the metal gate structure and wrapping edge portions of each of the semiconductor layers.

Methods of forming a semiconductor device with corner isolation protection

Multi-gate devices and methods for fabricating such are disclosed herein. An exemplary method includes forming a diffusion blocking layer on a semiconductor substrate; forming channel material layers over the diffusion blocking layer; patterning the semiconductor substrate, the channel material layers, and the diffusion blocking layer to form a trench in the semiconductor substrate, thereby defining an active region being adjacent the trench; filling the trench with a dielectric material layer and a solid doping source material layer containing a dopant; and driving the dopant from the solid doping source material layer to the active region, thereby forming an anti-punch-through (APT) feature in the active region.

Multi-channel devices and method with anti-punch through process

A method includes providing a substrate including a first semiconductor layer over a dielectric layer, thinning the first semiconductor layer, forming a stack of alternating second semiconductor layers and third semiconductor layers over the thinned first semiconductor layer, forming a fin active region protruding from the substrate including a portion of the thinned first semiconductor layer and the stack of alternating second semiconductor layers and third semiconductor layers, forming isolation features over an exposed portion of the dielectric layer, forming a dummy gate stack over the fin active region, forming a source/drain (S/D) recess in the fin active region adjacent to the dummy gate stack, forming an epitaxial S/D feature in the S/D recess, removing the second semiconductor layers to form openings between the third semiconductor layers, and forming a metal gate stack in the openings and in place of the dummy gate stack.

Semiconductor structure with recessed top semiconductor layer in substrate and method of fabricating the same

A semiconductor device with different gate structure configurations and a method of fabricating the semiconductor device are disclosed. The method includes depositing a high-K dielectric layer surrounding nanostructured channel regions, performing a first doping with a rare-earth metal (REM)-based dopant on first and second portions of the high-K dielectric layer, and performing a second doping with the REM-based dopants on the first portions of the high-K dielectric layer and third portions of the high-K dielectric layer. The first doping dopes the first and second portions of the high-K dielectric layer with a first REM-based dopant concentration. The second doping dopes the first and third portions of the high-K dielectric layer with a second REM-based dopant concentration different from the first REM-based dopant concentration. The method further includes depositing a work function metal layer on the high-K dielectric layer and depositing a metal fill layer on the work function metal layer

Gate structures for semiconductor devices

A semiconductor structure and a method of forming the same are provided. In an embodiment, an exemplary method includes providing a workpiece having a first active region and a second active region protruding from a substrate, lined by cladding layers, and spaced by a first trench. The method also includes forming a dielectric layer over the workpiece to substantially fill the first trench, forming a mask film directly on a portion of the dielectric layer in the first trench after the forming of the dielectric layer, selectively recessing the dielectric layer after the forming of the mask film to form a dummy fin in and protruding from the first trench, performing an etching process to selectively remove the cladding layers to form second trenches, and forming a gate structure over the workpiece to fill the second trenches.

A semiconductor structure includes a power rail, a dielectric layer over the power rail, a first source/drain feature over the dielectric layer, a via structure extending through the dielectric layer and electrically connecting the first source/drain feature to the power rail, and two dielectric fins disposed on both sides of the first source/drain feature. Each of the dielectric fins includes two seal spacers, a dielectric bottom cover between bottom portions of the seal spacers, a dielectric top cover between top portions of the seal spacers, and an air gap surrounded by the seal spacers, the dielectric bottom cover, and the dielectric top cover.

Growing community of inventors

Hsinchu, Taiwan

Chang-Miao Liu