Gate-All-Around Channel Structures for Compact High-Current Transistors

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Solution Overview

Problem

Existing semiconductor device fabrication methods face challenges in achieving high performance and compact size due to limitations in channel structure design, which affect carrier mobility and driving current.

Innovation Solution

The implementation of a gate-all-around (GAA) transistor structure with embedded and sidewall channel structures, where a gate electrode encircles these channels, enhancing carrier mobility and allowing for increased channel size without increasing device volume.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional planar transistor structure is used, then device fabrication is simpler, but carrier mobility and driving current are limited

Engineering Contradiction:
Improvecarrier mobilityVSAvoidtransistor structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent transitions from a planar 2D channel structure to a 3D gate-all-around structure where the gate electrode completely surrounds the channel in three dimensions. This dimensional change enables the gate to control carrier flow from top, bottom, and sidewalls simultaneously, significantly enhancing carrier mobility and driving current while managing the increased structural complexity through systematic fabrication processes.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If channel size is increased to improve performance, then device volume increases

Engineering Contradiction:
Improvedriving currentVSAvoiddevice volume
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The gate electrode is nested around the channel in a gate-all-around configuration, with the gate wrapping completely around the channel structure. This nesting approach allows the channel to be positioned within the gate's controlling field from all directions, maximizing the effective channel utilization and driving current without requiring additional device footprint or volume, thereby achieving high performance in a compact form factor.

Inventive Principle:
Principle #7Nested doll (Nesting)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This design improves carrier mobility and driving current, enabling higher performance and compact device size, suitable for high-density semiconductor applications.

Implementation Method 1

forming an epitaxial stack on a substrate; forming an epitaxial cap covering the epitaxial stack; patterning the epitaxial stack and the epitaxial cap to form an embedded channel structure and a sidewall channel structure

Methodology Applied
Scientific EffectEpitaxy: Epitaxy

Data Source

PatentUS12389634B2Semiconductor device and method of fabricating a semiconductor device
Publication Date: 2025.08.12 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD
  • US12389634B2 patent drawing
  • US12389634B2 patent drawing
  • US12389634B2 patent drawing

AI summary

A semiconductor device including an embedded channel structure, a sidewall channel structure and a gate electrode structure is provided. The embedded channel structure is disposed on a substrate. The sidewall channel structure is disposed on the substrate, and located at a lateral side of the embedded channel structure. The gate electrode structure is disposed on the substrate, encircles the embedded channel structure and is located between the embedded channel structure and the sidewall channel structure.