Backside Gate Cut Layout for Lower Nanotransistor Coupling Capacitance

Solution Overview

Problem

Forming gate terminals with desired characteristics in nanostructure transistors is challenging, leading to difficulties in reducing parasitic capacitance and achieving improved switching speed and reduced power consumption in integrated circuits.

Innovation Solution

A backside gate cutting process is employed to selectively remove portions of the gate cap metal between adjacent gate electrodes, electrically isolating some gate electrodes and reducing parasitic capacitance by minimizing the gate metal between them.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If gate terminals are formed in nanostructure transistors to increase computing power, then transistor functionality is improved, but parasitic capacitance increases and switching speed deteriorates

Engineering Contradiction:

Improvetransistor functionalityVSAvoidswitching speed

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The gate terminal is segmented into multiple conductive portions separated by dielectric material. This segmentation divides the continuous gate electrode into discrete segments, reducing the parasitic capacitance between adjacent gates while maintaining the necessary electrical connections for transistor operation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Conductive portions of the gate terminal are selectively removed or extracted from regions where they would create excessive parasitic capacitance. This extraction eliminates harmful capacitive coupling between adjacent transistors while preserving the gate's essential functionality for controlling current flow.

Inventive Principle:

Principle #2Taking out (Extraction)

2Reliability

If gate terminals are formed in nanostructure transistors to increase computing power, then transistor functionality is improved, but power consumption increases

Engineering Contradiction:

Improvetransistor functionalityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The gate terminal is segmented into multiple conductive portions separated by dielectric material. This segmentation divides the continuous gate electrode into discrete segments, reducing the parasitic capacitance between adjacent gates while maintaining the necessary electrical connections for transistor operation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Conductive portions of the gate terminal are selectively removed or extracted from regions where they would create excessive parasitic capacitance. This extraction eliminates harmful capacitive coupling between adjacent transistors while preserving the gate's essential functionality for controlling current flow.

Inventive Principle:

Principle #2Taking out (Extraction)

3Quantity of substance

If gate electrodes are closely spaced to increase transistor density, then computing power is improved, but capacitive coupling between gates increases

Engineering Contradiction:

Improvetransistor densityVSAvoidcapacitive coupling

Core Design Contradiction:

Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

A dielectric material is introduced as an intermediary between adjacent conductive gate portions. This dielectric layer acts as an electrical insulator that prevents direct capacitive coupling between gates while allowing the gates to remain in close proximity, thereby maintaining high transistor density without excessive parasitic capacitance.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The gate terminal is segmented into multiple conductive portions separated by dielectric material. This segmentation divides the continuous gate electrode into discrete segments, reducing the parasitic capacitance between adjacent gates while maintaining the necessary electrical connections for transistor operation.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS12543364B2Integrated circuit with backside metal gate cut for reduced coupling capacitance

Publication Date: 2026.02.03 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

An integrated circuit includes a first nanostructure transistor and a second nanostructure transistor. The first and second nanostructure each include gate electrodes. A backside trench separates the first gate electrode from the second gate electrode. A bulk dielectric material fills the backside trench. A gate cap metal electrically connects the first gate electrode to the second gate electrode.