Barrier-Free Graphite Interconnects for Lower RC Delay

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The challenge of reducing resistance and capacitance in interconnects of integrated circuits (ICs) has limited further scaling down, leading to increased RC delay, which affects the performance of advanced IC technology nodes.

Innovation Solution

The implementation of barrier-free graphite-based interconnects, such as graphite plugs and metal via plugs like ruthenium, tungsten, or molybdenum, which reduce metal-metal interfaces and increase conductivity, thereby decreasing resistance and RC delay.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional metal interconnects are used, then manufacturing is well-established, but resistance and RC delay increase as geometry scales down

Engineering Contradiction:

ImproveRC delay performanceVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the material parameter from conventional metals (copper, aluminum) to graphite, fundamentally altering the interconnect's electrical properties. Graphite's unique structure provides lower resistance and reduced scattering at interfaces, directly addressing the RC delay problem while maintaining compatibility with existing fabrication processes through modified deposition techniques.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite interconnect structures combining graphite with metal via plugs (ruthenium, tungsten, or molybdenum). This composite approach leverages graphite's low resistance properties while using metal plugs for reliable electrical connection to underlying structures, creating a hybrid material system that optimizes both performance and manufacturability.

Inventive Principle:

Principle #40Composite materials

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

The use of graphite-based interconnects decreases resistance and improves IC device performance by enhancing conductivity and reducing scattering at interfaces, thus optimizing the performance of advanced IC technology nodes.

Implementation Method 1

The use of graphite-based interconnects decreases resistance and improves IC device performance by enhancing conductivity and reducing scattering at interfaces

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS20260026337A1Graphite-Based Interconnects and Methods of Fabrication Thereof

Publication Date: 2026.01.22 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

Barrier-free interconnects and methods of fabrication thereof are disclosed herein. An exemplary interconnect structure has a conductive line disposed over a conductive via. The conductive line has a first conductive plug disposed in a first dielectric layer, and the first conductive plug includes an electrically conductive non-metal material, such as graphite. The conductive via includes a second conductive plug disposed in a second dielectric layer, and the second conductive plug includes a metal material, such as tungsten, ruthenium, molybdenum, or combinations thereof. The first conductive plug physically contacts the second conductive plug and the second dielectric layer. The second conductive plug physically contacts the second dielectric layer. Spacers (which are insulators) may be disposed between sidewalls of the first conductive plug and the first dielectric layer. The spacers may further be disposed between the first dielectric layer and the second dielectric layer.