Graphene Deposition on Magnetic Layers Using RF PECVD

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Solution Overview

Problem

The semiconductor industry faces challenges in forming reliable semiconductor devices at smaller sizes due to the increasing complexity and difficulty of fabrication processes as feature sizes decrease, particularly in achieving a graphene layer with optimal conductivity on metal lines/via in IC structures using conventional chemical vapor deposition methods, which require lengthy deposition times.

Innovation Solution

A method involving a deposition system with an RF source is used to form a graphene layer on a magnetic layer, allowing for rapid heating to target temperatures, thereby shortening the deposition time and improving the efficiency, quality, and sheet resistance of the graphene layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional chemical vapor deposition methods are used to form a graphene layer on metal lines/via, then the graphene layer can be formed, but the deposition time is lengthy which reduces production efficiency

Engineering Contradiction:

Improvedeposition timeVSAvoiddeposition time

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The patent replaces the conventional thermal field-based chemical vapor deposition method with an electromagnetic field-based plasma-enhanced chemical vapor deposition method. The RF source generates plasma that enables graphene deposition at lower temperatures and shorter times, substituting the slow thermal diffusion process with faster plasma-mediated chemical reactions.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the deposition parameters by introducing RF power as a new control parameter. By adjusting RF power, plasma density, and gas flow rates, the process achieves faster deposition rates while maintaining graphene quality. The deposition time is reduced from hours to minutes through these parameter optimizations.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If feature sizes are decreased to increase functional density, then production efficiency improves and costs decrease, but the complexity and difficulty of fabrication processes increase

Engineering Contradiction:

Improvefunctional densityVSAvoidfabrication process complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent introduces a magnetic layer as an intermediary substrate between the metal lines/via and the graphene layer. This magnetic layer serves as a catalyst carrier that simplifies the graphene formation process, enabling controlled deposition even at reduced feature sizes where conventional methods become too complex.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite structure consisting of metal lines/via, magnetic layer, and graphene layer. This multi-material composite approach allows each layer to contribute its unique properties: the metal provides structural support and electrical connectivity, the magnetic layer facilitates graphene nucleation and growth, and the graphene enhances conductivity, together solving the complexity issue at smaller scales.

Inventive Principle:

Principle #40Composite materials

3Reliability

If conventional deposition methods are used, then the process is simpler, but the sheet resistance of the graphene layer is higher which reduces conductivity

Engineering Contradiction:

ImproveconductivityVSAvoiddeposition process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs periodic RF cycling during deposition, where the RF source is pulsed on and off in controlled cycles. This periodic action allows for controlled plasma exposure that optimizes graphene crystallinity and reduces defects, thereby lowering sheet resistance. The cyclic plasma treatment also enables better control over deposition uniformity across the substrate.

Inventive Principle:

Principle #19Periodic action

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 approach enables a significant reduction in graphene deposition time, enhancing production efficiency and quality, and achieving lower sheet resistance, which is crucial for improving the conductivity of multi-layer interconnects in integrated circuits.

Implementation Method 1

a deposition system with an RF source is used to form a graphene layer on a magnetic layer, allowing for rapid heating to target temperatures

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

allowing for rapid heating to target temperatures, thereby shortening the deposition time

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Data Source

PatentUS12191143B2Semiconductor device and method for forming the same

Publication Date: 2025.01.07 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A plasma enhanced chemical vapor deposition (PECVD) method includes loading a wafer having a magnetic layer thereon into a processing chamber equipped with a radio frequency (RF) system, introducing an aromatic hydrocarbon precursor into the processing chamber, and turning on an RF source of the RF system to decompose the aromatic hydrocarbon precursor into active radicals at a frequency greater than about 1000 Hz to form a graphene layer over the magnetic layer.