Alloy ALD Precursor Intermixing for Tunable Diffusion Barriers

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Solution Overview

Problem

Conventional atomic layer deposition (ALD) methods for creating diffusion barriers require separate deposition of metal monolayers followed by annealing, which lacks precise control over metal intermixing and work function tunability, especially at the interface with dielectric layers.

Innovation Solution

A method and system for depositing ALD alloy monolayers by simultaneously exposing a substrate to first and second metal precursors, followed by purging and exposure to a common reactant, allowing for controlled metal composition and work function tunability without annealing, using a processing chamber with precise control over gas distribution and flow rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If separate deposition of metal monolayers followed by annealing is used, then diffusion barrier layers can be formed, but precise control over metal intermixing and work function tunability is lost

Engineering Contradiction:

Improvecontrol over metal intermixingVSAvoiddeposition process complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines the deposition of multiple metal precursors into a single ALD cycle, allowing simultaneous introduction of first and second metal precursors to the substrate. This merging of deposition steps enables precise control over metal intermixing at the atomic layer level while simplifying the overall process by eliminating separate deposition and annealing steps.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent utilizes parameter changes in the ALD process, specifically controlling the flow rates and ratios of metal precursor gases during simultaneous deposition. By adjusting these parameters, precise control over the composition and intermixing of metal atoms is achieved, enabling work function tunability without requiring post-deposition annealing.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If separate deposition of metal monolayers is used, then alloy layers can be formed after annealing, but work function tunability at the interface with dielectric layers is limited

Engineering Contradiction:

Improvework function tunabilityVSAvoidinterface stability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies local quality by enabling independent control of metal composition at different locations within the alloy layer. By simultaneously depositing multiple metal precursors with controlled ratios, the work function can be tuned locally at the interface with dielectric layers while maintaining overall layer stability and uniformity.

Inventive Principle:

Principle #3Local quality

3Manufacturing precision

If conventional ALD cycles are used to deposit metal monolayers sequentially, then diffusion barriers can be created, but the process is time-consuming and lacks homogeneity

Engineering Contradiction:

Improvefilm homogeneityVSAvoiddeposition speed

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent merges multiple sequential deposition steps into a single ALD cycle by simultaneously introducing multiple metal precursors. This approach achieves homogeneous metal distribution throughout the alloy layer while significantly increasing deposition productivity, as the entire alloy composition is formed in one cycle rather than through multiple sequential steps.

Inventive Principle:

Principle #5Merging (Combining)

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 enhances film homogeneity, thermal stability, and work function tunability, offering improved diffusion barriers with low resistivity, high thermal conductivity, and mechanical stress resistance compared to traditional metal-organic/inorganic compounds and titanium nitride barriers.

Implementation Method 1

exposing the substrate to a gas mixture including a first metal precursor gas and a second metal precursor gas to deposit a first metal precursor and a second metal precursor onto the substrate at the same time

Methodology Applied

Scientific EffectPhysical Vapour Deposition: Physical Vapour Deposition

Implementation Method 2

deposit a first metal precursor and a second metal precursor onto the substrate

Methodology Applied

Scientific EffectAdsorption: Adsorption

Implementation Method 3

supplying a reactant common to both the first metal precursor and the second metal precursor to form a layer of an alloy on the substrate

Methodology Applied

Scientific EffectChemical Vapour Deposition: Chemical Vapour Deposition

Data Source

PatentUS11827976B2Systems and methods for homogenous intermixing of precursors in alloy atomic layer deposition

Publication Date: 2023.11.28 LAM RES CORP

AI summary

A method includes arranging a substrate in a processing chamber, and exposing the substrate to a gas mixture including a first metal precursor gas and a second metal precursor gas to deposit a first metal precursor and a second metal precursor onto the substrate at the same time. The method further includes purging the processing chamber, supplying a reactant common to both the first metal precursor and the second metal precursor to form a layer of an alloy on the substrate, and purging the processing chamber.