Inherently Selective Thermal ALD for Copper Metal Films

Solution Overview

Problem

Selective copper deposition in microelectronics devices is complicated and expensive, requiring chemical modifiers to prevent deposition on non-target areas, which increases process complexity and cost.

Innovation Solution

A method using a copper-containing compound and hydrazine vapor or alkyl-substituted hydrazine vapor at controlled temperatures to preferentially deposit copper metal films on metallic surfaces compared to non-metallic surfaces, employing atomic layer deposition (ALD) cycles to achieve precise selectivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If chemical modifiers are applied to non-target areas to prevent copper deposition, then deposition selectivity is improved, but process complexity and cost increase

Engineering Contradiction:

Improvedeposition selectivityVSAvoidprocess complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention changes the temperature parameter to achieve selective copper deposition. By controlling the substrate temperature within a specific range (200-400°C), copper is selectively deposited on metallic surfaces while non-metallic surfaces remain unaffected, eliminating the need for chemical modifiers and reducing process complexity

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention extracts and removes the chemical modifiers from the deposition process. Instead of using modifiers to achieve selectivity, the process relies solely on temperature-controlled inherent surface differences between metallic and non-metallic materials, simplifying the overall process

Inventive Principle:

Principle #2Taking out (Extraction)

2Manufacturing precision

If chemical modifiers are applied to non-target areas to prevent copper deposition, then deposition selectivity is improved, but manufacturing cost increases

Engineering Contradiction:

Improvedeposition selectivityVSAvoidmanufacturing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The invention changes the temperature parameter to achieve selective copper deposition. By controlling the substrate temperature within a specific range (200-400°C), copper is selectively deposited on metallic surfaces while non-metallic surfaces remain unaffected, eliminating the need for chemical modifiers and reducing process complexity

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention extracts and removes the chemical modifiers from the deposition process. Instead of using modifiers to achieve selectivity, the process relies solely on temperature-controlled inherent surface differences between metallic and non-metallic materials, simplifying the overall process

Inventive Principle:

Principle #2Taking out (Extraction)

3Manufacturing precision

If ALD process is used for selective copper deposition, then deposition control is improved, but process time increases

Engineering Contradiction:

Improvedeposition controlVSAvoidprocess time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The invention performs preliminary heating of the substrate to the optimal temperature range (200-400°C) before copper deposition. This preliminary thermal preparation enables the copper precursor to react selectively with metallic surfaces during the deposition process, achieving both precision and efficiency

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention optimizes the temperature parameter within a specific range (200-400°C) to accelerate the selective deposition process. This temperature optimization reduces the time required for copper to deposit selectively on metallic surfaces while maintaining precise control over the deposition

Inventive Principle:

Principle #35Parameter changes

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 method enables efficient and cost-effective selective deposition of copper metal films on metallic substrates, achieving a thickness ratio of up to 10:1 compared to non-metallic surfaces, suitable for microelectronic devices.

Implementation Method 1

The substrate is contacted with a vapor of a copper-containing compound and a hydrazine vapor and/or an alkyl-substituted hydrazine vapor at a sufficient temperature to preferentially form a copper metal coating on the at least one surface composed of a metallic material

Methodology Applied

Scientific EffectSelective chemical reaction: Chemical Bonding

Implementation Method 2

The substrate is contacted with a vapor of a copper-containing compound and a hydrazine vapor and/or an alkyl-substituted hydrazine vapor

Methodology Applied

Scientific EffectVapor deposition: Physical Vapour Deposition

Data Source

PatentUS20250283212A1Inherently selective thermal atomic layer deposition of copper metal films

Publication Date: 2025.09.11 WAYNE STATE UNIV

AI summary

A method for depositing a copper metal coating on a substrate's surface includes providing a substrate with a first face and a second face. The first face includes at least one exposed surface composed of a metallic material and at least one exposed surface composed of a non-metallic material. The substrate is contacted with a vapor of a copper-containing compound and hydrazine vapor at a sufficient temperature to preferentially form a copper metal coating on the surface composed of a metallic material as compared to the exposed surface composed of a non-metallic material.