Semiconductor Cleaning Composition for Cobalt Etch Residue Removal

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Solution Overview

Problem

Conventional cleaning solutions fail to effectively remove dry etching residue and dry etching-stopper layers from semiconductor substrates containing cobalt wiring materials without damaging the cobalt wiring layer or interlayer dielectric films, and often result in side etching of the dry etching-stopper layer.

Innovation Solution

A cleaning solution comprising 0.2-20 mass% of specific amine compounds, 40-70 mass% of water-soluble organic solvents with low viscosity, and water, with a pH range of 9.0-14, is used to selectively remove dry etching residue and dry etching-stopper layers while preventing corrosion of cobalt-containing metal wiring layers and interlayer dielectric films.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a redox agent is used in a cleaning solution to loosen dry etching residue, then the residue removal capability is improved, but the cleaning solution causes deterioration of performance due to decomposition of components and induces change in the quality of the substrate surface

Engineering Contradiction:

Improveresidue removal capabilityVSAvoidcleaning solution stability and substrate surface quality

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent changes the chemical parameters of the cleaning solution by using a peroxide-based oxidizing agent instead of traditional redox agents, and controls the pH within a specific range (2-14) to prevent decomposition and maintain solution stability while effectively removing residue

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces an anticorrosive agent as an intermediary substance that protects the substrate surface from damage caused by the cleaning solution, allowing effective residue removal while preventing deterioration of the substrate

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If an anticorrosive agent is used to prevent damage to the wiring material, then the protection of cobalt wiring layer is improved, but the adsorbed anticorrosive agent cannot be easily removed from the surface

Engineering Contradiction:

Improvecobalt wiring layer protectionVSAvoidsurface cleanliness for subsequent film formation

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent optimizes the pH range (2-14) and uses specific combinations of oxidizing agents and anticorrosive agents that allow the anticorrosive agent to protect the cobalt wiring layer during cleaning while being easily removable in subsequent rinsing steps, preventing interference with film formation

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses a nitrogen-containing heterocyclic compound that can be easily removed by water or mild cleaning, replacing traditional anticorrosive agents that form strong adsorption bonds and are difficult to remove

Inventive Principle:

Principle #26Copying

3Manufacturing precision

If a peroxide is used as an oxidant to dissolve dry etching residue, then the residue removal capability is improved, but damage to cobalt cannot be suppressed without adding an anticorrosive agent

Engineering Contradiction:

Improveresidue dissolution capabilityVSAvoidcobalt corrosion

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent combines a peroxide-based oxidizing agent with a nitrogen-containing heterocyclic compound in a synergistic formulation, where the peroxide effectively dissolves organic and silicon residue while the heterocyclic compound protects cobalt from oxidation, achieving both residue removal and corrosion prevention in a single cleaning solution

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

The solution effectively removes dry etching residue and dry etching-stopper layers while minimizing damage to cobalt wiring layers and interlayer dielectric films, reducing the risk of side etching and ensuring reliable film formation in semiconductor substrate manufacturing.

Implementation Method 1

a cleaning solution comprising 0.2-20 mass% of an amine compound (A), 40-70 mass% of a water-soluble organic solvent (B) and water... capable of selectively removing dry etching residue and a dry etching-stopper layer from a surface of a substrate

Methodology Applied

Scientific EffectChemical dissolution:

Implementation Method 2

suppressing damage to the cobalt-containing metal wiring layer... while removing dry etching residue and the dry etching-stopper layer

Methodology Applied

Scientific EffectCorrosion prevention:

Implementation Method 3

the amine compound (A) contains one or more selected from the group consisting of n-butylamine, hexylamine, octylamine, 1,4-butanediamine, dibutylamine, 3-amino-1-propanol... pH is in a range of 9.0-14

Methodology Applied

Scientific EffectBase neutralization:

Data Source

PatentEP3767666B1Cleaning solution for removing dry etching residue and method for manufacturing semiconductor substrate using same

Publication Date: 2024.03.27 MITSUBISHI GAS CHEM CO INC

Figure 1

AI summary

The present invention can provide a cleaning solution containing 0.2-20 mass% of an amine compound (A), 40-70 mass% of a water-soluble organic solvent (B), and water, wherein the amine compound (A) contains at least one selected from the group consisting of n-butylamine, hexylamine, octylamine, 1,4-butanediamine, dibutylamine, 3-amino-1-propanol, N,N-diethyl-1,3-diaminopropane, and bis(hexamethylene)triamine, and the water-soluble organic solvent (B) has a viscosity of 10 mPa·s or less at 20°C and a pH of 9.0-14.