Non-Corrosive Cleaning Composition for Semiconductor Etch Residue Removal

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Solution Overview

Problem

The semiconductor industry faces challenges in removing etch residues and metal oxides from substrates while controlling corrosion to ever lower levels, especially as feature sizes shrink, requiring effective and environmentally friendly cleaning solutions that are non-corrosive to exposed substrate materials.

Innovation Solution

The use of non-corrosive cleaning compositions containing corrosion inhibitors such as substituted benzotriazoles and aromatic anhydrides, along with organic solvents like alcohols, ketones, and ethers, which are specifically designed to remove plasma etch and ash residues without damaging metals or metal alloys like aluminum, copper, and titanium, while being safe for the environment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional cleaning chemistries are used to remove etch residues and metal oxides, then cleaning effectiveness is improved, but corrosion to substrate materials increases

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidcorrosion to substrate materials
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary substance (corrosion inhibitor) that mediates between the cleaning chemistry and the substrate materials. The corrosion inhibitor forms protective complexes with metal ions, preventing direct corrosive attack on aluminum, copper, and other substrate materials while allowing the cleaning solution to effectively remove etch residues and metal oxides.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The cleaning composition is formulated as a composite system combining multiple components: HF for effective residue removal, organic solvents for enhanced cleaning capability, and corrosion inhibitors (such as benzotriazole derivatives) to protect substrate materials. This composite approach allows the solution to simultaneously achieve high cleaning effectiveness while minimizing corrosion damage.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If cleaning solutions are made more aggressive to remove harder-to-remove residues, then cleaning effectiveness is improved, but safety and environmental friendliness deteriorate

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidsafety and environmental impact
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent modifies the chemical parameters of the cleaning solution by using controlled concentrations of HF combined with organic solvents and corrosion inhibitors. This parameter optimization allows the solution to maintain high cleaning effectiveness for difficult residues while reducing the overall aggressiveness and improving safety profiles compared to conventional strong acids or bases.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent converts the potentially harmful corrosive nature of the cleaning solution into a beneficial effect by adding corrosion inhibitors that selectively protect substrate materials. The same chemical environment that could cause damage is transformed into a controlled cleaning process that protects rather than harms the substrate, while still effectively removing residues.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

These compositions effectively remove a broad range of residues without corroding semiconductor substrates, maintaining compatibility with materials like titanium oxide and silicon nitride, and are safe for use in the manufacturing process, ensuring robust device performance and environmental sustainability.

Implementation Method 1

a) HF

Methodology Applied
Scientific EffectChemical etching: Chemical Bonding

Implementation Method 2

b) at least one organic solvent

Methodology Applied
Scientific EffectDissolution: Solvation

Implementation Method 3

c) at least one corrosion inhibitor selected from triazoles, aromatic anhydrides, and combinations thereof

Methodology Applied
Scientific EffectComplex formation: Chemical Bonding

Data Source

PatentEP3322838B1Cleaning compositions and methods of use therefor
Publication Date: 2022.05.04 FUJIFILM ELECTRONIC MATERIALS U S A INC

AI summary

The present disclosure is directed to non-corrosive cleaning compositions that are useful primarily for removing residues (e.g., plasma etch and/or plasma ashing residues) and/or metal oxides from a semiconductor substrate as an intermediate step in a multistep manufacturing process.