Lithography Cleaning Liquid for Cobalt Alloy Corrosion Control

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Solution Overview

Problem

Conventional cleaning liquids for lithography are ineffective in removing residue materials and suppressing corrosion of cobalt and its alloys during the etching process of semiconductor devices, leading to potential damage and processing impediments.

Innovation Solution

A cleaning liquid comprising hydroxylamine, at least one basic compound such as amine compounds or quaternary ammonium hydroxides, and water, with a pH value of 8 or higher, specifically designed to enhance the removal of residue materials and suppress corrosion of cobalt and its alloys.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional cleaning liquids composed mainly of quaternary ammonium hydroxides are used, then the capability of removing various residue materials is significantly improved, but the function of suppressing corrosion of cobalt and alloys thereof is poor

Engineering Contradiction:

Improveremoval capability of residue materialsVSAvoidsuppression of corrosion of cobalt and alloys

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent changes the chemical composition parameters of the cleaning liquid by adding hydroxylamine and controlling the pH to 11 or higher, which transforms the cleaning liquid's properties to simultaneously achieve strong residue removal capability and excellent corrosion suppression of cobalt and its alloys

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite cleaning liquid system combining hydroxylamine, quaternary ammonium hydroxides, and other basic compounds, where the synergistic interaction between components enables both effective residue removal and protection of cobalt-based materials from corrosion

Inventive Principle:

Principle #40Composite materials

2Productivity

If cleaning liquids are used to remove residue materials after etching, then the residue removal function is improved, but cobalt or alloys thereof are easily corroded

Engineering Contradiction:

Improveremoval of residue materialsVSAvoidcorrosion of cobalt and alloys

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the potentially harmful effect of strong cleaning action into a beneficial dual-function process where the high pH cleaning liquid with hydroxylamine not only removes residues effectively but also forms a protective effect on cobalt and its alloys, preventing corrosion while cleaning

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

The cleaning liquid effectively removes etching residues while preventing corrosion of cobalt and its alloys, ensuring improved processing outcomes and device integrity.

Implementation Method 1

hydroxylamine; at least one basic compound selected from the group consisting of amine compounds other than hydroxylamine, and quaternary ammonium hydroxides

Methodology Applied

Scientific EffectChemical dissolution:

Implementation Method 2

cleaning liquid comprising: hydroxylamine; at least one basic compound selected from the group consisting of amine compounds other than hydroxylamine, and quaternary ammonium hydroxides

Methodology Applied

Scientific EffectComplexation:

Implementation Method 3

excellent in the function of suppressing corrosion of at least one metal selected from the group consisting of cobalt and alloys thereof

Methodology Applied

Scientific EffectCorrosion inhibition through complexation:

Data Source

PatentUS9796953B2Cleaning liquid for lithography and method for cleaning substrate

Publication Date: 2017.10.24 TOKYO OHKA KOGYO CO LTD

AI summary

A cleaning liquid for lithography that is capable of removing residual material which remains after an etching process, as well as suppressing corrosion of at least one of cobalt and alloys thereof, and a method for cleaning a substrate using the cleaning liquid. The cleaning liquid for lithography includes hydroxylamine, at least one basic compound selected from amine compounds other than hydroxylamine, and quaternary ammonium hydroxides, and water, and has a pH value of 8 or higher. The cleaning liquid is used in cleaning a substrate containing at least one of cobalt and alloys thereof.