Chemical Liquid Defect Control via Ester Ratios

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Solution Overview

Problem

Semiconductor device manufacturing processes face defects due to metal impurities in chemical liquids used in wiring formation, such as photolithography, which can lead to yield reduction and electrical abnormalities like short circuits.

Innovation Solution

A chemical liquid containing an organic solvent, phosphoric acid ester, adipic acid ester, and metal impurities, with a specific mass ratio of phosphoric acid ester to adipic acid ester of 1 or higher, is used to inhibit metal impurity-containing defects, along with other organic impurities and stabilizers, in a chemical liquid storage body with a fluororesin or electropolished stainless steel container.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If organic solvents contain antioxidants to prevent decomposition, then the stability of the organic solvent is improved, but metal impurity-containing defects increase due to elution from manufacturing devices

Engineering Contradiction:

Improvestability of organic solventVSAvoidmetal impurity-containing defects

Core Design Contradiction:

Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters of the organic solvent by specifying precise ratios of phosphoric acid ester (0.1-100 ppm) to adipic acid ester (0.1-10 ppm), maintaining a mass ratio of 1 or higher. This parameter optimization reduces metal impurity adsorption while preserving solvent stability, resolving the contradiction between stability and defect generation.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite organic solvent system combining multiple components: phosphoric acid ester, adipic acid ester, and the base organic solvent. This composite formulation synergistically reduces metal impurity-containing defects while maintaining solvent performance, addressing both stability and defect reduction requirements.

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If chemical liquid contains organic impurities from manufacturing processes, then the chemical liquid can be produced cost-effectively, but defects in semiconductor devices increase

Engineering Contradiction:

Improveease of manufacturing chemical liquidVSAvoiddefect rate in semiconductor devices

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent optimizes the concentration parameters of organic impurities (phosphoric acid ester and adipic acid ester) to specific ranges rather than eliminating them completely. This parameter control allows cost-effective manufacturing while reducing defect rates by maintaining the phosphoric acid ester to adipic acid ester mass ratio at 1 or higher.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If metal impurities are present in chemical liquid, then the chemical liquid can be used as-is from manufacturing, but yield of semiconductor devices reduces due to defects

Engineering Contradiction:

Improveease of using chemical liquidVSAvoidmanufacturing yield of semiconductor devices

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The patent modifies the metal impurity profile by controlling the organic additive composition (phosphoric acid ester and adipic acid ester ratio), which reduces metal impurity adsorption and defect formation. This maintains ease of operation while improving manufacturing yield through reduced electrical abnormalities like short circuits.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20210222092A1Chemical liquid and chemical liquid storage body

Publication Date: 2021.07.22 FUJIFILM CORP

AI summary

An object of the present invention is to provide a chemical liquid and a chemical liquid storage body having excellent performance of inhibiting metal impurity-containing defects. The chemical liquid according to an embodiment of the present invention contains an organic solvent, organic impurities, and metal impurities, in which the organic impurities contain a phosphoric acid ester and an adipic acid ester, and a mass ratio of a content of the phosphoric acid ester to a content of the adipic acid ester is equal to or higher than 1.