Metal Sulfonate Stripping Composition for Organic Resin Removal

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Solution Overview

Problem

Current methods for removing organic substances and residues from microelectronic substrates, such as photoresists and dielectrics, are inefficient and can damage underlying metals, leading to incomplete removal, yield loss, and environmental concerns, particularly in the transition from aluminum to copper-based devices.

Innovation Solution

A composition comprising a solvent system and a metal sulfonate salt of isophthalic acid or its diester, combined with additives, is applied to the substrate, heated to dissolve the organic resin, and then rinsed with a suitable agent to effectively remove the resin without harming the substrate or adjacent metals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If aggressive materials such as strong acids or bases are used to remove cured organic dielectrics, then the organic substance can be removed, but the substrate or adjacent metals are damaged

Engineering Contradiction:
Improveremoval effectivenessVSAvoidsubstrate damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical parameters of the stripping composition by using metal sulfonate salts with specific functional groups that provide selective reactivity. The composition includes metals such as lithium, sodium, or potassium combined with organic acid radicals, creating a chemistry that dissolves cured organic dielectrics without the extreme pH values that damage substrates and metals

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite chemical system consisting of multiple components: metal sulfonate salts, organic solvents, and optional additives. This composite composition works synergistically to achieve effective removal of cured organics while protecting sensitive substrates and metal interconnects from damage

Inventive Principle:
Principle #40Composite materials

2Productivity

If conventional stripper chemistries are used to remove photoresist and residues, then some organic material can be removed, but the removal is incomplete and yields loss occurs

Engineering Contradiction:
Improveremoval efficiencyVSAvoidcomplete removal
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent modifies the chemical parameters of conventional strippers by incorporating metal sulfonate salts that specifically target cured organic materials. This chemical parameter change enables complete removal of photoresist, etch residues, and cured dielectrics that conventional chemistries cannot fully eliminate

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The metal sulfonate salt acts as an intermediary chemical agent that facilitates the dissolution of cured organic materials. The sulfonate group serves as a bridge between the metal cation and the organic polymer chains, enabling effective stripping of crosslinked and cured organics without requiring extreme pH conditions

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If copper-based devices are manufactured, then device performance improves, but organic residues are more difficult to remove and environmental concerns increase

Engineering Contradiction:
Improvedevice performanceVSAvoidcleaning difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent adjusts the chemical parameters of the stripping composition to be compatible with copper interconnects. The metal sulfonate salt chemistry provides selective dissolution of organic residues without attacking copper metal, enabling effective cleaning of copper-based devices while addressing environmental concerns by avoiding harsh acids and bases

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 solution enables rapid, complete removal of organic resins and residues from various substrates, including copper-based materials, while maintaining substrate integrity and reducing environmental impact, thus improving manufacturing efficiency and safety.

Implementation Method 1

heating the substrate to a temperature and for a time sufficient to achieve dissolution of the organic resin

Methodology Applied
Scientific EffectSolvation: Solvation

Implementation Method 2

heating the substrate to a temperature and for a time sufficient to achieve dissolution of the organic resin

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentUS8309502B2Compositions and methods for removing organic substances
Publication Date: 2012.11.13 VERSUM MATERIALS US LLC

AI summary

Compositions and methods useful for the removal of organic substances from substrates, for example, electronic device substrates such as microelectronic wafers or flat panel displays, are provided. A method is presented which applies a minimum volume of the composition as a coating to the inorganic substrate whereby sufficient heat is added and immediately rinsed with water to achieve complete removal. These compositions and methods are particularly suitable for removing and completely dissolving photoresists of the positive and negative varieties as well as thermoset polymers from electronic devices.