Post-Etch Cleaning Composition for Residue Removal Without Metal Corrosion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current cleaning solutions for semiconductor substrates are inadequate in selectively removing photoresist and etch residues without corroding or dulling metallic circuitry, and they often fail to provide stable pH levels and effective cleaning over time.
Innovation Solution
An aqueous composition comprising oxalic acid, corrosion inhibitors such as amino acids, non-phenolic organic acids, and phenols, which selectively removes residues from semiconductor substrates without attacking metals or dielectric materials, maintaining stable pH and cleaning efficacy even after aging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If dilute sulfuric peroxide (DSP) is used to remove photoresist from aluminum surface, then photoresist removal is achieved, but metal corrosion and pitting occur
Solution Approach 1:
A corrosion inhibitor is introduced as an intermediary substance that mediates between the oxidizing cleaning solution and the metal surface. The corrosion inhibitor adsorbs onto the metal surface, forming a protective layer that prevents direct contact between the oxidizing agents (sulfuric acid, hydrogen peroxide) and the metal, thereby eliminating pitting corrosion while maintaining photoresist removal effectiveness
Solution Approach 2:
The patent modifies the chemical composition parameters of the cleaning solution by adding corrosion inhibitors and adjusting the ratios of oxidizing agents to acids. This parameter change transforms the solution from a highly corrosive mixture into a controlled cleaning composition that maintains oxidative cleaning power while reducing metal attack through balanced chemistry
2Manufacturing precision
If intentional under-etching of metal structures is performed to enable polymer removal, then polymer lift-off is improved, but over-etching risk increases causing metal structure damage
Solution Approach 1:
The corrosion inhibitor acts as a protective intermediary between the oxidizing cleaning solution and the metal structures. By adsorbing onto metal surfaces, it creates a barrier that prevents excessive etching, allowing the process to achieve complete polymer removal without the need for intentional under-etching, thus eliminating the over-etching risk
3Productivity
If strong oxidizing agents are used to remove post-etch residues, then cleaning effectiveness is improved, but metal corrosion is exacerbated
Solution Approach 1:
The corrosion inhibitor serves as a protective intermediary that allows strong oxidizing agents to remain in the cleaning solution for effective residue removal, while the inhibitor itself absorbs the harmful effects by forming a protective film on metal surfaces, decoupling the oxidizing power from metal corrosion
4Duration of action of stationary object
If cleaning solutions are used repeatedly over time, then processing continuity is maintained, but pH stability and cleaning efficacy deteriorate
Solution Approach 1:
The corrosion inhibitor and buffer system provide self-regulating properties to the cleaning solution. The buffer components automatically resist pH changes as the solution is used, and the corrosion inhibitor continuously regenerates the protective film on metal surfaces, enabling the solution to maintain stable performance throughout its service life without external intervention
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 composition effectively removes photoresist and etch residues from semiconductor substrates while preventing corrosion and maintaining cleaning performance over time, ensuring the stability and integrity of metallic and dielectric materials.
Implementation Method 1
The composition effectively removes photoresist and etch residues from semiconductor substrates while preventing corrosion
Implementation Method 2
corrosion inhibitors such as amino acids, non-phenolic organic acids, and phenols, which selectively removes residues from semiconductor substrates without attacking metals
Data Source
AI summary
A microelectronic device (semiconductor substrate) cleaning composition is provided that comprises water; oxalic acid, and two or more corrosion inhibitors and methods of using the same.