HF Cleaning Solution with Polymer Inhibitor for Silicon Nitride
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Solution Overview
Problem
Existing cleaning solutions for semiconductor substrates, particularly those containing hydrofluoric acid, tend to corrode silicon nitride surfaces, leading to unintended polishing during chemical mechanical polishing (CMP), which can result in material loss and process inefficiencies.
Innovation Solution
A cleaning solution comprising hydrofluoric acid and a polymer with specific carboxylic acid amide bonds and unsaturated double bonds as a corrosion inhibitor, which effectively protects silicon nitride surfaces by preventing corrosion and ensuring the removal of photoresist and etching residues without damaging the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hydrofluoric acid is used as a cleaning solution to remove photoresist residues and hard mask residues, then cleaning effectiveness is improved, but corrosion of silicon nitride stopper layer occurs
Solution Approach 1:
The patent introduces a corrosion inhibitor as an intermediary substance that mediates between the hydrofluoric acid cleaning solution and the silicon nitride stopper layer. The corrosion inhibitor forms a protective film on the silicon nitride surface, preventing direct contact and chemical reaction between the hydrofluoric acid and the stopper layer, thus eliminating the harmful corrosion effect while maintaining cleaning effectiveness
Solution Approach 2:
The patent creates a composite cleaning solution system comprising hydrofluoric acid, corrosion inhibitor, and water. This composite formulation combines substances with different functions: hydrofluoric acid for cleaning organic residues, corrosion inhibitor for protecting silicon nitride, and water as a solvent. The synergistic interaction of these components resolves the contradiction by enabling both effective cleaning and corrosion prevention simultaneously
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 provides excellent anticorrosion properties to silicon nitride, allowing for effective cleaning and residue removal while maintaining the integrity of the substrate, thereby enhancing the precision and efficiency of CMP processes.
Implementation Method 1
a corrosion inhibitor (B) and a solvent (S), wherein the corrosion inhibitor includes a polymer including one or more units represented by the following formula (b1) or formula (b2)
Implementation Method 2
hydrofluoric acid (A)... effectively cleaning and remove these residues
Data Source
AI summary
A cleaning solution that is used, inter alia, for removal of residue of a photoresist pattern or etching residue, and has exceptional anticorrosion properties with respect to silicon nitride; and a method for cleaning a substrate using the cleaning solution. In a cleaning solution containing a hydrofluoric acid and a solvent, a polymer that includes units derived from a compound of a specific structure having a carboxylic acid amide bond (—CO—N<) and an unsaturated double bond is blended as an anticorrosive agent. Polyvinylpyrrolidone is preferred as the polymer used as the anticorrosive agent.