Semiconductor Cleaning Composition for Residue Removal and Copper Protection
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Solution Overview
Problem
Current cleaning compositions for post-etch or post ash residue removal in the semiconductor industry fail to effectively remove residues from multiple layers such as photoresist, bottom anti-reflective coating, etch mask, and low k material layers without damaging copper or low k materials, leading to low yields and reliability in semiconductor devices.
Innovation Solution
A cleaning composition comprising fluoride etchants, alkanolamines, sulfonic acids, corrosion inhibitors, citric acid, and water, specifically formulated to remove residues from various layers while preserving copper and low k materials, with a pH range of 2.5 to 5.5, and a copper etching rate of 0.01 to 0.1 nm/min at 20° to 60°C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If current cleaning compositions are used for residue removal, then residues from multiple layers can be removed, but copper and low k materials are damaged
Solution Approach 1:
The patent changes the chemical parameters of the cleaning composition by specifying precise pH ranges (2.5-5.5) and controlled concentrations of fluoride etchants (0.001-1 wt.-%) to achieve effective residue removal while minimizing damage to copper and low k materials. This parameter optimization resolves the contradiction between cleaning effectiveness and material preservation.
Solution Approach 2:
The invention uses a composite cleaning composition containing multiple carefully selected components including fluoride etchants, alkanolamines, sulfonic acids, corrosion inhibitors, and citric acid. This composite formulation works synergistically to remove residues from photoresist, BARC, etch mask, and low k material layers while protecting copper interconnects and low k dielectric materials from damage.
2Manufacturing precision
If multiple rinsing steps are performed to remove residues, then cleaning effectiveness is improved, but manufacturing process complexity increases
Solution Approach 1:
The cleaning composition is designed with multi-functionality to simultaneously remove residues from multiple layer types (photoresist, BARC, etch mask, low k materials) in a single formulation. This universal cleaner reduces the need for multiple specialized rinsing steps, simplifying the manufacturing process while maintaining high cleaning effectiveness.
3Adaptability or versatility
If queue time is extended for processing flexibility, then manufacturing flexibility is improved, but residue accumulation and material damage increase
Solution Approach 1:
The cleaning composition performs preliminary protective action by incorporating corrosion inhibitors and pH buffers that prevent material degradation during extended queue times. The formulation proactively protects copper and low k materials from damage while maintaining residue removal capability, enabling extended processing flexibility without compromising reliability.
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 increases yields of functioning transistors by 1.9% and simplifies manufacturing processes by reducing the number of rinsing steps, while allowing extended queue times and minimizing damage to copper and low k materials, thus enhancing the flexibility and efficiency of semiconductor device production.
Implementation Method 1
comprising (i) one or more etchants comprising fluoride
Implementation Method 2
one or more alkanolamines... one or more sulfonic acids... with a pH range of 2.5 to 5.5
Implementation Method 3
citric acid... particularly effective in removing copper oxide and copper hydroxide compounds
Implementation Method 4
one or more corrosion inhibitors... cleaning composition... remove residues from various layers
Data Source
AI summary
A cleaning composition for post-etch or post ash residue removal from a substrate used in semiconductor industry and a corresponding use of said cleaning composition is described. Further described is a process for the manufacture of a semiconductor device from a semiconductor substrate, comprising the step of post-etch or post ash residue removal from a substrate by contacting the substrate with a cleaning composition according to the invention.