SLAM Etching Composition for Copper-Selective Semiconductor Removal
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Solution Overview
Problem
Existing etching processes struggle to selectively remove sacrificial light absorbing material (SLAM) without damaging underlying materials like metal conductors or insulators during the manufacturing of high-performance integrated circuits.
Innovation Solution
A composition comprising quaternary ammonium hydroxide, polar aprotic organic solvent, inorganic base, and sulfur-containing compounds, along with water, is used to selectively etch SLAM while minimizing damage to copper lines and dielectric materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional etching processes are used to remove sacrificial light absorbing material, then the SLAM can be removed, but underlying materials such as metal conductors, barrier materials, and insulator materials are damaged
Solution Approach 1:
The patent modifies the chemical composition parameters of the etching solution by incorporating specific compounds (quaternary ammonium hydroxide, polar aprotic organic solvent, inorganic base, and sulfur-containing compounds) to achieve selective etching. This parameter change enables high SLAM removal rates while minimizing damage to underlying materials through controlled chemical reactivity.
Solution Approach 2:
The patent introduces an intermediary chemical system that selectively interacts with SLAM while being inert or minimally reactive toward underlying materials. The combination of quaternary ammonium hydroxide, polar aprotic organic solvent, inorganic base, and sulfur-containing compounds acts as a mediator that facilitates SLAM removal without transferring harmful effects to copper, dielectric, or barrier layers.
2Productivity
If aggressive etching chemicals are used to increase SLAM removal rate, then productivity improves, but selectivity against underlying materials deteriorates
Solution Approach 1:
The patent achieves both high productivity and high selectivity by changing the chemical parameters of the etching solution. The specific combination of quaternary ammonium hydroxide, polar aprotic organic solvent, inorganic base, and sulfur-containing compounds creates a chemical environment that is highly reactive toward SLAM but selective against underlying materials, simultaneously improving removal rate and etching precision.
Solution Approach 2:
The patent employs a composite chemical system consisting of multiple components (quaternary ammonium hydroxide, polar aprotic organic solvent, inorganic base, and sulfur-containing compounds) that work synergistically. This composite etching solution provides both the aggressiveness needed for high SLAM removal rates and the selectivity required to protect underlying materials, resolving the contradiction between productivity and manufacturing precision.
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 achieves a high SLAM removal rate with minimal impact on copper lines and dielectric materials, providing a selective etching process that maintains the integrity of semiconductor devices.
Implementation Method 1
A composition comprising quaternary ammonium hydroxide, polar aprotic organic solvent, inorganic base, and sulfur-containing compounds, along with water, is used to selectively etch SLAM
Implementation Method 2
at least one polar aprotic organic solvent
Data Source
AI summary
The present disclosure is directed to etching compositions that are useful for, e.g., selectively removing sacrificial light absorbing material (SLAM) from a semiconductor substrate as an intermediate step in a multistep semiconductor manufacturing process.