Semiconductor Etching Composition for Nitride Selectivity Without Particles
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Solution Overview
Problem
Current etching compositions for semiconductor manufacturing struggle to selectively remove nitride films while minimizing the etch rate for oxide films, often resulting in decreased etch selectivity and particle generation issues.
Innovation Solution
A high-selectivity etching composition comprising a first inorganic acid, a first additive represented by Chemical Formula 1, and a solvent, along with an optional second additive such as a silane inorganic acid salt, is used to selectively etch nitride films with respect to oxide films.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If phosphoric acid is used to etch nitride films, then the etching capability for nitride films is improved, but the etch selectivity between nitride films and oxide films decreases
Solution Approach 1:
The patent changes the chemical parameters of the etching composition by combining phosphoric acid with specific additives (hydrofluoric acid at 0.01-5 wt% and nitric acid at 0.01-5 wt%). This parameter optimization allows the composition to selectively etch nitride films while minimizing oxide film etching, resolving the selectivity issue while maintaining etching capability.
Solution Approach 2:
The patent creates a composite etching composition that integrates multiple acids (phosphoric acid, hydrofluoric acid, and nitric acid) in specific proportions. This composite formulation leverages the synergistic effects of each component: phosphoric acid for nitride etching, hydrofluoric acid for selectivity control, and nitric acid for oxidation assistance, achieving high etch selectivity while maintaining effective nitride removal.
2Stability of the object's composition
If deionized water is added to prevent etch rate decrease, then the stability of etch rate is improved, but the process robustness deteriorates due to sensitivity to water amount variations
Solution Approach 1:
The patent optimizes the water content parameter to a specific range (94-99.99 wt%) in the etching composition. This precise parameter control ensures sufficient deionized water is present to stabilize the etch rate and prevent composition changes, while avoiding excessive water that would make the process sensitive to variations. The optimized parameter range achieves both stability and robustness.
3Speed
If silicic acid or silicic acid salt is added to improve etching performance, then the etching capability is enhanced, but particle generation occurs that adversely affects the substrate
Solution Approach 1:
The patent extracts and removes silicic acid and silicic acid salt components from the etching composition to eliminate the source of particle generation. Instead, the patent uses an alternative formulation with hydrofluoric acid and nitric acid additives that provide effective etching capability without the harmful particle generation associated with silicic acid-based compositions.
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 high etch selectivity for nitride films over oxide films, preventing particle generation and maintaining device characteristics, thereby enhancing the efficiency and reliability of semiconductor device manufacturing processes.
Implementation Method 1
a first inorganic acid component, a first additive component, and a solvent component... capable of selectively removing a nitride film while minimizing the etching rate for an oxide film
Implementation Method 2
preventing particle generation and maintaining device characteristics
Data Source
AI summary
The present invention relates to a composition for etching, comprising a first inorganic acid, a first additive represented by Chemical Formula 1, and a solvent.The composition for etching is a high-selectivity composition that can selectively remove a nitride film while minimizing the etch rate of an oxide film, and which does not have problems such as particle generation, which adversely affect the device characteristics.