Silicon Etchant Composition for High-Selectivity Fine Patterning
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Solution Overview
Problem
Existing etching processes for silicon-based films in semiconductor devices face challenges in achieving high etching selectivity and uniformity while forming fine patterns, often leading to excessive etching of protective films.
Innovation Solution
An etchant composition comprising an alkaline compound, a nitrogen-containing fused ring compound with a polar functional group, and a metal salt is used to enhance etching efficiency and selectivity, forming a protective layer on silicon oxide and nitride films to prevent corrosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If an increase in etching rate is achieved for the silicon film to be removed, then productivity is improved, but the protective film is excessively etched leading to decreased manufacturing precision
Solution Approach 1:
The patent modifies the chemical composition parameters of the etchant by incorporating specific nitrogen-containing fused ring compounds (such as quinoline or quinoxaline derivatives) along with metal salts and alkaline compounds. This chemical parameter change enables the etchant to achieve high etching rate for silicon while maintaining excellent selectivity against protective films like silicon oxide and silicon nitride, thus resolving the contradiction between productivity and manufacturing precision
Solution Approach 2:
The patent employs a composite etchant formulation combining multiple components: nitrogen-containing fused ring compounds, metal salts, alkaline compounds, and water. This composite material approach creates synergistic effects where each component contributes specific functionality - the nitrogen-containing compound provides selective etching capability, the metal salt enhances etching rate, and the alkaline compound maintains solution stability - thereby achieving both high productivity and precision simultaneously
2Productivity
If conventional etching processes are used to achieve high etching rate, then productivity is improved, but etching uniformity deteriorates making it difficult to form fine dimensional patterns
Solution Approach 1:
The patent optimizes the concentration ratios and chemical structure parameters of the etchant components. Specifically, it uses nitrogen-containing fused ring compounds with particular structural characteristics (Formula 1 with specific R1-R4 substituents) in controlled concentrations (0.01-20 wt%). This parameter optimization ensures uniform etching front propagation while maintaining high etching rate, enabling precise formation of fine dimensional patterns with excellent uniformity
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 etching rates for silicon films while minimizing etching of protective films, enabling the formation of reliable nanoscale semiconductor device patterns with improved etching selectivity and uniformity.
Implementation Method 1
forming a protective layer on silicon oxide and nitride films to prevent corrosion
Implementation Method 2
Etchant composition for etching silicon including: an alkaline compound; a metal salt; a nitrogen-containing fused ring compound
Data Source
AI summary
An etchant composition for etching silicon includes an alkaline compound, a metal salt, a compound including a fused structure of a nitrogen-containing ring to which a polar functional group is bonded and a nitrogen-free ring, and water. A method of forming a pattern includes etching a silicon-containing film using the etchant composition for etching silicon.