Etching Composition Using Silane Inorganic Acid Salts
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Solution Overview
Problem
Current etching compositions for semiconductor manufacturing, particularly those using phosphoric acid, face challenges in achieving high selectivity for nitride layers while minimizing oxide layer etch rates and preventing particle generation, which can lead to defects and variations in the etching process.
Innovation Solution
An etching composition comprising silane inorganic acid salts produced by reacting a second inorganic acid with a silane or siloxane compound, combined with a solvent, which allows for controlled etch rates and selective removal of nitride layers without damaging oxide layers, thereby improving etching selectivity and preventing particle formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If phosphoric acid is used as etching composition, then nitride layer can be removed, but oxide layer etch rate increases and selectivity deteriorates
Solution Approach 1:
The patent modifies the chemical composition parameters by introducing silane inorganic acid salts and controlling the concentration ratios of phosphoric acid, nitric acid, and hydrofluoric acid. This parameter optimization achieves high etching selectivity (oxide layer etch rate < 1 nm/min) while maintaining effective nitride layer removal
Solution Approach 2:
The etching composition uses a composite formulation combining phosphoric acid, nitric acid, hydrofluoric acid, and silane inorganic acid salts. This composite approach synergistically enhances nitride layer etching while suppressing oxide layer damage, resolving the selectivity-integrity contradiction
2Stability of the object's composition
If deionized water is added to phosphoric acid, then etching rate stability is maintained, but handling difficulty and corrosiveness increase
Solution Approach 1:
The patent employs deionized water as a disposable diluent that is consumed during the etching process. The water serves its purpose of stabilizing etching rate through controlled dilution, and the composition is designed for single-use or limited reuse cycles, simplifying safety handling protocols
3Manufacturing precision
If silicate or silicic acid is added to phosphoric acid, then etching selectivity improves, but particle generation occurs
Solution Approach 1:
The patent extracts the beneficial etching selectivity function from silicate/silicic acid by using silane inorganic acid salts instead. This substitution removes the harmful particle-generating property while retaining the selective etching capability, as silane salts dissolve completely without forming particulate byproducts
Solution Approach 2:
Silane inorganic acid salts serve as an intermediary substance that mediates between the desired etching selectivity and the avoidance of particle generation. The silane compounds provide controlled chemical reactivity for selective nitride removal while maintaining solution clarity and preventing particulate formation
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 enables high selectivity for nitride layers relative to oxide layers, allowing for precise control of effective field oxide height and preventing electrical characteristic deterioration and particle generation, thus enhancing semiconductor device reliability and performance.
Implementation Method 1
silane inorganic acid salts produced by reaction between a second inorganic acid and a silane or siloxane compound
Data Source
AI summary
The disclosure is related to a composition for etching, a method for manufacturing the composition, and a method for fabricating a semiconductor using the same. The composition may include a first inorganic acid, at least one of silane inorganic acid salts produced by reaction between a second inorganic acid and a silane compound, and a solvent. The second inorganic acid may be at least one selected from the group consisting of a sulfuric acid, a fuming sulfuric acid, a nitric acid, a phosphoric acid, and a combination thereof.