Selective Metal Nitride Etching Composition
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Solution Overview
Problem
The semiconductor industry faces challenges in forming fine patterns with good profiles due to instability in hydrogen peroxide-based wet etching processes, leading to insufficient etching selectivity and corrosion of metal films during the etching of metal nitride films, which affects the manufacturing of microelectronic devices.
Innovation Solution
An etching composition comprising sulfuric acid, hydrogen peroxide, and organic peroxide, with a specific weight ratio, is used to selectively etch metal nitride films while preventing corrosion of metal wiring and liner films, enhancing the etch selection ratio and storage stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If hydrogen peroxide is used as the etchant composition, then the etching process is simple, but the etching selectivity is insufficient and metal films are corroded
Solution Approach 1:
The patent uses a composite etchant composition containing sulfuric acid, hydrogen peroxide, and organic peroxide (peracetic acid, performic acid, perpropionic acid, or perbenzoic acid) in specific ratios. This composite formulation provides both strong oxidizing power for effective etching and selective action that prevents metal film corrosion while removing metal nitride films, resolving the contradiction between process simplicity and etching selectivity.
Solution Approach 2:
The patent optimizes the concentration parameters of each component in the etchant composition. Specifically, sulfuric acid is used at 70-90 wt%, hydrogen peroxide at 0.5-5 wt%, and organic peroxide at 0.001-3 wt%. These parameter adjustments ensure the etchant has sufficient oxidizing capability for effective etching while maintaining selectivity to avoid corrosion of underlying metal films.
2Productivity
If the etching degree of metal nitride film is increased, then the hard mask removal is improved, but the etching degree of metal film increases causing corrosion
Solution Approach 1:
The organic peroxide acts as an intermediary substance that enhances the oxidizing power of the etchant composition specifically for metal nitride films. This intermediary component enables aggressive etching of the hard mask while the controlled composition prevents excessive oxidation and corrosion of the underlying metal films, allowing high productivity without harmful side effects.
Solution Approach 2:
The patent employs strong oxidizing agents including hydrogen peroxide and organic peroxides in combination with sulfuric acid. This strong oxidizing system accelerates the etching of metal nitride films for improved productivity while the specific composition ratios and presence of organic peroxide provide selectivity that prevents corrosion of metal films, resolving the contradiction between removal efficiency and film protection.
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 etching composition effectively controls the etch rate of metal films, improving the etch selection ratio and maintaining excellent etching characteristics over time, thus enhancing the manufacturing process of microelectronic devices without requiring additional anti-corrosion agents.
Implementation Method 1
an etching composition mainly containing hydrogen peroxide is used in the wet etching process
Implementation Method 2
decomposition of the hydrogen peroxide is generated due to instability of the hydrogen peroxide
Implementation Method 3
The wet etching process is an etching method using an etchant composition that is a liquid corroding and dissolving only a target metal
Data Source
AI summary
Provided are an etching composition and an etching method using the same, and more particularly, an etching composition for selectively etching a metal nitride film, an etching method of the metal nitride film using the same, and a method of manufacturing a microelectronic device including a process performed using the same.