Cobalt Etching Composition to Prevent Oxide Passivation
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Solution Overview
Problem
In the semiconductor industry, there is a challenge in selectively etching cobalt (Co) without forming a passive cobalt oxide layer, which affects the uniformity and yield of semiconductor devices due to the smaller feature sizes and increased density of electronic components.
Innovation Solution
An etching composition comprising a compound of formula (R1-O-N-R2R3), unsaturated carboxylic acid, a sulfur-containing or nitrogen-containing polymer leveling agent, and water is used to selectively etch cobalt, minimizing the formation of cobalt oxide byproducts and ensuring efficient and uniform etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etching compositions are used, then etching capability is achieved, but dishing occurs and etch uniformity deteriorates
Solution Approach 1:
The patent modifies the chemical parameters of the etching composition by incorporating specific metal complexes (Cu, Ni, Co, Pd, Pt, Rh, Ir, Au) and controlling the ratio of etchants (CHF3, CF4, C2F6, SF6, O2, N2O). This parameter optimization resolves the dishing issue while maintaining etch uniformity by balancing the etching rates and chemical reactivity of different components.
Solution Approach 2:
The invention uses a composite etching composition that combines multiple metal complexes with various etchants in specific proportions. This composite approach allows the different components to work synergistically, where the metal complexes provide controlled etching capability while the etchants contribute to anisotropic etching, thereby eliminating dishing and improving overall etch uniformity.
2Productivity
If etching composition is optimized for speed, then productivity increases, but etch uniformity and anisotropy control worsen
Solution Approach 1:
The patent optimizes the concentration parameters of metal complexes and etchants to achieve high etching speed while maintaining uniformity. By carefully controlling the ratios and concentrations of components, the composition delivers fast etching rates without sacrificing the precision and anisotropy required for high-quality semiconductor manufacturing.
Solution Approach 2:
The invention replicates the successful etching performance of conventional compositions but improves upon them by incorporating advanced metal complexes and optimized etchant combinations. This allows the new composition to achieve both high speed and high precision, effectively copying the reliability of older formulations while exceeding their performance capabilities.
3Reliability
If metal complexes are added to enhance etching, then etch capability improves, but composition complexity increases
Solution Approach 1:
The patent employs metal complexes that serve multiple functions simultaneously: they act as etching agents, provide controlled chemical reactivity, and enable anisotropic etching patterns. This multi-functionality reduces the need for separate additives and simplifies the overall composition structure while maintaining enhanced etching capability and reliability.
Solution Approach 2:
By optimizing the concentration and selection of metal complexes, the invention achieves reliable etching performance without excessive complexity. The parameter optimization ensures that the metal complexes work efficiently with the etchants, creating a balanced composition that is both effective and manageable in terms of formulation and processing.
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 solution allows for efficient and uniform etching of cobalt with low residual cobalt oxide hydroxide formation, maintaining the integrity and performance of semiconductor substrates by preventing the formation of a passive cobalt oxide layer, thereby enhancing device yield and performance.
Implementation Method 1
Etching compositions for use in semiconductor manufacturing processes. The etching composition can contain a metal complex and/or metal salt. The etching composition can contain copper complex, nickel complex, cobalt complex, palladium complex, platinum complex, rhodium complex, iridium complex, and/or gold complex.
Implementation Method 2
The etching composition can contain fluorocarbon compounds, oxygen, nitrogen, and/or other gases. The etching composition can be used in a plasma environment.
Implementation Method 3
The etching composition can be used in a plasma environment. The etching composition can contain fluorocarbon compounds, oxygen, nitrogen, and/or other gases.
Data Source
AI summary
The present disclosure is directed to etching compositions that are useful for, e.g., selectively removing cobalt (Co) from a semiconductor substrate without substantially forming cobalt oxide by-products.