Atomic Layer Etching Using Vapor-Phase Amines for Clean Metal Removal
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Solution Overview
Problem
Existing atomic layer etching processes fail to completely remove parasitic metal or metal oxides from dielectric substrate surfaces, leading to incomplete material removal and surface contamination.
Innovation Solution
The use of vapor-phase N-substituted derivatives of amine compounds as etch reactants, which contact the substrate surface and remove reaction by-products through purging, allowing for controlled etching of metal, metal oxide, or metal nitride layers, including cyclic processes with oxidants or halides to form volatile species for efficient material removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If existing ALE processes utilize halides or plasma generated etchants, then etching capability is provided, but complete removal of parasitic metal or metal oxides is not achieved
Solution Approach 1:
The patent changes the chemical parameters of the etchant from traditional halides or plasma-generated species to organometallic compounds with specific ligands (beta-diketonates, alkoxides, carboxylates). This parameter change enables complete removal of parasitic metal and metal oxides while maintaining process reliability and avoiding surface contamination.
Solution Approach 2:
The patent introduces organometallic compounds as intermediary substances that facilitate complete material removal. These compounds act as mediators between the substrate and the etching process, enabling thorough removal of parasitic materials without leaving residual contamination on the dielectric substrate surface.
2Manufacturing precision
If sequential pulses of vapor phase reactants are used, then controlled etching is achieved, but process time increases
Solution Approach 1:
The patent utilizes periodic pulsing of vapor phase organometallic reactants onto the substrate surface. This periodic action provides precise control over the etching process while maintaining high productivity, as each pulse delivers a controlled amount of reactive species that efficiently removes material without requiring excessively long process times.
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
This method enables precise and complete removal of target materials, reducing surface contamination and improving the selectivity and conformality of the etching process, ensuring thorough material removal while minimizing damage to the substrate.
Implementation Method 1
a substrate surface is contacted with an etch reactant comprising a vapor phase N-substituted derivative of an amine compound. Reaction by-products comprising atoms of the target material may be removed from the vicinity of the substrate surface
Implementation Method 2
cyclic processes with oxidants or halides to form volatile species for efficient material removal
Data Source
AI summary
Atomic layer etching (ALE) processes are disclosed. In some embodiments, the methods comprise at least one etch cycle in which a substrate comprising a metal, metal oxide, metal nitride or metal oxynitride layer is contacted with an etch reactant comprising an vapor-phase N-substituted derivative of amine compound. In some embodiments the etch reactant reacts with the substrate surface to form volatile species including metal atoms from the substrate surface. In some embodiments a metal or metal nitride surface is oxidized as part of the ALE cycle. In some embodiments a substrate surface is contacted with a halide as part of the ALE cycle. In some embodiments a substrate surface is contacted with a plasma reactant as part of the ALE cycle.