Hypervalent Iodine Etching Composition for Selective Metal Layer Removal
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Solution Overview
Problem
Existing etching compositions for semiconductor manufacturing fail to provide excellent etching rates, selectivity to adjacent layers, and storage stability, leading to reliability issues and inefficiencies in the etching process.
Innovation Solution
An etching composition comprising a hypervalent iodine-containing compound, acid, and pH regulator, which selectively etches metal-containing layers with improved uniformity and selectivity, enhancing the etching process's efficiency and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional etching compositions are used, then etching processes can be performed, but etching selectivity to metal-containing layers is insufficient and storage stability is poor
Solution Approach 1:
The patent changes the chemical composition parameters of the etching solution by incorporating hypervalent iodine compounds (such as iodosylbenzene, triphenylsulfonium iodide, or phenyliodine bis(trifluoroacetate)) combined with specific acids (hydrofluoric acid, nitric acid, or sulfuric acid) and chelating agents (EDTA or citric acid). This parameter change enables the solution to achieve both high etching selectivity for metal-containing layers and improved storage stability, resolving the contradiction between these two properties.
2Manufacturing precision
If existing etching compositions are used, then etching can proceed, but etching uniformity across different substrate sizes is inconsistent
Solution Approach 1:
The patent introduces chelating agents (EDTA or citric acid) as intermediaries that complex with metal ions during the etching process. These intermediaries mediate the interaction between the hypervalent iodine compounds and metal-containing layers, ensuring uniform etching rates across substrates of varying sizes while maintaining consistent etching quality, thus resolving the contradiction between etching uniformity and productivity.
3Ease of manufacture
If conventional etching methods are used, then metal-containing layers can be removed, but post-etch residue remains on surfaces
Solution Approach 1:
The patent employs hypervalent iodine compounds as strong oxidizing agents that completely oxidize metal-containing layers during etching. This accelerated oxidation process ensures thorough removal of metal materials without leaving residual deposits on the substrate surface, thereby eliminating post-etch residue while maintaining high etching efficiency.
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 selectivity and uniformity, improving the productivity and performance of semiconductor devices by effectively removing specific metal-containing layers while minimizing residue and maintaining consistent etching rates across varying substrate sizes.
Implementation Method 1
an etching composition may include a hypervalent iodine-containing compound
Implementation Method 2
the acid may include a fluorine-based inorganic acid
Data Source
AI summary
Provided are an etching composition including a hypervalent iodine-containing compound, a method of etching a metal-containing layer by using the same, and a method of manufacturing a semiconductor device by using the same.