Selective TiSiN Etching Composition for Semiconductor Substrates
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Solution Overview
Problem
The semiconductor industry faces challenges in selectively etching titanium silicon nitride (TiSiN) without damaging adjacent materials like metal conductors and dielectrics, as existing etching processes can harm the gate insulating layer and semiconductor substrate, leading to reduced device performance and increased costs.
Innovation Solution
A composition and process involving an etching solution with an oxidizing agent, chelating agent, organic solvent, amine compound, and water, with a pH between 6.5 and 9.5, which selectively etches TiSiN while minimizing etching and corrosion of other semiconductor materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If plasma etching process is used on TiSiN layer, then etching efficiency is improved, but damage to gate insulating layer and semiconductor substrate occurs
Solution Approach 1:
The patent changes the chemical parameters of the etching solution by specifying precise concentrations of oxidizing agents (0.1-30%), chelating agents (0.01-1%), organic solvents (1-30%), and amine compounds (0.1-5%), along with controlling pH (6.5-9.5) and temperature (20-80°C). These parameter adjustments enable selective etching of TiSiN while protecting other materials, resolving the contradiction between etching efficiency and material damage.
Solution Approach 2:
The patent introduces a specifically formulated wet etching solution as an intermediary medium that selectively interacts with TiSiN. The solution contains multiple chemical components working together: oxidizing agents for etching, chelating agents for metal ion complexation, organic solvents for dissolution, and amine compounds for pH control. This intermediary etching solution enables selective removal of TiSiN without direct plasma damage to other layers.
2Productivity
If wet etching with hydrofluoric acid is used for TiSiN, then etching capability is improved, but selectivity against silicon based dielectrics and metals deteriorates
Solution Approach 1:
The patent applies local quality by making the etching solution selectively reactive only with TiSiN through the synergistic combination of specific chemical components. The oxidizing agents target TiSiN specifically, while chelating agents protect metal surfaces by forming protective complexes, and organic solvents provide selective dissolution. This localized chemical reactivity achieves high etching capability for TiSiN while maintaining selectivity against other materials.
Solution Approach 2:
The patent uses a composite etching solution formulation combining multiple chemical agents: oxidizing agents (e.g., H2O2, peracetic acid), chelating agents (e.g., EDTA, DTPA), organic solvents (e.g., alcohols, ketones), and amine compounds. This composite chemical system provides both the etching capability needed for TiSiN removal and the selectivity to protect dielectrics and metals, resolving the contradiction between etching power and material selectivity.
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 effectively etches TiSiN with high selectivity and low etch rates for other materials, reducing damage to the semiconductor substrate and improving device performance without significant additional manufacturing costs.
Implementation Method 1
The composition includes: 1) at least one oxidizing agent
Implementation Method 2
The composition includes: 2) at least one chelating agent
Data Source
AI summary
This disclosure relates to etching compositions containing 1) at least one oxidizing agent; 2) at least one chelating agent; 3) at least one organic solvent; 4) at least one amine compound; and 5) water.