Plasma-Resistant Glass for Semiconductor Etching
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Solution Overview
Problem
Semiconductor device manufacturing faces challenges with particle detachment and contamination due to exposure to high-density fluorine-based plasma etching environments, leading to defects and yield reduction, especially with oxide-based ceramics like alumina and yttria.
Innovation Solution
A plasma-resistant glass with a high glass stability index (KH) of 2.0 or greater, composed of 32 to 52 mol % SiO2, 5 to 15 mol % Al2O3, 30 to 55 mol % CaO, and 0.1 to 15 mol % CaF2, exhibiting an etching rate of 10 nm/min or lower in a mixed plasma of fluorine and argon, is developed. The glass is manufactured by mixing SiO2 powder, Al2O3 precursor, and CaF2 powder, melting, rapid cooling, heat-treating, and annealing to achieve the desired composition and properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oxide-based ceramics such as alumina and yttria are used in high-density plasma environments, then corrosion resistance is improved, but particle detachment occurs due to local erosion leading to contamination
Solution Approach 1:
The patent applies composite material principle by combining multiple glass components (SiO2, Al2O3, CaO, CaF2) to create a plasma-resistant glass that integrates the corrosion resistance of oxide ceramics with the smooth surface properties of glass, preventing particle detachment while maintaining durability in high-density plasma environments
Solution Approach 2:
The patent changes the material parameters by optimizing the chemical composition ratios (32-52 mol% SiO2, 5-15 mol% Al2O3, 30-55 mol% CaO, 0.1-15 mol% CaF2) and thermal processing parameters (heat treatment temperature, cooling rate) to achieve a glass structure with high corrosion resistance and particle-free surface
2Productivity
If polycrystalline materials are exposed to high-density plasma etching environment for long periods, then etching process continues, but particles detach due to local erosion increasing contaminant probability
Solution Approach 1:
The patent changes the material state from polycrystalline to amorphous glass structure, which eliminates grain boundaries and crystalline defects that serve as particle detachment sites, allowing continuous etching operation without particle generation
Solution Approach 2:
The patent creates a composite glass material that combines the chemical stability of oxide ceramics with the amorphous structure of glass, providing both etching process continuity and particle-free operation
3Object-generated harmful factors
If glass materials are used to reduce particle detachment, then smooth surface is maintained, but plasma resistance and etching rate control become challenging
Solution Approach 1:
The patent optimizes the chemical composition parameters (specific ratios of SiO2, Al2O3, CaO, and CaF2) to achieve the precise balance needed for both smooth surface maintenance and plasma resistance, with etching rate controlled at 10 nm/min or lower
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 plasma-resistant glass provides sufficient durability and prevents particle generation and contamination in plasma environments, maintaining a smooth surface and reducing outgassing when used in semiconductor or display device manufacturing processes.
Implementation Method 1
a plasma-resistant glass including 32 to 52 mol % of SiO2, 5 to 15 mol % of Al2O3, 30 to 55 mol % of CaO, and 0.1 to 15 mol % of CaF2 as chemical components... exhibiting plasma resistance properties with an etching rate of 10 nm/min or lower for a mixed plasma of fluorine and argon
Implementation Method 2
When a polycrystalline material is exposed for a long period of time to a high-density plasma etching environment in which a fluorine-based gas is used, particles are detached due to local erosion... The plasma-resistant glass provides sufficient durability and prevents particle generation and contamination
Implementation Method 3
melting the plasma-resistant glass raw material in an oxidizing atmosphere, rapidly cooling the melt
Implementation Method 4
rapidly cooling the melt
Implementation Method 5
heat-treating the rapidly cooled resultant product at a temperature higher than the glass transition temperature
Implementation Method 6
annealing the heat-treated resultant product to obtain a plasma-resistant glass
Data Source
AI summary
The present invention relates to plasma-resistant glass containing 32-52 mol % of SiO2, 5-15 mol % of Al2O3, 30-35 mol % of CaO, and 0.1-15 mol % of CaF2 as chemical components, and a manufacturing method thereof. According to the present invention, a glass stability index KH is 2.0 or higher, and a plasma-resistant characteristic of an etch rate of lower than 10 nm/min for a mixed plasma of fluorine and argon (Ar) is exhibited.