Plasma Cleaning Gas Selectivity for Silicon Nitride Removal
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Solution Overview
Problem
Existing deposition apparatuses face challenges in efficiently removing silicon nitride films from processing vessels while minimizing damage to quartz components, as conventional cleaning methods may not effectively differentiate between silicon nitride and quartz, leading to potential damage during the cleaning process.
Innovation Solution
A method involving a cleaning gas formed into plasma, comprising a fluorine-containing gas and oxygen, is used to selectively etch silicon nitride films from the processing vessel and its components, thereby effectively removing the films while protecting quartz parts by controlling the plasma formation and gas flow to concentrate the cleaning action in specific regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional cleaning methods are used to remove silicon nitride films, then cleaning effectiveness is improved, but damage to quartz components occurs
Solution Approach 1:
The cleaning gas composition is changed from conventional single-gas systems to a mixed gas system containing fluorocarbon and oxygen. This parameter change enables selective etching where fluorine atoms react with silicon nitride at lower rates than conventional methods, while oxygen enhances the removal of organic residues, achieving effective cleaning with reduced quartz damage
Solution Approach 2:
The cleaning process uses a composite gas system combining fluorocarbon and oxygen components. The fluorocarbon provides selective silicon nitride etching capability while oxygen contributes to complete removal of carbon-containing residues and reduces damage to quartz through oxidative protection mechanisms
2Speed
If plasma cleaning is used to remove silicon nitride films, then cleaning speed is improved, but selectivity between silicon nitride and quartz deteriorates
Solution Approach 1:
The plasma parameters are optimized by adjusting the ratio of fluorocarbon to oxygen in the cleaning gas, controlling plasma power and pressure conditions. This enables the plasma to etch silicon nitride at high speed while the oxygen component suppresses excessive etching of quartz through competitive surface reactions
Solution Approach 2:
The cleaning gas composition is designed to create different chemical environments at different surfaces: fluorine-rich conditions at silicon nitride surfaces for high-rate etching, and oxygen-rich conditions at quartz surfaces for protective passivation, achieving spatially selective cleaning behavior
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 approach allows for efficient removal of silicon nitride films with reduced risk of damaging quartz components, ensuring the integrity and longevity of the deposition apparatus by selectively etching silicon nitride relative to quartz, thus enhancing the cleaning process's precision and effectiveness.
Implementation Method 1
cleaning, with a cleaning gas formed into a plasma, the interior of a processing vessel on which a silicon nitride film is deposited
Implementation Method 2
The cleaning gas includes a fluorine-containing gas and oxygen gas... selectively etch silicon nitride films from the processing vessel
Implementation Method 3
selectively etch silicon nitride films from the processing vessel and its components, thereby effectively removing the films while protecting quartz parts
Data Source
AI summary
A method of cleaning a deposition apparatus is provided. The method includes cleaning, with a cleaning gas formed into a plasma, an interior of a processing vessel on which a silicon nitride film is deposited. The cleaning gas includes a fluorine-containing gas and oxygen gas.