Substrate Etching Circulation With Inert Gas Oxygen Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing substrate processing methods face challenges in efficiently controlling the etching rate of polysilicon films due to varying dissolved oxygen concentrations in alkaline chemical liquids, which affect the oxidation and etching rates of polysilicon films.
Innovation Solution
A substrate processing apparatus and method that incorporates a circulation line with an inert gas supply to reduce dissolved oxygen concentrations in the chemical liquid by mixing inert gases with the chemical liquid, enhancing the etching efficiency by controlling the oxygen levels and optimizing the etching process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If oxygen gas is dissolved in the chemical liquid to control etching rate, then etching rate control is improved, but dissolved oxygen concentration becomes unstable
Solution Approach 1:
The patent introduces an inert gas supply mechanism that supplies inert gas to the chemical liquid in the reservoir. This inert gas environment prevents oxygen from dissolving into the chemical liquid, thereby stabilizing the dissolved oxygen concentration at a low level while maintaining controlled etching rates. The inert atmosphere counteracts the harmful effect of oxygen dissolution and stabilizes the etching process.
2Productivity
If chemical liquid is recovered and reused, then productivity is improved, but dissolved oxygen concentration varies
Solution Approach 1:
The inert gas supply mechanism operates continuously during the chemical liquid circulation and reuse process. As the chemical liquid is pumped from the processing chamber back to the reservoir, the inert gas maintains an oxygen-free environment, preventing re-dissolution of oxygen during the return trip. This ensures that even when chemical liquid is reused multiple times, the dissolved oxygen concentration remains stable and controlled.
3Stability of the object's composition
If inert gas is supplied to circulation line, then dissolved oxygen concentration is reduced, but device complexity increases
Solution Approach 1:
The inert gas supply system is integrated with the existing chemical liquid circulation system. The inert gas supply line is connected to the circulation line, allowing the same circulation pump and piping to serve dual purposes: transporting chemical liquid and maintaining inert atmosphere. This multi-functional integration minimizes additional device complexity while achieving oxygen concentration control.
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 apparatus effectively reduces dissolved oxygen concentrations, thereby improving the control over etching rates, ensuring consistent and efficient processing of polysilicon films by adjusting the inert gas flow rates and supply methods.
Implementation Method 1
the circulation line includes an ejection port configured to eject a mixed fluid of the inert gas supplied by the first gas supply line and the chemical liquid taken out from the reservoir into the chemical liquid stored in the reservoir
Implementation Method 2
supply an inert gas to the circulation line, wherein the circulation line includes an ejection port configured to eject a mixed fluid of the inert gas supplied by the first gas supply line and the chemical liquid taken out from the reservoir into the chemical liquid stored in the reservoir
Data Source
AI summary
A substrate processing apparatus includes: at least one processing part for etching a polysilicon film or an amorphous silicon film formed on a substrate using an alkaline chemical liquid; a reservoir configured to recover and store the chemical liquid used in the at least one processing part; processing lines configured to supply the chemical liquid stored in the reservoir to the at least one processing part; a circulation line configured to take out the chemical liquid from the reservoir and to return the same to the reservoir; and a first gas supply line connected to the circulation line and configured to supply an inert gas to the circulation line. The circulation line includes an ejection port configured to eject a mixed fluid of the inert gas supplied by the first gas supply line and the chemical liquid taken out from the reservoir into the chemical liquid stored in the reservoir.