Plasma Gas Supply Flow Control for Mixed-Gas Pressure Ratios
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas supply systems for plasma processing fail to effectively control the flow rate of main gases when additive gases are mixed, as they do not account for the pressure increase caused by the additive gases, leading to suboptimal processing results in semiconductor manufacturing.
Innovation Solution
A gas supply system with a controller that calculates and proportionally controls the flow rates of main and additive gases using reference PQ characteristics and flow factors, ensuring accurate pressure ratios across different regions of the substrate, even when the gases have different physical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If additive gases are mixed with main gases in gas supply systems, then the processing results in semiconductor manufacturing are improved, but the pressure control accuracy deteriorates due to pressure increase caused by additive gases
Solution Approach 1:
The patent introduces a mediator substance (additive gas) that is mixed with the main gas to improve processing results. The flow rate control valve acts as an intermediary device to control the mixing ratio, allowing the additive gas to enhance processing while the system maintains pressure control through coordinated valve operation.
Solution Approach 2:
The patent changes the flow rate parameters of both main gas and additive gas dynamically. By adjusting the flow rate control valve, the system modifies the mixing ratio and pressure parameters in real-time, allowing optimization of processing results while compensating for pressure increases caused by additive gases.
2Productivity
If the flow rate of additive gas is increased to improve processing, then the processing efficiency is improved, but the flow rate control of main gas becomes inaccurate
Solution Approach 1:
The patent implements a feedback control mechanism where the flow rate control valve continuously monitors and adjusts the flow rates of both main gas and additive gas. The controller receives feedback on the actual flow rates and pressure conditions, then modifies valve opening to maintain accurate control even when additive gas flow is increased for improved processing efficiency.
Solution Approach 2:
The system transitions from static flow rate control to dynamic control. The flow rate control valve adjusts in real-time based on changing conditions, allowing the system to increase additive gas flow for improved efficiency while dynamically compensating to maintain accurate flow rate control of the main gas.
3Adaptability or versatility
If multiple gases with different physical properties are mixed, then the versatility of gas processing is improved, but the pressure ratio control between different regions deteriorates
Solution Approach 1:
The patent applies local quality control by independently managing the flow rates of different gases to different regions. The flow rate control valve enables different mixing ratios for main gas and additive gas in different regions, allowing versatility in gas processing while maintaining precise pressure ratio control tailored to each region's specific requirements.
Data Source
AI summary
A system includes: gas supply flow paths for supplying independently a main gas to a processing chamber; a flow rate control valve disposed in each gas supply flow path; an additive-gas flow path connected to the flow rate control valve; a valve for addition disposed in the additive-gas flow path; and a controller for controlling the flow rate control valve and the valve for addition to execute controls of: calculating flow rates of the main gas and an additive gas to be mixed with the main gas; calculating a total of the flow rates; calculating an internal pressure of each gas supply flow path with the total flow rate, and first and second relationships between previously acquired gas flow rates and gas pressures of the main gas and the additive gas, respectively; calculating an internal pressure ratio; and proportionally controlling openings of flow rate control valves based on the ratio.