Foreline Pressure Control for Plasma Abatement
Solution Overview
Problem
Current methods lack the ability to control the operating pressure of the foreline in electronic device manufacturing systems, which hampers the efficient abatement of perfluorocarbons (PFCs) and global warming gases (GWGs).
Innovation Solution
The implementation of a system that includes a plasma source, a reagent source, and a foreline gas injection kit with a pressure regulator, gauge, and controller to control the pressure and deliver reagents and gases for optimal abatement, synchronized with the tool process recipe to enhance efficiency and throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If RPS or IPS is installed in the foreline to abate PFCs and GWGs, then abatement capability is provided, but the operating pressure of the foreline cannot be controlled to optimize abatement efficiency
Solution Approach 1:
The system dynamically adjusts the foreline pressure by controlling the backing pump speed and adding foreline gas flow, allowing the pressure to be maintained at optimal values for maximum abatement efficiency. The pressure control valve and flow controller continuously modulate system parameters to maintain optimal operating conditions.
Solution Approach 2:
The invention changes the pressure parameter of the foreline from a fixed, uncontrolled state to a dynamically controllable state. By using a pressure control valve and flow controller, the system can maintain the foreline pressure within a specific range (e.g., 1-10 mTorr) that optimizes plasma generation and abatement efficiency.
2Reliability
If higher plasma power is used to improve abatement efficiency, then destruction removal efficiency increases, but energy consumption and utility usage increase
Solution Approach 1:
The system optimizes plasma power by controlling the foreline pressure to the minimum level necessary for effective abatement. By maintaining pressure in the optimal range (1-10 mTorr), the system achieves high destruction removal efficiency while minimizing the plasma power and energy consumption required.
Solution Approach 2:
The foreline gas flow contributes to both pressure maintenance and plasma generation. The gas itself serves dual purposes: it maintains the necessary pressure environment and provides additional fuel for the plasma reaction, reducing the need for external energy input.
3Productivity
If continuous operation is maintained to maximize substrate throughput, then productivity increases, but deposits accumulate on plasma abatement device surfaces reducing performance
Solution Approach 1:
The system implements periodic cleaning cycles where the plasma abatement device is pulsed with cleaning gas flows at intervals during substrate processing. This periodic maintenance action removes accumulating deposits while minimizing interruption to substrate throughput, maintaining device performance over extended operation.
Solution Approach 2:
The foreline gas flow continuously prevents deposit accumulation by maintaining optimal pressure and providing a flow that sweeps reaction products away from surfaces. This continuous protective action allows the system to operate at high substrate throughput without performance degradation.
4Reliability
If foreline pressure is reduced to optimize plasma conditions, then abatement efficiency improves, but system stability and plasma maintenance become difficult
Solution Approach 1:
The system maintains foreline pressure within an optimal range (1-10 mTorr) rather than reducing it to extreme lows. This controlled parameter range provides the stability needed for reliable plasma generation while maintaining the low pressure conditions necessary for high abatement efficiency and minimal gas-phase reactions.
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 improves abatement efficiency by maintaining optimal plasma conditions, reducing utility usage, and extending equipment lifespan by controlling pressure and reagent delivery in real-time, thereby optimizing the breakdown of PFCs and GWGs.
Implementation Method 1
forming a plasma from the exhaust gas and reagent gas to convert the exhaust gas to abatable byproduct gases
Data Source
AI summary
Methods and apparatus for treating an exhaust gas in a foreline of a substrate processing system are provided herein. In some embodiments, a method for treating an exhaust gas in an exhaust conduit of a substrate processing system includes: flowing an exhaust gas from a process chamber into a plasma source via a foreline; injecting a reagent into the foreline; forming a plasma in the plasma source from the exhaust gas and the reagent; and injecting a cleaning gas into the foreline, wherein the cleaning gas and the reagent are different gases.