Common Foreline Pressure Control for Multi-Chamber Uniformity
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Solution Overview
Problem
Unwanted pressure variation within semiconductor processing chambers leads to process non-uniformity, making it challenging to maintain consistent yields across multiple chambers in semiconductor manufacturing.
Innovation Solution
A foreline pressure control system that independently regulates foreline pressure using modulating valves and gas injection, coupled with pressure feedback control, to maintain desired set points and reduce pressure fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pump operation is used to control foreline pressure, then pressure control is achieved, but pressure variation and instability occur
Solution Approach 1:
The system employs a feedback control mechanism where a pressure sensor continuously monitors foreline pressure and feeds this information to a controller. The controller adjusts the valve position based on the pressure deviation from the setpoint, creating a closed-loop control system that maintains stable foreline pressure despite variations in pump operation or chamber conditions.
Solution Approach 2:
A valve is introduced as an intermediary component between the pump and the foreline. This valve acts as a mediator that modulates the gas flow to compensate for pressure variations, allowing independent control of foreline pressure from pump operation. The valve serves as a buffer that decouples the direct relationship between pump speed and foreline pressure.
2Adaptability or versatility
If multiple processing chambers share a common foreline, then system integration is achieved, but chamber-to-chamber pressure variations increase
Solution Approach 1:
The control system is segmented to provide independent pressure control for each processing chamber. Each chamber has its own valve controlled by a feedback mechanism that monitors its specific foreline pressure. This segmentation allows each chamber to maintain its desired pressure independently, even though they share a common physical foreline infrastructure.
Solution Approach 2:
The system implements local quality control by providing individualized pressure control for each chamber connection point on the foreline. Pressure sensors and control valves are positioned at or near each chamber interface, allowing localized adjustments that account for the specific requirements of each chamber while maintaining overall system integration.
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 system enhances processing uniformity, increases yield, reduces waste, and lowers the cost of ownership by stabilizing foreline and processing chamber pressures.
Implementation Method 1
coupled with pressure feedback control, to maintain desired set points and reduce pressure fluctuations
Implementation Method 2
A foreline pressure control system that independently regulates foreline pressure using modulating valves and gas injection
Data Source
AI summary
A system and method for controlling pressure in a common foreline coupled a processing systems is disclosed herein which reduce variation of pressure in the common foreline. In one example, a processing system is provided that includes a first process chamber, a first pump, a first foreline segment, and a first foreline pressure control system. The first pump is coupled to a first exhaust port of the first process chamber. The processing system further includes a second process chamber, a second pump, a second foreline segment, and a second foreline pressure control system. The second pump coupled to a second exhaust port of the second process chamber. The common foreline is coupled downstream of the first pump and the second pump. The first and second foreline pressure control system is operable to control the pressure in the common foreline independent from operation of the first or second pump.