Process Chamber Pressure Control With Dual-Loop Exhaust Valve Filtering
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Solution Overview
Problem
Existing semiconductor heat treatment devices face substantial pressure fluctuations in the process chamber, leading to uneven film thickness and reduced product yield due to external environment pressure variations and complex internal changes, which traditional relative and absolute pressure control methods fail to adequately address.
Innovation Solution
A dual-loop control system is implemented, utilizing a primary control loop based on actual pressure values and a secondary control loop to filter out invalid data, ensuring the exhaust valve opening adjustments align with preset fluctuation ranges, thereby stabilizing pressure within the process chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If relative pressure control method is used to control pressure in process chamber, then ease of operation is improved, but pressure control precision deteriorates due to external environment pressure fluctuations
Solution Approach 1:
A pressure conversion unit is introduced as an intermediary component that converts relative pressure values to absolute pressure values. This mediator translates the easy-to-obtain relative pressure measurements into accurate absolute pressure control, resolving the contradiction between operational ease and control precision.
Solution Approach 2:
The patent replaces the traditional mechanical relative pressure control system with an electronic control system that uses a pressure sensor, microcontroller, and pressure conversion algorithm. This substitution enables automatic absolute pressure control while maintaining ease of operation through automated compensation for environmental pressure variations.
2Measurement precision
If absolute pressure control method is used to control pressure in process chamber, then pressure control precision is improved, but device reliability deteriorates due to substantial pressure fluctuations triggering alarms
Solution Approach 1:
The control system performs preliminary actions by predicting required valve opening changes based on current pressure deviations from target values. The system calculates anticipated valve adjustments and applies them proactively, preventing substantial pressure fluctuations before they occur and avoiding alarm triggers while maintaining precise pressure control.
Solution Approach 2:
The patent implements dynamic control by continuously adjusting the exhaust valve opening based on real-time pressure feedback. The system adapts valve opening changes dynamically according to the current process stage and pressure deviation magnitude, enabling precise pressure control while preventing excessive fluctuations that would trigger alarms and shutdowns.
3Device complexity
If traditional pressure control methods are used, then device complexity is reduced, but manufacturing precision deteriorates due to uneven film thickness from pressure fluctuations
Solution Approach 1:
The patent implements a feedback control mechanism where the pressure sensor continuously monitors the actual pressure in the process chamber and feeds this information back to the microcontroller. The system compares the measured pressure with the target pressure and automatically adjusts the exhaust valve opening to eliminate deviations, ensuring uniform pressure conditions for consistent film thickness while maintaining manageable device complexity through standard feedback control architecture.
Data Source
AI summary
A method of controlling a pressure in a process chamber of a semiconductor heat treatment device includes: obtaining an actual pressure value in the process chamber; determining a first valve opening value for controlling opening an exhaust valve according to a difference between the actual pressure value and a preset target pressure value; determining a first valve opening change value according to the first valve opening value and a current valve opening value; determining whether the first valve opening change value is within a preset fluctuation range of a valve opening change value corresponding to a current process stage; and in response to the first valve opening change value being within the fluctuation range, adjusting opening of an exhaust valve according to the first valve opening value.