Mass Flow Controller Zero-Point Calibration Using Dual Pressure Sensors
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Solution Overview
Problem
Semiconductor manufacturing processes face challenges in accurately controlling gas fluid flow rates, leading to inconsistencies in the quality of semiconductor devices due to inadequate zero point calibration methods for mass flow controllers (MFCs).
Innovation Solution
A method involving the use of dual pressure sensors and a zero point calibration process that includes closing valves to prevent fluid flow, determining leak rates, stabilizing pressure values, and calculating calibration values based on power and flow times to accurately calibrate MFCs, ensuring precise fluid control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional zero point calibration methods are used, then the calibration process is simple, but the measurement precision of mass flow rate is insufficient
Solution Approach 1:
The system performs preliminary actions by closing valves to isolate the flow path and stabilizing pressure before calibration measurements are taken. This ensures that zero point calibration is performed under controlled, known conditions, improving measurement accuracy without requiring complex external equipment.
Solution Approach 2:
The system uses feedback by continuously monitoring pressure values from pressure sensors and comparing them against expected values. Based on this feedback, the system automatically adjusts and determines zero point calibration values, enabling precise measurement without manual intervention or complex calibration procedures.
2Productivity
If manual calibration procedures are used, then the process is easy to understand, but productivity is reduced due to high manpower requirements
Solution Approach 1:
The MFC system performs self-service by automatically executing the entire zero point calibration process. The controller autonomously closes valves, monitors pressure stabilization, calculates calibration values based on sensor readings, and updates measurement parameters without requiring operator intervention, thereby significantly improving productivity while maintaining operational simplicity through automated workflows.
Solution Approach 2:
The system replaces manual mechanical calibration operations with an automated electronic control system. The controller electronically manages valve actuation, pressure monitoring, data processing, and calibration value determination, substituting manual mechanical procedures with an integrated electronic system that improves efficiency while keeping the interface simple.
3Reliability
If zero point calibration is not performed accurately, then the device complexity is low, but the reliability of semiconductor manufacturing process deteriorates
Solution Approach 1:
The system performs preliminary pressure stabilization and leak detection before calibration measurements, ensuring that measurements are taken under verified stable conditions. This preliminary action sequence guarantees reliable calibration results and consistent manufacturing process quality without requiring overly complex calibration systems.
Solution Approach 2:
The system replaces complex manual calibration procedures with an automated electronic control and measurement system. The controller electronically coordinates valve operations, pressure monitoring, data analysis, and calibration value determination, achieving high reliability through systematic automated control while avoiding the need for complex manual calibration equipment or procedures.
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 enhances the accuracy of mass flow rate measurements and improves the quality of semiconductor manufacturing processes by stabilizing fluid flow, reducing errors, and automating the calibration process, thus increasing efficiency and reducing manpower requirements.
Implementation Method 1
a first pressure value output by a first pressure sensor provided in the flow path and a second pressure value output by a second pressure sensor provided in the flow path
Implementation Method 2
closing a valve installed in a flow path of the MFC to prevent a fluid from flowing therein due to a closure of the flow path
Data Source
AI summary
A method of manufacturing using a mass flow controller (MFC) includes closing a valve installed in a flow path of the MFC to prevent a fluid from flowing therein due to a closure of the valve, determining that the fluid is not leaking, determining that the fluid is stabilized, determining that a pressure sensor is normal, calculating a zero point calibration value of the pressure sensor based on a zero point of the pressure sensor, a time when power is supplied to the MFC, and a time when a flow is supplied to the MFC, applying the zero point calibration value to the pressure sensor, and measure the mass flow rate through the flow path with the pressuring sensor and adjusting the valve based on the mass flow rate to regulate the flow of the fluid to a manufacturing device.