Flow Controller Self-Testing for Semiconductor Manufacturing
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Solution Overview
Problem
Existing flow controllers in semiconductor manufacturing apparatuses face challenges in maintaining accurate flow rate control due to equipment aging, which requires periodic shutdowns for testing, disrupting continuous operation and requiring additional infrastructure for testing accuracy.
Innovation Solution
A flow controller with integrated flow rate detection, control valve mechanism, and control means that allows for continuous operation by associating valve drive control information with detected flow rates and pressures, storing this information for later analysis to determine deviations and automatically correct flow rates, enabling on-the-fly adjustments without stopping the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If periodic shutdowns are performed to test flow controller accuracy, then measurement precision of flow control accuracy is improved, but productivity of semiconductor manufacturing is deteriorated
Solution Approach 1:
The system performs preliminary actions by continuously collecting and storing valve drive control information and corresponding flow rate data during normal operation. This preliminary data accumulation enables subsequent accuracy testing without requiring shutdowns, as the necessary test data is already gathered from routine manufacturing operations.
Solution Approach 2:
The flow controller maintains continuous operation by implementing a testing mechanism that works during normal manufacturing processes. The control means continuously collects data, performs gradient computations, and determines flow control accuracy without interrupting the semiconductor manufacturing workflow, thus maintaining continuous useful action.
2Measurement precision
If separate testing infrastructure is added to test flow controller accuracy, then measurement precision is improved, but device complexity is deteriorated
Solution Approach 1:
The patent merges the testing functionality with the existing flow controller by integrating a control means that uses the same valve drive control information and flow rate detection mechanisms already present in the system. This eliminates the need for separate testing infrastructure, as the testing capability is combined with the operational control system.
Solution Approach 2:
The flow controller performs self-testing by using its own valve drive control information and flow rate detection capabilities to determine its own accuracy. The control means computes gradients and determines flow control accuracy using internally available data, enabling the system to self-diagnose without external testing equipment.
3Ease of operation
If equipment aging is not accounted for, then ease of operation is maintained, but manufacturing precision is deteriorated
Solution Approach 1:
The system implements feedback by continuously monitoring the relationship between valve drive control information and actual flow rates. The control means computes gradients and determines flow control accuracy, then uses this feedback to detect deviations caused by equipment aging. This automatic feedback mechanism maintains manufacturing precision without complicating operation, as the system self-adjusts based on detected deviations.
Data Source
AI summary
A flow controller and a test method therefor are provided which enable testing of the flow control of a process gas passing through a fluid path during operation of semiconductor manufacturing apparatuses. While the flow control is being performed to adjust the flow rate through the fluid path to a flow rate set value, a predetermined number of pieces of test sampling information is collected and associated with the flow rate set value for storage. The test sampling information is made up of a detected flow rate value of the process gas, a detected pressure value, and valve drive control information delivered to a flow control valve mechanism. Then, coefficients of association are sequentially determined which indicate the associations of the predetermined number of detected flow rate values and pieces of valve drive control information, which are stored as the test sampling information. When the value of a coefficient of association is out of the range of predetermined threshold values, a difference is determined between the valve drive control information made available based on a newly received detected flow rate value and the reference valve drive control information obtained with reference to a valve property information table pre-registered for testing. This difference is employed as test information.