Mass Flow Verifier for Calibrating Gas Flow Controllers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In substrate processing systems, there is a lack of methods to confirm correct splitting of process gases by flow controllers and no on-tool apparatus to monitor or compare drift between flow controllers in multi-chamber systems, leading to inconsistencies in gas flow rates across chambers.
Innovation Solution
The implementation of a substrate processing system with a mass flow verifier and conduits to selectively couple flow controllers to the verifier, allowing for independent verification and calibration of each flow controller, ensuring accurate and uniform gas flow rates across chambers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If flow controllers are used to provide process gases to multiple chambers from a shared gas panel, then gas distribution is achieved, but there is no method to confirm correct flow splitting or detect drift between chambers
Solution Approach 1:
A mass flow verifier is introduced as an intermediary device between the flow controllers and chambers. The verifier selectively couples to individual flow controllers through conduits to measure and verify flow rates, providing independent confirmation of flow splitting accuracy without disrupting the normal gas distribution function.
Solution Approach 2:
The mass flow verifier provides feedback measurements of actual flow rates from each flow controller. By comparing verified flow rates against expected values, the system can detect drift and calibration issues, enabling corrective actions to maintain flow rate accuracy across all chambers.
2Manufacturing precision
If no on-tool monitoring apparatus is installed, then device complexity is reduced, but inability to monitor or compare drift between flow controllers leads to inconsistent process results
Solution Approach 1:
The mass flow verifier serves multiple functions: it verifies flow rates from different flow controllers, detects drift between chambers, provides calibration data, and enables comparison of flow consistency. This single multi-functional device improves process consistency without requiring separate monitoring systems for each function.
Solution Approach 2:
The verification system uses the existing flow controller infrastructure and adds minimal external components. The conduits selectively couple to already-present flow controllers, allowing the system to self-verify its own performance without requiring complete redesign or extensive additional hardware.
3Measurement precision
If traditional calibration methods are used without selective coupling, then calibration can be performed, but calibration time increases and uniformity between flow controllers deteriorates
Solution Approach 1:
The calibration process is segmented into individual flow controller verifications. Each flow controller can be selectively coupled to the mass flow verifier through separate conduits, allowing independent calibration and verification of each controller. This segmentation enables parallel processing and reduces total calibration time compared to sequential methods.
Solution Approach 2:
The mass flow verifier is positioned and configured in advance to receive flows from multiple flow controllers. Conduits are pre-arranged to enable selective coupling, so that when calibration is needed, the verification process can begin immediately without extensive setup time, improving both speed and uniformity.
Data Source
AI summary
Methods and apparatus for calibrating a plurality of gas flows in a substrate processing system are provided herein. In some embodiments, a substrate processing system may include a cluster tool comprising a first process chamber and a second process chamber coupled to a central vacuum transfer chamber; a first flow controller to provide a process gas to the first process chamber; a second flow controller to provide the process gas to the second process chamber; a mass flow verifier to verify a flow rate from each of the first and second flow controllers; a first conduit to selectively couple the first flow controller to the mass flow verifier; and a second conduit to selectively couple the second flow controller to the mass flow verifier.