Wafer Tool Gas Line Leak Check Around MFC and Upstream Valve
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Solution Overview
Problem
Current semiconductor wafer processing tools cannot effectively detect leaks at the mass flow controller (MFC) and upstream valve, as the typical leak check only isolates downstream components, missing potential leaks at these critical locations.
Innovation Solution
A modified pneumatic control line with a relay is introduced, allowing for extended leak checking up to the upstream valve, including the MFC and upstream valve, by blocking pneumatic pressure to the upstream valve and maintaining it closed while opening the downstream valve, enabling more thorough leak detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the typical leak check isolates only downstream components, then the leak check procedure is simple and quick, but leaks at the MFC and upstream valve cannot be detected
Solution Approach 1:
The pneumatic control line is segmented into multiple independent branches: a first branch connected to the downstream valve and a second branch connected to the upstream valve. This segmentation allows selective activation of different valve combinations during leak checking, enabling comprehensive detection from downstream to upstream components without requiring complete system disassembly or complex reconfiguration.
Solution Approach 2:
The system dynamically reconfigures valve states based on the leak check phase. During the first leak check, the downstream valve is opened while the upstream valve remains closed. During the second leak check, the downstream valve is closed and the upstream valve is opened. This dynamic switching of valve configurations enables comprehensive leak detection at different system locations using the same pneumatic control infrastructure.
2Reliability
If the leak check is extended to include the MFC and upstream valve, then comprehensive leak detection is achieved, but the pneumatic control system becomes more complex
Solution Approach 1:
The pneumatic control line is designed with multi-functionality to serve both normal operational valve control and comprehensive leak checking functions. By incorporating multiple branches that can be selectively activated, the same pneumatic control line structure performs dual purposes: routine valve actuation during processing and extended leak detection covering all components from downstream to upstream, eliminating the need for separate dedicated leak check infrastructure.
Solution Approach 2:
The system performs preliminary leak checks at different stages before full processing begins. The first leak check is performed with the downstream valve open to detect leaks in downstream components. The second leak check is performed with the upstream valve open to detect leaks in the MFC and upstream valve. This preliminary, staged approach ensures comprehensive validation of gas line integrity before committing to full processing operations.
Data Source
AI summary
A leak check is performed on a semiconductor wafer processing tool that includes a process chamber and process gas lines, and a semiconductor wafer is processed using the semiconductor wafer processing tool if the leak check passes. Each gas line includes a mass flow controller (MFC) and normally closed valves including an upstream and downstream valves upstream and downstream of the MFC. Leak checking includes: leak checking up to the downstream valves of the gas lines with the upstream valves closed and the downstream valves of the gas lines closed; and leak checking up to the upstream valve of each the process gas line with the upstream valves of the of the process gas lines closed and with the downstream valve of the of the process gas line being leak checked open and the downstream valve of every other process gas line closed.