Humidity Sensor Leak Detection for Wafer Chuck Coolant
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional methods for detecting leaks in coolant used for semiconductor wafer processing are not responsive enough, leading to wastage of wafers due to thermal stress-induced cracks in the wafer chuck, which cause coolant leaks during heating and cooling cycles.
Innovation Solution
A device and method that utilize a humidity sensor to measure relative humidity at the outlet of a dry wafer processing chamber, triggering a shutdown when a change above a threshold is detected, indicating a leak in deionized water coolant, thereby preventing further processing and reducing scrap wafers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional leak detection techniques are used, then the system is simple to implement, but the detection responsiveness is insufficient leading to wafer scrap
Solution Approach 1:
The patent replaces traditional mechanical or pressure-based leak detection methods with a humidity sensing system. The humidity sensor detects water vapor in the exhaust gas, providing responsive electrical signal-based detection that avoids the lag of mechanical systems while maintaining implementation simplicity through standard sensor integration.
Solution Approach 2:
The patent introduces humidity as an intermediary parameter to detect coolant leaks. Instead of directly detecting liquid coolant or pressure changes, the system measures water vapor concentration in the exhaust gas, which serves as an indirect but highly responsive indicator of leaks, enabling early detection before significant wafer damage occurs.
2Measurement precision
If continuous monitoring is implemented to improve detection accuracy, then leak detection precision improves, but energy consumption increases
Solution Approach 1:
The patent implements periodic sampling of humidity levels rather than truly continuous monitoring. The controller periodically reads the humidity sensor and compares against threshold values, achieving high detection accuracy through frequent sampling while consuming minimal energy compared to constant high-rate monitoring. This allows precise leak detection while maintaining low power consumption suitable for process control systems.
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
The solution enables early and accurate detection of coolant leaks, minimizing material loss by instantly shutting down the processing when a leak is detected, improving reliability and reducing costs associated with scrapped wafers.
Implementation Method 1
a humidity sensor configured to measure relative humidity (RH) at an outlet of the dry wafer processing chamber
Implementation Method 2
cooling the wafer chuck during a cooling phase of the processing
Data Source
AI summary
Device and method of configuring a device to process a wafer is disclosed. The device includes a wafer chuck configured to mount the wafer, a dry wafer processing chamber configured to enclose the wafer chuck, a humidity sensor configured to measure relative humidity (RH) at an outlet of the dry wafer processing chamber, a humidity controller coupled to the humidity sensor, the humidity controller being configured to detect a change in RH above a threshold, and a process chamber controller coupled to the humidity controller. The change is triggered by a leakage in deionized water used as a coolant for cooling the wafer chuck and the wafer during the processing. The process chamber controller is configured to trigger a shutdown of the processing of the wafer in response to the leakage.