Substrate Chamber Leak Detection After Controlled Cooldown
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Solution Overview
Problem
Existing substrate processing apparatuses face challenges in accurately detecting leaks in chambers during flash lamp annealing, particularly when handling reactive gases like ammonia, due to temperature-dependent gas density and discharge efficiency, leading to potential false detections and reduced accuracy.
Innovation Solution
A method and apparatus that involve waiting for the ambient temperature in the chamber to decrease to a predetermined specified temperature after substrate removal, allowing for precise leak determination by using threshold values associated with this temperature in a correspondence table, ensuring accurate detection without interference from ongoing substrate heating or gas supply/discharge processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If leak determination is performed during substrate heating process, then productivity is improved by continuous monitoring, but measurement precision deteriorates due to temperature-dependent gas density variations
Solution Approach 1:
The system performs preliminary cooling of the chamber to a predetermined temperature before initiating leak determination. This preliminary action ensures that temperature-dependent gas density variations do not affect measurement accuracy, while still enabling continuous monitoring capability through automated temperature management and scheduling.
2Loss of time
If leak determination is performed immediately after substrate removal, then loss of time is reduced, but measurement precision deteriorates due to residual heat affecting gas density
Solution Approach 1:
The system changes the temperature parameter by cooling the chamber to a predetermined temperature before leak determination. This parameter change compensates for residual heat effects on gas density, ensuring accurate measurements while minimizing time loss through automated temperature control and scheduling.
3Reliability
If hardware sensors are mounted on quartz window for leak detection, then reliability of leak detection is improved, but device complexity increases and may interfere with flash lamp irradiation
Solution Approach 1:
The system uses pressure gauges as intermediary measurement devices to indirectly detect leaks by monitoring pressure changes in the chamber. This intermediary approach avoids direct mounting of sensors on the quartz window, maintaining flash lamp irradiation capability while achieving reliable leak detection through pressure-based measurement.
4Measurement precision
If chamber pressure is reduced to detect leaks, then measurement precision is improved, but productivity deteriorates due to additional process time required
Solution Approach 1:
The system uses the existing vacuum system and pressure gauges already present in the substrate processing apparatus to perform leak determination. This self-service approach utilizes existing infrastructure without requiring additional equipment or significant process time, achieving accurate leak detection while maintaining productivity.
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 enables accurate detection of leaks in the chamber, reducing false positives and improving the reliability of leak determination by stabilizing gas supply and discharge processes and accounting for temperature-dependent conditions.
Implementation Method 1
Flash light irradiation in an extremely short time of a few milliseconds or less is also found to be able to selectively increase a temperature of only a portion near the surface of the semiconductor wafer
Implementation Method 2
an atmosphere in a chamber is evacuated before supply of a reactive gas into the chamber to reduce a pressure in the chamber to approximately 100 Pa
Data Source
AI summary
A leak determination method includes: a heating step of heating a semiconductor wafer in a chamber; a transport step of transporting the semiconductor wafer from the chamber after the heating step; a temperature measurement step of measuring an ambient temperature in the chamber; and a leak determination step of performing leak determination processing of the chamber. After the semiconductor wafer is transported from the chamber, waiting is continued until the ambient temperature decreases to a predetermined waiting specified temperature, and the leak determination processing is started when the ambient temperature reaches the waiting specified temperature.