CMP Fluid Line Leak Checking Using Pressure-Matched Flow Measurement
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Solution Overview
Problem
The leakage of fluid from fluid lines in chemical mechanical polishing (CMP) apparatuses leads to deteriorated polishing rates and contamination of wafers, necessitating quick and efficient leakage testing to maintain throughput.
Innovation Solution
A method and system for checking fluid leakage in CMP apparatuses involving a leakage checking line with a pressure regulator, flowmeter, and controller to compare flow rates with a threshold, ensuring rapid detection of leaks by maintaining equal pressure in the checking line with the main fluid line.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If leakage testing is performed periodically to detect fluid leakage, then wafer quality is maintained, but polishing apparatus throughput is deteriorated due to testing time
Solution Approach 1:
The leakage checking line is pre-connected to the fluid line between the supply valve and return valve during system setup. This preliminary configuration allows leakage detection to be performed quickly by simply operating valves and reading the flowmeter, without requiring complex test setup procedures that would consume polishing apparatus throughput.
Solution Approach 2:
A dedicated leakage checking line with an opening/closing valve and flowmeter is introduced as an intermediary system. This separate checking line allows leakage detection to occur independently from the main polishing operation, enabling rapid testing by simply closing the supply and return valves and reading the flowmeter, thus maintaining wafer quality without significantly impacting throughput.
2Measurement precision
If pressure is increased in the fluid line to improve flow rate measurement accuracy, then leakage detection precision is improved, but fluid leakage from the fluid line increases
Solution Approach 1:
The leakage checking line serves as an intermediary system that operates at lower pressures than the main fluid line. By connecting this separate checking line between the supply valve and return valve, the system can perform leakage detection without subjecting the main fluid line to high pressures that would cause leakage, thereby maintaining measurement precision while reducing harmful effects.
Solution Approach 2:
The invention replaces direct high-pressure testing of the main fluid line with a low-pressure flowmeter-based detection system in the leakage checking line. The flowmeter can accurately measure leakage flow rates at low pressures, substituting the need for high-pressure mechanical testing and thereby improving measurement precision while reducing fluid leakage from the main system.
3Speed
If a flowmeter is installed directly in the fluid line to monitor flow rate, then leakage detection speed is improved, but device complexity increases
Solution Approach 1:
The system is segmented into a main fluid line for polishing operation and a separate leakage checking line for detection. The flowmeter is installed only in the leakage checking line, not in the main fluid line. This segmentation allows rapid leakage detection by simply closing valves and reading the flowmeter in the checking line, improving detection speed while avoiding the complexity of installing and managing flowmeters in the main high-pressure fluid line.
Solution Approach 2:
The leakage checking line with flowmeter acts as an intermediary detection system. Instead of installing the flowmeter directly in the complex main fluid line, the checking line provides a simpler, dedicated pathway for flow measurement. This intermediary approach enables fast leakage detection while keeping the main fluid line configuration simple and unchanged.
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
Enables quick and accurate leakage detection, reducing downtime and maintaining polishing efficiency by preventing fluid attachment to the polishing pad, thus preserving wafer quality and throughput.
Implementation Method 1
a heat exchanger 111 that performs a heat exchange with a polishing pad 103
Implementation Method 2
acquiring a flow rate of the fluid that flows in the leakage checking line by a flowmeter disposed in the leakage checking line
Implementation Method 3
regulating a pressure regulator disposed in the leakage checking line such that a pressure of fluid of the leakage checking line becomes the same as a pressure of fluid of the fluid line
Data Source
AI summary
A method of checking a leakage of fluid from a fluid line includes connecting a leakage checking line to the fluid line between a supply valve and a return valve, regulating a pressure regulator disposed in the leakage checking line such that a pressure of fluid of the leakage checking line becomes the same as a pressure of fluid of the fluid line; closing the supply valve and the return valve and opening an opening/closing valve disposed in the leakage checking line; acquiring a flow rate of the fluid that flows in the leakage checking line by a flowmeter disposed in the leakage checking line; comparing the flow rate of the fluid acquired at the acquiring with a predetermined threshold; and determining that the fluid of the fluid line is leaked, when the flow rate of the fluid acquired at the acquiring is larger than the predetermined threshold.