SEMI F35 - Test Method for Ultra-High Purity Gas Distribution System Integration Verification Using Non-Invasive Oxygen Measurement
This test method was technically approved by the Global Gases Committee and is the direct responsibility of the North American Gases Committee. Current edition approved by the North American Regional Standards Committee on December 4, 2003. Initially available at www.semi.org February 2004; to be published March 2004. Originally published September 1998.
NOTICE: This Standard or Safety Guideline has an Inactive Status because the conditions to maintain Current Status have not been met. Inactive Standards or Safety Guidelines are available from SEMI and continue to be valid for use.
This test method defines a procedure to monitor the integrity of ultra-high purity (UHP) gas distribution systems by detecting the ingress of atmospheric oxygen. This test method would be used to evaluate an "active" UHP gas distribution system on a continuous basis by using non-invasive O2 measurement, without requiring an interruption of the process tools using the UHP gases of interest.
This test method should be used to protect semiconductor fabrication processes using the UHP gases, which may be sensitive to contamination by any of the common atmospheric impurities, such as N2, O2, H2O, CO2, before product yield problems develop.
This is the first such test method that describes a noninvasive leak detection and locating procedure. It differs from SEMI F1, which is an invasive technique for identifying leak sources using a mass spectrometer and a helium tracer gas.
This test method applies to UHP gas distribution systems used in semiconductor manufacturing facilities and comparable research and development areas.
This test method applies to bulk gas distribution systems carrying UHP gases such as N2, Ar, He, H2, N2O, SF6, and many halocarbons. In most cases, O2 is present only in ultra-low trace levels (typically less than 1.0 ppb).
This test method will provide real-time monitoring of UHP gas distribution systems, resulting in meaningful system integrity verification, atmospheric contaminant trending analysis, and leak locating.
This test method will provide the user with sufficient information to identify and troubleshoot sources of atmospheric leakage into the UHP gas distribution system.
This test method includes the specification of the required O2 analytical equipment, standard methods for proper use of the O2 analytical equipment, and manipulation of the O2 data in identifying atmospheric leak sources.
Referenced SEMI Standards
SEMI F1 — Specification for Leak Integrity of HighPurity Gas Piping Systems and Components