A Cryogenic, Low-PPB Range Moisture Analyzer for Process Gases

A commercial cryogenic chilled mirror moisture analyzer has been developed and tested for use with semiconductor process gases. The system is continuously reading, responds to moisture upsets within 40 sec, and can be used reliably at single-digit ppb moisture levels.

The CR-1 was evaluated by the methodology proposed at the Microcontamination '92 Conference. The evaluation shows that the instrument provides accurate and stable readings within the requirement specifications for gases used in semiconductor processing. With the CR-1, the gas system can be connected, purged-down, and be able to monitor at the 10 ppb level within 2 hr.