Download turnkey industrial system for moisture

JPACSM
136
…the Journal of Process Analytical Chemistry
TURNKEY INDUSTRIAL SYSTEM FOR MOISTURE ANALYSIS
IN CORROSIVE GASES
Richard T. Meyer and Jorge E. Perez
CIC Photonics, Inc.
Albuquerque, NM
EXTENDED ABSTRACT
The presence of moisture as an impurity in specialty gases supplied to the semiconductor industry
remains a critical issue, as does the development of process analytical instruments for moisture monitoring. This
paper describes a turnkey Integrated Real-time Gas
Analysis System (IRGAS), consisting of a newly-designed
4-meter pathlength White Cell which has been functionally-combined with a low-cost FTIR spectrometer, multifeature stainless steel gas handling manifold, high-vacuum
corrosive gas pumping stations, industrial-ruggedized
computer hardware and software package, and purgeable
stainless steel safety enclosure. The software permits
overall operation and control of individual system components as well quantitative analysis of moisture content.
This industrial system is being tested for application to
online monitoring of ppb concentrations of water both in
corrosive gas production operations and for semiconductor wafer processing. The results of laboratory tests at
concentrations of moisture in HCl in the 20-100 ppb range
will be presented, including a calculation of the limit of
detection. Key factors in the performance of the system
are the ultimate sensitivity of the high energy throughput
White Cell combined with the reproducibility of the FTIR
spectrometer.
DATA
At the poster session, data charts will be presented on: (1) N2/CO2 and N2/HCl exchange rates as a
function of temperature and flow rates; (2) drydown rates
for N2 purge of atmospheric moisture and for moisture
from HCl flow in a dry cell; an (3) detection limits of
moisture in N2 and moisture in HCl.
CONCLUSION
Without any sophisticated treatment of collected
spectral data, limits of detection of 25 ppb of moisture in
nitrogen and of 50 ppb of moisture in HCl can be
achieved with this system.
ACKNOWLEDGMENTS
The author acknowledges the assistance of personnel at Matheson Gas Products in the collection of data
at their facility in Longmont, CO.
REFERENCES
B.R. Stallard, L.H. Espinoza, R.K. Rowe, M.J. Garcia,
and T.M. Niemczyk, J. Electrochem. Soc., Vol. 141,
2777-2782, (1995).