March 18, 2020
Notice Regarding Development of Trace Moisture Analyzer
in Nitrogen Using a Metal Organic Framework
Taiyo Nippon Sanso Corporation (“TNSC”) hereby announces that it has successfully developed a
trace moisture analyzer in nitrogen using properties from a metal organic framework (MOF) with
optical characteristics that change depending on absorption and desorption of moisture.

1. BackgroundIf moisture contaminates high-purity gases used in many industries, including semiconductor
manufacturing, it can cause oxidization, worsening product performance or yields. Moisture not
only exists in massive amounts within the atmosphere it can easily attach to a variety of substances
because of its nature as a polar molecule. Once moisture has contaminated the manufacturing
process, removal requires large amounts of high-purity gases. Consequently, multipoint monitoringof moisture concentration in industrial-use gases is needed for manufacturing processes vulnerable
to trace moisture, but no compact, inexpensive trace moisture analyzer existed that satisfied
requirements for timeliness, high sensitivity and high reliability.
TNSC conducted research jointly with Associate Professor Shin-Ichi Ohira of the Faculty of
Advanced Science and Technology at Kumamoto University to develop a analyzer for tracemoisture in nitrogen using an MOF with a porous structure as a moisture-sensitive agent that
fulfills a response speed of less than 5 minutes and lower detection limit of 10 vol. ppb at a cost ofless than ¥1 million.
2. Technical Overview
MOF is a porous agent group formed through a coordinate bond between metal ions and organicligands, and is a next-generation functional material expected to be used in applications such as gas
storage, separation, or catalyst.
Cu-BTC is an MOF formed by divalent copper ion (Cu2+) and benzene-1,3,5-tricarboxylate(BTC) that absorbs and desorbs moisture molecules at room temperature and specific wavelength
absorbance changes in conjunction with that (Fig. 1). The analyzer’s basic principle is to detect theabsorbance change and convert that to moisture concentration.
In trace amounts, changes in moisture concentration have a rapid and high correlation withchanges in absorbance, so showing this enables highly reliable measurements of high sensitivityand rapid responsiveness. As shown in the measurement example in Fig. 2, the indicated valuesrose immediately after the introduction of nitrogen gas containing trace amounts of moisture,
confirming that the analyzer responds faster than conventional general-purpose analyzers andsolidifying that it can be used as a moisture impurity concentration control device in processes withextreme moisture aversion.

Fig. 1: Cu-BTC structure and absorbance change

Fig. 2: Example of measurements of trace amounts of moisture in nitrogen

3. Future Plans
TNSC plans to move forward with testing at its related plants, and progress to public sales within
the fiscal year ending 2021 (from April 2020 to March 2021) through long-term field testing in
actual environments. The Company will also move ahead on technological development andcommercialization for application with other types of gases and greater sensitivity.

Taiyo Nippon Sanso Corporation
Tnsc.Info@tn-sanso.co.jp