1570 Pacheco Street, Ste E-11
Santa Fe, NM 87505
Project Title: Diode Laser Absolute Moisture Sensor
NIST Award(s): 50-DKNB-5-00189
Technology Developed: Water vapor is present as an impurity even in extremely pure gases. Southwest Sciences developed an instrument for measuring water vapor with sufficient sensitivity for the next generation of semiconductor manufacturing processes. Achieving this performance required developing a sensitive optical measurement, a method of handling the sample of gas to be measured without changing its water content, and techniques to prevent water vapor from outside the sample affecting the measurement.
Key Words: Water vapor, hygrometer, semiconductor proces, low frost point gene
Uses of Technology/Products/Service: Modern semiconductor processing relies on carefully-controlled chemistry to create wafers with the targeted semi-conducting electrical properties. When water vapor is present as an impurity, it can change the chemistry to create oxide layers that are insulating (glass is a silicon oxide). Semiconductor manufacturers try to keep water vapor below a few parts per billion (one part per billion is one molecule of water vapor in 1,000,000,000 molecules of the gas). To verify that this level of purity has been achieved every day for every wafer, the manufacturers use sensitive instrumentation. Existing instruments had problems measuring water vapor below 10 parts per billion. A patent already developed at Southwest Sciences was one key to achieving this sensitivity, as was a newly-invented and patented signal-processing algorithm. Because a path of just one millimeter through room air produces a water signal equivalent to that of one part per billion in the sample, another key was a newly-invented and patented method to suppress signals that result when the laser beam must pass through air outside of the sample.
Benefit to Company: The NIST SBIR project took a promising technology — diode-laser-based absorption spectroscopy— and showed this technology could be used to measure water vapor with precision better than one part per billion. Demonstrating the technical advantages of our approach allowed Southwest Sciences to develop a license with Delta F Corporation for the manufacture and sale of commercial instruments. Royalties from this license significantly increased the profitability of the company. We have reinvested some of the profits in new R&D and have distributed some of the profits to owners and employees.
The relationship with Delta F has resulted in new product ideas which are in the early stages of commercialization.
Impact on Company Growth: Strategic
How Product Was Commercialized: Southwest Sciences licensed the technology to Delta F to address opportunities in the semiconductor gas monitoring industry. Delta F was already the recognized leader in oxygen sensors for this industry, based on an instrument that uses a completely different technology. They had a clear understanding of the marketplace, including the need for compact packaging, high reliability, and ease of operation. They used the software and hardware developed at Southwest Sciences as the starting point for a beta instrument. Southwest Sciences personnel worked closely with Delta F during the beta design and testing. Through calendar year 2008, Delta F has sold several hundred units of their "Nanotrace" analyzer under this license and Southwest Sciences has received royalties of several hundred thousand dollars.
Other Comments Related to Company's Success Story: Showing that we developed a stable instrument required an even more stable source of moisture. The NIST low frost point generator (LFPG) was under development at the time. We used this source to test our hygrometer, and at the same time our hygrometer helped verify the performance of the LFPG. Using the LFPG was a key part of demonstrating the performance of our instrument.
Commercial success required both technical expertise and a detailed knowledge of the marketplace. Southwest Sciences provided the optical measurement expertise, while Delta F was able to leverage their knowledge of how customers used their oxygen sensors to develop a better water sensor.