Abstract
The analysis of water vapor impurity is important in a number of specialty gas applications. However the main driver for the development and advancement of trace H
2O analysis techniques has been the microelectronics industry. The International Technology Roadmap for Semiconductors (ITRS) details the gas purity requirements for various wafer fabrication processes on their web-site (
www.itrs.net). Oxygenated contaminants such as water vapor in the materials used and in the wafer environment are primary causes of defects and process variations that compromise yield. Since even trace levels of water in the process gases can seriously decrease device performance, analytical techniques must be capable of detecting water vapor from ppmv concentrations down to the low and even sub-ppbv range. This chapter focuses on technologies that not only provide high sensitivity for H
2O but can also be applied to a wide range of specialty gases. They can be broadly categorized into sensor and spectroscopic-based approaches. Aspects related to water standards and calibration, are also discussed.