Development of a tape for the determination of silane using ethyleneglycol

Abstract

A tape for detecting such hydride gases as phosphine and arsine is impregnated with a coloring solution, including silver p-toluenesulfonate, p-toluenesulfonic acid, glycerin and methanol. Unfortunately, it cannot detect low concentrations of silane. However, a tape using ethyleneglycol, which serves as an efficient solvent, instead of glycerin, shows a high responsibility for silane. Silane is absorbed on the surface of the tape, and reacts with silver p-toluenesulfonate to form a stain, the intensity of which can be measured quantitatively by an optical system to determine the concentration of silane. The tape remains substantially light-resisting without impairing the mechanical strength, particu-larly the tensile strength. The detection limit was 1 ppm for silane at a sampling time of 40 s and a flow rate of 350 ml/min. This method is hardly affected by other gases, such as hydrogen, 2-propanol and acetone.