Electrical Conductivity Measurement in Liquified Hydrogen Chloride

Abstract

A measurement technology for trace impmrities in hydrogen chloride (HCI) was developed in relation to future ultralarge scale integration (ULSI). We developed an electrical conductivity measurement system for analyzing liquified HCI with an in-line high pressure cell. The detection limit of this measurement system is 1.0 x I0-~ S/cm, and the external leak rate of the cell is below 1.5 • I0-" Torr . liter/s. The apparent temperature coefficient of the electrical conductivity is negative in the range from -12 to 20~ at constant pressure, which is caused by a decrease of the density of HCI with increasing temperature. The real temperature coefficient of the electrical conductivity is positive at constant density. We observed differences in the electrical conductivity of HCI at different lapsed times after filling and between different gas sources. An electrical conductivity of 5.5 • i0 70 S/cm was obtained by repeated liquifaction of HCI at a pressure of 41 kg/cm 2 and 15~

A theoretical study on a reaction of iron(III) hydroxide with boron trichloride by ab initio calculation

“…The prime suspect is rust from the welded spots in the ductwork. Although the ductwork for semiconductor gases has corrosion resistance, the welded spots are relatively weak against halogen-contained gases, especially, under the presence of water [6]. Note that at most a few parts-per-million (ppm) of water is mixed in the ductwork.…”