Vapor Pressure measurements for dichlorosilane

Abstract

In the processing of silicon-based materials, such as those used for electronic and photovoltaic materials, one of the key initial components is dichlorosilane. Dichlorosilane is often used in mixtures that include other pure silanes, like trichlorosilane and silicon tetrachloride, or other chemicals which are not in the silane family. Accurate information about the vapor pressure is necessary in the production of these mixtures. Measurements reported previously for the vapor pressure of pure dichlorosilane are sparse. For those that are available, there is little or no discussion about the methods employed from the start of the process through completion, thereby making difficult a quantitative analysis of the accuracy of the measurements. Vapor pressure measurements for dichlorosilane have been performed by the isochoric method in the Thermodynamics Research Laboratory at Texas A&M University. Details have been provided from the purchase of the dichlorosilane through the disposal of the waste product. Care has been taken to address all of the intermediate procedures to give an overall view of the process, not just the data analysis and results. Common problems and solutions have also been given attention for the benefit of future studies.