NIST Database of the Thermophysical Properties of Gases Used in the Semiconductor Industry

The 1999 Semiconductor Industry Association (SIA) International Technology Roadmap for Semiconductors (ITRS) identifies 'Equipment Modeling' as first in a list of 'Technology Requirements' and states that 'the drivers for equipment modeling are equipment design, process control, . . . ' The ITRS indicates that continuing research is needed to obtain experimental data for 'transport and thermal constants.' This Project will generate transport and thermodynamic property data for the gases used in semiconductor processing. The data will be useful for equipment modeling in chemical vapor deposition (CVD) processes and the data will also provide a rational basis for the calibration of mass flow controllers (MFCs) used to meter process gases. NIST is measuring the thermophysical properties of the process gases, the 'surrogate' gases, and binary mixtures of process and carrier gases. The process gases are used in CVD and the surrogate gases are used to calibrate MFCs. The results will be disseminated in this data base providing the heat capacity, thermal conductivity, viscosity, and the virial coefficients for the virial equation of state providing the pressure-density-temperature relation for the process gases.