Simulation of the SEMATECH gravimetric mass flowmeter calibrator

Many different processes in the fabrication of microelectronic circuits require precise metering of process gas flows. A facility is being designed at Oak Ridge National Laboratory (ORNL) to provide calibration of high-precision gas flowmeters for the Semiconductor Manufacturing Technology (SEMATECH) consortium. To provide proof-of-principle and to aid in the design of the facility, a digital computer simulation was developed. The gravimetric mass flowmeter is a new and unique apparatus that has been proposed for use as a primary calibration standard. The basic operating principles suggest that system dynamics and control will influence measurement accuracy and precision. Hence, a simulation of high fidelity was required because of the precision and accuracy specifications of the proposed facility. This paper describes the mathematical model development and software implementation using the Advanced Continuous Simulation Language (ACSL). Results obtained establish the feasibility of the proposed calibration facility.