Stability and reproducibility are key enablers for success in semiconductor manufacturing since they are intimately associated with productivity and yield. More stable and reproducible processes lead to faster initial qualification times for new fab installations and longer up-time. The ability to accurately match pressures between chambers and from device to device is crucial, and the challenges created by the move to lower pressure set points, along with the fluorine burn-in effect, could lead to lack of reproducibility and stability, thus affecting yield.

MKS worked with semiconductor tool manufacturers and fab end users to understand these problems and their impact. MKS developed a new multi-physics model to predict how the Baratron® manometer would interact, on first exposure, with aggressive etch gases such as fluorine. We generated proposed solutions based on the model and developed a unique live gas test facility to iteratively test the solutions. The final solution is a new, "fluorine friendly" Baratron® manometer that provides greater immunity from fluorine burn-in effects. Additionally, we developed a novel calibration procedure that allows the calibrated accuracy of the Baratron® manometer to be extended to the lower pressure set points prevalent in some etch applications. This combination of improvements - Baratron® manometers with etch sensors, provides greater stability and reproducibility.