A New Near-Saturation Equation of State for Titanium Vapor for Use in Models Simulating Physical Vapor Deposition (PVD) Processes

Kevin Gotta, Anil Kulkarnib and Jogender Singhc

The Pennsylvania State University, State College, PA 16801, USA.



Standard physical vapor deposition models are analyzed to determine if any of the basic assumptions fail to accurately describe the flow field. Interestingly, the most basic assumption of ideal gas behavior appears to incorrectly convey the physics of PVD fabrication. Even though at first glance the ideal gas approximation seems to be a reasonable assumption given the low pressure/high temperature condition of the flow, recent research into the thermodynamic properties of titanium vapor indicates a very different behavior. Calculation of compressibility factors required to fit the thermodynamic data to other common equations of state such as Van der Waals, Dieterici, Berthelot, and Redlich-Kwong equations of state also showed unexpected behavior. Therefore, a new equation of state is suggested in this paper to more accurately describe titanium vapor and other similar vaporized metals near their saturated state. Properties calculated from this equation of state match the available thermodynamic data well.

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