Thermal Modeling Tool for a Spherical Capsule in a Sputtering Chamber

It is known that a film's temperature during a sputtering process greatly influences its mechanical structure. Currently, there is no known tool to effectively model the temperature history of a sputtered film on a spherical capsule in a sputtering chamber. Therefore, a tool has been developed that allows for the prediction of this temperature history using a lumped capacitance approximation for the capsule. This tool has been developed as part of LLNL's Diablo II multi-mechanics code to allow for the coupling of the capsule mechanics with the finite element-based sputtering chamber mechanics. The tool incorporates three forms of heat transfer: contact heat transfer between the capsule and the walls, enclosure radiation among all surfaces, and adsorption of chamber gas on all surfaces. The physics of the system have been validated by determining less than 1% difference in simulated results of twelve test runs to values determined via analytical or finite difference approaches, and validation of eight further tests involving capsule motion provide confidence in the model