Spline Interpolation-Based Multi-Scale Model for Etching in a Chlorine-Argon Inductively Coupled Plasma

A multi-variable spline interpolation is used in order to quickly obtain the wafer incident fluxes from inside an inductively coupled plasma chamber with a chlorine and argon chemistry. The data is obtained by performing a total of 18 750 chamber simulations while varying the inputs which include the inductive coil power, the gas flow rate, the chamber pressure, the chlorine gas concentration ratio, the temperature, and the applied bias voltage. The data is used to generate a six-dimensional hypercube for each flux of interest where each dimension corresponds to one of the varied parameters. The fluxes are then incorporated into a semi-empirical feature scale plasma etching model in the process simulation tool ViennaPS. The chemical sticking coefficient is derived from measurements and the model includes the etch rate resulting from the chemical etch component, ion sputtering, and ion-enhanced etching.