Numerical simulation of plasma-chemical reactors

Summary

The interest to the investigation of processes in the plasma-chemical etching reactors (PCER) is defined by their wide-spread use in industrial production of semiconductor devices. The large number and complicated interconnection of factors that determine a quality and etching rate of wafers essentially limit the abilities of empirical optimization of PCER. The natural alternative is their optimization based on the mathematical modelling for which adequate numerical models are necessary. In the paper the results of development of numerical model of plasma-chemical reactors based on Navier-Stokes equations in Boussinesq approximation are presented. The model contains the original elements essentially raising its prognostic abilities. In particular, it takes into account the infrared radiation of polyatomic molecules that substantially influence the temperature distribution in the reactors. The mass transfer of active particles additionally includes the process of thermodiffusion. The effects of medium rarefaction, adequate gas phase and heterogeneous kinetics are considered. The abilities of proposed model are illustrated by it applications to studies of processes in the reactors of different constructive schemes. The results of optimization of etching uniformity by mechanical protectors are considered. The influence of temperature nonuniformities and medium rarefaction on the quality of wafer processing are quantitatively estimated. The comparative investigation of commonly used chemical kinetics models in the PCER are presented. The optimum composition of parent gas mixture with respect to the etching rate are obtained. In conclusion some perspectives are discussed for further development of the model, in particular, the application to virtual plasma reactor in operating systems.