Modelling of an industrial moving belt chemical vapour deposition reactor forming SiO2SiO2 films

In order to improve the efficiency of an industrial atmospheric pressure chemical vapour deposition (APCVD) moving belt reactor depositing silicon dioxide SiO2SiO2 films from tetraethoxysilane Si(OC2H5)4Si(OC2H5)4 (TEOS) and ozone O3O3, a 2D simulation model based on the computational fluid dynamics (CFD) software ESTET has been developed.On the basis of the global chemical scheme of Zhou et al. [1997. Fifth International Conference on Advanced Thermal Processing of Semiconductors, RTP’97, New Orleans, LA, USA, pp. 257–268], a new kinetic model has been developed to conveniently represent our own set of experimental data. In particular, a chemical limitation for TEOS has been introduced, conferring increased chemical validity to the model. Simulations have shown that for the nominal conditions, TEOS conversion into SiO2SiO2 layers was too low and that an increase in ozone concentration or in the nitrogen flow rates through the injector did not offer any advantage. Conversely, a decrease in the curtain nitrogen flow rate or an increase in that of the shield can enhance the process productivity and TEOS conversion.