Fuzzy logic models for thermally based microelectronic manufacturing processes

This paper presents fuzzy logic models (FLM) to simulate two thermally based microelectronic manufacturing processes: the “pool boiling” in vapor phase soldering and silicon deposition process in a horizontal chemical vapor deposition (CVD) reactor. After a brief discussion of the various input-output models, we present our general approach to the development of FLM´s, followed by their application to the two case studies. For the pool boiling, experimental data are used to develop the fuzzy logic model. Results show that the FLM not only simulates the different regions of the pool boiling curve satisfactorily, but also faithfully represents the two transitions. For the CVD process, pseudo-analytical equations from Eversteyn´s paper are used to generate data under simulated production conditions. Results show that the model can describe the process very well. The physico-fuzzy model, incorporating the physical understanding of the process, is shown to improve the model´s extrapolation capability