2019 AIChE Annual Meeting
(110c) Multiscale Three-Dimensional CFD Modeling and Reactor Design for ALD of SiO2 Thin-Films
Authors
The microscopic surface reactions during the process directly influence the film quality and growth rate, which serves as the motivation for our previous work to develop a kinetic Monte-Carlo (kMC) microscopic model for the surface deposition along with a low computation cost data-driven model using standard feedforward and Bayesian regularized neural networks. The previously developed microscopic model successfully reproduces the surface deposition mechanisms and characterizing the growth per cycle (GPC) under a range of fixed boundary conditions [3].
However, the effect of the macroscopic gas phase development in the ALD reactor on the wafer surface microscopic deposition profile still remains unclear and is possible for further geometric and operational optimization [4]. Thus, in this study, we use ANSYS Fluent to create an accurate macroscopic CFD model of the ALD reactor chamber, which is linked with the microscopic kMC model through a message passing interface (MPI) using the user defined function (UDF) in Fluent [5]. The nature of the ALD process is comprehensively reproduced by the multiscale model. In addition, equipped with the multiscale workflow, optimized reactor geometries are designed and investigated, including a showerhead hole distribution optimization and an upstream shape modification. Also, operational optimizations are carried out by controlling the radial heating of the substrate surface and several reactor designs are evaluated to develop an optimal reactor design. Together, it is demonstrated that, for the deposited film, the spatial non-uniformity and required cycle-time are reduced.
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