CFD Simulation of the Dosing Behavior within the Atomic Layer Deposition Feeding System

The effective operation of atomiclayer deposition (ALD) feedingsystem is the premise of realizing specific ALD processes. In thepresent work, a detailed computational fluid dynamics (CFD) modelof the feeding system has been developed and validated, which accountsfor the roles of ALD valves and manifolds. A numerical simulationof the compressible fluid flow and heat/mass transfer within the feedingsystem was conducted. The dosing amounts and the spatiotemporal distributionsof the precursors can be accurately predicted using the CFD model,as validated by experimental results. Different precursors, operatingconditions, and structures of the feeding system were simulated andanalyzed to examine the operating flexibility of the feeding system.The simulation results can be adopted as the upstream boundary conditionsfor simulations of the ALD process in the reaction chamber. The substrate-scalesimulation indicates that the effect of the feeding system on thefilm deposition is highly related to the surface kinetics of ALD.The present work can serve as a guide for the development and optimizationof different ALD-based processes via proper operation and even thedesign of the feeding system.