Integration of Feedback Control and Run-to-run Control for Plasma Enhanced Atomic Layer Deposition of Hafnium Oxide Thin Films

Facilitated by the increasing importance and demand of thin-film materials, plasma-enhanced atomic layer deposition (PEALD) has gained tremendous industrial interest as it offers a way to efficiently deposit thin-films with ultra-high conformity. Despite the variety of PEALD processes, there lacks a fundamental and general methodology to understand, characterize and control a realistic PEALD process system. To fully understand the PEALD process, a series of studies have been carried out in our previous work. First, a kinetic Monte-Carlo (kMC)-based microscopic model that describes the surface dynamics was implemented and a multiscale CFD model was developed to characterize the PEALD process. Additionally, a corresponding multiscale data-driven model was derived to efficiently explore the optimal operating condition in the process domain based-on an elementary cost-analysis. The successful development of the aforementioned models enables the further study into the process control of PEALD where disturbances in operating conditions are present. In this work, an integrated control scheme using a proportional-integral (PI) controller and a run-to-run (R2R) controller is proposed and implemented. Using the developed multiscale CFD model, the PEALD process under typical disturbances is simulated, and the controllers are applied in the process domain. The result demonstrates the successful mitigation of disturbances in operating pressure, inlet molar fraction and gas feeder temperature under the combined effort of both controllers