Seminar - Reaction Factorization for the Dynamic Analysis of Thin-Film Deposition Systems

Time

-

Locations

Perlstein Hall Auditorium, Room 13110 West 33rd Street, Chicago

The Chemical and Biological Engineering department will be hosting a seminar featuring Professor of Chemical and Biomolecular Engineering and Institute for Systems Research at University of Maryland, Raymond Adomaitis. The title of the seminar will be "Reaction Factorization for the Dynamic Analysis of the Thin-Film Deposition Systems"

Abstract

Thin-film deposition processes are widely used in microelectronics and energy related manufacturing industries. Given the important role physically based models play in the design, optimization, and control of these systems, a surprising amount of ambiguity remains in how one derives well-posed mathematical models describing the surface species dynamics.

In this talk, I will present a factorization procedure to explicitly separate the slow (deposition), fast (equilibrium), and instantaneous (conserved) modes of thin-film deposition models describing the dynamics of the precursor, surface, and deposition chemical species, focusing primarily on the dynamics of atomic layer deposition (ALD) processes. The Gauss-Jordan factorization procedure provides an unambiguous means of translating sequences of equilibrium and irreversible reactions characterizing a deposition system into a low-dimensional DAE system when the reaction kinetics are predicted using transition-state theory. The factorization eliminates redundant dynamic modes; an implicit Euler procedure then is used to solve the singular-perturbation problem describing the time-evolution of the reaction species on the manifold defined by the combination of the equilibrium relationships and conserved quantities.

An alumina ALD process based on the TMA/water precursor system serves as the prime example used in this work; despite the intense study of this ALD process, several new observations regarding this reaction system are made and a number of new questions are raised using our approach. ALD processes for solar cell and spacecraft applications will be presented.