Electromagnetic fields are often used to manipulate matter in many technological processes including those applied in emerging fields related to nanotechnology. Generalizing this concept, manipulation processes use forces or fields generated by electromagnetic interactions (e.g. a thermal process at constant and uniform temperature uses lamps as heat sources). Often, in the description of the evolution induced by the process it is more convenient to identify a simplified scheme of the driven force/field (i.e. constant high temperature in the previous example). Of course, these simplifications affect also the theoretical analysis of the material modification promoted by the processes. Reconsidering the cited example of thermal process, temperature is just a parameter of the diffusion equations used to evaluate the material redistribution activated by the high temperature. In these cases also the experimental control of the process takes advantage of the definition of quasi-equilibrium thermodynamic parameters as process parameters. However, the effect of the interaction between the electromagnetic field and the material is more difficult to control in some processes where the amount of energy released from the field towards the samples depends dynamically and self-consistently on the material kinetic evolution. The self-consistency makes difficult inferring the manipulation effects on a new system from the previous phenomenology on different systems. In this case, optimized new applications usually need complex and expensive Design of Experiments (DoE) in terms of man power and materials. This PhD dissertation focuses on such processes. In particular, considering plasma and laser annealing processes, we aim to demonstrate that a reliable process control can be obtained by means of simulation methodologies which consider the full complexity of the process kinetics. In spite of the differences in terms of machines and role in the manufacturing flow, plasma and laser processes share two striking common features, from the modeling perspective: The manipulation results critically depend on the structure of the sample (especially if sub-micron structures are processed); Electromagnetic simulations coupled with many-component kinetic models are the key aspect of the multi-scale / multi-physics formalism implemented in the numerical codes.

Coupled Kinetic and Electromagnetic approaches for the simulation of complex processes

LOMBARDO, SALVATORE FRANCESCO
2017

Abstract

Electromagnetic fields are often used to manipulate matter in many technological processes including those applied in emerging fields related to nanotechnology. Generalizing this concept, manipulation processes use forces or fields generated by electromagnetic interactions (e.g. a thermal process at constant and uniform temperature uses lamps as heat sources). Often, in the description of the evolution induced by the process it is more convenient to identify a simplified scheme of the driven force/field (i.e. constant high temperature in the previous example). Of course, these simplifications affect also the theoretical analysis of the material modification promoted by the processes. Reconsidering the cited example of thermal process, temperature is just a parameter of the diffusion equations used to evaluate the material redistribution activated by the high temperature. In these cases also the experimental control of the process takes advantage of the definition of quasi-equilibrium thermodynamic parameters as process parameters. However, the effect of the interaction between the electromagnetic field and the material is more difficult to control in some processes where the amount of energy released from the field towards the samples depends dynamically and self-consistently on the material kinetic evolution. The self-consistency makes difficult inferring the manipulation effects on a new system from the previous phenomenology on different systems. In this case, optimized new applications usually need complex and expensive Design of Experiments (DoE) in terms of man power and materials. This PhD dissertation focuses on such processes. In particular, considering plasma and laser annealing processes, we aim to demonstrate that a reliable process control can be obtained by means of simulation methodologies which consider the full complexity of the process kinetics. In spite of the differences in terms of machines and role in the manufacturing flow, plasma and laser processes share two striking common features, from the modeling perspective: The manipulation results critically depend on the structure of the sample (especially if sub-micron structures are processed); Electromagnetic simulations coupled with many-component kinetic models are the key aspect of the multi-scale / multi-physics formalism implemented in the numerical codes.
30-nov-2017
Italiano
GRIMALDI, Maria Grazia
GRIMALDI, Maria Grazia
Università degli studi di Catania
Catania
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.14242/77618
Il codice NBN di questa tesi è URN:NBN:IT:UNICT-77618