Most of the research presented in this thesis deals with photochemistry applied to optical lithography, a technology used to manufacture computer chips, memories, and integrated circuits in the micro- and nano-regime.
Photochemical reactions induced in thin polymer films by laser radiation at 248, 193 and 157 nm were studied extensively, employing spectroscopy and microscopy techniques. Fluorescent dyes that would change their properties upon interaction with a chemical species were used to gain insights about the photoproducts formed during irradiation. Photolysis of photoacid generators (PAGs) leads to formation of acid, which will then catalyze deprotection of polymer pendant groups. The amount of acid formed as a function of incident dose was determined for different PAGs at various wavelengths and in different resist formulations using Coumarin 6, a fluorescent dye that changes its spectroscopic properties upon interaction with the proton. New and more transparent PAGs, obtained in the group, were characterized at different wavelengths.
The amount of acid determined by in polymer titration was used in calculation of the catalytic chain length (CCL). This is a novel method which employs two fluorescent sensors embedded in a polymer film.
Hydrofluoric acid (HF) was detected in films of fluorinated polymers exposed to laser radiation at 157 nm, using a fluorescent sensor especially designed and synthesized in the group.
The influence of laser radiation on the polymer film was studied using pyrene as fluorescent probes sensitive to the environment changes. Formation of excimers was observed in exposed areas; a very interesting finding is that the molecules forming the excimers do not separate after they emit light, remaining in close proximity for days. The influence of temperature on the excimers in thin polymer films was studied, using polymers with different Tg.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/29661 |
| Date | January 2007 |
| Creators | Ivan, Marius Gabriel |
| Publisher | University of Ottawa (Canada) |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 250 p. |
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