Date of Award

1996

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

First Advisor

William H. Daly

Abstract

Aliphatic polycarbonates were synthesized by condensation of the bischloroformate of 2,2,4,4-tetramethyl-1,3-cyclobutanediol with cyclic aliphatic diols. Polycarbonates that lacked flexible methylene units in the backbone processed T$\sb{\rm g}\ >$ 139$\sp\circ$C. Copolycarbonates acted as resists when combined with cobalt(III)-am(m)ine tetraphenylborate complexes which act as photointiators, with tetraphenylborate serving as counter anion. The photoinitiator liberates either ammonia or ethylene diamine base upon UV exposure and the polycarbonate backbone is subject to nucleophilic attack at the carbonyl linkage by the base. Image tone was dependent on the base used. Amine complexes, Co(NH$\sb3)\sb6\sp{3+}$ effected a positive tone due to ammonia induced main chain degradation at the carbonate linkage. Cobalt ethylenediamine complex, Co(en)$\sb3\sp{3+}$, en is ethylenediamine, effected a negative tone. The released ethylenediamine acted as a tetrafunctional crosslinking agent forming carbamate linkages. Resolution studies determined linewidths to 20 $\mu$m. The amine complex, under low intensity UV radiation, $>$0.35 mW/cm$\sp2$, and elevated temperatures, $>$40$\sp\circ$C, promoted vapor developed positive tone images in the resists layer. 1-Butene, 2-methyl-1-pentene, cyclohexene, and norbornene were copolymerized with sulfur dioxide. Thermal characterization revealed that these copolymers possess low T$\sb{\rm g}$, i.e., $<$35$\sp\circ$C, and two degradation transitions between 110-200$\sp\circ$C. They undergo main chain degradation forming positive tone images when exposed to synchrotron radiation and base development. Sensitivities were determined to be $<$25 mJ/cm$\sp2$ for poly (2-methyl pentene-1 sulfone). This copolymer vapor develops upon exposure of $\mu$M thick films to doses $>$800 mJ/cm$\sp2$. Features to 0.4$\mu$M were obtained in this manner using a test mask. Novel polysulfones were prepared by the polymerization of SO$\sb2$ with conjugated dienes. Polymerizations were perfonned at $-$78$\sp\circ$C in nitropropane as solvent using t-butyl hydroperoxide as initiator. The T$\sb{\rm g}$ of these polymers are $>$70$\sp\circ$C with similar degradation transitions seen for the poly (olefin sulfone) copolymers. These polymers are soluble in a common solvent, nitromethane. Poly(hexadiene-1,3 sulfone) acted as a positive tone resist when exposed to synchrotron radiation and developed in nitropropane. Sensivities $<$50 mJ/cm$\sp2$ were determined for this polymer, vapor development was not achieved. Resolution studies revealed line widths to 0.25 $\mu$M, the feature limits of the test mask used.

Pages

155

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