Effect of molecular resist structure on glass transition temperature and lithographic performance in epoxide functionalized negative tone resists

A series of five negative tone epoxide functionalized molecular resists have been synthesized and have had their glass transition temperature (T g ) and lithographic contrast behavior characterized. Introducing rigid structural features in the form of aromatic rings to a resist was found to increase its glass transition temperature. All resists but one, BHPF-2Ep, were found to have poor film stability which required the use of an underlayer. A trend was observed where PEB conditions performed at temperatures much higher than the T g of the molecular resist was found to induce propagation of polymerization outside of exposed regions. Di-functionalized resists were observed to have poor sensitivity due to their low degree of functionalization. A resist was synthesized (BHPF-2Ep) which was capable of resolving features down to 20 nm with an imaging dose of 70.5 mJ/cm 2 .