Study Of The Effects Of Ligands On Positive And Negative Tone Oxide Nanoparticle Photoresists
Motivated by Moore's law, hybrid nanoparticle photoresists composed of metal oxide (ZrO2 and HfO2) and carboxylic acid ligands have been developed as a novel resist for extreme ultraviolet (EUV) lithography. This thesis consists of two parts: a study of oxide nanoparticles made with substituted benzoate ligands and a study of dual tone patterning by some of the oxide nanoparticles. In order to investigate the influence of substituents on the patternability of aromatic-acid-based nanoparticles, nanoparticles with ZrO2 or HfO2 cores and a variety of benzoate ligands with a range of pKa's have been synthesized via a sol-gel reaction. After physical characterization of the product, lithographic tests were conducted with both deep UV and EUV radiation exposures. The thesis also investigated the dual-tone patternability of methacrylic acid bound ZrO2 which has been assessed by deep UV and electron beam lithography. By studying the lithographic process conditions and the tone-switch behavior, a better understanding of the working mechanism has been made possible. An update of the current thoughts on the solubility change mechanism is provided based on these studies.
nanoparticle; photoresist; EUV lithography
Materials Science and Engineering
M.S., Materials Science and Engineering
Master of Science
dissertation or thesis