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dc.contributor.advisorWillson, C. G. (C. Grant), 1939-en
dc.creatorJamieson, Andrew Thomasen
dc.date.accessioned2008-08-28T22:03:00Zen
dc.date.available2008-08-28T22:03:00Zen
dc.date.issued2004en
dc.identifierb5958855xen
dc.identifier.urihttp://hdl.handle.net/2152/1487en
dc.descriptiontexten
dc.description.abstractAdvances in semiconductor microlithography have resulted in reduced transistor dimensions and consequent improvements in chip performance and cost. In the microlithographic process a photoactive material called a photoresist is uniformly spun cast on a substrate and selectively exposed to radiation, causing a chemical change in the exposed areas. The polymer is subsequently removed in either the exposed or unexposed regions, typically using an aqueous base developer. An alternative to the traditional lithographic method is a process called Top Surface Imaging (TSI). TSI has a number of advantages over traditional base-development techniques but is highly susceptible to line edge deformities commonly referred to as line edge roughness (LER). In TSI, the top surface of the photoresist is exposed to radiation, resulting in the generation of reactive sites. A gas phase, silicon-containing compound called a silylation agent reacts with these sites, causing selective incorporation of silicon. The silicon then acts as an etch mask in an anisotropic oxygen etch process. As the industry continues to improve resolution by shifting to shorter wavelengths, TSI’s lax transparency requirements provide it with a distinct advantage over traditional lithographic techniques. In this work, TSI was evaluated for use with three industrially relevant radiation sources, including 157nm light, low-voltage electron beams, and extreme ultraviolet light. An investigation into the origins of low frequency LER in TSI systems showed it to be the result of surface tension induced capillary instabilities (also known as a Rayleigh instability). The polymer contribution to LER was investigated by the synthesis of numerous high-Tg TSI polymers. Although many of these polymers are capable of producing high-resolution features, they all suffer from significant levels of LER. The kinetics of the gas phase reaction of the TSI polymer poly(hydroxystyrene) and the silylation agent dimethylaminodimethylsilane was investigated using variable angle spectroscopic ellipsometry, and was found to be front propagated and reaction limited. It was found that the addition of base quenchers to chemically amplified photoresists greatly minimizes LER, and a theoretical approach to understand this effect is presented. Overall, TSI performs well, but the nature of LER in TSI systems is still not fully understood.
dc.format.mediumelectronicen
dc.language.isoengen
dc.rightsCopyright is held by the author. Presentation of this material on the Libraries' web site by University Libraries, The University of Texas at Austin was made possible under a limited license grant from the author who has retained all copyrights in the works.en
dc.subject.lcshMicrolithographyen
dc.subject.lcshPhotoresistsen
dc.subject.lcshSurface chemistryen
dc.subject.lcshSilylationen
dc.titleTop surface imaging for sub-100nm lithographyen
dc.description.departmentChemical Engineeringen
dc.identifier.oclc60409230en
dc.identifier.proqst3143891en
dc.type.genreThesisen
thesis.degree.departmentChemical Engineeringen
thesis.degree.disciplineChemical Engineeringen
thesis.degree.grantorThe University of Texas at Austinen
thesis.degree.levelDoctoralen
thesis.degree.nameDoctor of Philosophyen


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