Spin coating and photolithography using liquid and supercritical carbon dioxide

Abstract

HOGGAN, Erik Nebeker. Spin coating and photolithography using liquid and supercritical carbon dioxide. (Under the direction of Dr. Ruben G. Carbonell and Dr. Joseph M. DeSimone.) This thesis details work on the utilization of dense phase carbon dioxide (CO 2) in semiconductor processing. In particular, work is presented on the formulation of CO 2 soluble photoresists and the spin coating of those photoresists using only liquid CO 2 as a solvent. As part of this spin coating work, a novel high-pressure CO 2 spin coater was designed and constructed, and the theoretical equations governing its performance were derived. Also discussed in this thesis are 248 and 193 nm exposures of these CO 2 spun films and subsequent development in supercritical CO 2. Resist stripping was also performed in CO 2. In short, this thesis details the first steps towards a complete replacement of all aqueous and organic solvents in the conventional photolithographic processes of spin coating, developing, and resist stripping. This change not only confers significant environmental advantages, but opens up many new avenues in resist chemistry and promises improvements in large scale film uniformity, elimination of feature collapse, elimination of extraneous processing steps, and improved control of the lithographic process.

High-Quality Ultrathin Polymer Films Obtained by Deposition from Supercritical Carbon Dioxide As Imaged by Atomic Force Microscopy

“…Hoggan et al have deposited films from copolymers of 1H,1H-perfluorooctyl methacrylate and tert -butyl methacrylate on silicon substrates by the spin-coating method from solutions in liquid CO 2 . Coatings with a thickness of 0.1−3 μm have been prepared; however, films with a thickness less than 1 μm exhibit high degree of inhomogeneity.…”

Instalação e calibração do sistema de spin coating do LDCI

“…Figura 1 Condutividade elétrica em materiais orgânicos e inorgânicos. [9] .................................…”

“…[39] .. Figura 13 Impressão em gravuras, b) impressão em telas e c) impressão a jato. [9] .................... Figura 14 À esquerda, ilustração de um componente anfifílico e, à direita, sua orientação a uma dada interface. [42]…”

“…[7,8] Figura 1 Condutividade elétrica em materiais orgânicos e inorgânicos. [9] Há uma tendência a se tentar aumentar em grandes cifras o emprego de dispositivos eletrônicos feitos com semicondutores orgânicos. Isso ocorre em especial pela disponibilidade e facilidade de se manipular semicondutores orgânicos.…”

“…a menor unidade a ser impressa, de 20 a 100 mm, gerando filmes de 0,1 a centenas de micrômetros. [9] A resolução no caso das técnicas de impressão depende das propriedades da tinta e do substrato utilizados.…”