Defect reduction in non-topcoat resist by selective segregation removal step

Autor: Tomofumi Miyauchi, Yusaku Tanahashi, Takeshi Matsunobe, Takeo Ishibashi, Kosuke Doi, Tomoya Kumagai, Tetsuro Hanawa, Mamoru Terai, Takuya Hagiwara, Atsushi Sawano, Naoki Man, Hirofumi Seki, Teruhiko Kumada, Shinya Hori
Rok vydání: 2009
Předmět:
Zdroj: Advances in Resist Materials and Processing Technology XXVI.
ISSN: 0277-786X
DOI: 10.1117/12.813643
Popis: A non-topcoat (non-TC) resist is a photoresist that contains a hydrophobic additive, which segregates to the surface and forms a layer to minimize surface free energy. The improvement of surface hydrophobicity and the suppression of resist component leaching were confirmed by using this segregation layer. Compared to conventional topcoat process, it is speculated that the use of non-TC resist will reduce the cost of lithographic materials, improve throughput, and will be compatible for the scanning speed improvement of immersion scanners. One issue for the non-TC resist is the possibility of increased defect generation compared to processes using topcoats. It is assumed that the high resist surface hydrophobicity and the developer insolubility of the hydrophobic additive are main factors causing the increase in defect. Therefore, it is important to work out solutions for reducing these defects to realize the non-TC resists. A process of selectively removing the hydrophobic additive between exposure and development process for the purpose of defective reduction of non-TC resist was investigated. Specifically, wet processing was performed to the wafer after exposure using an organic solvent to dissolve the hydrophobic additive. As a result, defect count was reduced to less than 1/1000 with the effective removal of the segregation layer without affecting pattern size. These results prove the effectiveness of the proposed process named 'selective segregation removal (SSR)' treatment in reducing defects for non-TC resists.
Databáze: OpenAIRE