Recent Advances in the Design of Resist Materials for 157 nm Lithography

• Published in: Journal of Photopolymer Science and Technology Vol. 17; no. 4; pp. 621 - 630
• Main Authors: Houlihan, Francis, Sakamuri, Raj, Romano, Andrew, Rentkiewicz, David, Dammel, Ralph, Stephanko, Nickolay, Market, M., Vermeir, U. Mierau Inge, Hohle, Christoph, Conley, Sill, Miller, Daniel, Itani, Toshiro, Shigematus, Masato, Kawaguchi, Etsuo
• Format: Journal Article
• Language: English
• Published: Hiratsuka The Society of Photopolymer Science and Technology(SPST) 01.01.2004; Japan Science and Technology Agency
• Subjects: 157 nm; 193 nm immersion lithography; barrier coat; high transparency; photoacidgenertor; resist
• ISSN: 0914-9244; 1349-6336
• DOI: 10.2494/photopolymer.17.621

Further work is described on a new generation of more transparent, 157 nm resist platforms, which are based upon capping of fluoroalcohol-substituted, transparent perfluorinated resins (TFR) with a tert-butoxycarbonylmethyl (BOCME) moiety. By optimizing both resin structure and loading of photoacid generator and base additive a good compromise can achieved between resolution power, dark erosion resistance, sensitivity and transparency at 157 nm. In this manner, resist systems with a transparency as low as 0.87 AU/micron were designed capable of resolving 55 nm 1:1 features, at a dose of 92 mJ/cm2 using a phase shift mask on a Exitech 157 nm small field mini-stepper. Also, these have been imaged with a larger field tool (DUV30 Micrascan VII) to give 80 nm 1.1.5 L/S features at a dose of 135 mJ/cm2 employing using a Binary mask. A description is also given of our work on 193 nm/immersion lithography. Specifically, the effects of changing resist compoents such as PAG and Base content will be discussed. Also, a description of the utility of a protective base soluble barrier coat will be given.