Variation of absorption coefficient and determination of critical dose of SU-8 at 365 nm

Journal Article · Mon Jan 09 00:00:00 EST 2006 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.2164390· OSTI ID:20778513

Gaudet, Matthieu; Camart, Jean-Christophe; Buchaillot, Lionel; Arscott, Steve ^[1]

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1. Institut d'Electronique, de Microelectronique et de Nanotechnologie (IEMN), CNRS UMR8520, ISEN Dept., Avenue Poincare, Cite Scientifique, Villeneuve d'Ascq 59652 (France)

The absorption coefficient of thick-films of the negative photoresist SU-8 is observed to be time dependent during photolithographic exposure by I-line ultraviolet light ({lambda}=365 nm); varying linearly from 38{+-}1 cm{sup -1} to 49{+-}1 cm{sup -1} for a surface exposure dose of 415 mJ/cm{sup 2}. We develop a general model which enables the exposure dose to be calculated at a given photoresist depth for a given exposure time. We determine the critical exposure dose for the subsequent polymerization of SU-8 having an arbitrary thickness to be 49.4{+-}3.9 mJ cm{sup -2}.

• OSTI ID: 20778513
• Journal Information: Applied Physics Letters, Vol. 88, Issue 2; Other Information: DOI: 10.1063/1.2164390; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION
DEPTH
FILMS
POLYMERIZATION
POLYMERS
SURFACES
THICKNESS
TIME DEPENDENCE
ULTRAVIOLET RADIATION
VARIATIONS