Antireflection film and exposure method
US7655377B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 23, 2006 |
| Grant date | Feb 2, 2010 |
| Priority date | — |
| Expiry date | Mar 19, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70341
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An antireflection film wherein, even where exposure light enters obliquely in a liquid immersion lithography technique, a sufficiently reduced reflectance can be achieved at the interface between a resist layer and a silicon substrate. A two-layer antireflection film is used in exposure by an exposure system having a wavelength of 190 to 195 nm and a numerical aperture of 1.0 or less and formed between the resist layer and the silicon substrate. Where complex refractive indices N1 and N2 and film thicknesses of upper and lower layers of the antireflection film are represented by n1-k1i, n2-k2i and d1, d2, respectively, and a predetermined combination of values of [n10, k10, d10, n20, k20, d20] is selected, n1, k1, d1, n2, k2 and d2 satisfy {(n1-n10)/(n1m-n10)}2+{(k1-k10)/(k1m-k10)}2+{(d1-d10)/(d1m-d10)}2+{(n2-n20)/(n2m-n20)}2+{(k2-k20)/(k2m-k20)}2+{(d2-d20)/(d2m-d20)}2≦1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.