Advances in Optics and Exposure Devices Employed in Excimer Laser/EUV Lithography

Abstract

Semiconductor lithography currently provides a resolution close to 10 nm, with the aim of producing extremely fine patterning. Over the last decade, lithography techniques have progressed from ArF immersion to multiple patterning to extreme ultraviolet lithography (EUVL) operating at a wavelength of 13.5 nm. During this period, the first-generation lithography devices were immersion systems and achieved 40 nm resolution through a 1.35 numerical aperture (NA) projection lens in conjunction with an ArF laser (operating at 193 nm) and water immersion. To make full use of the capability of the projection lens, A. Suzuki (*) Head quarter, AS Lithography Consulting

Sensitivity improvement of fluoroalkylated EUV resist with electron-rich vinyl units

“…1,2 EUV photons possess significantly higher energy, approximately 14 times that of ArF excimer laser (193 nm) photons. 3,4 Consequently, when the EUVL process is conducted with the same exposure dose as ArF lithography, only a small fraction of photons, equivalent to 1/14 of ArF lithography, is put into the process. This characteristic induces a photon shot-noise effect, resulting in increased roughness of formed patterns (line edge roughness, LER).…”