15 March 2006 Early learning on hyper-NA lithography using two-beam immersion interference
Author Affiliations +
Two-beam interference of 193nm laser light can print dense line-space patterns in photoresist, down to a resolution that can only be obtained using hyper-NA scanners, and allows for early learning on hyper-NA imaging and process development. For this purpose, a dedicated two-beam interference immersion printer, operating at 193nm wavelength, was installed in the IMEC cleanroom. The interference printer consistently generates L/S patterns at 130nm, 90nm, and 72nm pitch with exposure latitudes in the 12-26% range (when using TE-polarized light). At these pitches, process and imaging issues have been studied that are of direct interest for hyper-NA lithography. On the imaging side, we discuss the flexibility of the printer towards working with various polarizations. We show how reflection reduction strategies at the high incidence angles of hyper-NA imaging can be tested in the interference printer. On the processing side, we have screened a number of resists at 90nm pitch. A methodology to study static and dynamic leaching was developed. Several liquids with refractive index >1.6 are currently being developed as potential candidates to replace water for optical lithography at 38nm half-pitch. We have used the interference printer at 72nm pitch, with both water and liquids of refractive index 1.65.
© (2006) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Eric Hendrickx, Eric Hendrickx, Maaike Op de Beeck, Maaike Op de Beeck, Roel Gronheid, Roel Gronheid, Janko Versluijs, Janko Versluijs, Lieve Van Look, Lieve Van Look, Monique Ercken, Monique Ercken, Geert Vandenberghe, Geert Vandenberghe, } "Early learning on hyper-NA lithography using two-beam immersion interference", Proc. SPIE 6154, Optical Microlithography XIX, 61541X (15 March 2006); doi: 10.1117/12.659007; https://doi.org/10.1117/12.659007

Back to Top