Karl Franzens University Graz | Graz University of Technology | |
Optical and EUV Lithography: Enablers of continued semiconductor scaling The size of the smallest features on nanoelectronics circuits is governed by the Abbe-Rayleigh criterion k1 lambda / NA, where lambda stands for the wavelength of the used light, NA is the numerical aperture and k1 is a technology-dependent factor. We briefly discuss the consequences of this criterion for the development of semiconductor lithography over the past decades. DUV immersion lithography with wavelength of 193 nm and NA of 1.35 has enabled the fabrication of features sizes below 50 nm. Optical- and material-driven resolution enhancements including off-axis illumination, optical proximity correction (OPC), phase shift masks, source-mask optimization (SMO) and double patterning enable the required k1 values below 0.4. |