Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Extreme ultraviolet lithography using a laser plasma source and multilayer optics

Extreme ultraviolet (EUV) lithography offers considerable potential as a method to image ultra-fine structures with dimensions well below 100 nm. In this method short wavelength radiation in the 5 to 20 nm interval is employed to produce diffraction-limited images by special EUV optical systems. Before this technique can be utilized in, for example, semiconductor fabrication, vigorous development of fundamental physical processes is required. This project concerns combining the source with a high-transmission system of curved multilayer EUV mirrors which will enable the demonstration of diffraction limited resolution of below 100 nm.

The main results of the collaboration work are :
development and construction of the comprehensive EUV facility;
optimization of the laser plasma source driven by the LPX350 excimer laser through a selection of targets and target irradiation conditions;
increase of conversion efficiency through application of a new double-pulse technique;
development of several novel techniques for elimination of laser plasma debris, bringing the source performance close to the 109 shots level;
development of electron beam and magnetron sputtering techniques for manufacture of large spherical multilayer mirrors, enabling to approach requirements of the pre-industrial phase;
development of several patterning techniques and manufacture of spherical reflection masks;
analysis of optical features of the projection system;
analysis of temperature stability of multilayer mirrors;
demonstration of applicability of the EUV source and multilayer projection system for fabrication of 0.1-nm scale lithographic structures.