Rigorous Simulation of Line-Defects in Extreme UV Masks

Patrick Schiavone (1) , Renaud Payerne (1)

1 LTM - Laboratoire des technologies de la microélectronique

In this study, rigorous electromagnetic simulation is used to investigate the behavior of line defects in extreme UV (EUV) masks. Using the modal method by Fourier expansion (MMFE), the geometry of the structure as well as the polarization state can be handled. A simple analytical model has been developed in order to generate the input geometry for the simulations. The deposition conditions can be mimicked by changing an empirical parameter representing the planarization properties of the process. The influence of the defect size and of its position in the multilayer mirror is analyzed. The position of the defect with respect to an absorber feature is very important and is also considered. It is shown that the size of the nucleation particle by itself is not a relevant parameter to describe a defect. The process conditions greatly modify the propagation of the defect into the multilayer mirror and induce a very large variation in its printability. Some defects that do not affect the surface of the mirror can induce a nonnegligible intensity drop.

Mots clés: EUV lithography; mask; multilayer; defect; simulation; rigorous electromagnetic model

Domaines: Micro et nanotechnologies/Microélectronique

Patrick Schiavone, Renaud Payerne. Rigorous Simulation of Line-Defects in Extreme UV Masks. Japanese Journal of Applied Physics, 2005, Vol. 44 (9A), pp.6810-6816. ⟨10.1143/JJAP.44.6810⟩. ⟨hal-00020640⟩