Title :
Simulation of light scatter from defects in EUV mask blanks
Author :
Ito, M. ; Ogawa, T. ; Nishiyama, I. ; Okazaki, S.
Author_Institution :
EUV Lithography Lab., Assoc. of Super-Advanced Electron. Technol., Atsugi, Japan
fDate :
Oct. 31 2001-Nov. 2 2001
Abstract :
Using light scatter simulations, we have predicted the PSL-equivalent sensitivity needed for mask blank inspection. The simulation procedure has two steps. First, the electromagnetic field scattered off a feature is calculated by solving Maxwell´s equations with a time-domain finite-element method. Then, the resultant near field is extrapolated to the far field using the Kirchhoff diffraction formula. We performed two-dimensional simulations at a wavelength of 488 nm (Ar laser). The mask blank is illuminated by an s-polarized plane wave at normal incidence. We also discuss the angular distribution of scattered intensity, as well as the effects of incident angle and wavelength on light scattering.
Keywords :
Maxwell equations; finite element analysis; inspection; light scattering; masks; semiconductor process modelling; time-domain analysis; ultraviolet lithography; 488 nm; Ar laser; EUV mask blanks; Kirchhoff diffraction formula; Maxwell equations; PSL-equivalent sensitivity; defects; electromagnetic field scattering; incident angle; light scatter simulations; mask blank inspection; near field extrapolation; s-polarized plane wave; scattered intensity angular distribution; time-domain finite-element method; two-dimensional simulations; Argon; Electromagnetic diffraction; Electromagnetic fields; Electromagnetic scattering; Finite element methods; Inspection; Light scattering; Maxwell equations; Predictive models; Time domain analysis;
Conference_Titel :
Microprocesses and Nanotechnology Conference, 2001 International
Conference_Location :
Shimane, Japan
Print_ISBN :
4-89114-017-8
DOI :
10.1109/IMNC.2001.984093