We have developed two types of fiducial marks (FMs) which are going to be used for defect mitigation process of EUV masks. Those FMs were prepared either on substrate by conventional lithography process or on multilayer (ML) by focused ion beam (FIB). The position accuracy of those FMs was evaluated in advanced electron beam writer, and the FMs prepared on ML showed excellent position repeatability of less than 2nm in 3sigma. Teron 610 blank inspection showed good position repeatability of defects lower than 100nm in maximum. We have developed FIB process for preparing FMs, which gives no defect adder being larger than 70nm. Thus, the fiducial mark process on ML by FIB would be preferable, and will be developed further.

Date Published: 13 March 2012
PDF: 7 pages
Proc. SPIE 8322, Extreme Ultraviolet (EUV) Lithography III, 832226 (13 March 2012); doi: 10.1117/12.919745

Published in SPIE Proceedings Vol. 8322:
Extreme Ultraviolet (EUV) Lithography III
Patrick P. Naulleau; Obert R. Wood II, Editor(s)