Application of actinic mask review system for the preparation of HVM EUV lithography with defect free mask

We introduce an extreme ultraviolet lithography (EUVL) mask defect review system (EMDRS) which has been developing in SAMUSNG. It applies a stand-alone high harmonic generation (HHG) EUV source as well as simple EUV optics consisting of a folding mirror and a zoneplate. The EMDRS has been continuously updated and utilized for various applications regarding defect printability in EUVL. One of the main roles of the EMDRS is to verify either mask repair or mask defect avoidance (MDA) by actinic reviews of defect images before and after the process. Using the MDA, small phase defects could be hidden below absorber patterns, but it is very challenging in case of layouts with high density patterns. The EMDRS clearly verify the success of the MDA while conventional SEM could not detect the images. In addition, we emulate images of the sub-resolution assist features (SRAFs) by the EMDRS and compared them with the wafer exposure results.

[1]  Renzo Capelli,et al.  Actinic review of EUV masks: performance data and status of the AIMS EUV System , 2016, SPIE Advanced Lithography.

[2]  Pei-Yang Yan,et al.  EUVL multilayer mask blank defect mitigation for defect-free EUVL mask fabrication , 2012, Advanced Lithography.

[3]  Kenneth A. Goldberg,et al.  Commissioning an EUV mask microscope for lithography generations reaching 8 nm , 2013, Advanced Lithography.

[4]  Ted Liang,et al.  EUV progress toward HVM readiness , 2016, SPIE Advanced Lithography.

[5]  Chang Hee Nam,et al.  Soft x-ray microscope constructed with a PMMA phase-reversal zone plate. , 2009, Optics letters.

[6]  P. Corkum,et al.  Plasma perspective on strong field multiphoton ionization. , 1993, Physical review letters.

[7]  Thomas I. Wallow,et al.  Subresolution assist features in extreme ultraviolet lithography , 2015 .

[8]  E. Anderson,et al.  Electro-optical system for scanning microscopy of extreme ultraviolet masks with a high harmonic generation source. , 2014, Optics express.

[9]  T. Bret,et al.  Repair of natural EUV reticle defects , 2011, Photomask Technology.

[10]  D G Lee,et al.  Wave-front phase measurements of high-order harmonic beams by use of point-diffraction interferometry. , 2003, Optics letters.

[11]  Sungmin Huh,et al.  Printability and inspectability of defects on EUV blank for 2xnm hp HVM application , 2012, Advanced Lithography.

[12]  Takeshi Yamane,et al.  Development of actinic full-field EUV mask blank inspection tool at MIRAI-Selete , 2009, Advanced Lithography.

[13]  T. Bret,et al.  Closing the gap for EUV mask repair , 2012, Advanced Lithography.

[14]  Donald W. Sweeney,et al.  Method for compensation of extreme-ultraviolet multilayer defects , 1999 .