Free-standing spectral purity filters for extreme ultraviolet lithography

Free-standing multilayer films consisting of Si, Zr, Mo and silicides of both metals have been fabricated and studied as spectral purity filters (SPF) for extreme ultraviolet (EUV) (13.5 nm) lithography tools. Comparative tests of multilayer SPF structures of various compositions have been performed at high power loads. It was found that a Mo/ZrSi2 structure with MoSi2 capping layers is featured with capability to withstand prolonged heating in vacuum (10−7  mbar) at 900-950°C. A technique of fabrication of large aperture free-standing multilayers was developed, and a pilot sample of the above film structure of 160 mm in diameter, 50 nm thick, with transparency at 13.5 nm above 70% was fabricated as a conceptual prototype of SPFs with large dimensions.

[1]  A. V. Mitrofanov,et al.  Fabrication of multilayer thin film filters on support screens and their properties , 1989 .

[2]  John M. Davis,et al.  Metalized polyimide filters for x-ray astronomy and other applications , 1997, Optics & Photonics.

[3]  Terry A. Johnson,et al.  Filter windows for EUV lithography , 2001, SPIE Advanced Lithography.

[4]  Charles A. Steinhaus,et al.  Atomic hydrogen cleaning of EUV multilayer optics , 2003, SPIE Advanced Lithography.

[5]  Martin Antoni,et al.  EUV spectral purity filter: optical and mechanical design, grating fabrication, and testing , 2004, SPIE Optics + Photonics.

[6]  M. S. Bibishkin,et al.  Laboratory methods for investigations of multilayer mirrors in extreme ultraviolet and soft x-ray region , 2004, International Conference on Micro- and Nano-Electronics.

[7]  Padraig Dunne,et al.  Optimizing 13.5nm laser-produced tin plasma emission as a function of laser wavelength , 2007 .

[8]  Padraig Dunne,et al.  Angle-resolved absolute out-of-band radiation studies of a tin-based laser-produced plasma source , 2007 .

[9]  Kunioki Mima,et al.  Absolute evaluation of out-of-band radiation from laser-produced tin plasmas for extreme ultraviolet lithography , 2008 .

[10]  Kunioki Mima,et al.  Pure-tin microdroplets irradiated with double laser pulses for efficient and minimum-mass extreme-ultraviolet light source production , 2008 .

[11]  M. S. Bibishkin,et al.  Multilayer Zr/Si filters for EUV lithography and for radiation source metrology , 2008, International Conference on Micro- and Nano-Electronics.

[12]  S. A. van der Westen,et al.  Spectral-purity-enhancing layer for multilayer mirrors. , 2008, Optics letters.

[13]  Mark S. Tillack,et al.  Efficient 13.5nm extreme ultraviolet emission from Sn plasma irradiated by a long CO2 laser pulse , 2008 .

[14]  Maarten M. J. W. van Herpen,et al.  Grid spectral purity filters for suppression of infrared radiation in laser-produced plasma EUV sources , 2009, Advanced Lithography.

[15]  W A Soer,et al.  Extreme ultraviolet multilayer mirror with near-zero IR reflectance. , 2009, Optics letters.

[16]  John Arnold,et al.  EUV lithography at the 22nm technology node , 2010, Advanced Lithography.

[17]  N. I. Chkhalo,et al.  Influence of annealing on the structural and optical properties of thin multilayer EUV filters containing Zr, Mo, and silicides of these metals , 2009, International Conference on Micro- and Nano-Electronics.

[18]  V M Krivtsun,et al.  Infrared suppression by hybrid EUV multilayer--IR etalon structures. , 2011, Optics letters.

[19]  K. Koshelev,et al.  Physical processes in EUV sources for microlithography , 2011 .

[20]  N. I. Chkhalo,et al.  Manufacturing and characterization of diffraction quality normal incidence optics for the XEUV range , 2011, Optics + Optoelectronics.