Background

Chris Walton is a materials scientist in the Condensed Matter and Materials Division. His areas of expertise are thin film deposition, optical thin films, multilayer thin films, x-ray optics, ultraclean/low-particle film deposition, and multiphysics deposition simulation. Chris joined LLNL in 1998.

Dr. Walton's main project work has involved

• Precision film thickness control – depositing films with custom thickness profiles on curved optics, using programmed motion of the optic across the deposition source.
• Low-defect deposition – depositing multilayer films with very low defect particle counts; detection and characterization of particles using laser light scatter, atomic-force microscopy and scanning electron microscopy, and experiments and simulation to track movement of defect particles during the deposition process.
• Film stress control – experiments and modeling on sources of intrinsic stress in sputtered films.
• Multiphysics modeling of magnetron sputter deposition – simulation of film deposition using established physics models of the 4 main process steps: plasma, ion-target impact, sputtered-atom propagation, and film deposition.

Dr. Walton is co-inventor on 5 US Patents and 3 R&D 100 awards.

Online documents

www.euvlitho.com/2010/Optics-1.pdf 

https://www-eng.llnl.gov/mod_sim/mod_sim_sputter.html 

Ph.D., Materials Science, University of California at Berkeley, 1997

M.S., Materials Science, University of California at Berkeley, 1992

B.S., Materials Science and Engineering, Massachusetts Institute of Technology, 1990

• C. C. Walton, G. Thomas, and J. B. Kortright, "X-ray optical multilayers: Microstructure limits on reflectivity at ultra-short periods," Acta Materialia 46, 3767-3775 (1998).
• C. C. Walton, P. A. Kearney, P. B. Mirkarimi, J. M. Bowers, C. J. Cerjan, A. L. Warrick, K. C. Wilhelmsen, E. R. Fought, C. E. Moore, C. Larson, S. L. Baker, S. C. Burkhart, and S. D. Hector, "Extreme ultraviolet lithography-reflective mask technology," SPIE-Int. Soc. Opt. Eng. Proceedings of the SPIE - The International Society for Optical Engineering 3997, 496-507 (2000).
• C. C. Walton, P. A. Kearney, J. A. Folta, D. L. Sweeney, and P. B. Mirkarimi, "Understanding particle defect transport in an ultra-clean sputter coating process," Proc. SPIE 5037, 470 (2003).
• A. F. Jankowski, Saw, C. K, Walton, C. C. Hayes, J. P. Nilsen, J, "Boron–carbide barrier layers in scandium–silicon multilayers," Thin Solid Films 469-470, 372-376 (2004).
• C. C. Walton, G. H. Gilmer, L. A. Zepeda-Ruiz, M. J. McNenly, J. P. Verboncoeur, S. C. Wilks, and T. W. Barbee, "Virtual Sputter Chamber - Multiphysics Simulation of Magnetron Sputter and Deposition," in EUV Litho Workshop, http://www.euvlitho.com/2010/Optics-1.pdf (2010).