AVS 47th International Symposium
    Surface Science Wednesday Sessions
       Session SS2-WeM

Paper SS2-WeM5
Super-smooth Neutron Optical Surfaces By Gas Cluster Ion Beam Processing

Wednesday, October 4, 2000, 9:40 am, Room 209

Session: Stimulated Surface Processes
Presenter: L.P. Allen, Epion Corporation
Authors: L. Stelmack, Epion Corporation and Northeastern University
L.P. Allen, Epion Corporation
V. DiFilippo, Epion Corporation and Tufts University
J.A. Greer, Epion Corporation
D.B. Fenner, Epion Corporation
R. Chandonnet, Epion Corporation
J. Hautula, Epion Corporation
A. Kirkpatrick, Epion Corporation
Correspondent: Click to Email
The neutron scattering research community has continuing need for advancing the technology required to produce improved neutron optical components, particularly in regard to increasing efficiency and reducing non-specular scattering from substrate surfaces and coating interfaces. A novel Ar gas cluster ion beam (GCIB) process was implemented in order to determine the effectiveness of the extreme GCIB surface smoothing technique as it applies to improving neutron optical component substrates and coatings. A matrix of GCIB smoothing conditions was applied on selected optical structures. Pre- and post-GCIB processed surfaces of Si, SiO2, Ni/Si, Ta, and Ni/Ta/ SiO2/Si substrates were examined with atomic force microscopy for surface roughness and overall film morphology. Silicon substrate surfaces coated with Ni were found to be consistently smooth to Ra ~1Å. In addition, results show that the Ni and Ta coated surfaces consistently achieved smoothness capable of supporting optical requirements for advanced neutron sources. The GCIB process parameters as applied to optical (SiO2, Ni/S, Al2O3), semiconductor (Si), and metallic (Cu, Ta, Ti, Ni) surfaces are shown to provide a predictable surface smoothness (Ra typically <3Å) for applications in a variety of material related fields.