4525 EUV and in situ Spectroscopic Ellipsometric Analysis of the Oxidation of Uranium Thin Films

 

Heidi Dumais, D.D. Allred, R.S. Turley,

 

Uranium thin films have found a variety of uses: such as EUV mirrors for space application and driver layers on inertial confinement fusion microspheres.  Uranium is chemically active and an unprotected surface oxidizes quickly.  More is known about the oxidation of bulk than thin films.  We have investigated the oxidation of uranium thin films and reactively sputtered uranium oxide films using spectroscopic ellipsometry, electron microscopy and XPS.  We find that uranium magnetron sputtered (1-10 mtorr) in Ar/oxygen forms a UO2 (fcc-structure) over a range of O2 partial pressures. It is reasonably stable in air for several hours. On the other hand, thin uranium films (20nm) left to oxidize in air form a higher oxide, probably U3O8.  This observation may help interpret EUV optical data previously made on uranium films.  

 

AVS 2010:

Actinides and Rare Earths Topical Conference
Room: Isleta - Session AC+TF-MoA
Actinide and Rare Earths Thin Films
Moderator: S.W. Yu, Lawrence Livermore National Laboratory
 

2:00pm AC+TF-MoA1 EUV and in situ Spectroscopic Ellipsometric
Analysis of the Oxidation of Uranium Thin Films, H. Dumais, D.D.
Allred, R.S. Turley, Brigham Young University