Oxidation behaviour of thin silver films deposited on plastic web characterized by spectroscopic ellipsometry (SE)

Silver layers were deposited on plastic web by DC magnetron sputtering using different additional oxygen inlet. Single Ag layers sputtered at an oxygen inlet below 14 sccm, which amounts to 12.3% (Ar: 100 sccm) of the whole gas flow, exhibited no noticeable change in optical properties. At 112 sccm O-2 the synthesis of Ag2O is reached. At higher flow, a semi transparent coating was formed, which is assumed to be AgO. The dispersions for synthesized single AgO fit the resulting oxide layer, grown by a subsequent oxygen rich plasma process, very well. The modeling of plasma oxidation of silver showed, that the formation of the AgO phase is not the only reason for the degradation of silver containing layer stacks. Beside that agglomeration of silver takes place, intrinsic stresses (caused by the oxidation) resulting in partial delaminations and a dramatic increased roughness occurs. (C) 2003 Elsevier B.V. All rights reserved.