| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1671733 | Thin Solid Films | 2008 | 4 Pages |
In this study, the adhesion and interface characteristics of NiCr/Cu metal film on PI film modified by O2 ion beam were investigated. The surface modification of PI film by O2 ion beam enabled a significant decrease of contact angles of water from 68° to 4.4° at an ion dose of 1 × 1018 ions/cm2, which resulted in an increase of surface energy by a factor of two. The XPS (X-ray Photoelectron Spectroscopy) spectrum showed that the functional groups of C–O and CO bonding on PI surface were increased by the interaction between scissored unstable chains and reactive ions. The peel strength between PI and NiCr/Cu metal film increased with an increase of ion dose and the highest peel strength of 0.70 N/mm was obtained at an ion dose of 1 × 1018 ions/cm2. According to the XPS depth profile from NiCr metal layer into modified PI film, the O1s peak was broadened at near-interface region with an increase of depth from NiCr layer, which indicates that the new chemical bonding state was formed. In addition to C–O and CO bonding, the newly formed chemical bonding at the interface between NiCr metal film and PI film was identified as metal-oxide compounds such as NiO, Cr2O3, and Cr–O by XPS curve fitting. Consequently, the improvement of adhesion is primarily attributed to the strong chemical bonding caused by the chemical interaction between NiCr and newly formed functional group by O2 ion beam.
