Influence of Glass Surface Modification on Thin Film Copper Electrodes

We investigate the impact of the glass surface on the structural and electrical properties of Ti/Cu film stacks as well as single Ti adhesion layer, by modifying Corning® Eagle XG® glass surfaces using four acids common in TFT-LCD microfabrication processes. Atomic force microscopy results indicate significant change of the surface topography of Ti and Cu, particularly found on hydrofluoric acid treated glass surfaces. The film microstructures are characterized by a comprehensive analysis using Bragg, grazing incidence and in-plane X-ray diffraction, and X-ray reflectivity methods as well as the transmission electron microscopy. The sheet resistance was measured using the four-point probe method. We demonstrate the role of the glass surface state through its impact on the structural and electrical properties of Ti/Cu electrodes emanating from glass surface treatments.