Nano-Scale Surface Morphology Evolution of Cu/Ti Thin Films

This paper discusses solid-phase reaction, agglomeration and dendritic growth of Cu/Ti/Si thin films with different sublayer thickness, 70 nm Cu/20 nm Ti/Si and 20 nm Cu/70 nm Ti/Si, annealed using rapid thermal annealing (RTA) method at the temperature from 500 °C to 800 °C. The crystal structure is examined using XRD, and the surface morphology is measured by SEM and AFM. The sheet resistance is measured using four-point probe method. The dendritic patterns can be obtained in both thin films at high temperature but the density is not similar. For 70 nm Cu/20 nm Ti/Si thin films, Cu agglomerates at the annealed temperature upon to 700 °C and thin film is still crystalline after 800 °C. For 20 nm Cu/70 nm Ti/Si thin films, Cu agglomerated completely only after 500 °C and thin film has amorphous structure annealed after 800 °C.