Phase Field Simulation on the Surface Morphology of Cu/Ti Nano Thin Film

Abstract

Cu/Ti binary thin film system has many applications for micro-/nano- electro mechanical systems (MEMS/NEMS), micro-electronics and optoelectronics. In nanoscale, the quality and many physical properties of nano thin films are strongly depended on its surface morphology. In the present paper the development of surface morphology of double layered Cu/Ti thin film heterostructure with different composition and thickness has been studied by using the phase field method. The developed method is based on solving Cahn-Hilliard equations of multi-order parameters with considering the interfacial energy and elastic energy. The simulation results show that the thickness of Ti layer and Cu layer in the double-layer thin film structure can affect the surface roughness. For the heterostructures with the Cu layer thickness was fixed at 20 nm, the surface roughness was found to vary from 0.608 nm to 0.712 nm, when the Ti layer thickness increased from 10 nm to 30 nm. The calculated surface morphology and roughness was similar to the experimentally measured values. It is believed that this simulation method is useful in designing multi-layered thin film structure for practical applications.