Effect of surface roughness on electrical conductivity and hardness of silver plated copper

Surface roughness is a quantity that emerges during a deposition process. It has an important role in the physical properties of thin films especially in ultra thin films. To study this effect, we have used pulse electrode- position method to construct different rough silver plated copper surfaces by changing pH and temperature of the bath deposition. By having AFM images and fractal analysis in hand, the dependency of the roughness exponent and the correlation length of surfaces to the pH and temperature parameters are obtained. Optimum electrical conductivity of specimens is acquired in pH = 4.5 and T = 50 °C for DC electrical current, as well as pH = 2 and T = 25 °C for AC electrical current. Furthermore, the nano-indentation technique is utilized to determine nano-mechanical properties of samples including hardness (H) and elasticity modulus (E r ). We consider Oliver-Pharr method to study the effect of roughness on the hardness.