Characteristic of CuMn Alloy Films Prepared by Using Electrochemical Deposition

Abstract

Abstract Copper-manganese (Cu-Mn) alloys are usually used in resistance materials with a low resistance and low temperature coefficient of resistance (TCR). However, current research and development has been mainly focused on thin film materials deposited by the sputtering method, which is also by the cost due to its vacuum equipment. In the study, three kinds of electrochemical deposition methods were used to prepare a Cu-Mn-Cu switch structure. Firstly, we prepared the Al thick film as the sacrificial layer by screen printing on the Al2O3 substrate, and then transformed the Al thick film into the Cu thick film by the chemical oxidation-reduction replacement reaction at 80°C for 75 minutes. Secondly, the electroplating method was used to deposit Mn on the as-replaced Cu film. Based on the results of the SEM and XRD, it could be seen that a high quality and desired Cu-Mn 9:1 ratio could be obtained by depositing at 1.6V for 10 minutes. Finally, the top Cu layer was coated on the surface again by electroless plating to complete the sandwich structure of the Cu-Mn-Cu. Sequentially, annealing under normal pressure in reducing the atmosphere was done to make the Cu and Mn interdiffusion into the alloy phase. Both the XPS and Raman confirmed that annealing in a nitrogen-hydrogen atmosphere could extremely reduce the possibility of manganese oxidation and showed promising electrical properties such as a low temperature coefficient of resistance at 900℃ (150 ppm).