Preparation of copper rhodium coatings

This invention provides a method for preparing copper–rhodium coatings. The method includes the following steps: (a) providing a vacuum sputtering system and a substrate; (b) introducing argon gas into the vacuum sputtering system to form a sputtering environment; (c) using copper and rhodium targets in the sputtering environment under a sputtering pressure of 1×10-3 to 1×10-2 torr and sputtering power of 150 to 200 W to perform a total sputtering step, thereby forming a coating on the substrate; and (d) annealing this coating to obtain the final copper–rhodium coating. The annealing temperature is between 340 and 700 °C, and the annealing time is greater than or equal to 1 h. Furthermore, depending on the total number of atoms in the copper–rhodium plating layer, the rhodium content ranges from 0.2 to 1.5 at%. Copper–rhodium plating layers prepared by the aforementioned method possess low resistivity and high stability.