Cycling reliability of RF-MEMS switches with gold-platinum multilayers as contact material

Low contact resistance and high cycling reliability are two important parameters for evaluating the quality of RF micro-electromechanical (RF-MEMS) switches. In this paper the use of a modified contact material is tested and compared to pure gold in cycling experiments performed on a RF MEMS switch in shunt capacitive configuration. The modified contact material is a gold-based multilayer with a thin layer of platinum sandwiched between two layers of gold. The experiment consists in comparing devices with the same layout but with different contact material. While the two types of switch start with similar RF performances, the device with the modified material shows a marked improvement in cycling stability and a lower series resistance up to 10⁶ cycles when compared to gold contact devices.