Design And Electronic-Mechanical Analysis For The Array-Actuator RF MEMS Switch

RF MEMS switches can offer a higher performance than the traditional solid-state switches. Compared to pin or field-effect transistor diode switches, it has a much smaller volume, a lower insertion, a higher isolation, and can be operation with a nearly-zero power consumption. So RF MEMS has been as an area which has potential to provide a major impact on existing RF architectures in wireless connection and satellite communications systems.In this research thesis, we devote our attentions to the main failure cause: the charging-effect in insulating layer of the RF capacitive switches, which could stick the moveable cantilever (or bridge) to the SiN insulating layer for ever, or could shield the static-electronic pull-down force. We have improved the whole switch to prolong its life in two ways: the material optimization and structural optimization.In optimization for the SiN insulating layer, we establish a sandwich structure which can be called MIS (metal-insulating layer-silicon substrate) structure. We use it to simulate MIM (metal actuation pad- insulating layer-metal cantilever) structure of the real switch clinging together by electric field at down-state. The electron charging will happen in this position. By crossing in C-V testing for the MIS structure, we have known the charging degree of the SiN insulating layer which is provided in our research center. And then, we have influence the charging degree of the original SiN later by annealing technique and B, P ion injection technique. It has improved that it's feasible to prolong the switch life by changing the charging effect in insulating layer.At another hand, in structural optimization, we have given a new structure design theory is to "make the actuation pad (including the insulating layer which is on the top of it) can't contact with the movable cantilever (or bridge), and the touch parts isn't in a high electric field". And we have designed a switch model which has a pair of array actuation pads. In same time, we have given the processing techniques for the new actuation pads. We have also demarcated the dimension for every part of the model. In the end, we use ANSYS finite analytics software to give this switch model an electronic- mechanical coupled simulation. As the simulation result it can be see, the "array-actuator" RF MEMS switch can not only realize the "contactless" theory, but also has the suitable operation voltage, high resonate frequency and short switching time.