Notched Anchor Design for Low Voltage Operation of Nanoelectromechanical (NEM) Memory Switches

Because nanoelectromechanical (NEM) memory switches generally have higher pull-in voltage (V_PI) and lower reliability than CMOS devices, reducing V_PI and maximum stress (σ_MAX) of NEM memory switches have been critical issues for the implementation of monolithic-3D (M3D) CMOS-NEM hybrid reconfigurable logic (RL) circuits. In this paper, a novel notched anchor design is proposed to reduce the V_PI and σ_MAX of NEM memory switches. Moreover, the novel design has an advantage in terms of chip density over the conventional design under the same V_PI condition. In the case of our proposed NEM memory switches, their anchors are placed in the vias of metal interconnection layers. Thus, even if notched patterns are formed on the anchors, it will be helpful to effectively increase beam length, which eventually lowers V_PI and σ_MAX. In this manuscript, the proposed notched anchor design has been confirmed by finite-element-method (FEM) simulation. According to the simulation results, the proposed notched anchor design lowers V_PI by ~23% and σ_MAX by ~24%.