Device Design Guideline for HfO2-Based Ferroelectric-Gated Nanoelectromechanical System

Previous studies have suggested that the operating voltage and energy-delay properties of a nanoelectromechanical (NEM) system can be improved using the negative capacitance (NC) effect of ferroelectric materials. However, the advantages of using the NC effects alone have been utilized for perovskite ferroelectric materials, which is incompatible in complementary metal-oxide-semiconductor (CMOS) fabrication processes. In this work, a CMOS-compatible HfO2-based ferroelectric material is used for the NC + NEM system. The effects of the ferroelectric properties [i.e., remnant polarization (P-r) and coercive field (E-c)] on the NC + NEM system performance are studied in detail. The results show that the NC + NEM system can operate as a relay or a memory device depending on the P-r and E-c values. Moreover, the pull-in/out voltages of the NC + NEM system are more sensitively affected by E-c rather than P-r and decrease as E-c increases. The device design guideline with appropriate P-r and E-c values of the HfO2-based ferroelectric material is thus developed and discussed to improve the electrical characteristics of NC + NEM relay/memory devices.