Bottom Contact 100 nm Channel-Length α-In₂ Se₃ In-Plane Ferroelectric Memory

Owing to the emerging trend of non-volatile memory and data-centric computing, the demand for more functional materials and efficient device architecture at the nanoscale is becoming stringent. To date, 2D ferroelectrics are cultivated as channel materials in field-effect transistors for their retentive and switchable dipoles and flexibility to be compacted into diverse structures and integration for intensive production. This study demonstrates the in-plane (IP) ferroelectric memory effect of a 100 nm channel-length 2D ferroelectric semiconductor α-In₂ Se₃ stamped onto nanogap electrodes on Si/SiO₂ under a lateral electric field. As α-In₂ Se₃ forms the bottom contact of the nanogap electrodes, a large memory window of 13 V at drain voltage between ±6.5 V and the on/off ratio reaching 10³ can be explained by controlled IP polarization. Furthermore, the memory effect is modulated by the bottom gate voltage of the Si substrate due to the intercorrelation between IP and out-of-plane (OOP) polarization. The non-volatile memory characteristics including stable retention lasting 17 h, and endurance over 1200 cycles suggest a wide range of memory applications utilizing the lateral bottom contact structure.