Ferroelectric mirrorbit-integrated field-programmable memory array for the TCAM, storage, and in-memory computing applications

Abstract

In-memory computing (IMC) on a reconfigurable architecture is the emerging field that performs an application-based resource allocation for computational efficiency and energy optimization. In this work, we propose a ferroelectric MirrorBit-integrated field-programmable reconfigurable memory. We show the conventional 1-Bit ferroelectric field-effect transistor (FeFET), the MirrorBit, and MirrorBit-based ternary content-addressable memory (MCAM or MirrorBit-based TCAM) within the same field-programmable array. Apart from the conventional uniform up and down polarization states, the additional states in the MirrorBit are programed by applying a nonuniform electric field along the transverse direction, which produces a gradient in the polarization and the conduction band energy, thereby creating a total of four states or 2-bit of information. The gradient in the conduction band resembles a Schottky barrier (Schottky diode), whose orientation can be configured by applying an appropriate field. The TCAM operation is demonstrated using the MirrorBit-based diode on the reconfigurable array. The reconfigurable array architecture can switch from AND-type to NOR-type and vice versa. The AND-type array is appropriate for programming the conventional bit and the MirrorBit. The MirrorBit-based Schottky diode in the NOR-array resembles a crossbar structure, which is appropriate for diode-based content-addressable memory (CAM) operation. Our proposed memory system can enable fast write via 1-bit FeFET, the dense data storage capability by Mirrorbit technology, and the fast search capability of the MCAM. Furthermore, the dual-configurable ability enables power, area, and speed optimization making the reconfigurable Fe-Mirrorbit memory a compelling solution for in-memory and associative computing.