FeFET-Based Computing-in-Memory Unit Circuit and Its Application.

With the increasing challenges facing silicon complementary metal oxide semiconductor (CMOS) technology, emerging non-volatile memory (NVM) has received extensive attention in overcoming the bottleneck. NVM and computing-in-memory (CiM) architecture are promising in reducing energy and time consumption in data-intensive computation. The HfO2-doped ferroelectric field-effect transistor (FeFET) is one of NVM and has been used in CiM digital circuit design. However, in the implementation of logical functions, different input forms, such as FeFET state and gate voltage, limit the logic cascade and restrict the rapid development of CiM digital circuits. To address this problem, this paper proposes a Vin-Vout CiM unit circuit with the built-in state of FeFET as a bridge. The proposed unit circuit unifies the form of logic inputs and describes the basic structure of FeFET to realize logic functions under the application of gate-source voltage. Based on the proposed unit circuit, basic logic gates are designed and used to realize CiM Full Adder (FA). The simulation results verify the feasibility of FeFET as the core of logic operations and prove the scalability of FeFET-based unit circuit, which is expected to develop more efficient CiM circuits.