Introduction of 3D AND-type Flash Memory and It’s Applications to Computing-in-Memory (CIM)

Abstract

In this paper, we will first introduce the recently developed 3D AND-type Flash memory [1]- [3] for 3D NOR Flash and CIM solutions. 3D AND inherits the processing advantages of 3D NAND Flash that can produce hundreds of layers eventually, while the memory transistors are connected in parallel to enable much larger sensing current (>6uA) for fast read like NOR Flash (contrary to the slow-read of NAND Flash). Good device performances in endurance and retention are demonstrated. In addition to the NOR Flash applications, 3D AND has potential to provide CIM solutions. The major device advantages of 3D AND for CIM are: (1) 3D high-density CIM enhances the TOP/s/mm2 performances; (2) Large transistor Ion/Ioff ratio > 4 orders; (3) Flexible and tunable Icell ranging from 150nA to 1.5uA, with tight distribution (<2%); (4) Read-disturb free; and (5) Small random telegraph noise. These advantages of 3D AND CIM can help to construct an inference accelerator to support a heavy-weight deep neural network and save data (weight) movement in computing.