학술논문

0.5T0.5R—An Ultracompact RRAM Cell Uniquely Enabled by van der Waals Heterostructures
Document Type
Periodical
Source
IEEE Transactions on Electron Devices IEEE Trans. Electron Devices Electron Devices, IEEE Transactions on. 68(4):2033-2040 Apr, 2021
Subject
Components, Circuits, Devices and Systems
Engineered Materials, Dielectrics and Plasmas
Performance evaluation
Neuromorphics
Microprocessors
Computer architecture
Switches
Smart devices
Optical pulse generation
1T1R
2-D-FET
3-D-integration
graphene
h<%2Fitalic>-BN%22">h-BN
in-memory computing
memristor
neural circuit
neuromorphic computing
plasticity
RRAM
smart transistor
switching-energy
switching-speed
synapse
transition metal di-chalcogenide
van der Waals (vdW) materials
WS₂
Language
ISSN
0018-9383
1557-9646
Abstract
Conventional designs of the extensively studied resistive-random access-memory (RRAM) cell involve one transistor and one RRAM—“1T1R,” i.e., two separate devices thereby constraining its integration density. In this work, we overcome this longstanding limitation by experimentally demonstrating a novel memory architecture that combines the 1T and 1R into a single hybrid device by uniquely leveraging both lateral and vertical van der Waals (vdW) heterostructures. This ultracompact device, which can be considered as a “0.5T0.5R” memory cell, reduces the device count by half—the first of its kind in RRAM technology history, and simultaneously allows higher lateral as well as vertical (3-D) integration density w.r.t. the conventional 1T1R architecture. The unique “smart” device that can retain information after power is turned off is structurally designed by utilizing a shared graphene edge-contact and resistively switchable hexagonal boron nitride ( ${h}$ -BN) insulator. Aided by design optimization, record performance (1000), benchmarked against current vdW-material-based RRAM devices, have been achieved by this 0.5T0.5R memory cell. Moreover, the RRAM’s fine tunability with ultrashort pulsewidth, pulse amplitude, and gate voltage, enables synaptic plasticity and makes it an integrated three-terminal RRAM with considerable potential for neuromorphic and in-memory computing applications.