Work

Ferroelectric HfO2 Tunnel Junction Memory With High TER and Multi-Level Operation Featuring Metal Replacement Process

Year: 2018

Type: article

Abstract: We have investigated device design of HfO2-based ferroelectric tunnel junction (FTJ) memory. Asymmetry of dielectric screening property in top and bottom electrodes is the key for high tunneling electroresistance (TER) ratio. Thus, metal and semiconductor electrodes are proposed. There exists a design space of ferroelectric material parameters to achieve high TER ratio under the constraint of depolarizing field. We have developed an FTJ fabrication process to realize the design. Large polarization charge and symmetric switching voltage are obtained by top metal replacement process. High TER ratio >30 and multi-level cell operation have been successfully demonstrated. Retention characteristics is promising, however, endurance characteristics should be improved for reliable operation.

Source: IEEE Journal of the Electron Devices Society

DOI: 10.1109/jeds.2018.2885932

Authors: Masaharu Kobayashi, Yusaku Tagawa, Fei Mo, Takuya Saraya, Toshiro Hiramoto

Institutions: Institute of Industrial Science, The University of Tokyo, The University of Tokyo

Language: English

Topic: Ferroelectric and Negative Capacitance Devices

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,350

Funder: Precursory Research for Embryonic Science and Technology