公开(公告)号：US20230012093A1

公开(公告)日：2023-01-12

申请号：US17781803

申请日：2020-12-04

Applicant: Tokyo Institute of Technology

Inventor： Kuniyuki KAKUSHIMA ,  Hiroshi FUNAKUBO ,  Shun-ichiro OHMI ,  Joel MOLINA REYES ,  Ichiro FUJIWARA ,  Atsushi HORI ,  Takao SHIMIZU ,  Yoshiko NAKAMURA ,  Takanori MIMURA

IPC: H01L27/11502 ,  H01L27/11585 ,  H01L27/11 ,  G11C11/22 ,  H01L27/11524

Abstract: The invention provides a non-volatile storage element and non-volatile storage device employing a ferroelectric material with low power consumption, excellent high reliability, and especially write/erase endurance, which can be mixed with advanced CMOS logic. The non-volatile storage element has at least a first conductive layer, a second conductive layer, and a ferroelectric layer composed of a metal oxide between both conductive layers, with a buffer layer having oxygen ion conductivity situated between the ferroelectric layer and the first conductive layer and/or second conductive layer. An interface layer composed of a single-layer film or a multilayer film may be also provided between the first conductive layer and the ferroelectric layer, the interface layer as a whole having higher dielectric constant than silicon oxide, and when the buffer layer is present between the first conductive layer and the ferroelectric layer, the interface layer is situated between the first conductive layer and the buffer layer. The non-volatile storage device comprises at least a memory cell array comprising low-power-consumption ferroelectric memory elements formed in a two-dimensional or three-dimensional configuration, and a control circuit. The ferroelectric layer is scalable to 10 nm or smaller and is fabricated at a low temperature of ≤400° C., and is subjected to low temperature thermal annealing treatment at ≤400° C. after the buffer layer has been formed, to provide high reliability.

公开(公告)号：US20220178012A1

公开(公告)日：2022-06-09

申请号：US17606440

申请日：2020-04-27

Applicant: Tokyo Institute of Technology

Inventor： Hiroshi FUNAKUBO ,  Takao SHIMIZU ,  Takanori MIMURA ,  Yoshiko NAKAMURA ,  Reijiro SHIMURA ,  Yu-ki TASHIRO

IPC: C23C14/08 ,  C23C14/58 ,  C23C14/34 ,  C01G27/02 ,  C01G27/00 ,  H01L41/18 ,  H01L41/317

Abstract: Provided is a method for forming a ferroelectric film of a metal oxide having a fluorite-type structure at a low temperature of lower than 300° C., and a ferroelectric film obtained at a low temperature. The present invention provides a production method of a ferroelectric film comprising a crystalline metal oxide having a fluorite-type structure of an orthorhombic crystal phase, which comprises using a film sputtering method comprising sputtering a target at a substrate temperature of lower than 300° C., to deposit on the substrate a film of a metal oxide which is capable of having a fluorite-type structure of an orthorhombic crystal phase, and having a subsequent thermal history of said film of lower than 300° C.; or applying an electric field to said film after said deposition or after said thermal history of lower than 300° C. Also provided are the ferroelectric film, which is formed on an organic substrate, glass, or metal substrate, which can be used only at low temperatures, and a ferroelectric element and a ferroelectric functional element or device using the ferroelectric film.