Agency of Industrial Science and Technology

Tokyo Institute of Technology

Ichiro Fujiwara

Hiroshi Funakubo

Atsushi Hori

Takao Shimizu

Takanori Mimura

Kuniyuki Kakushima

Yoshiko Nakamura

Shun-ichiro Ohmi

Joel Molina Reyes

Totaro Goto

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.

Non-volatile ferroelectric storage element and devices comprising them

The invention provides a novel method for the storage and recovery of thel energy by utilizing a medium substance for the storage of heat. The medium substance is a liquid complex of sodium iodide and ammonia, which absorbs heat as latent heat when brought under a reduced partial pressure of ammonia to effect liberation of ammonia and releases the thermal energy as sensible heat when brought under an increased partial pressure of ammonia to absorb ammonia. Different from conventional solid medium substances for storage of heat, the liquid medium proposed is very convenient in handling so that a chemical heat pump with simple structure can be contrived by use of the inventive method.

Method for storage and recovery of thermal energy

Growing community of inventors

Tokyo, Japan

Ichiro Fujiwara