CN-121985559-A - Synaptic device and method of making same

CN121985559ACN 121985559 ACN121985559 ACN 121985559ACN-121985559-A

Abstract

The invention discloses a synaptic device and a preparation method thereof, wherein the synaptic device comprises an insulating substrate; the semiconductor device comprises an insulating substrate, a first electrode layer, a two-dimensional ferroelectric dielectric layer, a two-dimensional semiconductor layer, a second electrode layer and a two-dimensional semiconductor layer, wherein the insulating substrate is arranged on the semiconductor device, the two-dimensional ferroelectric dielectric layer is arranged on a part of the first electrode layer, the two-dimensional semiconductor layer at least covers a part of the two-dimensional ferroelectric dielectric layer, the two-dimensional semiconductor layer covers at least a part of the first electrode layer on one side of the two-dimensional ferroelectric dielectric layer, and the second electrode layer is arranged on the two-dimensional semiconductor layer on the two-dimensional ferroelectric dielectric layer. According to the invention, the first electrode layer and the second electrode layer are respectively arranged below and above the two-dimensional ferroelectric dielectric layer, so that depolarization fields in the two-dimensional ferroelectric dielectric layer can be effectively inhibited, and ferroelectric polarization retentivity of the two-dimensional ferroelectric dielectric layer is remarkably improved, thereby effectively improving performance of a synaptic device.

Inventors

TIAN ZIHUA
WANG XIAOWEI
ZHANG TING
SUN FUQIN
GUAN KEJIE
Pi Xiaoshuang
LIU FAN
XU JUN
GUO CHENFEI

Assignees

中国科学院苏州纳米技术与纳米仿生研究所

Dates

Publication Date: 20260505
Application Date: 20260121

Claims (10)

1. A synaptic device, the synaptic device comprising: An insulating substrate; A first electrode layer on the insulating substrate; a two-dimensional ferroelectric layer on a portion of the first electrode layer; a two-dimensional semiconductor layer which covers at least part of the two-dimensional ferroelectric medium layer and at least part of the first electrode layer on one side of the two-dimensional ferroelectric medium layer; and a second electrode layer on the two-dimensional semiconductor layer on the two-dimensional ferroelectric layer.
2. The synaptic device of claim 1, wherein the two-dimensional semiconductor layer covers a sidewall of the two-dimensional ferroelectric layer.
3. The synaptic device of claim 1, wherein the two-dimensional ferroelectric layer is formed with an oxide layer on a surface thereof.
4. The synaptic device of claim 1, wherein the material of the two-dimensional ferroelectric layer is any one of indium selenide or copper indium phosphide.
5. The synaptic device of claim 1, wherein the material of the two-dimensional semiconductor layer is any one of molybdenum disulphide, tungsten diselenide or molybdenum ditelluride.
6. The synaptic device of claim 1, wherein the first electrode layer is any one of a graphene layer, a gold metal layer, a platinum metal layer or a titanium nitride layer.
7. The synaptic device of claim 1, wherein the insulating substrate comprises a silicon substrate and a silicon oxide layer on the silicon substrate, or, The insulating substrate is a sapphire substrate.
8. A method of manufacturing a synaptic device, the method comprising the steps of: providing an insulating substrate; Preparing a first electrode layer on an insulating substrate; Preparing a two-dimensional ferroelectric medium layer on part of the first electrode layer; Preparing a two-dimensional semiconductor layer which at least covers part of the two-dimensional ferroelectric medium layer and at least covers part of the first electrode layer on one side of the two-dimensional ferroelectric medium layer; A second electrode layer is prepared on the two-dimensional semiconductor layer on the two-dimensional ferroelectric dielectric layer.
9. The method of fabricating a synaptic device of claim 8, wherein fabricating a two-dimensional ferroelectric layer on a portion of the first electrode layer comprises: Obtaining a two-dimensional ferroelectric medium layer by using a mechanical stripping method; the two-dimensional ferroelectric layer is transferred onto the first electrode layer.
10. The method of manufacturing a synaptic device of claim 9, further comprising, prior to the step of transferring the two-dimensional ferroelectric layer onto the first electrode layer: and oxidizing the two-dimensional ferroelectric dielectric layer to form an oxide layer on the surface of the two-dimensional ferroelectric dielectric layer.

Description

Synaptic device and method of making same Technical Field The invention belongs to the technical field of semiconductor devices, and particularly relates to a synaptic device and a preparation method thereof. Background With the rapid growth of artificial intelligence and high performance computing demands, traditional computing systems based on von neumann architecture face bottlenecks due to "memory separation". In a traditional computing system, frequent data transmission between a memory and a processor can cause energy consumption overhead, delay accumulation and bandwidth limitation, so that the existing system is difficult to meet the requirement of large-scale real-time computing. Therefore, constructing a memory device capable of simultaneously bearing both information storage and information processing functions has become a key technological path for future development of computing architectures. Among the many novel memory materials, ferroelectric materials are considered to be ideal candidates for weight storage in brain-like computation because of their ability to retain their spontaneous polarization for long periods of time without an applied electric field, and their naturally nonvolatile character. Ferroelectric polarization state can be mapped into synaptic conductivity state directly, and polarization part can be turned over to realize multi-stage regulation of conductivity, so that it is very in line with the physical mechanism of simulating weight plasticity in synapse. However, conventional ferroelectric materials (e.g., PZT, hfO 2 -based ferroelectric thin films) often need to be in direct contact with semiconductor or insulating materials when actually applied to a synaptic device, and these materials lack sufficient free carriers to effectively compensate for the bound charge generated by polarization of the ferroelectric layer. In the absence of compensation charges, a reverse depolarizing electric field is formed inside the ferroelectric layer, which counteracts the spontaneous polarization, causing the ferroelectric polarization to decay over time and even disappear completely. This phenomenon results in ferroelectric materials that are difficult to maintain stable polarization, and their nonvolatile storage capacity is greatly reduced, which cannot meet the requirement for long-term weight retention in brain-like computation. As device dimensions shrink, depolarization effects will become more pronounced as ferroelectric layer thickness decreases to nanometer scale. In the absence of a high quality interface matching layer, the polarization of the ferroelectric dielectric layer is not only difficult to maintain stably, but also difficult to achieve continuous and controllable conductance regulation, limiting its application in neuromorphic synaptic devices. In contrast, two-dimensional ferroelectric materials (such as In 2Se3、CuInP2S6 and the like) provide important opportunities for constructing novel ferroelectric synaptic devices due to their excellent characteristics of atomic-scale thickness, van der Waals contact, no dangling bond structure, and stable polarization at room temperature. The polarization of the two-dimensional ferroelectric material can be finely regulated under extremely low voltage, and the spontaneous polarization of the two-dimensional ferroelectric material can directly form a high-quality van der Waals interface with the two-dimensional semiconductor, so that the depolarization effect can be inhibited and the polarization retention property can be enhanced. Although two-dimensional ferroelectric materials provide a new platform for brain-like computation, how to suppress depolarization fields and realize high-performance nonvolatile synaptic devices has yet to be developed. Accordingly, in view of the above-described problems, there is a need for a synaptic device and a method for making the same. Disclosure of Invention The invention aims to provide a synaptic device and a preparation method thereof, which can effectively inhibit depolarization field in a two-dimensional ferroelectric medium layer to obtain a high-performance synaptic device. In order to achieve the above object, an embodiment of the present invention provides the following technical solution: A synaptic device, the synaptic device comprising: An insulating substrate; A first electrode layer on the insulating substrate; a two-dimensional ferroelectric layer on a portion of the first electrode layer; a two-dimensional semiconductor layer which covers at least part of the two-dimensional ferroelectric medium layer and at least part of the first electrode layer on one side of the two-dimensional ferroelectric medium layer; and a second electrode layer on the two-dimensional semiconductor layer on the two-dimensional ferroelectric layer. In one embodiment, the two-dimensional semiconductor layer covers sidewalls of the two-dimensional ferroelectric layer. In one embodiment, an oxide laye