Polycrystalline-ferroelectric-film-based ferroelectric resistive random access memory

Abstract

The invention relates to a polycrystalline-ferroelectric-film-based ferroelectric resistive random access memory. Defect regulation and control layers are contained between a lower electrode layer and a polycrystalline ferroelectric film layer and/or between the polycrystalline ferroelectric film layer and an upper electrode layer. The relative dielectric constant of material of the defect regulation and control layers is no smaller than 5 and no larger than the relative dielectric constant of ferroelectric material, the thickness of each defect regulation and control layer ranges from 1 nm to 20 nm, and the ratio of the thickness of each defect regulation and control layer to the thickness of the polycrystalline ferroelectric film layer ranges from 0.001 to 0.2. The energy band gap of the material of the defect regulation and control layers is larger than 3eV, and the lattice mismatch of the material of the defect regulation and control layers with the polycrystalline ferroelectric film is smaller than 0.1. Because the defect regulation and control layers are implanted between the lower electrode layer and the polycrystalline ferroelectric film layer and/or between the polycrystalline ferroelectric film layer and the upper electrode layer, defects in the memory unit and the control difficulty of the defects are reduced, unfavorable influences of the defects on the resistance random access behavior are reduced, and thus the data retentivity and the anti-fatigue property of the memory are remarkably improved, the high-low resistance ratio of the memory is remarkably increased, and data volatility is reduced.

Description

technical field [0001] The invention belongs to the technical field of information storage, and in particular relates to a polycrystalline ferroelectric film-based ferro-resistance variable memory. Background technique [0002] Non-volatile memory is a memory that can retain information even when power is off. It is widely used in portable electronic devices and occupies an increasing share in the entire memory market. At present, the main representative of non-volatile memory in the market is still flash memory (Flash). However, the operating voltage, reading and writing time, anti-fatigue characteristics, and storage density of Flash are approaching their physical limits. Therefore, the development of a new type of non-volatile memory with superior performance has attracted the attention of researchers. [0003] The ferroelectric resistance variable memory based on ferroelectric thin film has a unit structure of "electrode / ferroelectric thin film / electrode", which has th...

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Problems solved by technology

[0004] However, there are a large number of grain boundary defects and oxygen defects in the polycrystalline ferroelectric film, and there are interface defects between the polycrystalline ferroelectric film and the electrode layer, and these defects are difficult to control, and the drift and diffusion of defects will cause the data retention of the memory. Insufficient reliability such as anti-fatigue, relatively small switch resistance, and large data fluctuations

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