NAND ferroelectric storage unit with three-dimensional structure and preparation method thereof

Abstract

Provided are a NAND ferroelectric storage unit with a three-dimensional structure and a preparation method thereof. The ferroelectric storage unit comprises an oxide insulating layer, a channel layer,a channel buffer layer, a ferroelectric layer, a gate buffer layer and a gate which are sequentially arranged from inside to outside; a channel buffer layer is arranged between the channel layer andthe ferroelectric layer; and / or a gate buffer layer is arranged between the ferroelectric layer and the gate. According to the storage unit, the buffer layer has the following effects: 1, the ferroelectric film can be induced to crystallize to generate a ferroelectric phase; 2, adverse effects caused by different crystallization characteristics of the channel layer and the ferroelectric layer during unified annealing crystallization can be reduced, and the quality and the uniformity of a deposited film are improved; and 3, the buffer layer can improve the interface performance of the channel layer, reduce the leakage current and improve the anti-fatigue performance of the device. Therefore, the buffer layer can integrally improve the storage performance and uniformity of the storage unit in the three-dimensional structure, increase the storage window of the storage unit, improve the fatigue performance of the storage unit and improve the uniformity of the storage performance of a plurality of transistors.

Description

technical field [0001] The invention relates to the technical field of designing semiconductor memory and integration, in particular to a three-dimensional structure NAND ferroelectric memory unit and a preparation method thereof. Background technique [0002] The new hafnium oxide-based ferroelectric field-effect transistor (FeFET) is a new type of non-volatile memory that uses two polarization states of hafnium oxide-based ferroelectric materials to realize channel regulation. Compared with other traditional ferroelectric materials, such as PZT and SBT, hafnium oxide materials have CMOS process compatibility, high-K characteristics and higher integration. Since it was reported in 2011 that ferroelectricity was found in hafnium oxide-based materials, organizations and units in many countries have successively entered into this research work. However, the currently prepared devices are mainly planar structures, and hafnium oxide-based FeFETs with three-dimensional structure...

AI Technical Summary

Problems solved by technology

Another problem is that a major shortcoming of current devices is their fatigue performance ≤10 5 Cycling, the current mainstream view is that there is an interface layer degradation problem at the interface between the channel and the ferroelectric material under the cyclic electric field

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