Topological insulator nonvolatile memory device and preparation method thereof

Abstract

The invention discloses a topological insulator nonvolatile memory device and a preparation method thereof. The topological insulator nonvolatile memory device includes: a substrate; the buried gate that is formed in the substrate, and the upper surface of the buried gate is flush with the upper surface of the substrate; the ferroelectric material that covers the buried gate; the two-dimensional topological insulator that is formed on the ferroelectric material; the source electrode and the drain electrode that are formed on the substrate and partially cover the two-dimensional topological insulator, where the surface charge density corresponding to the residual polarization of the ferroelectric material is greater than the surface charge density of the two-dimensional topological insulator. The transportation property of surface state carriers of the two-dimensional topological insulator is regulated and controlled by utilizing polarization flipping of the ferroelectric material, and a nonvolatile storage function is realized by utilizing residual polarization of the ferroelectric material.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a topological insulator nonvolatile storage device based on ferroelectric polarization regulation and a preparation method thereof. Background technique [0002] With the continuous development of integrated circuits, high-speed, high-density new electrical access non-volatile memory (NVM) has been recognized as the key to the development of future information technology. Existing NVMs include molecular memory, random access memory, flash memory, and ferroelectric NVM, among which ferroelectric NVM has attracted extensive attention because of its low power consumption, high write-erase speed, and high-endurance performance. However, there are still some obstacles to the commercialization of perovskite ferroelectric NVM, such as low storage density and high integration cost; [0003] Topological insulator (TI) is a material whose body is an insulator (or semiconductor) and...

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Problems solved by technology

However, due to some inherent defects (vacancies, lattice deformation, etc.) in topological insulators, its surface charge density is often very large (10^13), making it difficult to effectively control the surface conduction state by traditional electrical means.

In addition, traditional methods such as SiO 2 、Al 2 o 3 The polarized surface charge density of other dielectric materials under the electric field is very small, and the bulk conduction of TI must be excluded under extremely low temperature conditions to realize the transport and regulation of surface state carriers, which is difficult to achieve at room temperature

Moreover, the polarization charge of traditional dielectric materials is volatile under the action of an electric field, that is, the control of the surface state of the topological insulator will be lost after the external electric field is removed, and the non-volatile storage of the logic state cannot be realized.

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