Polymorphic coexistence-based phase field analysis method for hafnium oxide-based ferroelectric film

Abstract

The invention discloses a polymorphic coexistence-based phase field analysis method for a hafnium oxide-based ferroelectric film. The method comprises the following steps: determining the number of sequence parameters according to the number of states of the polymorphic coexisting hafnium oxide-based ferroelectric film; determining an energy equation expression and a coefficient of the ferroelectric film based on the sequence parameter, the Ginzburg-Landau theory and the block energy, the elastic energy, the gradient energy and the electrostatic energy of the ferroelectric film; in combinationwith a mechanical equilibrium equation, a Maxwell equation and a Ginzburg-Landau phase field kinetic equation, deducing weak forms of a force field, an electric field and a polarization field, and establishing a hafnium oxide-based ferroelectric film polymorphic coexistence phase field model under force-electricity coupling; and simulating a domain structure and an evolution rule of the polymorphic coexisting hafnium oxide-based ferroelectric film according to the phase field model. The formation and growth process of the domain structure of the HfO2-based ferroelectric film is dynamically simulated, the redistribution of the domain structure under the action of different external fields is researched, guidance is provided for experimenters, and the experiment cost is reduced.

Description

technical field [0001] The invention relates to the technical field of simulation analysis of ferroelectric thin films, in particular to a phase field analysis method based on multi-state coexistence of hafnium oxide-based ferroelectric thin films. Background technique [0002] In the 1T-1C type ferroelectric memory of the traditional perovskite ferroelectric film, the thickness of the ferroelectric film is relatively large, the area of ​​the memory unit is large, and the storage capacity is low, which is difficult to meet the application requirements. While hafnium oxide (Hf0 2 )-based ferroelectric thin film material is a new type of ferroelectric material with high dielectric constant, large coercive field and remanent polarization, which can be combined with advanced CMOS technology (Complementary Metal Oxide Semiconductor, that is, complementary metal oxide Compatible with material semiconductors; at the same time, when the film thickness is less than 10nm, it still ha...

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Problems solved by technology

[0005] Therefore, the phase field model established based on traditional ferroelectric thin films is no longer suitable for analyzing the distribution and evolution of ferroelectric domains in hafnium oxide-based ferroelectric thin films where ferroelectric phases and various non-ferroelectric phases coexist, so traditional phase field theory cannot be used. Model Analysis of the Microscopic Mechanism of Fatigue Failure of Hafnium Oxide-Based Ferroelectric Thin Films

[0006] In addition, in the current phase field method, the coefficient of the bulk energy is obtained by fitting the relationship between the spontaneous polarization of the single crystal and the temperature, while in the current research status, the Hf0 2 It is difficult to prepare a single crystal, so Hf0 cannot be obtained 2 The relationship between the spontaneous polarization and temperature of the base ferroelectric thin film, that is, the relationship between spontaneous polarization and temperature cannot be used to obtain Hf0 2 The bulk energy coefficient of the base ferroelectric thin film, so it is impossible to use the method of the traditional phase field theory model coefficient to obtain Hf0 2 Phase Field Model Coefficients of Base Ferroelectric Thin Film Materials

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