Method for preparing hafnium-oxide-based thin ferroelectric film by using all-inorganic precursor solution and application

Abstract

The invention, which belongs to the technical field of material preparation, discloses a method for preparing a hafnium-oxide-based thin ferroelectric film by using an all-inorganic precursor solutionand application of the film. A hafnium-oxide-based precursor solution doped with different elements is prepared by using inorganic hafnium salt and an inorganic high-symmetry phase stabilizer as rawmaterials; a substrate is cleaned based on a standard RCA process to remove impurity contamination on the surface of the substrate and then the substrate is preprocessed to enhance wettability of thesurface of the substrate; a hafnium-oxide-based thin film is deposited on the surface of the substrate; and then pre-heat treatment and annealing crystallization are carried out on the thin film to realize stability of the high-symmetry quadrature phase, tetragonal phase, cubic phase or other mixed phase at a room temperature, so that the thin film having the initially intrinsic property may generate a ferroelectric property under the field induction. According to the method, the prices of the raw materials are low and thus the cost is lowered; the equipment and operation environment requirements are simple; the types of the doped elements are diversified and thus selection becomes flexible; the ferroelectric property is easy to control; and the industrialized production is realized easily.

Description

technical field [0001] The invention belongs to the field of microelectronic devices, and relates to a preparation method and application of a hafnium dioxide-based ferroelectric thin film. Background technique [0002] With the continuous development of microelectronic integrated circuit products in the direction of high performance and high density, the feature size of the transistor structure is continuously reduced. When the feature size enters the range below 0.1 μm, the traditional silicon dioxide (SiO 2 ) The thickness of the gate dielectric layer is close to the "physical limit" of 2nm, and the direct tunneling effect of electrons leads to a sharp increase in gate leakage current, which makes the device face serious stability and reliability problems. This problem can be solved by replacing SiO with high dielectric constant (high-k) materials 2 It is solved as a gate dielectric layer, and among many high dielectric constant materials, hafnium dioxide (HfO 2 ) thin ...

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Problems solved by technology

In the article "Low-Energy Path to Dense HfO 2 Thin Films with Aqueous Precursor, Chemistry of Materials, 23(4|), 945-952(2011)" reported a method using HfOCl 2 ·8H 2 Precursor solution synthesized by cheap inorganic reagents such as O, followed by spin-coating to prepare undoped HfO 2 The thin film method, the thin film after annealing and crystallization all presents a single low-symmetry monoclinic (m-) phase structure, so it does not have ferroelectric properties

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