Preparation method for high-K medium film

Abstract

The invention provides a preparation method for a high-K medium film. Organics on the surface of a sample can be removed and the purity of the surface of a substrate can be improved by adding the step of washing with H2SO4 and H2O2 before adopting a standard RCA washing method. The thickness of an interface layer of the film can be effectively reduced by removing a surface oxide layer by using hydrogen fluoride (HF) again after adopting the standard RCA washing method. A layer of very thin oxynitride passivation layer grows between the high-K medium film and Si by a plasma atomic layer deposition method and the technology of treating the surface of the Si through in-situ O2 and NH3 plasmas. The high-K medium film passivation layer can inhibit the growth of the interface layer. The high-K medium film is grown in a plasma growing way and oxygen plasma post treatment is performed on the high-K medium film in situ so as to reduce oxygen vacancy in the film. The thickness of an interface buffering layer and the roughness of the interface are reduced by the method, element diffusion between the substrate and the film is inhibited, and equivalent grid oxygen thickness is reduced.

Description

technical field [0001] The invention belongs to the technical field of microelectronics and solid electronics, and in particular relates to a preparation method of a high-k dielectric thin film. Background technique [0002] With the continuous development of large-scale integrated circuit technology, the feature size of metal oxide semiconductor field effect transistor (MOSFET), which is the core device of silicon-based integrated circuits, has been continuously shrinking in accordance with Moore's law. However, the thickness of the MOS tube gate dielectric is getting smaller and smaller, and it is close to its limit. When the thickness of the silicon dioxide gate dielectric is below 10nm (the processing limit of silicon material is generally considered to be 10nm line width), there will be problems such as increased tunneling current, pinhole defects, and poor reliability of performance failure. In order to solve these problems, some integrated circuit research and manufa...

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Problems solved by technology

[0006] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a method for preparing a high-k dielectric film, which is used to solve the problems of excessively thick interface layers and high-k dielectric films produced in the prior art when preparing high-k dielectric films. There are too many oxygen vacancies in the medium, which leads to problems such as the thickness of the high-k dielectric film is difficult to meet the standard, the leakage current increases, and the electrical performance decreases.

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