Corrosive agent and corrosion method of HfSiON high-K gate dielectric material

Abstract

The present invention relates to a corrosive agent of an HfSiON high-K gate dielectric material and a corrosion method by using the corrosive agent, which belong to the technical field of integrated circuit manufacture. The corrosive agent comprises 0.19-4.83 percent by weight of hydrofluoric acid. The corrosion method by using the corrosive agent comprises the following steps: forming the HfSiON high-K gate dielectric material on an Si substrate, an Si / SiO2 interface layer or Si / SiON interface layer, and soaking the HfSiON high-K gate dielectric material in the corrosive agent for wet method corrosion. The corrosive agent is used for carrying out corrosion on the HfSiON high-K gate dielectric material and can reduce the hydrolysis of the hydrofluoric acid, thereby the corrosion speed of the HfSiON high-K gate dielectric material is improved, the corrosion speed of field oxide region SiO2 can be reduced, and the selection ratio of HfSiON to the field oxide region SiO2 can be further improved.

Description

technical field [0001] The invention relates to an etchant and an etching method using the etchant, in particular to an etchant for a HfSiON high-K gate dielectric material and an etching method using the etchant, belonging to the technical field of integrated circuit manufacturing. Background technique [0002] As the feature size of semiconductor devices enters the 45nm technology node, the leakage current of the silicon dioxide or silicon nitride gate dielectric increases significantly, so it is necessary to introduce a high K (dielectric) with a thicker physical thickness under the same equivalent oxide layer thickness. Electric constant) material to reduce gate leakage and reduce power consumption of the device. Hf-based high-K materials such as HfSiON have become the focus of high-K dielectric research because of their large dielectric constant, large band gap, good thermodynamic stability on Si substrates, and good interface properties. In order to make Hf-based high...

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Problems solved by technology

When dry etching Hf-based high-K materials, although anisotropic etching profiles can be obtained, the dry etching of high-K dielectrics has a negative impact on SiO 2 Or the selection of Si is relatively low, which will cause the consumption of Si in the source and drain regions of the device during the integration process, which will increase the resistance of the device and reduce the driving capability of the device; Therefore, after dry etching, there will be a large amount of etching residues on the sidewall of the etched section and the surface of the device, and it is generally necessary to use a wet method to remove the etching residues

However, when wet etching Hf-based high-K materials, although a high selective ratio etching of Si substrates can be achieved, it takes a long time to completely remove the high-K dielectrics after high-temperature annealing, which will cause field oxidation. A large consumption of layers, which is not conducive to integration

In addition, isotropic wet corrosion is also one of the reasons for limiting its long-term corrosion

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