Formation method of transistor

Abstract

The invention provides a formation method of a transistor, which comprises the steps of providing a transistor, forming a pseudo gate structure on the substrate, forming a source region and a drain region in the substrate at two sides of the pseudo gate structure, forming an interlayer dielectric layer, which is flush with the pseudo gate structure, on the substrate, removing the pseudo gate structure and forming an opening from which part of the substrate is exposed, forming a hafnium-based high-dielectric layer at the bottom of the opening so as to act as a gate dielectric layer, carrying out first annealing, wherein an oxygen-containing gas is charged in the process of the first annealing, and carrying out second annealing, wherein hydrogen is charged in the process of the second annealing. In the first annealing, oxygen ions supplement oxygen vacancies in the hafnium-based high-dielectric layer, and the number of traps caused by the oxygen vacancies is reduced; and in the second annealing, hydrogen ions supplement an interface between the gate dielectric layer and the substrate, and the number of traps caused by an interface state defect is reduced, thereby being capable of optimizing the performance of the transistor.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a method for forming a transistor. Background technique [0002] With the rapid development of integrated circuit (abbreviated as IC) manufacturing technology, the size of semiconductor devices is constantly shrinking, which affects the performance of semiconductor devices. [0003] For example: channel length and gate dielectric layer (usually SiO2) in MOS transistors 2 ) thickness is scaled down, resulting in defects such as polysilicon loss, higher gate resistance, and increased leakage current. For this reason some high K (dielectric constant) dielectric materials replace traditional SiO 2 It can effectively reduce gate leakage current, but high-K dielectric materials are not compatible with polysilicon, so most current integrated circuits use metal gate electrodes instead of polysilicon gate electrodes, and achieve good results. [0004] The equivalent oxide thi...

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Problems solved by technology

[0006] However, when a hafnium-based high-K material is used as a gate dielectric material, it is easy to generate defects in the semiconductor device and affect the performance of the semiconductor device.

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