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.