Complementary field effect transistor with double-work function metal gates and manufacturing method thereof

Abstract

The invention relates to a manufacturing method of a complementary field effect transistor with double-work function metal gates. The complementary field effect transistor comprises a first transistor, a second transistor and an isolation structure used for isolating the first transistor and the second transistor. The manufacturing method is characterized by comprising the steps of depositing a gate dielectric layer on a substrate, depositing a first conducting material layer on the gate dielectric layer, forming a second conducting material layer at the position, corresponding to the first transistor, of the first conducting material layer, and forming a third conducting material layer at the position corresponding to the second transistor, wherein the second conducting material layer has a second work function lower than a third work function of the third conducting material layer. In addition, the invention further relates to the complementary field effect transistor with the double-work function metal gates. By means of the technical scheme, the double-work function metal gates can be obtained through the simple process, so that the large saturation current of a CMOS is obtained, and the threshold voltage is reduced.

Description

technical field [0001] The invention relates to the technical field of semiconductors, and more specifically relates to a complementary field effect transistor with a double work function metal gate and a manufacturing method thereof. Background technique [0002] The so-called work function refers to the responsiveness of all conductive materials in the semiconductor to the applied energy, which is usually expressed in electron volts (eV). The work function of a material usually refers to the minimum energy required to just move an electron from the interior of a solid to the surface. Different materials have different Fermi energies and electronic structures, so different amounts of energy need to be applied to remove an electron. [0003] Typically, conventional semiconductor materials have been selectively doped, resulting in N-type or P-type materials. N-type semiconductor materials have a Fermi level closer to the conduction band of silicon than to the valence band o...

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Problems solved by technology

However, the fabrication method of this double-edge work function metal gate is a difficult problem

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