A method for adjusting the threshold of a cmos device and a cmos device

Abstract

The invention belongs to the technical field of a semiconductor and discloses a method for adjusting CMOS device threshold value and a CMOS device. The method comprises the following steps: providing a substrate; depositing a first barrier layer; enabling a first fin and a second fin to have different thickness of first barrier layers; forming a first work function layer in an NMOS region; forming a second work function layer in a PMOS region; and enabling a third fin and a fourth fin to have different thickness of second work function layers. The device comprises the substrate, the first barrier layer, the first work function layer and the second work function layer. The method solves the problems that CMOS device threshold value adjusting process is complex, association parasitic influence occurs easily between NMOS and PMOS, threshold control precision is low, a PMOS metal grid lamination structure is complex and small-size metal gate filling uniformity and threshold control effect are influenced in the prior art, and achieves the technical effects of small threshold modulation association influence between the NMOS and PMOS and simple metal grid lamination structure.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for adjusting the threshold of a CMOS device and a CMOS device. Background technique [0002] The existing method for adjusting the threshold of CMOS devices is: first deposit a barrier layer on the metal gates of NMOS and PMOS, then adjust the thickness of the barrier layer, then first deposit a PMOS work function layer (PMOS WFL), and then change the thickness of the PMOS WFL to adjust the PMOS threshold; The NMOS work function layer (NMOS WFL) is then deposited, and the NMOS WFL adjusts the NMOS threshold in combination with the thickness change of the previous barrier layer. Because the NMOS threshold adjustment process in the existing method needs to be divided into two stages, the threshold adjustment process of the CMOS device is complex, and the associated parasitic influence between the NMOS and the PMOS is easy to occur, and the threshold control accurac...

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Problems solved by technology

[0003] The embodiment of the present application provides a method for adjusting the threshold of a CMOS device and a CMOS device, which solves the problem of the complex threshold adjustment process of CMOS devices in the prior art, the associated parasitic influence between NMOS and PMOS, the low accuracy of threshold control, and the low accuracy of PMOS metals. The gate stack structure is complex, which affects the filling uniformity and threshold control effect of small-sized metal gates

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