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; forming a first work function layer in an NMOS region; depositing a second work function layer; enabling different fins in the NMOS and PMOS regions to have different thickness of second work function layers; depositing a third work function layer; and removing the third work function layer on the second and fourth fins. The device comprises the substrate, the first barrier layer, the first work function layer, the second work function layer and the third work function layer. The method solves the problems that the CMOS device threshold value adjusting process is complex, association parasitic influence occurs easily between NMOS and PMOS, threshold control precision is low and a device lamination structure is complex in the prior art, and achieves the technical effects of small threshold modulation association influence between the NMOS and PMOS and simple CMOS device 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: the metal gates of NMOS and PMOS first deposit a barrier layer, then adjust the thickness of the barrier layer, then 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 deposited, and the NMOS WFL adjusts the NMOS threshold in combination with the thickness change of the previous barrier layer. Since the NMOS threshold adjustment process in this method needs to be divided into two stages, the CMOS device threshold adjustment process is complex, and the associated parasitic influence between NMOS and PMOS is easy to occur, which affects the accuracy of threshold control. In addition, the PMOS ...

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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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