A kind of formation method of nickel silicide

Abstract

The invention discloses a method for forming nickel silicide. With the application of the stress technology, TiN layers of opposite stresses are applied to an NMOS (N-channel metal oxide semiconductor) and a PMOS (P-channel metal oxide semiconductor) as protection layers of NiPt. In a following nickel silicide forming process, different stresses are recorded through reactions and phase change, and the formed nickel silicide is enabled to apply a pulling stress to a channel of the NMOS and a pressing stress to a channel of the PMOS, so that negative effect caused by introduction of a stress layer is prevented in the metal silicide forming process, and the device performance is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor integrated circuit manufacturing, and more specifically, to a method for forming nickel silicide using stress technology. Background technique [0002] In semiconductor manufacturing technology, metal silicide is widely used in source / drain contacts and gate contacts to reduce contact resistance due to its low resistivity and good adhesion with other materials. Metals with high melting points such as Ti, Co, Ni, etc. can react with silicon to form metal silicides with low resistivity through one-step or multi-step annealing process. With the continuous improvement of the semiconductor process level, especially at the technology node of 45nm and below, in order to obtain lower contact resistance, nickel and nickel alloys (such as NiPt) have become the main materials for forming metal silicides. [0003] As the miniaturization of the feature size of VLSI continues, the size of field effect tr...

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Problems solved by technology

[0006] However, the above-mentioned existing Ni silicide formation process adopts TiN with a single stress to cover NMOS and PMOS as a protective layer of NiPt, and TiN with a single stress (tensile stress or compressive stress) can only be applied to NMOS or PMOS. Contributes to the enhancement of either the electron mobility or the hole mobility of one of the PMOS devices, but in favor of one of them, it can adversely affect the electrical performance of the other device

[0007] Therefore, the existing Ni silicide formation process does not take into account the negative effects brought by the TiN stress layer introduced during the formation of metal silicide, and needs to be optimized

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