Gate structure and forming method thereof, semiconductor structure and forming method thereof

Abstract

The invention discloses a gate structure, a forming method of the gate structure, a semiconductor structure with the gate structure and a forming method of the semiconductor structure. The forming method of the gate structure comprises the steps that a semiconductor substrate is provided; a stack structure is formed on the surface of the semiconductor substrate, wherein the stack structure comprises a gate oxide layer located on the surface of the semiconductor substrate and polysilicon gate located on the surface of the gate oxide layer; carbon ion implantation is conducted on the top of the stack structure and the surface of the side wall of the stack structure; nitrogen ion implantation is conducted on the top of the stack structure and the surface of the side wall of the stack structure; first monox layers are formed on the top of the stack structure and the surface of the side wall of the stack structure. Due to the fact that nitrogen ions and carbon ions implanted into the polysilicon gate can serve as impurity traps, the enhanced diffusion effect of foreign ions, close to the surface, of the polysilicon gate is restrained, the dosage concentration of the foreign ions, close to the surface, of the polysilicon gate and the dosage concentration of foreign ions inside the polysilicon gate are the same almost, and the resistance of the polysilicon gate will not improved.

Description

technical field [0001] The present invention relates to the field of semiconductors, in particular to a gate structure and a forming method, a semiconductor structure having the gate structure and a forming method. Background technique [0002] Polysilicon gate structures are often used in the fabrication of metal oxide semiconductor (MOS) transistors. In a typical polysilicon gate structure formation process, a silicon oxide layer is first formed on the surface of the semiconductor substrate, a polysilicon layer is formed on the surface of the silicon oxide layer, and a patterned photoresist is formed on the surface of the polysilicon layer by photolithography. Layer, using the patterned photoresist layer as a mask, dry-etching the polysilicon layer and the silicon oxide layer in sequence to form a polysilicon gate structure on the surface of the semiconductor substrate, and the polysilicon gate The structure includes a gate oxide layer on the surface of the semiconductor ...

AI Technical Summary

Problems solved by technology

[0003] However, in the process of dry etching the polysilicon layer and the silicon oxide layer to form the gate oxide layer and the polysilicon gate, the dry etching process will cause damage to the gate oxide layer and the polysilicon gate, so that the gate oxide layer and the polysilicon gate Gate sidewalls can generate many defects

The defects will affect the integrity of the gate oxide layer, which will easily reduce the reliability of the gate oxide layer and reduce the breakdown voltage of the gate oxide layer. At the same time, the defects will also easily increase the leakage current of the MOS transistor.

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