Contact window structure, metal plug and forming method thereof, and semiconductor structure

Abstract

The invention discloses a contact window structure, a metal plug and a forming method thereof, the forming method of the contact window structure and a semiconductor structure, an annular gasket is formed on the surface of a target layer, and the middle of the annular gasket is provided with a central through hole exposing part of the surface of the target layer; forming a dielectric layer covering the substrate, the target layer and the annular gasket; etching the dielectric layer, and forming an etching hole communicated with the central through hole in the dielectric layer; and the annular gasket is removed along the etching hole and the central through hole, so that the size of the central through hole is enlarged, and the etching hole and the central through hole with the enlarged size form a contact window structure. Through the formed annular gasket, when the contact window structure is formed and the annular gasket is removed, the size of the central through hole can be increased, so that the size of the bottom of the contact window structure can be increased, and when a metal plug is formed in the contact window structure, the contact area between the bottom of the metal plug and a target layer is increased; and the contact resistance between the two is reduced.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to a contact window structure, a metal plug and a method for forming the same, and a semiconductor structure. Background technique [0002] With the development of integrated circuits to ultra-large-scale integrated circuits, the circuit density inside integrated circuits is increasing, and the number of components contained is also increasing. This development makes the surface of the wafer unable to provide enough area to manufacture the required interconnecting wires. [0003] In order to meet the requirements of interconnection lines after shrinking components, the design of two or more layers of multilayer metal interconnection lines has become a method commonly used in VLSI technology. At present, the conduction between different metal layers or metal layers and pad layers can be realized through metal plugs, refer to figure 1 , the formation of the metal plug includes: forming...

AI Technical Summary

Problems solved by technology

In the process of miniaturization, the performance of the circuit requirements put forward by the design side will also be compromised

In addition, the size of the bottom opening of the via hole often limits the resistance value of the entire contact window, and the reduced size will greatly reduce the contact area with the target metal layer

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