Fabrication method of metal interconnection structure

Abstract

The invention relates to a method for manufacturing a metal interconnection structure, which comprises the steps that a semiconductor substrate is provided, a dielectric layer, a first buffer layer, a first pattern hard mask layer, a second buffer layer and a second pattern hard mask layer are sequentially formed on the semiconductor substrate, the first pattern hard mask layer and the second pattern hard mask layer are line-shaped patterns which are mutually crossed, the second pattern hard mask layer and the first pattern hard mask layer are used as masks to etch the second buffer layer and the first buffer layer until the second buffer layer and the first buffer layer are exposed out of the dielectric layer so as to form a buffer layer pattern, the buffer layer pattern is used as a mask to etch the dielectric layer, the etching is stopped after the second buffer layer under the second pattern hard mask layer disappears and before the first buffer layer under the first pattern hard mask layer disappears so as to form a plurality of through holes and grooves connected to the at least two through holes in the dielectric layer, and the residual first buffer layer is removed. According to the manufacturing method disclosed by the invention, the buffer layer pattern is used as the mask to etch the dielectric layer, and the grooves and the through holes in the metal interconnection structure are formed simultaneously in the dielectric layer.

Description

technical field [0001] The invention relates to a semiconductor manufacturing process, in particular to a method for manufacturing a metal interconnection structure. Background technique [0002] Metal interconnection in the manufacturing process of semiconductor integrated circuits refers to the connection made of conductive materials, such as aluminum, polysilicon or copper, to realize the interconnection between various devices on the chip, so as to transmit electrical signals to different parts of the chip. Generally, the metal interconnection structure includes a contact structure / via structure, and a metal interconnection groove. Among them, the contact structure refers to the structure that realizes the connection between the device in the chip and the first metal layer on the surface of the silicon wafer, and the through hole structure refers to the structure that realizes the formation of electrical connections from a certain metal layer to another adjacent metal la...

AI Technical Summary

Problems solved by technology

If relying on the existing technology, it is very difficult to realize the metal interconnection structure of semiconductor devices with a feature size below 22nm

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