Method for forming a semiconductor structure

Abstract

A method for forming a semiconductor structure comprises the following steps: providing a semiconductor substrate, and forming a first dielectric layer on the semiconductor substrate; forming a plurality of discrete first metal layers in the first dielectric layer, wherein the tops of the first metal layers are higher than the top surface of the first dielectric layer; forming a second dielectric layer on the first dielectric layer between the adjacent first metal layers; performing oxidation treatment on the first metal layer to form a metal oxide layer; forming a third dielectric layer on the surfaces of the second dielectric layer and the metal oxide layer; and etching the third dielectric layer until the metal oxide layer is exposed to form a through hole. According to the forming method, the through hole can be formed in a self-alignment mode, the limitation of the bottom size of the through hole is enlarged, and the short circuit problem is avoided.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a method for forming a semiconductor structure. Background technique [0002] As the production of integrated circuits develops towards ultra-large-scale integrated circuits (ULSI), the internal circuit density is increasing, and the number of components contained is increasing, so that the surface of the wafer cannot provide enough area to make the required interconnection lines. (Interconnect). In order to meet the increased demand for interconnection lines after the shrinkage of components, the design of multilayer metal interconnection lines with more than two layers realized by using through holes has become a method that must be adopted in VLSI technology. [0003] However, with the continuous reduction of semiconductor process nodes, the metal interconnection lines in semiconductor devices are becoming denser and the critical dimensions (CD) of interco...

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Problems solved by technology

However, when the existing self-alignment process forms the through hole, the problem of the expansion of the through hole will occur, which will cause the metal line adjacent to the connected lower layer metal line after the conductive plug is filled in the through hole. A bridge occurs between them, resulting in a short circuit

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