Redundant structure and forming method thereof

Abstract

The invention provides a redundant structure and a forming method thereof. A polycrystalline silicon layer covering a dielectric constant film layer is formed, an etching process is executed, and thepolycrystalline silicon layer and the dielectric constant film layer are selectively etched to stop on an isolation layer so as to expose the part of the isolation layer. The etching process is stopped on the isolation layer so that the polycrystalline silicon layer in the active region can be prevented from being etched, and the etched residual polycrystalline silicon layer is prevented from being generated on the semiconductor substrate in the active region. Furthermore, the polycrystalline silicon layer covers the high dielectric constant film layer so that the high dielectric constant filmlayer is prevented from being exposed and the semiconductor substrate is prevented from being polluted.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, in particular to a redundant structure and a forming method thereof. Background technique [0002] In the prior art, in the process of forming the redundant structure, it is necessary to form a film layer on the semiconductor substrate. When the film layer is etched, the etching process includes a certain amount of over-etching. A trench is formed in the semiconductor substrate, and in the subsequent film formation and etching process, there will be residues on the sidewalls of the trench in the semiconductor substrate, and the residues will be peeled off in the subsequent process flow, thus causing Contaminate the semiconductor substrate, thereby causing defects in the semiconductor substrate. Contents of the invention [0003] The purpose of the present invention is to provide a redundant structure and its forming method, so as to solve the pollution and defects caused by the red...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a redundant structure and its forming method to solve the pollution and defects caused by the redundant structure during the formation process

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