Planarization method

Abstract

The present invention provides a planarization method. The photoresist in the traditional reverse process is replaced by the second filling layer to cover the surface of the first filling layer, and the second depression in the first filling layer is removed by the first chemical mechanical polishing. and using the second filling layer in the second recess as a mask, use the first etching to remove most of the first filling layer, after removing the second filling layer in the second recess, The remaining first filling layer is removed by the second chemical mechanical polishing, thereby reducing the process cost while avoiding the severe loading effect produced by the chemical mechanical polishing process.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a planarization method. Background technique [0002] In the manufacture of existing semiconductor devices, in order to obtain a planarized surface, a chemical mechanical polishing process is often used. The chemical mechanical polishing process mainly uses the chemical action of the polishing liquid and the physical action of the rotation of the grinding head to make the object to be polished comprehensively planarized. [0003] In practical applications, chemical mechanical polishing is susceptible to load effects due to the impact of the grinding object. Specifically, for a wafer with depressions formed on the surface, since the density of depressions formed on the surface of the wafer and the opening area of ​​the depressions are not the same, the polishing rates of different regions of the wafer surface during chemical mechanical polishing are different. Generally s...

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Problems solved by technology

[0005] However, the reverse process using the existing photoresist will undoubtedly increase the process cost due to the need to form a photoresist layer and separately make a photomask suitable for the reverse process

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