Chemical-mechanical polishing liquid

Abstract

The invention discloses polishing liquid used for a shallow trench isolation polishing process. The polishing liquid contains silicon-based abrasive, anion type surfactant and water. The polishing liquid has higher removing rate of high-density silicon dioxide (HDP-Oxide) and higher selection ratio to the removing rate of silicon nitride. A polished crystal circle has perfect surface appearance and lower surface pollutant residue.

Description

technical field [0001] The invention relates to a chemical mechanical polishing liquid. Background technique [0002] The manufacture of CMOS chips usually integrates hundreds of millions of active devices (including NMOS and PMOS) on silicon substrate materials, and then designs various circuits to realize complex logic functions and analog functions. To ensure electrical isolation between different devices, it is necessary to use insulating materials to isolate them. Shallow trench isolation (STI) is an industrialized method to form isolation regions between active devices. This isolation method is to grow a layer of silicon dioxide on the substrate, and then deposit a layer of silicon nitride film, the typical thickness of the two is 10-20nm and 50-100nm, and then apply glue, expose and develop, as in figure 1 shown. [0003] It can be seen from the figure that the steps (5)-(6) need to use CMP planarization process, which requires rapid removal of silicon dioxide and ...

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Problems solved by technology

[0005] The purpose of the invention is to solve the problem of the polishing selectivity ratio of high-density silicon dioxide (HDP-Oxide) and silicon nitride in the shallow trench isolation polishing process

Improve planarization efficiency

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