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 COMS chips usually integrates hundreds of millions of active devices (including NMOS and PMOS) on a silicon substrate material, and then designs various circuits to implement complex logic functions and analog functions. To ensure electrical isolation between different devices, insulating materials must be used to isolate them. Shallow Trench Isolation (STI) is an industrialized method for forming 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 are 10-20nm and 50-100nm, and then apply glue, exposure And developing like figure 1 Shown. [0003] The figure shows that the steps (5)-(6) require a CMP planarization process, which requires rapid removal of silicon dioxide and stops on silicon nitri...

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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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