A kind of chemical mechanical polishing fluid and its application

Abstract

The invention provides a chemical mechanical polishing liquid, which comprises silicon dioxide abrasive particles and a nitrogen-containing heterocyclic compound containing one or more carboxyl groups. The polishing liquid of the present invention has a relatively high polishing rate of silicon nitride and silicon dioxide.

Description

technical field [0001] The invention relates to the field of chemical mechanical polishing, in particular to a chemical mechanical polishing liquid and its application. Background technique [0002] in wafer fabrication. Silicon nitride material is usually used as a barrier layer or etch stop layer to protect the underlying structure. In the production of semiconductor devices, the step of removing the silicon nitride layer is performed at various stages, for example, in the step of forming an element separation structure, the silicon nitride layer as a barrier layer is removed. The currently commonly used method for removing the silicon nitride layer is to remove the silicon nitride layer by wet etching at a high temperature of about 150° C. using a liquid such as a phosphoric acid / nitric acid mixed solution. [0003] For chemical mechanical polishing fluids, most of the polishing fluids try to reduce the removal rate of silicon nitride, and obtain relatively high removal...

AI Technical Summary

Problems solved by technology

And existing above-mentioned polishing fluid, most of the difference between silicon nitride and silicon dioxide polishing rate is bigger, and can not have higher silicon nitride and silicon dioxide polishing rate simultaneously

Images