Chemi-mechanical polishing fluid for polishing semiconductor wafer

Abstract

The invention provides a chemi-mechanical polishing fluid for polishing a semiconductor wafer, which is prepared from the following components in percentage by weight: 0.2-5% of acidic pH regulator, 0.01-5% of piperidine nitroxide free radical, 0.1-15% of surfactant, 0.5-20% of grinding particle and the balance of water. The polishing fluid provided by the invention can obviously change the removal rate of silicon nitride under acidic conditions, can regulate the selection ratio of silicon dioxide to silicon nitride, and has the advantages of simple preparation technique, high polishing precision and the like.

Description

technical field [0001] The present invention relates to a kind of chemical mechanical polishing liquid, especially a kind of polishing liquid suitable for carrying out chemical mechanical polishing to silicon dioxide and silicon nitride on semiconductor wafer in the CMP process of semiconductor shallow trench isolation (STI) . Background technique [0002] Chemical Mechanical Polishing (CMP) is a technology that combines chemical action and mechanical action. With the help of the mechanical grinding action of ultra-fine abrasive particles in the CMP polishing liquid and the chemical corrosion of the polishing liquid, it can be polished on silicon wafers. Creates a highly level surface. CMP technology combines the advantages of chemical polishing and mechanical polishing. Pure chemical polishing has a fast polishing rate, high surface finish, low damage, and good perfection, but its surface flatness and parallelism are poor, and the polishing consistency is also poor; pure ...

AI Technical Summary

Problems solved by technology

The selection ratio of silicon dioxide and silicon nitride using this polishing liquid is 20:1 to 60:1, which is relatively high, but the polishing accuracy is not enough, and scratches are easy to occur

[0007] It can be seen from the above that the chemical mechanical polishing fluid currently used in the CMP process of semiconductor shallow trench isolation (STI) has the disadvantages of easy introduction of metal ions, narrow application range, and low polishing accuracy.

Images