Non-spherical abrasives with ordered mesoporous structures for chemical mechanical polishing

Abstract

The chemical mechanical polishing (CMP) technology has been widely used for surface modification of critical materials and components with high quality and efficiency. In a typical CMP process, the mechanical properties of abrasives play a vital role in obtaining the ultra-precision and damage-free surface of wafers for improvement of their performances. In this work, a series of fine structured rod-shaped silica (RmSiO2)-based abrasives with controllable sizes and diverse ordered mesoporous structures were synthesized via a soft template approach, and successfully applied in the sustainable polishing slurry for improving the surface quality of cadmium zinc telluride (CZT) wafers. Compared with commercial silica gel, solid and mesoporous silica spheres, the RmSiO2 abrasives present superior elastic deformation capacity and surface precision machinability on account of their mesoporous structures and rod shapes. Especially, ultra-precision surface roughness and relatively effective material removal speed were achieved by the CMP process using the RmSiO2 abrasives with a length/diameter (L/d) ratio of 1. In addition, a potential CMP mechanism of the developed polishing slurry to CZT wafer was elucidated by analyzing X-ray photoelectron spectra and other characterizations. The proposed interfacial chemical and mechanical effects will provide a new strategy for improving abrasives’ machinability and precision manufacture of hard-to-machine materials.