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 (RmSiO 2 )-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 RmSiO 2 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 RmSiO 2 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.

Intermolecular and surface forces in atomic-scale manufacturing

“…To overcome this challenge, green CMP is developed for copper [89], sapphire [90], alloys [91] and diamond [92]. These works are a great contribution to the traditional CMP and manufacturing, effectively eliminating the pollution to the environment [90,93].…”

Atomic-level flatness on oxygen-free copper surface in lapping and chemical mechanical polishing

“…The surface roughness (Ra) value of the polished copper wafers was 0.5 nm. Gao et al 18 synthesized a series of fine-structured rod-shaped silica (RmSiO 2 )-based abrasives with controllable sizes and diverse ordered mesoporous structures via a soft template approach, and successfully applied these in a sustainable polishing slurry to improve the surface quality of cadmium zinc telluride (CZT) wafers. Jeong et al 19 studied a mixed abrasive slurry (MAS), which is a non-traditional slurry with two differently sized abrasives, and controlled the mixing ratio in order to improve the CMP removal rate (RR).…”

Designing Inorganic Semiconductors with Cold‐Rolling Processability

“…[ 8 , 9 , 10 , 11 , 12 , 13 ] Recently, several top‐down mechanical processing methods have been developed for both layered and bulk inorganic semiconductors, such as mechanical grinding [ 14 , 15 , 16 , 17 , 18 ] and polishing. [ 19 , 20 , 21 , 22 ] However, the intrinsic brittleness plays a pivotal role in controlling the quality of the samples and the resulting flakes are difficult to reproduce, highly fragile, and very small in size. To overcome these three roadblocks, there is a pressing need for the design of inorganic semiconductors that are amenable to plastic deformation.…”