Surface Modified Alumina Particles and Their Chemical Mechanical Polishing (CMP) Behavior on C-plane (0001) Sapphire Substrate

To improve the Chemical Mechanical Polishing (CMP) performance of alumina particles in aqueous solution, a suitable modification method was explored. Meanwhile, in order to improve their chemical mechanical performance, alumina particles were surface modified with N-(2-aminoethyl)-3-aminopropyltrimethoxysilane through silanization chemical reaction with their surface hydroxyl groups and complexation with Al and secondary amine. This work gives a detailed and thorough chemical reaction mechanism that N-(2-aminoethyl)-3-aminopropyltrimethoxysilane grafted onto the surface of alumina. The compositions and structures of the modified alumina particles were characterized by Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The results supported that the N-(2-aminoethyl)-3-aminopropyltrimethoxysilane was perfectly grafted onto the surface of alumina particles, which led to the modified alumina particles with better surface chemical and mechanical properties than unmodified alumina particles. Then, CMP performance of the unmodified and modified alumina particles on the sapphire substrate was tested. The results showed that the modified alumina particles exhibited higher material removal rate (MRR) and better surface quality than unmodified alumina particle. The focus is that the modified alumina particles manifested higher MRR at pH 10.00 than the unmodified alumina particles at PH 13.00, which may open a way to reduce corrosion of equipment.