Effects of polishing media on the surface chemical and micromechanical properties of SiC

Abstract

Hydrogen peroxide(H2O2) has been widely used to improve polishing performance in chemical mechanical polishing(CMP) of silicon carbide(SiC), but the reaction processes and mechanism of the generated hydroxyl radicals during CMP have not yet been reported in detail. In this paper, the reactions of H2O and H2O2 molecules with SiC were simulated by ReaxFF-MD model. The results show that H-Si and O-Si bonds are formed when H2O reacts with SiC surface and however, suppressed with the introduction of H2O2. Meanwhile, it is successfully observed the whole processes of forming and breaking bonds of the peroxy bonds on the surface of SiC. The indentation hardness, elastic modulus, bond energy and bond length were obtained by LAMMPS and ReaxFF-MD model. The results indicate that, compared with unreacted SiC, the physical and bonding properties of SiC after being reacted with H2O and H2O2 are significantly altered. The performance improvement of SiC polishing is attributed to the reduction of indentation hardness and bond energy caused by chemical reaction.