Chemical mechanical polishing mechanisms for gallium nitride: Quantum chemical molecular dynamics simulations

We developed a chemical mechanical polishing (CMP) simulator based on tight-binding quantum chemical molecular dynamics method and applied it to gallium nitride (GaN) CMP process. We successfully clarified the chemical reaction dynamics at the friction interface between the GaN substrate and an abrasive grain in pure water; surface-adsorbed H₂O molecules, OH groups, and H atoms are generated by the adsorption and dissociation of water on the GaN surface. Our developed CMP simulator is capable of predicting the CMP processes controlled by chemical reactions.