CMP is a planarization process that is carried out by chemical and mechanical effects. It preferentially removes the uneven parts on the surface to make it a surface with consistent height and height. It can effectively obtain an ultra-smooth surface. Its polishing process has reached the micro-nano level and is A mature processing technology.
The picture below is a schematic diagram of CMP work: First, the material to be polished is fixed on the sample tray and the polishing pad is installed. Both the polishing disc and the material to be polished rotate on their own axis of symmetry. In addition, transport the polishing liquid to the polishing pad. Through the chemical reaction between the polishing fluid and the material to be polished, and the mechanical interaction between the abrasive particles and the material to be polished, the material is removed and the surface is globally planarized.
CMP instrument is mainly composed of polishing disc, polishing pad, polishing fluid, etc. Among them, polishing pad and polishing fluid account for the absolute main factors.
1. Polishing pad
In CMP, the polishing pad is an important consumable product. Generally, the pad is a material with appropriate mechanical properties and porous water-absorbing properties. It is a key component for storing and transporting polishing fluid. It mechanically grinds the workpiece to a certain extent and plays the role of transporting polishing residue.
