Study on a non-contact polishing method using motion coupling confined etchant layer technique

The confined etchant layer technique (CELT) has been proved not only an effective electrochemical microstructures fabrication method, but also a potential polishing method due to its distance sensitiveness. To verify its polishing capability in motion mode and examine the influence of motion parameters on polishing efficiency and material removal rate, motion coupling confined etchant layer technique (MCCELT) polishing experiments were carried out on n-GaAs wafers by adopting central composite inscribe (CCI) design of response surface methodology. Furthermore, the interactions between motion, electrochemical reaction and substrate deformation were analysed using multi-physics coupling finite element simulations. Statistical model shows that sample surface roughness decreases with the decreases of working distance (between the electrode and the substrate) and feeding velocity, and indicates it still has potential to reach more smooth results.