Solution for polymer and capping layer removing with wet dipping in HK metal gate etching process

摘要

The present disclosure provides a method for making metal gate stacks of a semiconductor device. The method includes applying a first etching process to the substrate to remove a polysilicon layer and a metal gate layer on the substrate; applying a diluted hydrofluoric acid (HF) to the substrate to remove polymeric residue; thereafter applying to the substrate with a cleaning solution including hydrochloride (HCl), hydrogen peroxide (H2O2) and water (H2O); applying a wet etching process diluted hydrochloride (HCl) to the substrate to remove a capping layer; and applying to the substrate with a second etching process to remove a high k dielectric material layer.