Wet etching has been widely used in IC fabrication. It could eliminate the plasma damage for Silicon wafer,float SiO2,remove the residues,and peel the wafer surface[1~3]. With the etching technology development,dry etching has partially replaced the wet etching,but the wet etching cannot be replaced thoroughly due to the following reason:the wet etching has a superior corrosion ratio than the dry etching between the horizontal and vertical dimension. The wet etching could change the structure of polycrystalline silicon,and then removes the residues. Wet etching has been widely used in IC fabrication. It could eliminate the plasma damage for Silicon wafer, float SiO2, remove the residues, and peel the wafer surface [1 ~ 3]. With the etching technology development, dry etching has partially replaced the wet etching, but the wet etching can not be replaced thoroughly due due to the dry etching between the horizontal and vertical dimensions. the residues.