Removal of Post-dry Etch Residue uing Ultra Low Environmental Load Technique

Abstract

A novel ultra low environmental load removal technique of post-dry etch residue is developed, by applying physical force cleaning technique using high-speed steam-water mixture spray. It is found that the removal rate of the proposed technique depends on the dry-etch processes, and that the steam-water mixture spray almost completely removes the post-dry etch residue from some kinds of dry etched wafers without help of any chemicals. It is also found that the proposed technique requires very dilute concentration of inorganic solution, if necessary, to remove post-dry etch residue completely from other kinds of wafers and that removal process using amine compound with isopropyl alcohol is unnecessary. By contrast, air-water mixture spray could not remove the dry-etch residue at all even with some chemicals. Therefore it is understood that steam atmosphere significantly contributes the proposed technique. The characteristic feature and efficiency of the proposed technique are discussed.