PRECLEANING METHOD FOR METAL PLUG WHICH MINIMIZES DAMAGE OF LOWκDIELECTRIC

摘要

PROBLEM TO BE SOLVED: To provide a process for cleaning the contact region of a metal which minimizes the damage on a low-κcarbon-contained dielectric positioned on the upper side of a metal conductor on a semiconductor work piece. SOLUTION: A contact opening is formed in a low-κdielectric (step 104), so that a contact region of a metal conductor positioned on the lower side is exposed. Then a work piece is exposed to an atmosphere where the mixing of hydrogen-contained gas and helium gas is plasma-decomposed (stop 106) so that the contact region is cleaned. Related to the precleaning process, the damage on the dielectric is repaired by a proceeding process step such as an oxygen plasma ashing process for removing a photoresist (step 105).