| 摘要 |
PROBLEM TO BE SOLVED: To prevent corrosion of an exposed metal plug and to improve performance of a device by forming a protective film on the surface of a metal plug which is exposed because of thermal oxidation or the like after ashing photoresist by oxygen plasma and before wet cleaning. SOLUTION: In a method for preventing loss of a metal plug 206, after eliminating photoresist 218, a protective film 222, for example an oxide film is formed on the exposed metal plug 206 for preventing electrical charge from being collected on it. Then a substrate 200 is subject to wet cleaning. Since the exposed metal plug 206 is covered with the protective film 222, contact between the metal plug 206 and an alkaline solution can be avoided by the protective film 22 even if electrical charge is collected on the surface of the metal plug 206 in an atmosphere of oxygen plasma. In this way, contact resistance can be made correct, the device performance can be improved and the yields can be also improved. |
