| 摘要 |
PURPOSE: A gate formation method is provided to be capable of preventing damage of a copper film due to plasma upon etch process, by forming a gate in a copper film using damascene process. CONSTITUTION: A gate insulating film(12) and a polysilicon film are deposited on a semiconductor substrate(10) and are then patterned to form a dummy pattern(13) on a predetermined region for a gate. Source and drain(14A,14B) are formed on both sides of the dummy pattern. The first insulating film(15) is then formed on the dummy pattern and the surface of the substrate. After forming the second insulating film(16) on the first insulating film, the second insulating film and the first insulating film are treated by blanket etch process so that the dummy pattern can be exposed and the exposed dummy pattern is planarized. Next, the dummy pattern is removed to form a trench having a gate shape through which the gate insulating film is exposed. A barrier metal film(17) is formed on the second insulating film and the surface of the trench. A low resistance metal film is formed on the barrier metal film so that the trench in which the barrier metal film is formed can be filled. Thereafter, the low resistance metal film and the barrier metal film are treated by blanket etch process so that the second insulating film can be exposed, thus forming a gate the bottom and the side of which is surrounded by the barrier metal film.
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