Method of forming dual damascene metal interconnection employing sacrificial metal oxide layer

摘要

There is provided a method of forming a dual damascene metal interconnection by employing a sacrificial metal oxide layer. The method includes preparing a semiconductor substrate. An interlayer insulating layer is formed on the semiconductor substrate, and a preliminary via hole is formed by patterning the interlayer insulating layer. A sacrificial via protecting layer is formed on the semiconductor substrate having the preliminary via hole to fill the preliminary via hole, and cover an upper surface of the interlayer insulating layer. A sacrificial metal oxide layer is formed on the sacrificial via protecting layer, the sacrificial metal oxide layer is patterned to form a sacrificial metal oxide pattern having an opening crossing over the preliminary via hole, and exposing the sacrificial via protecting layer. The sacrificial via protecting layer and the interlayer insulating layer are etched using the sacrificial metal oxide pattern as an etch mask to form a trench located inside the interlayer insulating layer.