METHOD FOR FORMING CONTACT HOLE OF SEMICONDUCTOR DEVICE TO INCREASE CONTACT AREA OF CONTACT HOLE

摘要

PURPOSE: A method for forming a contact hole of a semiconductor device is provided to increase contact area of a contact hole and to secure minimum thickness of an interlayer dielectric by using two insulating layers with different etch rate. CONSTITUTION: A semiconductor substrate(100) defined by an isolation region(110) and an active region(120) is prepared. A first insulating layer(130a) is formed on the resultant structure. A second insulating layer(140) including lower and upper oxide layers(140a,140b) with different etch rate is formed on the first insulating layer. A contact hole is formed by selectively etching the second insulating layer. The bottom contact area of the contact hole is widen by wet-etching using the different etch rate between the lower and upper oxide layer. The lower oxide layer of the second insulating layer is a doped oxide layer, and the upper oxide layer is an undoped oxide layer.