Method of fabricating contact holes in high density integrated circuits using polysilicon landing plug and self-aligned etching processes

摘要

A method of fabricating contact holes in high density integrated circuits uses landing plugs to reduce the aspect ratio of the the node contact holes in order to improve the processing window of deep contact holes. Along with nitride spacers on the sidewalls of a transistor gate structure, polysilicon hard masks and polysilicon spacers are used as etching masks in a self-aligned contact process. In addition, the landing plugs incorporate the polysilicon spacers as part of landing plug to increase the contact area. As a result, wide contact processing windows can be achieved in high density integrated circuits.