Method of connecting wirings through connection hole.

摘要

A method includes the steps of forming an insulating layer on a first conductive layer, forming a connection hole in the insulating layer, performing etching using an ion having a very low etching rate with respect to the first conductive layer and a high etching rate with respect to the insulating layer, thereby forming a taper on a side wall of the connection hole, and forming a second conductive layer on the first layer and the insulating layer. A typical example of an etching ion is an oxygen ion.