Patent ID: 8610871

Claim:
A method for forming a multilayer structure, comprising: forming a first conductive layer on a substrate; forming a first insulating layer on the first conductive layer; forming a patterned second conductive layer on the first insulating layer; forming a second insulating layer over the substrate so as to cover the patterned second conductive layer; forming a third insulating layer on the second insulating layer, wherein an etching speed of the third insulating layer is faster than an etching speed of the second insulating layer for a prescribed etching method; and forming a contact hole that penetrates through the first insulating layer, the second insulating layer and the third insulating layer at once using the prescribed etching method to expose at least a part of the first conductive layer, wherein a portion of the first insulating layer exposed by the contact hole has a first surface that is inclined with respect to a surface of the substrate and a second surface that is substantially parallel to the surface of the substrate, and the second surface of the first insulating layer has a substantially flat top surface profile adjacent to a boundary with the second insulating layer, wherein constituent elements of processing gases used for forming the first insulating layer are the same as constituent elements of processing gases used for forming the second insulating layer, and flow rates of the constituent elements of the processing gases in forming the first insulating layer are the same as corresponding flow rates of the constituent elements of the processing gases in forming the second insulating layer.