Method of fabricating a stacked via in copper/polyimide beol

A method for connecting two levels of interconnect vertically spaced from each other by another level of interconnect comprising the steps of:

• a) forming a first interconnect region to which contact is to be made;
• b) forming a first insulating layer over the interconnect region;
• c) forming an etch-stop layer over the first insulating layer;
• d) etching the etch stop layer to form an opening at a position over said first interconnect region;
• e) forming a second interconnect region in contact with said first insulating layer and above and in contact with said first interconnect region;
• f) forming a second insulating layer over said first insulation layer, said etch stop layer, the etch stop layer opening and said second interconnect region;
• g) forming an opening in said second insulating layer, said opening in said second insulating layer overlapping said opening in said etch stop layer;
• h) extending said opening in said second insulating layer through said opening in said etch stop layer and said first insulating layer;
• and
• i) filling the openings in said first and second insulating layers with a conductor to create a connection between said first interconnect region and a region above said second insulating layer, the portion of the conductor in said first insulating layer being filled to conform to the opening in said etch stop layer.

A method for connecting two levels of interconnect vertically spaced from each other by another level of interconnect comprising the steps of:

• a) forming a first interconnect region to which contact is to be made, said first interconnect region comprising a conductive line formed in said first insulating layer;
• b) forming a first insulating layer over the interconnect region;
• c) forming an etch-stop layer over the first insulating layer;
• d) etching the etch stop layer to form an opening at a position over said first interconnect region;
• e) forming a second interconnect region in contact with said first insulating layer and above and in contact with said first interconnect region, said second interconnect region including a conductor formed in said first insulating layer;
• f) forming a second insulating layer over said first insulation layer, said etch stop layer and said second interconnect region;
• g) forming an opening in said second insulating layer, said opening in said second insulating layer overlapping said opening in said etch stop layer;
• h) extending said opening in said second insulating layer through said first insulating layer;
• and
• i) filling the openings in said first and second insulating layers with a conductor to create a connection between said first interconnect region and a region above said second insulating layer.

A method for connecting two levels of interconnect vertically spaced from each other by another level of interconnect comprising the steps of:

• a) forming a first interconnect region to which contact is to be made;
• b) forming a first insulating layer over the interconnect region;
• c) forming an etch-stop layer over the first insulating layer;
• d) etching the etch stop layer to form an opening at a position over said first interconnect region;
• e) forming a second interconnect region in contact with said first insulating layer and above said first interconnect region, said second interconnect region including a conductor formed in said first insulating layer;
• f) forming a second insulating layer over said first insulation layer and said etch stop layer;
• g) forming an opening in said second insulating layer, said opening in said second insulating layer overlapping said opening in said etch stop layer;
• h) extending said opening in said second insulating layer through said first insulating layer;
• and
• i) filling the openings in said first and second insulating layers with a conductor to create a connection between said first interconnect region and a region above said second insulating layer.

A method for connecting two levels of interconnect vertically spaced from each other by another level of interconnect comprising the steps of:

• a) forming a first interconnect region to which contact is to be made;
• b) forming a first insulating layer over the interconnect region;
• c) forming an etch-stop layer over the first insulating layer;
• d) etching the etch stop layer to form an opening at a position over said first interconnect region;
• e) forming a second interconnect region in contact with said first insulating layer and above and in contact with said first interconnect region, said second interconnect region including a conductor formed in said first insulating layer;
• f) forming a second insulating layer over said first insulation layer, said etch stop layer and said second interconnect region;
• g) forming an opening in said second insulating layer, said opening in said second insulating layer overlapping said opening in said etch stop layer;
• p1 h) extending said opening in said second insulating layer through said first insulating layer;
• and
• i) filling the openings in said first and second insulating layers with a conductor to create a connection between said first interconnect region and a region above said second insulating layer.