Method For Creating A Fully Self-Aligned Via

A method to provide a via, comprising:

• providing a substrate comprising a first insulating layer having a plurality of parallel recessed first conductive lines extending in a first direction, the recessed first conductive lines having a top surface recessed below a top surface of the first insulating layer;
• forming first pillars on the recessed first conductive lines, the first pillars extending orthogonal to the top surface of the first insulating layer;
• depositing a second insulating layer around the first pillars and on the top surface of the first insulating layer;
• selectively removing at least one of the first pillars to form at least one opening in the second insulating layer, leaving at least one first pillar on the recessed first conductive lines;
• depositing a second conductive material in the at least one opening to form a first via and second conductive lines, the first via connecting the recessed first conductive lines to the second conductive lines;
• removing the at least one first pillar left on the recessed first conductive lines to form at least one bridging opening in the second insulating layer;
• forming at least one bridging pillar on the recessed first conductive lines through the at least one bridging opening, the at least one bridging pillar extending orthogonal to a top surface of the second insulating layer;
• depositing a third insulating layer around the at least one bridging pillar and on a portion of the second insulating layer;
• removing the at least one bridging pillar to form at least one bridging opening in the second insulating layer and third insulating layer;
• and
• depositing a third conductive material in the at least one bridging opening to form a bridging via and third conductive lines, the bridging via connecting the recessed first conductive lines to the third conductive lines.

A method to provide a via, comprising:

• providing a substrate comprising a first insulating layer having a plurality of parallel recessed first conductive lines extending in a first direction, the recessed first conductive lines having a top surface recessed below a top surface of the first insulating layer, the first insulating layer comprising ultra low-κ and the recessed first conductive lines comprising copper or cobalt;
• forming a first pillar metal film comprising tungsten on the recessed first conductive lines and growing at least one first pillar comprising tungsten oxide from the first pillar metal film on the recessed first conductive lines, the at least one first pillar extending orthogonal to the top surface of the first insulating layer;
• depositing a second insulating layer on the first insulating layer, around the first pillars and on a top of the at least one first pillar to form an overburden of the second insulating layer, the second insulating layer comprising a flowable silicon oxide;
• planarizing the second insulating layer to remove the overburden of the second insulating layer and expose the top of the at least one first pillar;
• forming a hardmask on the second insulating layer, the hardmask having an opening over at least one first pillar;
• removing the at least one first pillar to form the at least one opening in the second insulating layer, leaving at least one first pillar on the recessed first conductive lines;
• depositing a second conductive material in the at least one opening in the second insulating layer to form a first via and second conductive lines, the first via connecting the recessed first conductive lines to the second conductive lines;
• removing the at least one first pillar left on the recessed first conductive lines to form at least one bridging opening in the second insulating layer;
• forming a bridging pillar metal film comprising tungsten on the recessed first conductive lines through the at least one bridging opening;
• growing at least one bridging pillar comprising tungsten oxide from the bridging pillar metal film, the at least one bridging pillar extending orthogonal to a top surface of the second insulating layer;
• depositing a third insulating layer around the at least one bridging pillar and on a portion of the second insulating layer, the third insulating layer selected from the group consisting of oxides, carbon doped oxides, porous silicon dioxide, carbides, oxycarbides, nitrides, oxynitrides, oxycarbonitrides, polymers, phosphosilicate glass, fluorosilicate (SiOF) glass, organosilicate glass (SiOCH), or any combinations thereof;
• removing the at least one bridging pillar to form at least one bridging opening in the second insulating layer and third insulating layer;
• and
• depositing a third conductive material comprising copper or cobaltin the at least one bridging opening to form a bridging g via and third conductive lines, the bridging via connecting the recessed first conductive lines to the third conductive lines.