Self-aligned via process flow

Abstract

A device includes a first dielectric layer having at least one conductive feature embedded therein. A first plurality of conductive lines are embedded in a second dielectric layer disposed above the first dielectric layer. A first conductive line in the first plurality of conductive lines contacts the conductive feature and includes a conductive via portion and a recessed line portion. A second plurality of conductive lines are embedded in a third dielectric layer disposed above the second dielectric layer. A second conductive line in the second plurality of conductive lines contacts the conductive via portion and the conductive via portion has a first cross-sectional dimension corresponding to a width of the first conductive line and a second cross-sectional dimension corresponding to a width of the second conductive line.

What is claimed: 
     
         1 . A device, comprising:
 a first dielectric layer having at least one conductive feature embedded therein;   a first plurality of conductive lines embedded in a second dielectric layer disposed above said first dielectric layer, wherein a first conductive line in said first plurality of conductive lines contacts said conductive feature and comprises a conductive via portion and a recessed line portion; and   a second plurality of conductive lines embedded in a third dielectric layer disposed above said second dielectric layer, wherein a second conductive line in said second plurality of conductive lines contacts said conductive via portion and said conductive via portion has a first cross-sectional dimension corresponding to a width of said first conductive line and a second cross-sectional dimension corresponding to a width of said second conductive line.   
     
     
         2 . The device of  claim 1 , wherein said second dielectric layer has a reduced thickness in a region disposed beneath each of said second plurality of conductive lines, and the device further comprises air gaps disposed in said third dielectric layer between pairs of adjacent second conductive lines. 
     
     
         3 . The device of  claim 1 , further comprising air gaps disposed in said second dielectric layer between pairs of adjacent second conductive lines. 
     
     
         4 . The device of  claim 1 , wherein said first plurality of conductive lines are perpendicular to said second plurality of conductive lines. 
     
     
         5 . The device of  claim 1 , wherein said third dielectric layer directly contacts said second dielectric layer. 
     
     
         6 . The device of  claim 5 , wherein said second and third dielectric layers comprise low-k dielectric materials. 
     
     
         7 . A device, comprising:
 a first plurality of conductive lines embedded in a first dielectric layer, wherein a first conductive line in said first plurality of conductive lines comprises a conductive via portion and a recessed line portion; and   a second plurality of conductive lines embedded in a second dielectric layer disposed above said first dielectric layer, wherein a second conductive line in said second plurality of conductive lines contacts said conductive via portion and said conductive via portion has a first cross-sectional dimension corresponding to a width of said first conductive line and a second cross-sectional dimension corresponding to a width of said second conductive line.   
     
     
         8 . The device of  claim 7 , wherein said first dielectric layer has a reduced thickness in a region disposed beneath each of said second plurality of conductive lines, and the device further comprises air gaps disposed in said second dielectric layer between pairs of adjacent second conductive lines. 
     
     
         9 . The device of  claim 7 , further comprising air gaps disposed in said first dielectric layer between pairs of adjacent second conductive lines. 
     
     
         10 . The device of  claim 7 , wherein said first plurality of conductive lines are perpendicular to said second plurality of conductive lines. 
     
     
         11 . The device of  claim 7 , wherein said second dielectric layer directly contacts said first dielectric layer. 
     
     
         12 . The device of  claim 11 , wherein said first and second dielectric layers comprise low-k dielectric materials. 
     
     
         13 . A device, comprising:
 a first dielectric layer having at least one conductive feature embedded therein;   a first plurality of conductive lines embedded in a second low-k dielectric layer disposed above said first dielectric layer, wherein a first conductive line in said first plurality of conductive lines contacts said conductive feature and includes a conductive via portion and a recessed line portion; and   a second plurality of conductive lines embedded in a third low-k dielectric layer disposed above said second low-k dielectric layer, wherein said first plurality of conductive lines are perpendicular to said second plurality of conductive lines, said third low-k dielectric layer directly contacts said second low-k dielectric layer, a second conductive line in said second plurality of conductive lines contacts said conductive via portion, and said conductive via portion has a first cross-sectional dimension corresponding to a width of said first conductive line and a second cross-sectional dimension corresponding to a width of said second conductive line.   
     
     
         14 . The device of  claim 13 , wherein said second low-k dielectric layer has a reduced thickness in a region disposed beneath each of said second plurality of conductive lines, and the device further comprises air gaps disposed in said third low-k dielectric layer between pairs of adjacent second conductive lines. 
     
     
         15 . The device of  claim 13 , further comprising air gaps disposed in said second low-k dielectric layer between pairs of adjacent second conductive lines.