Patent ID: 8298943

Claim:
A method for patterning a self-aligned via in a dielectric, the method comprising the steps of: forming a hard mask on top of a dielectric; forming a first plurality of masking layers on top of the hard mask; patterning a first trench image in the first plurality of masking layers; forming a first lithography mask covering one or more portions of the first trench image; etching at least a portion of the first trench image, not covered by the first lithography mask, through the first plurality of masking layers, to expose a first area of the hard mask; etching the exposed first area of the hard mask to form a first trench extending partially through a depth of the hard mask; forming a second plurality of masking layers over the hard mask; patterning a second trench image in the second plurality of masking layers; forming a second lithography mask covering one or more portions of the second trench image; etching at least a portion of the second trench image, not covered by the second lithography mask, through the second plurality of masking layers, to expose a second area of the hard mask; etching the exposed second area of the hard mask to form a second trench intersecting at least a portion of the first trench, wherein the intersection of the first and second trench creates a hole pattern extending through the depth of the hard mask to expose a first area of the dielectric; etching the exposed first area of the dielectric to create a via hole extending into the dielectric; exposing a second area of the dielectric by re-etching the first trench to extend through the depth of the hard mask, wherein the exposed second area of the dielectric includes the via hole; etching the exposed area of the dielectric corresponding to the first trench to create a wiring path in the dielectric, wherein the wiring path extends partially through a depth of the dielectric and wherein the wiring path intersects the via hole; and depositing a conductive material into the via hole and wiring path of the dielectric to form a metal layer.