10. A method for forming a multi-layer interconnection
, comprising [
a lower conductor disposed in a first dielectric, an interlayer dielectric disposed on the first dielectric, first and second upper conductors disposed in the interlayer dielectric, and a self-aligned via conductor in electrical contact with and interconnecting the lower conductor and the first upper conductor, the method comprising] :
[ forming the self-aligned via conductor, the first upper conductor, and the second upper conductor comprising:]
providing a substrate having thereon a [ the ] first dielectric for supporting the multi-layer interconnection, wherein the multi-layer interconnection has a lower conductor MN, upper conductor MN+1, an interlayer dielectric and interconnecting via conductor VN+1/N; [ and the lower conductor disposed in the first dielectric, wherein the lower conductor is elongated in a first horizontal direction and has a width in a second horizontal direction orthogonal to the first horizontal direction, and ]
wherein the lower conductor MN has a first [ an ] upper surface [ of the lower conductor is ] located in a recess below a second [ an ] upper surface of the first dielectric;
[ depositing the interlayer dielectric on the first dielectric and the lower conductor; ]
forming the interlayer dielectric above the first and second surfaces;
etching a cavity through the interlayer dielectric from a desired location of the upper conductor MN+1 and exposing the first surface in the recess [ , in desired locations of the first and second upper conductors, respective first and second upper cavities in the interlayer dielectric wherein etching a lower portion of the first upper cavity comprises selectively etching the interlayer dielectric with respect to the first dielectric and the selective etching exposes the upper surface of the lower conductor and a portion of the first dielectric] ; and
filling the cavity [ the first and second upper cavities ] with an electrical conductor to form the upper conductor MN+1 and the connecting via conductor VN+1/N making electrical contact between a first of upper conductor MN+1 and the first upper surface in the recess; and
removing excess electrical conductor overlying the interlayer dielectric, thereby electrically separating the first and a second of upper conductor MN+1 [ an excess of electrical conductor overlying the interlayer dielectric to electrically separate the first upper conductor and the second upper conductor,
wherein an upper portion of the self-aligned via conductor is self-aligned to the first upper conductor and a lower portion of the self-aligned via conductor is self-aligned to the lower conductor] .
