Sandwich structure for via and interconnect

An interconnect comprising:

• an underling layer;
• a first metal line located on top of the underlying layer, wherein a first via is located on top of the first metal line, wherein at least one line divot is located adjacent to the first via, wherein the at least one-line divot extends downwards into the first metal line;
• a second metal line located on top of the underlying layer;
• and
• a second via located on top of the second metal line, wherein a first sandwich layer is located between the second via and the second metal line, wherein the first sandwich layer is comprised of a first layer and a second layer.

A method comprising:

• forming a Mx metal layer on an underlying layer;
• forming a sandwich layer on top of the Mx metal layer;
• forming a trench within the sandwich layer, wherein the trench exposes a top surface of the Mx metal layer;
• forming a top metal layer on top of the sandwich layer, wherein the top metal layer fills the trench;
• etching the top metal layer, the first layer, and the Mx metal layer to form a plurality of lines;
• and
• subtractively etching the top metal layer to remove it from most locations, wherein the subtractive etching of the top metal layer forms a first via aligned with location of the trench on one of the plurality of lines, wherein the dimensions of the first via differ from the dimensions of the trench, such that line divots are formed in the Mx metal layer from the subtractive etching process, wherein the subtractive etching of the top metal layer forms a second via located on top of the sandwich layer on one of the plurality of lines.