Abstract: One method includes, among other things, forming a bi-layer etch stop layer above a conductive contact comprised of titanium nitride, the bi-layer etch stop layer consisting of an upper second layer that is made of aluminum nitride, forming a patterned etch mask comprised of a layer of titanium nitride above a second layer of insulating material, with the bi-layer etch stop layer in position above the conductive contact, performing an etching process through the patterned etch mask to define a cavity in the second layer of insulating material, performing a second etching process to remove at least the layer of titanium nitride of the patterned etch mask, forming an opening in the bi-layer etch stop layer so as to thereby expose a portion of the conductive contact and forming a conductive structure in the cavity that is conductively coupled to the exposed portion of the conductive contact.

Abstract: A process for making an alignment structure in manufacturing a semiconductor device, comprising copper interconnect (Cu-interconnect) fabrication involving chemical-mechanical planarization (CMP) is disclosed. The process comprises tailoring said CMP process to produce a sufficiently high dishing on a designated alignment key area during bulk removal of Cu. The additional dishing step would have sufficient step height for optical pickup to produce alignment signal. Subsequent photolithographic processes specifically for making conventional alignment structure may thus be omitted. Preferably, the additional dishing is achieved by control over any one or combination of pressuring, vacuuming and/or venting of a CMP head's membrane, inner tube and retaining ring chambers, and selection of any one or combination of pads, slurry, pad conditioner and recipe, and may only need to achieve a removal of up to 100 {dot over (A)}.