Deep alignment marks on edge chips for subsequent alignment of opaque layers

A method of manufacturing a magnetic memory device, comprising:

• providing a workpiece, the workpiece including a plurality of die regions and a kerf region, each die region comprising an alignment mark region at the edges thereof, and an array region disposed within the alignment mark region;
• forming a first insulating layer over the workpiece;
• forming at least one first alignment mark over the alignment mark region of each die region and a plurality of first conductive lines over the array region of each die region within the first insulating layer, wherein forming the at least one first alignment mark comprises filling the at least one first alignment mark with a conductive material;
• forming at least one second alignment mark within at least the first insulating layer over the kerf region of the workpiece, the at least one second alignment mark comprising a trench having a bottom and sidewalls;
• forming a second insulating layer over the at least one second alignment mark, the at least one first alignment mark, the plurality of first conductive lines, and the first insulating layer, wherein the second insulating layer lines the bottom and sidewalls of the at least one second alignment mark trench;
• forming a conductive via in the second insulating layer over the array region of each die region using a damascene process, wherein the conductive via material lines the second insulating layer lining the at least one second alignment mark bottom and sidewalls;
• depositing a first magnetic stack over the conductive via and the second insulating layer, wherein a depression is formed in the first magnetic stack over each at least one second alignment mark;
• depositing a first masking layer over the first magnetic stack;
• patterning the first masking layer using a lithography mask or tool, removing the first masking layer from over the at least one first alignment mark, using the depression in the first magnetic stack over the at least one second alignment mark to align the lithography mask or tool used to pattern the first masking layer over the first magnetic stack;
• removing the first magnetic stack from over the at least one first alignment mark using the first masking layer as a mask, leaving the at least one first alignment mark exposed;
• removing the first masking layer;
• depositing a second masking layer over the first magnetic stack and the at least one first alignment mark;
• patterning the second masking layer with a pattern for the first magnetic stack in the array region of each die region using the at least one first alignment mark for alignment;
• and
• patterning the first magnetic stack using the second masking layer as a mask, wherein the patterned first magnetic stack comprises a magnetic memory cell.

A method of forming alignment marks of a semiconductor workpiece, the method comprising:

• providing a semiconductor workpiece, the workpiece including a plurality of die regions and at least one kerf region, the at least one kerf region comprising regions where no die is formed or where an incomplete die is formed, the workpiece including at least one material layer disposed thereon;
• forming a first set of alignment marks in a first kerf region where no die is formed or where an incomplete die is formed;
• forming a second set of alignment marks in a second kerf region where no die is formed or where an incomplete die is formed, wherein the first set of alignment marks and the second set of alignment marks extend at least about 8,000 Angstroms into the at least one material layer disposed on the workpiece, or into the at least one material layer and the workpiece and
• using the first and second set of alignment marks for alignment in order to expose alignment marks in an underlying layer of the workpiece.