Patent ID: 8093099

Claim:
A method of fabricating a stacked device structure comprising the steps of: a. fabricating on a first substrate a first device layer comprising a first set of circuits and first set of interconnects; b. etching a first set of deep openings for vias and alignment marks that extend through said device layer and interconnects, to a certain depth into said first substrate; c. providing a first insulating lining to protect the side walls of said first set of openings for via and alignment marks and filling and planarizing said first set of openings with a first conductive material; d. disposing contact vias and bonding pads connected to said filled vias; e. further disposing an insulator layer and an adhesive layer over the top and providing openings in said insulator and said adhesive layers at said bonding pads and etching a second set of deep via openings that extend all the way into some depth of said first substrate; f. fabricating on a second substrate a second device layer comprising a second set of circuits and second set of interconnects; g. forming a damascene interconnect level comprising conductive studs embedded in a dielectric and connecting to selected locations on said second interconnects and recessing said dielectric to expose a portion of the height of said conductive studs; h. aligning said first substrate on top of said second substrate face to face such that a first subset of said conductive studs on said second substrate are aligned to said bonding pads on said first substrate and a second subset of said conductive studs on said second substrate are inserted into said second set of deep via openings in said first substrate; i. laminating said first substrate and said second substrate to bond them together using said adhesive layer, said adhesive flowing and filling any gaps between said substrates and around said conductive studs forming a bonded structure; j. removing the bulk of the thickness of said first substrate from the top of said bonded structure by a combination of grinding, polishing and etching to expose the bottom of said filled vias and said filled alignment marks and to open up the bottom of said second set of deep via openings; k. disposing a second insulating lining to protect the side walls of said second set of deep via openings and filling and planarizing said via openings with a second conductive material; l. constructing additional interconnect and input output terminals on the top of said thinned bonded structure using said filled alignment marks for reference, thus completing a three dimensional device stack structure.