An electronic package may be fabricated by forming a first layer of insulating material on a first substrate such that the first layer covers a contact pad; forming an opening through the first layer to expose the contact pad; forming an un-patterned second layer on the first layer, the second layer including an adhesive having a viscosity less than that of the first layer, wherein a region of the second layer obstructs the contact pad; removing the region to re-expose the contact pad; aligning a second substrate with the first substrate such that a via of the second substrate is aligned with the opening; bonding the first substrate and the second substrate together at the second layer; and forming an interconnect in contact with the contact pad by depositing a conductive material through the via and the opening.

An integrated circuit device includes a first semiconductor substrate having a frontside surface and a backside surface opposite to each other, an FEOL structure on the frontside surface of the first semiconductor substrate, a first BEOL structure on the FEOL structure, a second BEOL structure on the backside surface of the first semiconductor substrate, and a second semiconductor substrate apart from the first semiconductor substrate in a vertical direction with the FEOL structure and the first BEOL structure The second semiconductor substrate is locally bonded to the first BEOL structure. The second semiconductor substrate includes a main surface facing the first BEOL structure, and the main surface of the second semiconductor substrate defines a local trench region in which trenches are defined in a regular pattern and local bonding areas bonded to the first BEOL structure.