Bond pad structure for bonding improvement

An integrated circuit (IC), comprising:

• a first substrate;
• an interconnect structure under the first substrate, wherein the interconnect structure comprises a plurality of metal layers;
• and
• a bond pad recess extending through the first substrate and into the interconnect structure and terminating at a bond pad, wherein the bond pad comprises a base portion and an upper portion, wherein a bottom surface of the base portion of the bond pad directly contacts a topmost surface of a metal layer of the interconnect structure, wherein a lower surface of the upper portion of the bond pad is level with a lower surface of an oxide layer defining the bond pad recess.

An integrated circuit (IC), comprising:

• a first substrate;
• an interconnect structure contacting a bottom face of the first substrate, wherein the interconnect structure comprises a plurality of metal layers;
• a bond pad recess extending into a topmost surface of and toward a bottommost surface of the interconnect structure, the bond pad recess being defined by an oxide layer including multiple sets of inner sidewalls, wherein at least one of the multiple sets of inner sidewalls are vertical and disposed beneath a horizontal surface of the oxide layer within the bond pad recess;
• and
• a bond pad exposed to the bond pad recess and in direct contact with a first metal layer of the plurality of metal layers.