A contact pad includes a solder-wettable porous network (310) which wicks the molten solder (130) and thus restricts the lateral spread of the solder, thus preventing solder bridging between adjacent contact pads.

A method of producing a bonded chip stack is described. A first nanofluidic device chip having a first through-wafer via is formed. A second nanofluidic device chip having a second through-wafer via is formed. The first nanofluidic device chip and the second nanofluidic device chip are washed with a detergent solution. A first surface of the first nanofluidic device chip and a second surface of the second nanofluidic device chip are activated by treating the first surface and the second surface with an activation solution. The first nanofluidic device chip and the second nanofluidic device chip are arranged in a stack. The first through-wafer via is aligned with the second through-wafer via in a substantially straight line. The stack of first and second nanofluidic device chips is subjected to annealing conditions.

A method of producing a bonded chip stack is described. A first nanofluidic device chip having a first through-wafer via is formed. A second nanofluidic device chip having a second through-wafer via is formed. The first nanofluidic device chip and the second nanofluidic device chip are washed with a detergent solution. A first surface of the first nanofluidic device chip and a second surface of the second nanofluidic device chip are activated by treating the first surface and the second surface with an activation solution. The first nanofluidic device chip and the second nanofluidic device chip are arranged in a stack. The first through-wafer via is aligned with the second through-wafer via in a substantially straight line. The stack of first and second nanofluidic device chips is subjected to annealing conditions.

A contact pad includes a solder-wettable porous network (310) which wicks the molten solder (130) and thus restricts the lateral spread of the solder, thus preventing solder bridging between adjacent contact pads.

A contact pad includes a solder-wettable porous network (310) which wicks the molten solder (130) and thus restricts the lateral spread of the solder, thus preventing solder bridging between adjacent contact pads.

A contact pad includes a solder-wettable porous network (310) which wicks the molten solder (130) and thus restricts the lateral spread of the solder, thus preventing solder bridging between adjacent contact pads.

A contact pad includes a solder-wettable porous network (310) which wicks the molten solder (130) and thus restricts the lateral spread of the solder, thus preventing solder bridging between adjacent contact pads.

A method includes forming a conductive pad over an interconnect structure of a wafer, forming a capping layer over the conductive pad, forming a dielectric layer covering the capping layer, and etching the dielectric layer to form an opening in the dielectric layer. The capping layer is exposed to the opening. A wet-cleaning process is then performed on the wafer. During the wet-cleaning process, a top surface of the capping layer is exposed to a chemical solution used for performing the wet-cleaning process. The method further includes depositing a conductive diffusion barrier extending into the opening, and depositing a conductive material over the conductive diffusion barrier.

A process for the production of a permanent, electrically conductive connection between a first metal surface of a first substrate and a second metal surface of a second substrate, wherein a permanent, electrically conductive connection is produced, at least primarily, by substitution diffusion between metal ions and/or metal atoms of the two metal surfaces.

A method includes forming a conductive pad over an interconnect structure of a wafer, forming a capping layer over the conductive pad, forming a dielectric layer covering the capping layer, and etching the dielectric layer to form an opening in the dielectric layer. The capping layer is exposed to the opening. A wet-cleaning process is then performed on the wafer. During the wet-cleaning process, a top surface of the capping layer is exposed to a chemical solution used for performing the wet-cleaning process. The method further includes depositing a conductive diffusion barrier extending into the opening, and depositing a conductive material over the conductive diffusion barrier.