Capacitive coupling in a direct-bonded interface for microelectronic devices

A microelectronic device, comprising:

• a dielectric-to-dielectric direct bond between a first die and a second die, the first die and the second die being direct-bonded together at a bonding interface;
• a plurality of conductive interconnects, each of the plurality of conductive interconnects comprising a metal-to-metal direct bond between a first metal pad of the first die and a first metal pad of the second die;
• and
• a plurality of capacitive interconnects forming signal-passing interfaces between the first die and the second die, each of the plurality of capacitive interconnects comprising a second metal pad of the first die, a second metal pad of the second die, and a dielectric region therebetween, wherein:
• the first metal pads of the first and second dies have a greater width than a width of the second metal pad of the first die in a direction parallel to the bonding interface.

A process, comprising:

• creating a first direct bond between respective dielectric surfaces at a bonding interface of a first die and a second die;
• creating a plurality of conductive interconnects, each of the plurality of conductive interconnects comprising second direct bonds between first metal pads of the first die and first metal pads of the second die;
• and
• creating a plurality of capacitive interconnects forming signal-passing interfaces between the first die and the second die, each of the plurality of capacitive interconnects comprising capacitive couplings between second metal pads of the first die and second metal pads of the second die at the bonding interface for a capacitive interconnect between the first and second dies, wherein:
• the first metal pads of the first and second die have a greater width than a width of the second metal pads of the first die in a direction parallel to the bonding interface for the capacitive interconnect between the first and second dies;
• and
• the plurality of capacitive interconnects each comprises a dielectric region disposed between the second metal pad of the first die, and the second metal pad of the second die.