Stacked semiconductor assemblies, and related systems and methods, are disclosed herein. A representative stacked semiconductor assembly can include a lowermost die and two or more modules carried by an upper surface of the lowermost die. Each of the module(s) can include a base die and one or more upper dies and/or an uppermost die carried by the base die. Each of the dies in the module is coupled via hybrid bonds between adjacent dies. Further, the base die in a lowermost module is coupled to the lowermost die by hybrid bonds. As a result of the modular construction, the lowermost die can have a first longitudinal footprint, the base die in each of the module(s) can have a second longitudinal footprint smaller than the first longitudinal footprint, and each of the upper die(s) and/or the uppermost die can have a third longitudinal footprint smaller than the second longitudinal footprint.

In one embodiment, a semiconductor device includes a first chip that includes a first interconnect layer, a first insulator provided on the first interconnect layer, a first metal portion provided on the first interconnect layer and provided in the first insulator and including at least one of palladium, platinum and gold, and a second interconnect layer provided on the first metal portion and provided in the first insulator. The device further includes a second chip that includes a second insulator provided on the first insulator, and a third interconnect layer provided in the second insulator and provided on the second interconnect layer.

A stacking structure including a first die, a second die stacked on the first die, and a third die and a fourth die disposed on the second die. The first die has a first metallization structure, and the first metallization structure includes first through die vias. The second die has a second metallization structure, and second metallization structure includes second through die vias. The first through die vias are bonded with the second through die vias, and sizes of the first through die vias are different from sizes of the second through die vias. The third and fourth dies are disposed side-by-side and are bonded with the second through die vias.

A Cu.sub.3Sn electrical interconnect and method of making same in an electrical device, such as for hybrid bond 3D-integration of the electrical device with one or more other electrical devices. The method of forming the Cu.sub.3Sn electrical interconnect includes: depositing a Sn layer in the via hole; depositing a Cu layer atop and in contact with the Sn layer; and heating the Sn layer and the Cu layer such that the Sn and Cu layers diffuse together to form a Cu.sub.3Sn interconnect in the via hole. During the heating, a diffusion front between the Sn and Cu layers moves in a direction toward the Cu layer as initially deposited, such that any remaining Cu layer or any voids formed during the diffusion are at an upper region of the formed Cu.sub.3Sn interconnect in the via hole, thereby allowing such voids or remaining material to be easily removed.

A method includes forming a dielectric layer over a carrier, forming a plurality of bond pads in the dielectric layer, and performing a planarization to level top surfaces of the dielectric layer and the plurality of bond pads with each other. A device die is bonded to the dielectric layer and portions of the plurality of bond pads through hybrid bonding. The device die is encapsulated in an encapsulating material. The carrier is then demounted from the device die and the dielectric layer.

A method includes forming a dielectric layer over a carrier, forming a plurality of bond pads in the dielectric layer, and performing a planarization to level top surfaces of the dielectric layer and the plurality of bond pads with each other. A device die is bonded to the dielectric layer and portions of the plurality of bond pads through hybrid bonding. The device die is encapsulated in an encapsulating material. The carrier is then demounted from the device die and the dielectric layer.

Devices and techniques including process steps make use of recesses in conductive interconnect structures to form reliable low temperature metallic bonds. A fill layer is deposited into the recesses prior to bonding. First conductive interconnect structures are bonded at ambient temperatures to second metallic interconnect structures using direct bonding techniques, with the fill layers in the recesses in one or both of the first and second interconnect structures.

Devices and techniques including process steps make use of recesses in conductive interconnect structures to form reliable low temperature metallic bonds. A fill layer is deposited into the recesses prior to bonding. First conductive interconnect structures are bonded at ambient temperatures to second metallic interconnect structures using direct bonding techniques, with the fill layers in the recesses in one or both of the first and second interconnect structures.

In one embodiment, a semiconductor device includes a first chip that includes a first interconnect layer, a first insulator provided on the first interconnect layer, a first metal portion provided on the first interconnect layer and provided in the first insulator and including at least one of palladium, platinum and gold, and a second interconnect layer provided on the first metal portion and provided in the first insulator. The device further includes a second chip that includes a second insulator provided on the first insulator, and a third interconnect layer provided in the second insulator and provided on the second interconnect layer.

A method of liquid assisted micro cold binding is provided. The method includes: forming a conductive pad on the substrate in which the conductive pad consists essentially of indium; forming a liquid layer on the conductive pad; placing a micro device having an electrode facing the conductive pad over the conductive pad such that the micro device is in contact with the liquid layer and is gripped by a capillary force produced by the liquid layer between the micro device and the conductive pad in which the electrode consists essentially of indium; and evaporating the liquid layer such that the electrode is bound to the conductive pad and is in electrical contact with the conductive pad.