A method of manufacturing a semiconductor structure includes the following steps: providing a first semiconductor wafer, wherein the first semiconductor wafer includes a first dielectric layer and at least one first top metallization structure embedded in the first dielectric layer, and a top surface of the first dielectric layer is higher than a top surface of the first top metallization structure by a first distance; providing a second semiconductor wafer, wherein the second semiconductor wafer includes a second dielectric layer and at least one second top metallization structure embedded in the second dielectric layer, and a top surface of the second top metallization structure is higher than a top surface second dielectric layer of the by a second distance; and hybrid-bonding the first semiconductor wafer and the second semiconductor wafer.

The present disclosure provides a mothed of method of manufacturing a semiconductor device. The method includes steps of forming a dielectric layer on a substrate; etching the dielectric layer to create a plurality of openings in the dielectric layer; applying a sacrificial layer in at least one of the openings to cover at least a portion of the dielectric layer; forming at least one first conductive feature in the openings where the sacrificial layer is disposed and a plurality of bases in the openings where the sacrificial layer is not disposed; removing the sacrificial layer to form at least one air gap in the dielectric layer; and forming a plurality of protrusions on the bases.

A semiconductor die includes a first pad-level dielectric layer embedding first bonding pads and located over a first substrate. Each of the first bonding pads is located within a respective pad cavity in the first pad-level dielectric layer. Each of the first bonding pads includes a first metallic liner containing a first metallic liner material and contacting a sidewall of the respective pad cavity, a first metallic fill material portion embedded in the first metallic liner, and a metallic electromigration barrier layer contacting the first metallic fill material portion and adjoined to the first metallic liner.

In an embodiment, a device includes: an interposer; a first integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds; a second integrated circuit device bonded to the interposer with dielectric-to-dielectric bonds and with metal-to-metal bonds; a buffer layer around the first integrated circuit device and the second integrated circuit device, the buffer layer including a stress reduction material having a first Young's modulus; and an encapsulant around the buffer layer, the first integrated circuit device, and the second integrated circuit device, the encapsulant including a molding material having a second Young's modulus, the first Young's modulus less than the second Young's modulus.

A bonded assembly includes a first die containing first bonding pads having sidewalls that are laterally bonded to sidewalls of second bonding pads of a second die.

A method of manufacturing a semiconductor structure includes the following steps: providing a first semiconductor wafer, wherein the first semiconductor wafer includes a first dielectric layer and at least one first top metallization structure embedded in the first dielectric layer, and a top surface of the first dielectric layer is higher than a top surface of the first top metallization structure by a first distance; providing a second semiconductor wafer, wherein the second semiconductor wafer includes a second dielectric layer and at least one second top metallization structure embedded in the second dielectric layer, and a top surface of the second top metallization structure is higher than a top surface second dielectric layer of the by a second distance; and hybrid-bonding the first semiconductor wafer and the second semiconductor wafer.

A first metal layer can be deposited over first dielectric material layers of a first substrate, and can be patterned into first metallic plates. First bonding pads including a respective one of the first metallic plates are formed. A first polymer material layer can be formed over the first bonding pads. A second semiconductor die including second bonding pads is bonded to the first bonding pads to form a bonded assembly.

A first semiconductor die includes first bonding pads. The first bonding pads include proximal bonding pads embedded within a first bonding dielectric layer and distal bonding pads having at least part of the sidewall that overlies the first bonding dielectric layer. A second semiconductor die includes second bonding pads. The second bonding pads are bonded to the proximal bonding pads and the distal bonding pads. The proximal bonding pads are bonded to a respective one of a first subset of the second bonding pads at a respective horizontal bonding interface and the distal bonding pads are bonded to a respective one of a second subset of the second bonding pads at a respective vertical bonding interface at the same time. Dielectric isolation structures may vertically extend through the second bonding dielectric layer of the second semiconductor die and contact the first bonding dielectric layer.

A bonded assembly and a method of forming a bonded assembly includes providing a first semiconductor die including a first substrate, first semiconductor devices, and first bonding pads that are electrically connected to a respective node of the first semiconductor devices, providing a second semiconductor die including a second substrate, second semiconductor devices, and second bonding pads that are electrically connected to a respective node of the second semiconductor devices, forming a dielectric bonding pattern definition layer including bonding pattern definition openings therethrough over the second bonding pads, and bonding the second bonding pads to the first bonding pads, where the first metal pads expand through the bonding pattern definition openings and are bonded to a respective one of the second bonding pads.

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. The fill layer is composed of noble metal (such as copper) and active metal (such as Zn). Then the fill metal layer is turned into a metal alloy after annealing. A dealloying is performed to the metal alloy to remove the active metal from the metal alloy while the noble metal remains to self-assemble into porous (nanoporous) structure metal. First conductive interconnect structures are bonded at ambient temperatures to second metallic interconnect structures using dielectric-to-dielectric direct bonding techniques, with the fill nanoporous metal layer in the recesses in one of the first and second interconnect structures. After the following batch annealing, the fill nanoporous metal layer turns into pure bulk metal same as conductive interconnect structures due to the heat expansion of conductive interconnect structures and nanoporous metal densification.