Disclosed herein are methods for direct bonding. In some embodiments, a direct bonding method comprises preparing a first bonding surface of a first element for direct bonding to a second bonding surface of a second element; and after the preparing, providing a protective layer over the prepared first bonding surface of the first element, the protective layer having a thickness less than 3 microns.

A bonded assembly includes a first semiconductor die and a second semiconductor die. The first semiconductor die includes first metallic bonding pads embedded in first dielectric material layers, the second semiconductor die includes second metallic bonding pads embedded in second dielectric material layers, the first metallic bonding pads are bonded to a respective one of the second metallic bonding pads; and each of the first metallic bonding pads includes a corrosion barrier layer containing an alloy of a primary bonding metal and at least one corrosion-suppressing element that is different from the primary bonding metal.

A method of manufacturing a semiconductor device includes forming a cell chip including a first substrate, a source layer on the first substrate, a stacked structure on the source layer, and a channel layer passing through the stacked structure and coupled to the source layer, flipping the cell chip, exposing a rear surface of the source layer by removing the first substrate from the cell chip, performing surface treatment on the rear surface of the source layer to reduce a resistance of the source layer, forming a peripheral circuit chip including a second substrate and a circuit on the second substrate, and bonding the cell chip including the source layer with a reduced resistance to the peripheral circuit chip.

A semiconductor device includes a first die, the first die including a first dielectric layer and a plurality of first bond pads formed within apertures in the first dielectric layer, and a second die bonded to the first die, the second die including a second dielectric layer and a plurality of second bond pads protruding from the second dielectric layer. The first die is bonded to the second die such that the plurality of second bond pads protrude into the apertures in the first dielectric layer to establish respective metallurgical bonds with the plurality of first bond pads. A reduction in the distance between the respective bond pads of the dies results in a lower temperature for establishing a hybrid bond.

Structures and techniques provide bond enhancement in microelectronics by trapping contaminants and byproducts during bonding processes, and arresting cracks. Example bonding surfaces are provided with recesses, sinks, traps, or cavities to capture small particles and gaseous byproducts of bonding that would otherwise create detrimental voids between microscale surfaces being joined, and to arrest cracks. Such random voids would compromise bond integrity and electrical conductivity of interconnects being bonded. In example systems, a predesigned recess space or predesigned pattern of recesses placed in the bonding interface captures particles and gases, reducing the formation of random voids, thereby improving and protecting the bond as it forms. The recess space or pattern of recesses may be placed where particles collect on the bonding surface, through example methods of determining where mobilized particles move during bond wave propagation. A recess may be repeated in a stepped reticule pattern at the wafer level, for example, or placed by an aligner or alignment process.

A method for forming a direct hybrid bond and a device resulting from a direct hybrid bond including a first substrate having a first set of metallic bonding pads, preferably connected to a device or circuit, capped by a conductive barrier, and having a first non-metallic region adjacent to the metallic bonding pads on the first substrate, a second substrate having a second set of metallic bonding pads capped by a second conductive barrier, aligned with the first set of metallic bonding pads, preferably connected to a device or circuit, and having a second non-metallic region adjacent to the metallic bonding pads on the second substrate, and a contact-bonded interface between the first and second set of metallic bonding pads capped by conductive barriers formed by contact bonding of the first non-metallic region to the second non-metallic region.

A metal-dielectric bonding method includes providing a first semiconductor structure including a first semiconductor layer, a first dielectric layer on the first semiconductor layer, and a first metal layer on the first dielectric layer, where the first metal layer has a metal bonding surface facing away from the first semiconductor layer; planarizing the metal bonding surface; applying a plasma treatment on the metal bonding surface; providing a second semiconductor structure including a second semiconductor layer, and a second dielectric layer on the second semiconductor layer, where the second dielectric layer has a dielectric bonding surface facing away from the second semiconductor layer; planarizing the dielectric bonding surface; applying a plasma treatment on the dielectric bonding surface; and bonding the first semiconductor structure with the second semiconductor structure by bonding the metal bonding surface with the dielectric bonding surface.

A method of manufacturing a semiconductor device comprising embedding electrodes in insulating layers exposed to the joint surfaces of a first substrate and a second substrate, subjecting the joint surfaces of the first substrate and the second substrate to chemical mechanical polishing, to form the electrodes into recesses recessed as compared to the insulating layers, laminating insulating films of a uniform thickness over the entire joint surfaces, forming an opening by etching in at least part of the insulating films covering the electrodes of the first substrate and the second substrate, causing the corresponding electrodes to face each other and joining the joint surfaces of the first substrate and the second substrate to each other, heating the first substrate and the second substrate joined to each other, causing the electrode material to expand and project through the openings, and joining the corresponding electrodes to each other.

Dies and/or wafers including conductive features at the bonding surfaces are stacked and direct hybrid bonded at a reduced temperature. The surface mobility and diffusion rates of the materials of the conductive features are manipulated by adjusting one or more of the metallographic texture or orientation at the surface of the conductive features and the concentration of impurities within the materials.

Embodiments of bonded semiconductor structures and fabrication methods thereof are disclosed. In an example, a method for forming a semiconductor device is disclosed. A first device layer is formed above a first substrate. A first bonding layer including a first bonding contact is formed above the first device layer. The first bonding contact is made of a first indiffusible conductive material. A second device layer is formed above a second substrate. A second bonding layer including a second bonding contact is formed above the second device layer. The first substrate and the second substrate are bonded in a face-to-face manner, such that the first bonding contact is in contact with the second bonding contact at a bonding interface.