Wafer bonding methods and wafer bonding structures are provided. An exemplary wafer bonding method includes providing a first wafer; forming a first interlayer dielectric layer and a first bonding layer passing through the first interlayer dielectric layer on the surface of the first wafer; providing a second wafer; forming a second interlayer dielectric layer and a second bonding layer passing through the second interlayer dielectric layer on surface of the second wafer; forming a self-assembling layer on at least one of a surface of the first interlayer dielectric layer and a surface of the second interlayer dielectric layer; and bonding the first wafer with the second wafer, the first bonding layer and the second bonding layer being fixed with each other, and the first interlayer dielectric layer and the second interlayer dielectric layer being fixed with each other by the self-assembling molecular layer.

A method of forming a hybrid bonding structure includes depositing an etch stop layer over surface of a substrate, wherein the substrate comprises a conductive structure, and the etch stop layer contacts the conductive structure. The method further includes depositing a dielectric material over the etch stop layer. The method further includes depositing a first diffusion barrier layer over the dielectric material. The method further includes forming an opening extending through the etch stop layer, the dielectric material and the diffusion barrier layer. The method further includes lining the opening with a second diffusion barrier layer. The method further includes depositing a conductive pad on the second diffusion barrier layer in the opening, wherein a surface of the first diffusion barrier layer is aligned with a surface of the conductive pad.

A first semiconductor structure including a first bonding oxide layer having a first metallic bonding structure embedded therein and a second semiconductor structure including a second bonding oxide layer having a second metallic bonding structure embedded therein are provided. A nitride surface treatment process is performed to provide a nitrided surface layer to each structure. Each nitrided surface layer includes nitridized oxide regions located in an upper portion of the bonding oxide layer and nitridized metallic regions located in an upper portion of the metallic bonding structures. The nitrogen within the nitridized metallic regions is then removed to restore the upper portion of the metallic bonding structures to its original composition. Bonding is performed to form a dielectric bonding interface between the nitridized oxide regions present in the first and second structures, and a metallic bonding interface between the first and second metallic bonding structures.

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.

Representative techniques and devices, including process steps may be employed to mitigate undesired dishing in conductive interconnect structures and erosion of dielectric bonding surfaces. For example, an embedded layer may be added to the dished or eroded surface to eliminate unwanted dishing or voids and to form a planar bonding surface. Additional techniques and devices, including process steps may be employed to form desired openings in conductive interconnect structures, where the openings can have a predetermined or desired volume relative to the volume of conductive material of the interconnect structures. Each of these techniques, devices, and processes can provide for the use of larger diameter, larger volume, or mixed-sized conductive interconnect structures at the bonding surface of bonded dies and wafers.

Representative techniques and devices, including process steps may be employed to mitigate undesired dishing in conductive interconnect structures and erosion of dielectric bonding surfaces. For example, an embedded layer may be added to the dished or eroded surface to eliminate unwanted dishing or voids and to form a planar bonding surface. Additional techniques and devices, including process steps may be employed to form desired openings in conductive interconnect structures, where the openings can have a predetermined or desired volume relative to the volume of conductive material of the interconnect structures. Each of these techniques, devices, and processes can provide for the use of larger diameter, larger volume, or mixed-sized conductive interconnect structures at the bonding surface of bonded dies and wafers.

A first semiconductor structure including a first bonding oxide layer having a first metallic bonding structure embedded therein and a second semiconductor structure including a second bonding oxide layer having a second metallic bonding structure embedded therein are provided. A nitride surface treatment process is performed to provide a nitrided surface layer to each structure. Each nitrided surface layer includes nitridized oxide regions located in an upper portion of the bonding oxide layer and nitridized metallic regions located in an upper portion of the metallic bonding structures. The nitrogen within the nitridized metallic regions is then removed to restore the upper portion of the metallic bonding structures to its original composition. Bonding is performed to form a dielectric bonding interface between the nitridized oxide regions present in the first and second structures, and a metallic bonding interface between the first and second metallic bonding structures.

A representative device includes a patterned opening through a layer at a surface of a device die. A liner is disposed on sidewalls of the opening and the device die is patterned to extend the opening further into the device die. After patterning, the liner is removed. A conductive pad is formed in the device die by filling the opening with a conductive material.

Disclosed herein is a semiconductor device, including: a first substrate including a first electrode, and a first insulating film configured from a diffusion preventing material for the first electrode and covering a periphery of the first electrode, the first electrode and the first insulating film cooperating with each other to configure a bonding face; and a second substrate bonded to and provided on the first substrate and including a second electrode joined to the first electrode, and a second insulating film configured from a diffusion preventing material for the second electrode and covering a periphery of the second electrode, the second electrode and the second insulating film cooperating with each other to configure a bonding face to the first substrate.

A method for attaching a semiconductor die to a substrate includes providing a substrate that includes an attachment layer at a surface of the substrate. The attachment layer is covered by a protective flash plating layer. The protective flash plating layer has a reflow temperature less than or equal to a reflow temperature of the attachment layer. The method further includes preheating the substrate to a temperature greater than or equal to a reflow temperature of the attachment layer, attaching a semiconductor die to the attachment layer, and cooling the substrate and semiconductor die.