Bonded assembly containing a dielectric bonding pattern definition layer and methods of forming the same
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.
1. A bonded assembly, comprising:
a first semiconductor die comprising a first substrate, first semiconductor devices, and first bonding pads that are electrically connected to a respective node of the first semiconductor devices;
a second semiconductor die comprising a second substrate, second semiconductor devices, and second bonding pads that are electrically connected to a respective node of the second semiconductor devices; and
a dielectric bonding pattern definition layer located between the first semiconductor die and the second semiconductor die and including bonding pattern definition openings therethrough,
wherein each of the second bonding pads comprises a respective second bonding-side surface having a second-bonding-surface center region that is bonded to a respective one of the first bonding pads through a respective one of the bonding pattern definition openings in the bonding pattern definition layer, and having a second-bonding-surface peripheral region that laterally surrounds the second-bonding-surface center region and contacts a surface of the dielectric bonding pattern definition layer.
2. The bonded assembly of claim 1 , wherein each contact area between a bonded pair of the first bonding pads and the second bonding pads coincides with an area of a respective one of the bonding pattern definition openings.
3. The bonded assembly of claim 2 , wherein:
the first bonding pads are embedded in a first pad-level dielectric layer;
the second bonding pads are embedded in a second pad-level dielectric layer; and
the second pad-level dielectric layer is vertically spaced from the first pad-level dielectric layer at least by the dielectric bonding pattern definition layer.
4. The bonded assembly of claim 1 , wherein the dielectric bonding pattern definition layer comprises a dielectric material selected from silicon oxide, silicon carbonitride, silicon nitride, silicon oxynitride, or a dielectric metal oxide, and has a thickness in a range from 10 nm to 50 nm.
5. The bonded assembly of claim 1 , wherein each interface between the second-bonding-surface center regions of the second bonding pads and the first bonding pads is vertically offset from a horizontal plane including surfaces of the second-bonding-surface peripheral regions of the second bonding pads by a vertical offset distance that is at least one half of a thickness of the dielectric bonding pattern definition layer.
6. The bonded assembly of claim 5 , wherein each of the first bonding pads comprises a respective first bonding-side surface having a first-bonding-surface center region that is bonded to a respective one of the second bonding pads, and having a first-bonding-surface peripheral region that laterally surrounds the first-bonding-surface center region.
7. The bonded assembly of claim 6 , further comprising a dielectric cover layer located between, and contacting, the dielectric bonding pattern definition layer and the first semiconductor die, and including cover layer openings therethrough, wherein each of the bonding pattern definition openings have a smaller lateral area than each of the cover layer openings.
8. The bonded assembly of claim 7 , wherein:
each of the bonding pattern definition openings is located entirely within an area of a respective one of the cover layer openings and has a respective periphery that is laterally offset inward from a periphery of the respective one of the cover layer openings;
the dielectric cover layer comprises a first dielectric material selected from silicon oxide, silicon carbonitride, silicon nitride, silicon oxynitride, or a dielectric metal oxide, and has a thickness in a range from 5 nm to 50 nm; and
the bonding pattern definition layer comprises a second dielectric material selected from silicon oxide, silicon carbonitride, silicon nitride, silicon oxynitride, or a dielectric metal oxide, and has a thickness in a range from 5 nm to 50 nm.
9. The bonded assembly of claim 7 , wherein each of the first-bonding-surface peripheral regions contacts the bonding pattern definition layer at an inner periphery thereof, and contacts a respective portion of the dielectric bonding pattern definition layer at an outer periphery thereof.
10. The bonded assembly of claim 5 , wherein:
each of the first-bonding-surface peripheral region contacts the dielectric bonding pattern definition layer; and
the first-bonding-surface peripheral regions are vertically spaced from the second-bonding-surface peripheral regions by a vertical spacing that is the same as a thickness of the dielectric bonding pattern definition layer.
11. The bonded assembly of claim 1 , wherein each bonded pair of the first bonding pad and the second bonding pads is bonded to each other by metal-to-metal bonding induced by metal diffusion across a respective bonding interface.
12. The bonded assembly of claim 1 , wherein:
one of the first semiconductor die and the second semiconductor die comprises a memory die including a three-dimensional array of memory elements; and
another of the first semiconductor die and the second semiconductor die comprises a logic die including a logic circuitry configured to operate the three-dimensional array of memory elements.
13. A method of forming a bonded assembly, comprising:
providing a first semiconductor die comprising 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 comprising 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, wherein the first metal pads expand through the bonding pattern definition openings and are bonded to a respective one of the second bonding pads;
wherein:
each of the second bonding pads comprises a respective second bonding-side surface have a second-bonding-surface center region that is physically exposed within a respective one of the bonding pattern definition openings, and have a second-bonding-surface peripheral region that laterally surrounds the second-bonding-surface center region and is covered by the dielectric bonding pattern definition layer;
the second bonding pads are embedded in a second pad-level dielectric layer; and
the dielectric bonding pattern definition layer is formed by depositing and patterning a dielectric material layer over the second bonding pads and the second pad-level dielectric layer.
14. The method of claim 13 , wherein the dielectric bonding pattern definition layer comprises a dielectric material selected from silicon oxide, silicon carbonitride, silicon nitride, silicon oxynitride, or a dielectric metal oxide, and has a thickness in a range from 10 nm to 50 nm.
15. The method of claim 13 , wherein each bonded pair of the first bonding pad and the second bonding pad has a respective bonding interface having a periphery that coincides with a respective one of the bonding pattern definition openings.
16. The method of claim 13 , further comprising forming a dielectric cover layer including cover layer openings therethrough on the first bonding pads, wherein the dielectric cover layer is disposed between the dielectric bonding pattern definition layer and the first semiconductor die during and after bonding the second bonding pads to the first bonding pads, and wherein each of the bonding pattern definition openings is located entirely within an area of a respective one of the cover layer openings.
17. The method of claim 16 , wherein the bonding pattern definition layer contacts each of the first bonding pads after the first bonding pads are bonded to the second bonding pads.
18. The method of claim 13 , wherein:
each of the first bonding pads comprises a first bonding-side surface that faces the second semiconductor die; and
an entirety of each of the first bonding-side surfaces contacts the bonding pattern definition layer or a respective one of the second bonding pads.
19. The method of claim 13 , wherein:
each bonded pair of the first bonding pad and the second bonding pad is bonded to each other by metal-to-metal bonding induced by metal diffusion across a respective bonding interface;
one of the first semiconductor die and the second semiconductor die comprises a memory die including a three-dimensional array of memory elements; and
another of the first semiconductor die and the second semiconductor die comprises a logic die including a logic circuitry configured to operate the three-dimensional array of memory elements.