Dimension compensation control for directly bonded structures
A method of direct hybrid bonding first and second semiconductor elements of differential thickness is disclosed. The method can include patterning a plurality of first contact features on the first semiconductor element. The method can include second a plurality of second contact features on the second semiconductor element corresponding to the first contact features for direct hybrid bonding. The method can include applying a lithographic magnification correction factor to one of the first patterning and second patterning without applying the lithographic magnification correction factor to the other of the first patterning and the second patterning. In various embodiments, a differential expansion compensation structure can be disposed on at least one of the first and the second semiconductor elements. The differential expansion compensation structure can be configured to compensate for differential expansion between the first and second semiconductor elements to reduce misalignment between at least the second and fourth contact features.
1. A method of direct hybrid bonding first and second semiconductor elements of differential thickness, the method comprising:
providing a plurality of first contact features on the first semiconductor element with a first pattern;
patterning a plurality of second contact features on the second semiconductor element with a second pattern, the second contact features corresponding to the first contact features; and
direct hybrid bonding the first semiconductor element to the second semiconductor element, including directly bonding nonconductive layers of the first and second semiconductor elements and directly bonding the first contact features with the corresponding second contact features,
wherein a lithographic magnification correction factor is applied to the second pattern without applying the lithographic magnification correction factor to the first pattern.
2. The method of claim 1 , further comprising thinning the second semiconductor element to produce the differential thickness.
3. The method of claim 2 , further comprising providing a differential expansion compensation structure on the second semiconductor element, the differential expansion compensation structure configured to compensate for differential expansion between the first and second semiconductor elements to reduce misalignment between opposing contact features.
4. The method of claim 3 , wherein providing the differential expansion compensation structure comprises providing one or more dielectric layers on a back side of the second semiconductor element, the back side opposite the second bonding surface, the one or more dielectric layers comprising a compressive layer configured to counterbalance stresses on the nonconductive layer of the second semiconductor element.
5. The method of claim 3 , wherein the differential expansion compensation structure comprises a plurality of dielectric layers, wherein the plurality of dielectric layers comprises a first dielectric layer on the back side of the second semiconductor element and a second dielectric layer on a third semiconductor element, and wherein providing the differential expansion compensation structure comprises directly bonding the second dielectric layer to the first dielectric layer without an adhesive.
6. The method of claim 3 , wherein the differential expansion compensation structure comprises a plurality of dielectric layers, wherein the plurality of dielectric layers comprises a first dielectric layer and a second dielectric layer, and wherein providing the differential expansion compensation structure comprises providing a metal layer between the first and second dielectric layers.
7. The method of claim 3 , wherein providing the differential expansion compensation structure comprises diffusing hydrogen ions in the second semiconductor element.
8. The method of claim 7 , wherein diffusing hydrogen ions comprises exposing the second semiconductor element to a hydrogen-containing plasma.
9. The method of claim 1 , wherein the first semiconductor element is thicker than the second semiconductor element, the method comprising applying the lithographic magnification correction factor to the first pattern, wherein the application of the lithographic magnification correction factor enlarges the first contact features of the first semiconductor element relative to the corresponding second contact features of the second semiconductor element, and wherein the application of the lithographic magnification correction factor enlarges first spacings between adjacent first contact features relative to corresponding second spacings between adjacent second contact features.
10. The method of claim 1 , wherein the first semiconductor element is thicker than the second semiconductor element, the method comprising applying the lithographic magnification correction factor to the second pattern, wherein the application of the lithographic magnification correction factor shrinks the second contact features of the second semiconductor element relative to the corresponding first contact features of the first semiconductor element, and wherein the application of the lithographic magnification correction factor shrinks second spacings between adjacent second contact features relative to corresponding first spacings between adjacent first contact features.
11. The method of claim 1 , further comprising applying the lithographic magnification correction factor to the first pattern and applying a second lithographic magnification correction factor to the second pattern, the second lithographic magnification correction factor different from the lithographic magnification correction factor.
12. A method of bonding a first semiconductor element and a second semiconductor element, the method comprising:
providing a first plurality of first contact features on a first bonding surface of a first semiconductor element in a first pattern;
providing a second plurality of second contact pads on a second bonding surface of a second semiconductor element in a second pattern;
with the first semiconductor element having a first thickness and the second semiconductor element having a second thickness, hybrid bonding the second plurality of second contact pads to the first plurality of first contact pads;
wherein a lithographic magnification correction factor is applied to the second pattern but not the first pattern.
13. The method of claim 12 , wherein the bonding comprises directly bonding without an intervening adhesive.
14. The method of claim 12 , further comprising providing a differential expansion compensation structure on at least one of the first semiconductor element and the second semiconductor element, the differential expansion compensation structure configured to compensate for differential expansion between the first and second semiconductor elements to reduce misalignment between opposing contact features.
15. The method of claim 1 , wherein the lithographic magnification correction factor is configured to compensate for differential expansion of the first and second semiconductor elements due to the differential thicknesses.
16. The method of claim 1 , further comprising obtaining the lithographic magnification correction factor.
17. The method of claim 16 , further comprising deriving the lithographic magnification correction factor from differential expansion of the first and second semiconductor elements due to the differential thicknesses.
18. The method of claim 16 , wherein the lithographic magnification correction factor is derived from differential expansion of the first and second semiconductor elements due to the differential thicknesses.
19. The method of claim 12 , wherein the lithographic magnification correction factor is configured to compensate for differential expansion between the first and second semiconductor elements if the first and second semiconductor elements are bonded together when the second thickness is less than the first thickness.
20. The method of claim 12 , wherein the first and second thicknesses are different.