Interconnect structure with improved conductive properties and associated systems and methods
Interconnect structures with improved conductive properties are disclosed herein. In one embodiment, an interconnect structure can include a first conductive member coupled to a first semiconductor die and a second conductive member coupled to second semiconductor die. The first conductive member includes a recessed surface defining a depression. The second conductive member extends at least partially into the depression of the first conductive member. A bond material within the depression can at least partially encapsulate the second conductive member and thereby bond the second conductive member to the first conductive member.
1. A method of forming a semiconductor die assembly, comprising:
forming a dielectric material on a second semiconductor die;
forming first openings in the dielectric material that expose underlying conductive features;
forming a mask on the dielectric material, wherein the mask includes second openings superimposed on the first openings such that portions of the dielectric material are exposed within the second openings;
depositing a conductive material on each of the conductive features and the portions of the dielectric material within the second openings, wherein the portions of the dielectric material are configured such that a plurality of depressions form in the conductive material in-situ with the deposition of the conductive material;
inserting at least a portion of a plurality of first conductive members on a first semiconductor die into at least a portion of the depressions in the corresponding conductive material on the second semiconductor die; and
covering at least a portion of each of the first conductive members with a bond material within the depression located in each of the corresponding conductive material.
2. The method of claim 1 , further comprising heating the bond material to form intermetallics within the depression located in each of the corresponding conductive material.
3. The method of claim 1 , further comprising heating the bond material to fully convert the bond material into one or more intermetallics.
4. The method of claim 1 wherein the bond material includes solder, and wherein the method further includes reflowing the solder.
5. The method of claim 1 , further comprising:
reacting the bond material with a portion of the corresponding first conductive member to form a first intermetallic at least partially within the depression in the corresponding conductive material; and
reacting the bond material with a portion of the corresponding conductive material to form a second intermetallic at least partially within the depression in the corresponding conductive material.
6. The method of claim 5 wherein the first intermetallic and the second intermetallic materials each include tin/nickel (SnNi).
7. The method of claim 5 wherein the first intermetallic includes tin/nickel (SnNi), and the second intermetallic includes tin/copper (SnCu).
8. The method of claim 1 wherein the bond material includes tin/silver (SnAg).
9. The method of claim 1 , further comprising forming a redistribution network on the first semiconductor die, wherein the first semiconductor die includes a plurality of through-substrate interconnects (TSVs) electrically coupled to the redistribution network.
10. The method of claim 1 , further comprising at least partially encasing the first semiconductor die and the second semiconductor die within a thermally conductive casing.
11. The method of claim 1 wherein:
the first conductive members include copper pillars;
the conductive material includes a copper cup;
the first semiconductor die is a logic die or a memory die; and
the second semiconductor die is a logic die or a memory die.
12. The method of claim 1 wherein the conductive material projects toward the first semiconductor die.
13. The method of claim 1 wherein the depression has a curved shape.
14. The method of claim 1 wherein the depression of the corresponding conductive material is defined by a recessed surface of the first conductive member, the method further comprising forming a barrier material over the recessed surface.