Semiconductor structure and method of manufacturing the same

1. A package structure, comprising:

a passivation layer formed over an interconnect structure;

an electrically-conductive structure on the passivation layer and extending through the passivation layer to electrically contact the interconnect structure;

a dielectric structure formed over the passivation layer and surrounding the electrically-conductive structure;

a metallic protection structure on a top surface of the electrically-conductive structure, wherein the top surface of the metallic protection structure is aligned with or lower than a top surface of the dielectric structure; and

a first barrier layer disposed between the metallic protection structure and the electrically-conductive structure,

wherein the electrically-conductive structure is made of a first metal with an oxidation temperature, the metallic protection structure is made of a second metal with an oxidation temperature, and the oxidation temperature of the second metal is higher than that of the first metal;

wherein the dielectric structure comprises:

a first dielectric layer formed over the passivation layer and surrounding the electrically-conductive structure; and

a second dielectric layer disposed between the electrically-conductive structure and the first dielectric layer and disposed between the first dielectric layer and the passivation layer; and

wherein an edge of the first barrier layer abuts the first dielectric layer.

2. The package structure of claim 1 , wherein the metallic protection structure comprises a single-layer structure and comprises an aluminum (Al) layer, a nickel (Ni) layer, a palladium (Pd) layer, a golden (Au) layer, a tungsten (W) layer, a nickel-gold (NiAu) layer, an aluminum-copper (AlCu) layer or a combination thereof.

3. The package structure of claim 1 , wherein the metallic protection structure comprises a multi-layer structure.

4. The package structure of claim 3 , wherein the metallic protection structure comprises a Ni layer, a Pd layer and an Au layer stacking on the electrically-conductive structure, wherein the Ni layer is formed on the top surface of the electrically-conductive structure; the Pd layer on the Ni layer; and the Au layer on the Pd layer.

5. The package structure of claim 1 , further comprising a second barrier layer disposed between the electrically-conductive structure and the passivation layer.

6. The package structure of claim 5 , wherein the first barrier layer is made of titanium (Ti), titanium nitride (TiN), tantalum (Ta), tungsten (W) or a combination thereof; and the second barrier layer is made of titanium (Ti), titanium nitride (TiN), tantalum (Ta), tungsten (W) or a combination thereof.

7. The package structure of claim 1 , wherein the top surface of the metallic protection structure is aligned with a top surface of the dielectric structure.

8. The package structure of claim 1 , wherein the top surface of the metallic protection structure is lower than a top surface of the dielectric structure.

9. The package structure of claim 8 , wherein the metallic protection structure on the top surface of the electrically-conductive structure extends along sidewall of the dielectric structure to partially cover a portion of the top surface of the dielectric structure.

10. The package structure of claim 1 , further comprising an external connection structure formed on the metallic protection structure.

11. A semiconductor structure, comprising:

an electrically-conductive structure stacking on a passivation layer and extending through the passivation layer to electrically contact an interconnect structure underneath the passivation layer;

a dielectric structure formed over the passivation layer and surrounding the electrically-conductive structure;

a protection structure formed on the electrically-conductive structure and comprising a Ni layer, a Pd layer and an Au layer stacking on the electrically-conductive structure, wherein the Ni layer is formed on at least a portion of a top surface of the electrically-conductive structure; the Pd layer on the Ni layer; and the Au layer on the Pd layer; and

a first barrier layer disposed between the metallic protection structure and the electrically-conductive structure,

wherein the dielectric structure comprises:

a first dielectric layer formed over the passivation layer and surrounding the electrically-conductive structure; and

a second dielectric layer disposed between the electrically-conductive structure and the first dielectric layer and disposed between the first dielectric layer and the passivation layer; and

wherein an edge of the first barrier layer abuts the first dielectric layer.

12. The semiconductor structure of claim 11 , wherein the electrically-conductive structure comprises an upper portion overlaid on the passivation layer and a lower portion formed in the passivation layer and extending from the upper portion to the interconnect structure.

13. The semiconductor structure of claim 11 , wherein a ratio of thicknesses of the Ni layer to that of the Pd layer is from about 75:1 to about 85:1.

14. The semiconductor structure of claim 11 , wherein a ratio of thicknesses of the Ni layer to that of the Au layer is from about 10:1 to about 11:1.

15. The semiconductor structure of claim 11 , further comprising a second barrier layer disposed between the electrically-conductive structure and the protection structure.

16. A method for manufacturing a semiconductor structure, comprising:

receiving a substrate with a interconnect structure formed thereon;

forming a passivation layer on the interconnect structure;

forming an electrically-conductive structure on a portion of a top surface of the passivation layer and extending through the passivation layer to electrically contact the interconnect structure;

forming a dielectric structure over the electrically-conductive structure and the passivation layer by applying a lower dielectric layer over the electrically-conductive structure and a portion of the top surface of the passivation layer exposed from the electrically-conductive structure; applying an upper dielectric layer over the lower dielectric layer; and exposing at least a portion of a top surface of the electrically-conductive structure, so that the upper dielectric layer surrounds the electrically-conductive structure, and the lower dielectric layer is disposed between the electrically-conductive structure and the upper dielectric layer and is also disposed between the upper dielectric layer and the passivation layer; forming a first barrier layer on the electrically-conductive structure, wherein an edge of the first barrier layer abuts the upper dielectric layer;

forming a protection structure over the first barrier layer; and

performing a test on the semiconductor structure at a heating temperature,

wherein the electrically-conductive structure is made of a first metal with an oxidation temperature, the protection structure is made of a second metal with an oxidation temperature, and the oxidation temperature of the second metal is higher than that of the first metal.

17. The method of claim 16 , wherein the oxidation temperature of the second metal is higher than the heating temperature.

18. The method of claim 16 , further comprising forming an external connection structure on the protection structure after heating the semiconductor structure.

19. The method of claim 16 , further comprising forming a second barrier layer on the electrically-conductive structure before forming the protection structure over the electrically-conductive structure.

20. The method of claim 16 , wherein forming the protection structure comprises:

forming a nickel (Ni) layer over the electrically-conductive structure;

depositing a palladium (Pd) layer on the Ni layer; and

depositing a golden (Au) layer on the Pd layer.