Conductive external connector structure and method of forming

Patent metadata

Field	Value
Publication number	US-10163836-B2
Application number	US-201815877186-A
Country	US
Kind code	B2
Filing date	Jan 22, 2018
Priority date	Nov 16, 2015
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

External electrical connectors and methods of forming such external electrical connectors are discussed. A method includes forming an external electrical connector structure on a substrate. The forming the external electrical connector structure includes plating a pillar on the substrate at a first agitation level affected at the substrate in a first solution. The method further includes plating solder on the external electrical connector structure at a second agitation level affected at the substrate in a second solution. The second agitation level affected at the substrate is greater than the first agitation level affected at the substrate. The plating the solder further forms a shell on a sidewall of the external electrical connector structure.

First claim

What is claimed is:

1. A semiconductor device comprising:
a conductive pillar located over a conductive member over a substrate;
a reflowable material located over the conductive pillar, wherein the reflowable material further comprises:
a first portion located over a first surface of the conductive pillar, wherein the first surface faces away from the conductive member, wherein the first portion has a first concentration of a first component; and
a second portion located adjacent to but not fully covering a second surface of the conductive pillar, wherein the second surface extends from the first surface towards the substrate, wherein the second portion has a second concentration of the first component greater than the first concentration, wherein the second portion comprises an intermetallic compound, the intermetallic compound having a thickness that is equal to or greater than about half of a width of the second portion.

2. The semiconductor device of claim 1 , wherein the first component is silver.

3. The semiconductor device of claim 1 , wherein the conductive pillar has a first width at a first point covered by the reflowable material and a second width less than the first width at a second point not covered by the reflowable material, wherein the first width is parallel to a major surface of the substrate.

4. The semiconductor device of claim 3 , wherein the second width is between about 38 μm and about 68 μm.

5. The semiconductor device of claim 4 , wherein the first width is between about 40 μm and about 70 μm.

6. The semiconductor device of claim 1 , wherein the first concentration of the first component is between about 1.4% and about 2.2%.

7. The semiconductor device of claim 6 , wherein the first component is silver, wherein the first portion has a third concentration of tin of between about 97.8% and about 98.6%.

8. The semiconductor device of claim 1 , further comprising a barrier layer between the conductive pillar and the reflow able material.

9. The semiconductor device of claim 8 , wherein the barrier layer comprises nickel.

10. A semiconductor device comprising:
a continuous reflowable material over a substrate, the continuous reflowable material comprising:
a first portion with a first concentration of a first component; and
a second portion with a second concentration of the first component different from the first concentration of the first component;

a conductive pillar extending between the first portion and the second portion, wherein a sidewall of the conductive pillar has a first part covered by the first portion and a second part uncovered by the continuous reflowable material, wherein the first portion has a width that is equal to or less than about 1 μm; and
an underbump metallization in electrical connection with the conductive pillar.

11. The semiconductor device of claim 10 , wherein the conductive pillar has a first width adjacent to the first part and a second width adjacent to the second part, the first width being larger than the second width.

12. The semiconductor device of claim 10 , wherein the continuous reflowable material has a height over the conductive pillar, and wherein the first portion has a width that is between about 1% and about 5% of the height.

13. The semiconductor device of claim 10 , wherein the first portion comprises an intermetallic compound.

14. The semiconductor device of claim 13 , wherein the intermetallic compound has a thickness that is equal to or greater than about half of a width of the first portion.

15. The semiconductor device of claim 10 , further comprising a barrier layer located between the conductive pillar and the continuous reflowable material.

16. A semiconductor device comprising:
a conductive pillar over an underbump metallization over a substrate, wherein the conductive pillar comprises aluminum;
a first reflowable material in physical contact with a first surface of the conductive pillar facing away from the substrate, the first reflowable material having a first concentration of a first component; and
a second reflowable material in physical contact with a second surface of the conductive pillar, the second surface being perpendicular to the first surface, the second reflowable material having a second concentration of the first component, wherein a portion of the second surface remains free of the first reflowable material and the second reflowable material.

17. The semiconductor device of claim 16 , further comprising a barrier layer between the conductive pillar and the second reflowable material.

18. The semiconductor device of claim 17 , wherein a sidewall comprising the second surface and a surface of the barrier layer has a first height of between about 40 μm and about 70 μm.

19. The semiconductor device of claim 18 , wherein the second reflowable material has a second height that is between about 5% and about 10% of the first height.

20. The semiconductor device of claim 17 , wherein the barrier layer comprises nickel.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Shih Meng-Fu
• Lo Chun-Yen
• Huang Cheng-Lin
• Chen Wen-Ming
• Huang Chien-Ming
• Liu yuan-fu
• Cheng Yung-Chiuan
• Huang Wei-Chih
• Liu Chen-Hsun
• Chan Chien-Pin
• Hsu Yu-Nu
• Lin Chi-Hung
• Pang Te-Hsun
• Ku Chin-Yu

Classifications

• H10W72/952

  comprising metals or metalloids, e.g. PbSn, Ag or Cu · CPC title

• H10W72/9415

  relative to the surface, e.g. recessed, protruding · CPC title

• H10W72/923

  Bond pads having multiple stacked layers · CPC title

• H10W72/29

  Bond pads specially adapted therefor · CPC title

• H10W72/019

  of bond pads · CPC title