Copper interconnect post for connecting a semiconductor chip to a substrate and method of fabricating the same

• US 20060223313A1
• Filed: 03/31/2006
• Published: 10/05/2006
• Est. Priority Date: 04/01/2005
• Status: Abandoned Application

• Current Assignee: Agency For Science Technology and Research
• Original Assignee: Agency For Science Technology and Research
• Inventors: Zhang, Xiao Wu, Witarsa, David, Yoon, Seung Uk, Kripesh, Vaidyanathan
• Application Number:
  US11/394,843
• Publication Number:
  US 20060223313A1
• Time in Patent Office: Days
• US Class Current: 438/687
• CPC Class Codes: H01L 2224/03462 Electroplating
• CPC Class Codes: H01L 2224/03912 the bump being used as a mask for patterning the bonding area
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/05166 Titanium [Ti] as principal constituent
• CPC Class Codes: H01L 2224/05171 Chromium [Cr] as principal constituent
• CPC Class Codes: H01L 2224/05644 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/05647 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/05655 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/11462 Electroplating
• CPC Class Codes: H01L 2224/11464 Electroless plating
• CPC Class Codes: H01L 2224/11472 Profile of the lift-off mask
• CPC Class Codes: H01L 2224/11849 Reflowing
• CPC Class Codes: H01L 2224/11901 with repetition of the same manufacturing step
• CPC Class Codes: H01L 2224/13017 being non uniform along the bump connector
• CPC Class Codes: H01L 2224/13018 comprising protrusions or indentations
• CPC Class Codes: H01L 2224/13023 the whole bump connector protruding from the surface
• CPC Class Codes: H01L 2224/1308 being stacked
• CPC Class Codes: H01L 2224/13083 Three-layer arrangements
• CPC Class Codes: H01L 2224/13084 Four-layer arrangements
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2224/13111 : Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/13144 : Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/13147 : Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/13155 : Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 24/03 : Manufacturing methods
• CPC Class Codes: H01L 24/05 : of an individual bonding area
• CPC Class Codes: H01L 24/11 : Manufacturing methods for bumps on insulating substrates H01L21/4853
• CPC Class Codes: H01L 24/13 : of an individual bump connector
• CPC Class Codes: H01L 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00013 : Fully indexed content
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01011 : Sodium [Na]
• CPC Class Codes: H01L 2924/01015 : Phosphorus [P]
• CPC Class Codes: H01L 2924/01018 : Argon [Ar]
• CPC Class Codes: H01L 2924/0102 : Calcium [Ca]
• CPC Class Codes: H01L 2924/01022 : Titanium [Ti]
• CPC Class Codes: H01L 2924/01023 : Vanadium [V]
• CPC Class Codes: H01L 2924/01024 : Chromium [Cr]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01042 : Molybdenum [Mo]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01059 : Praseodymium [Pr]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/013 : Alloys
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/01327 : Intermediate phases, i.e. intermetallics compounds
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/14 : Integrated circuits

Abstract

A semiconductor chip comprising at least one contact area for electrically connecting the chip to a substrate, the contact area comprising a metallic contact pad covered by a seed layer and at least one copper interconnect post having a base surface directly contacting the contact area and extending from the contact area in a direction at least substantially perpendicular thereto in a tapered manner. A method for manufacturing a semiconductor chip with a copper interconnect post is also disclosed.

Claims

1. A semiconductor chip comprising:

at least one contact area for electrically connecting the chip to a substrate;

the contact area comprising a metallic contact pad covered by a seed layer; and

at least one copper interconnect post having a base surface directly contacting the contact area and extending from the contact area in a direction at least substantially perpendicular thereto in a tapered manner.

2. The semiconductor chip of claim 1, wherein the copper interconnect post comprises a base fillet in direct contact with the contact area.

3. The semiconductor chip of claim 1, wherein the copper interconnect post has a height between about 30 to about 500 μ

m.

4. The semiconductor chip of claim 1, wherein the copper interconnect post has a top surface opposite to and at least substantially parallel with the base surface.

5. The semiconductor chip of claim 4, wherein a layer of solder is deposited on the top surface of the copper interconnect post.

6. The semiconductor chip of claim 5, wherein the layer of solder has a thickness between about 30 to about 500 μ

m.

7. The semiconductor chip of claim 5, wherein a layer of one of nickel and nickel-alloy is deposited between the top surface of the copper interconnect post and the layer of solder.

8. The semiconductor chip of claim 7, wherein the layer of nickel has a thickness between about 1 to about 20 μ

m.

9. A method for manufacturing a semiconductor chip with a copper interconnect post comprising:

depositing a seed layer on a surface of the semiconductor chip comprising at least one contact pad;

the contact pad with the seed layer thereon defining a contact area;

applying a photosensitive dry film to a surface of the seed layer;

processing the dry film so as to expose the contact area of the semiconductor chip via a through-hole in the dry film;

filling at least a substantial portion of the through-hole with copper thereby forming a copper post, a base surface thereof being in direct contact with the contact area of the semiconductor chip; and

removing the dry film.

10. The method of claim 9, wherein filling the through-hole with copper is carried out by electroplating.

11. The method of claim 9, further comprising forming a layer of solder on a top surface of the copper post opposite to its base surface.

12. The method of claim 11, wherein the forming of the layer of solder is performed by a process which includes one of electroplating and solder paste printing.

13. The method of claim 12, wherein the electroplated layer of solder is reflowed.

14. The method of claim 11, further comprising forming a layer of one of nickel and nickel-alloy on the top surface of the copper post prior to forming the layer of solder.

15. The method of claim 14, wherein the forming of the layer of nickel is performed by a process which includes one of electroplating and electroless plating.

16. The method of claim 9, wherein processing the dry film comprises

applying a mask on the dry film;

exposing the dry film to radiation; and

developing the dry film so as to expose the contact area.

17. The method of claim 16, wherein the radiation includes ultra-violet radiation or optical radiation.

18. The method of claim 9, wherein the dry film is developed with a solution of calcium carbonate.

19. The method of claim 9, wherein the dry film is removed with a solution of sodium hydroxide.

20. The method of claim 9, wherein the seed layer is etched away after removing the dry film.

21. A semiconductor device including:

a semiconductor chip comprising

at least one contact area for electrically connecting the chip to a substrate;

the contact area comprising a metallic contact pad covered by a seed layer; and

at least one copper interconnect post having a base surface directly contacting the contact area and extending from the contact area in a direction at least substantially perpendicular thereto in a tapered manner.