Conductive interconnect structures and methods for forming conductive interconnect structures

• US 6,469,394 B1
• Filed: 01/31/2000
• Issued: 10/22/2002
• Est. Priority Date: 01/31/2000
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Wong, Connie M., Lee, Michael G.
• Primary Examiner(s): Loke, Steven
• Assistant Examiner(s): Kang, Donghee
• Application Number:
  US09/494,756
• Time in Patent Office: 995 Days
• Field of Search: 257/778, 257/779, 257/780, 257/738, 438/108, 438/612, 438/614, 438/613
• US Class Current: 257/780
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/05647 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/05666 Titanium [Ti] as principal constituent
• CPC Class Codes: H01L 2224/05671 Chromium [Cr] as principal constituent
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2224/131 with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2224/81801 Soldering or alloying
• CPC Class Codes: H01L 23/49811 Additional leads joined to the metallisation on the insulating substrate, e.g. pins, bumps, wires, flat leads H01L23/49827 takes precedence
• 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 24/16 of an individual bump connector
• CPC Class Codes: H01L 24/81 using a bump connector
• 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 2924/01022 Titanium [Ti]
• 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 2924/01041 : Niobium [Nb]
• CPC Class Codes: H01L 2924/0105 : Tin [Sn]
• 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 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H05K 2201/0367 : Metallic bump or raised conductor not used as solder bump
• CPC Class Codes: H05K 2203/0369 : Etching selective parts of a metal substrate through part of its thickness, e.g. using etch resist
• CPC Class Codes: H05K 3/07 : being removed electrolytically
• CPC Class Codes: H05K 3/243 : characterised by selective plating, e.g. for finish plating of pads selective plating for making the circuit pattern H05K3/108, H05K3/182
• CPC Class Codes: H05K 3/3436 : having an array of bottom contacts, e.g. pad grid array or ball grid array components
• CPC Class Codes: H05K 3/4007 : Surface contacts, e.g. bumps H05K3/4092 takes precedence; deposition of finish layers on pads H05K3/24; forming solder bumps H05K3/3457
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product

Abstract

Interconnect structures and methods for making interconnect structures are disclosed. A typical interconnect structure has a tapered first end portion having a first substantially planar surface and a concave surface adjacent to the first planar surface. A second end portion of the interconnect structure includes a second substantially planar surface. The second planar surface has a larger area than the first planar surface. An intermediate portion is disposed between the first end portion and the second end portion.

Claims

1. A conductive post comprising:

a tapered first end portion having a first substantially planar surface and a concave surface adjacent to the first substantially planar surface;

a second end portion including a second substantially planar surface, wherein the second substantially planar surface has a larger area than the first substantially planar surface; and

an intermediate portion disposed between the first end portion and the second end portion, said intermediate portion comprises a horizontal cross-sectional area which increases from said second end portion in a vertical axial direction.

2. The conductive post of claim 1, wherein the conductive post has a length of about 40 microns or more.

3. The conductive post of claim 1, wherein the concave surface surrounds the first substantially planar surface.

4. The conductive post of claim 1, wherein the conductive post has an aspect ratio of about 4:

1 or more.

5. The conductive post of claim 1 wherein the cross-sectional area of the intermediate portion and the cross-sectional area of the second end portion are substantially the same.

6. The conductive post of claim 1 wherein the conductive post comprises copper.

7. The conductive post of claim 1 wherein said concave surface terminates in said first substantially planar surface and comprises a uniform downwardly sloping concave surface.

8. The conductive post of claim 7 wherein said intermediate portion comprises a horizontal cross-sectional area which increases from said second end portion in a vertical axial direction.

9. The conductive post of claim 8 wherein said, intermediate portion comprises an exterior wall outwardly diverging from said second end portion.

10. The conductive post of claim 1 wherein said intermediate portion comprises an exterior wall outwardly diverging from said second end portion.

11. An electrically conductive article comprising:

a conductive post having

a tapered first end portion having a first substantially planar surface and a concave surface adjacent to the first substantially planar surface, said concave surface terminates in said first substantially planar surface and comprises a uniform downwardly sloping concave surface commencing from said first substantially planar surface;

a second end portion including a second substantially planar surface, wherein the second substantially planar surface has a larger area than the first substantially planar surface;

an intermediate portion disposed between the first end portion and the second end portion;

a dielectric layer;

a conductive region on the dielectric layer; and

the conductive post coupled to the conductive region, wherein the second end portion of the post is proximate to the conductive region and the tapered first end portion is distal to the conductive region.

12. The electrically conductive article of claim 11 further comprising a solder body disposed around the tapered first end portion of the conductive post.

13. The electrically conductive article of claim 11 wherein said intermediate portion comprises a horizontal cross-sectional area which increases from said second end portion in a vertical axial direction.

14. The electrically conductive article of claim 13 wherein said intermediate portion comprises an exterior wall outwardly diverging from said second end portion.

15. An electrically conductive article comprising:

a conductive post having

a tapered first end portion having a first substantially planar surface and a concave surface adjacent to the first substantially planar surface;

a second end portion including a second substantially planar surface, wherein the second substantially planar surface has a larger area than the first substantially planar surface;

an intermediate portion disposed between the first end portion and the second end portion, said intermediate portion comprises a horizontal cross-sectional area which increases from said second end portion in a vertical axial direction;

a dielectric layer;

a conductive region on the dielectric layer; and

the conductive post coupled to the conductive region, wherein the second end portion of the post is proximate to the conductive region and the tapered first end portion is distal to the conductive region.

16. The electrically conductive article of claim 15 wherein said intermediate portion comprises an exterior wall outwardly diverging from said second end portion.