Insulator/metal bonding island for active-area silver epoxy bonding

• US 6,630,735 B1
• Filed: 04/07/2000
• Issued: 10/07/2003
• Est. Priority Date: 04/09/1999
• Status: Expired due to Term

• Current Assignee: Digirad Corporation
• Original Assignee: Digirad Corporation
• Inventors: Carlson, Lars S., Zhao, Shulai
• Primary Examiner(s): Cuneo, Kamand
• Assistant Examiner(s): CRUZ, LOURDES C
• Application Number:
  US09/547,061
• Time in Patent Office: 1,278 Days
• Field of Search: 257/723, 257/725, 257/737, 257/740, 257/738, 257/777, 257/778, 257/780, 257/734, 257/709
• US Class Current: 257/734
• CPC Class Codes: H01L 2224/05572 the external layer extending out of an opening
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/056 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 2224/05644 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/05655 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2224/13109 Indium [In] as principal constituent
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/29099 Material
• CPC Class Codes: H01L 2224/29101 the principal constituent melting at a temperature of less than 400°C
• CPC Class Codes: H01L 2224/2919 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/29199 Material of the matrix
• CPC Class Codes: H01L 2224/2929 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/29299 Base material
• CPC Class Codes: H01L 2224/29339 Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/8319 Arrangement of the layer connectors prior to mounting
• CPC Class Codes: H01L 2224/838 Bonding techniques
• 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 24/29 of an individual layer connector
• CPC Class Codes: H01L 24/83 : using a layer connector
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01015 : Phosphorus [P]
• CPC Class Codes: H01L 2924/01023 : Vanadium [V]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01049 : Indium [In]
• 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 2924/0665 : Epoxy resin
• CPC Class Codes: H01L 2924/0781 : being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/12032 : Schottky diode
• CPC Class Codes: H01L 2924/12043 : Photo diode
• CPC Class Codes: H01L 2924/3512 : Cracking

Abstract

A semiconductor interconnection device having a semiconductor die, a plurality of epoxy bonds, and an array of insulating islands is disclosed. The semiconductor die has a plurality of conductive contacts. The plurality of epoxy bonds has a metallic substance such as silver. The epoxy bonds are configured to provide interconnection between the semiconductor die and an external structure. The plurality of epoxy bonds is selectively applied to the plurality of conductive contacts on the semiconductor die and corresponding conductive contacts on the external structure. The array of insulating islands is coupled to the plurality of conductive contacts. The islands are configured to prevent migration of the metallic substance from the plurality of epoxy bonds to the semiconductor die through the plurality of conductive contacts.

Claims

1. A semiconductor interconnection system, comprising:

a semiconductor die;

first and second conductive contacts, said first conductive contact coupled to a surface of said semiconductor die, and said second conductive contact coupled to an external structure;

a silver epoxy bond interposed between said first and second conductive contacts, said epoxy bond providing electrical and mechanical interconnection between said semiconductor die and said external structure;

a plurality of silver migration regions in the first conductive contact extending from the silver epoxy bond toward the surface of said semiconductor die; and

an insulating island interposed between said silver migration regions and the surface of said semiconductor die,

wherein the first conductive contact is in contact with the surface of said semiconductor die in a region adjacent the insulating island.

2. The system of claim 1, wherein said semiconductor die is a photodetector.

3. The system of claim 2, wherein said photodetector is a p-i-n photodiode.

4. The system of claim 1, wherein said insulating island comprises a layer of oxide.

5. The system of claim 1, wherein the first conductive contact is in contact with the surface of said semiconductor die in a region surrounding the insulating island.

8. The system of claim 1, wherein said semiconductor die is silicon and the insulating island is thermally grown silicon dioxide.

9. The system of claim 1, wherein said insulating island provides reduction in transmission of mechanical stress from said silver epoxy bond into the semiconductor die.

6. A semiconductor interconnection system, comprising:

a semiconductor die;

first and second conductive contacts, said first conductive contact coupled to a surface of said semiconductor die, and said second conductive contact coupled to an external structure;

a silver epoxy bond interposed between said first and second conductive contacts, said epoxy bond providing electrical and mechanical interconnection between said semiconductor die and said external structure; and

an insulating island configured to prevent migration of silver from said silver epoxy bond to said semiconductor die through said first conductive contact; and

a conductive electrode heavily doped with p-type material at the surface of said semiconductor die to provide electrical connection between said semiconductor die and said external structure.

7. The system of claim 6, further comprising an insulator/metal bonding structure disposed above said insulating island, said insulator/metal bonding island providing direct contact between the silver epoxy bond and the conductive electrode, thereby providing required electrical connection between said semiconductor die and said external structure.

10. A semiconductor flip-chip, comprising:

a semiconductor die having a plurality of conductive contacts;

a plurality of epoxy bonds having a metallic component, said epoxy bonds configured to provide interconnection between said semiconductor die and an external structure, said plurality of epoxy bonds selectively applied to said plurality of conductive contacts on said semiconductor die and corresponding conductive contacts on the external structure;

a plurality of metallic component migration regions in each of said plurality of conductive contacts; and

an insulating island corresponding to each of the plurality of epoxy bonds, each insulating island interposed between one of said plurality of conductive contacts and a surface of the semiconductor die,

wherein each of said plurality of conductive contacts is in contact with the surface of the semiconductor die in a region adjacent the corresponding insulating island.

11. The flip-chip of claim 10, wherein said metallic substance is silver.

12. The flip-chip of claim 10, wherein said semiconductor die is a semiconductor illumination detector chip.

13. The flip-chip of claim 10, wherein said plurality of conductive contacts on said semiconductor die forms connections to an array of photodiode pixels.

14. The flip-chip of claim 13, wherein said array of insulating islands prevents degradation of low reverse-bias leakage currents in said array of photodiode pixels.