Electrode of semiconductor device, method of manufacturing thereof, and the semicondutor device

• US 6,184,061 B1
• Filed: 10/06/1998
• Issued: 02/06/2001
• Est. Priority Date: 04/24/1998
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Wu, Qiang, Tomita, Yoshihiro
• Primary Examiner(s): Smith, Matthew
• Assistant Examiner(s): Anya, Igwe U.
• Application Number:
  US09/166,908
• Time in Patent Office: 854 Days
• Field of Search: 257/738, 257/786, 257/731, 257/737, 257/780, 257/772, 257/784, 257/779, 257/781, 257/782, 438/106-108, 438/613-614, 438/653, 438/678
• US Class Current: 438/106
• CPC Class Codes: H01L 21/4853 Connection or disconnection of other leads to or from a metallisation, e.g. pins, wires, bumps
• CPC Class Codes: H01L 2224/05001 Internal layers
• CPC Class Codes: H01L 2224/05022 the internal layer being at least partially embedded in the surface
• CPC Class Codes: H01L 2224/05571 the external layer being disposed in a recess of the surface
• CPC Class Codes: H01L 2224/13023 the whole bump connector protruding from the surface
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• 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 2924/01004 Beryllium [Be]
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• 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 2924/01027 Cobalt [Co]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• 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 2924/01322 : 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 2924/15311 : being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/19043 : being a resistor
• CPC Class Codes: H05K 3/244 : Finish plating of conductors, especially of copper conductors, e.g. for pads or lands selective plating methods H05K3/243; finish plating of conductors made by printing techniques H05K3/246; solder as finish H05K3/3457, e.g. by plating H05K3/3473

Abstract

An electrode of a semiconductor device comprising: a pad; an electroless diffusion prevention film formed on a surface of the pad for preventing material of the pad from diffusing; a solder precoat film formed on a surface of the electroless diffusion prevention film, and having a thickness not larger than a predetermined value, for preventing a solder bump on the solder precoat film from defective breaking; and a predetermined intermetallic compound layer formed in the solder precoat film in the vicinity of a boundary surface between the solder precoat film and the electroless diffusion prevention film, the intermetallic compound layer having a bonded surface bonded substantially to the whole of the surface of the electroless diffusion prevention film.

Claims

1. A method of manufacturing an electrode of a semiconductor device comprising the steps of:

forming a pad on a substrate surface;

forming an electroless barrier metal film, as a pad protection film, on said pad; and

forming a solder precoat layer on a surface of said electroless barrier metal film, having a thickness so that an intermetallic compound layer having a bonded surface bonded substantially to the whole of the surface of said electroless barrier metal film is formed in said solder precoat layer in the vicinity of a boundary surface between said solder precoat film and said electroless barrier metal film.

2. The method of manufacturing an electrode of a semiconductor device as claimed in claim 1, further comprising the step of:

forming a solder bump on the solder precoat layer.

3. The method of manufacturing an electrode of a semiconductor device according to claim 2, wherein said step of forming a solder precoat layer is a step of forming a Pb—

Sn alloy containing lead not less than 37 wt %.

4. The method of manufacturing an electrode of a semiconductor device according to claim 2, wherein said step of forming a solder precoat layer is a step of forming a Pb—

Sn alloy containing lead not less than 50 wt %.

5. The method of manufacturing an electrode of a semiconductor device according to claim 2, wherein said solder bump is a spherical solder ball.

6. The method according to claim 2, wherein the intermetallic compound layer is formed in the solder bump.

7. The method of manufacturing an electrode of a semiconductor device according to claim 1, wherein said thickness is not larger than 15 μ

m.

8. The method of manufacturing an electrode of a semiconductor device according to claim 1, wherein said electroless barrier metal film is formed as a pad material diffusion prevention film.

9. The method of manufacturing an electrode of a semiconductor device according to claim 1, wherein said step of forming a solder precoat layer is a step of coating by a printing method.

10. The method of manufacturing an electrode of a semiconductor device according to claim 1, wherein said step of forming a solder precoat layer is a step of plating by electroless plating method.

11. The method according to claim 1, wherein the pad comprises copper.

12. A method of manufacturing an electrode of a semiconductor device comprising the steps of:

forming a pad having an upper surface and side surfaces on a substrate surface;

forming a passivation film on the substrate and on the side surfaces and portions of the upper surface of the pad, leaving an exposed portion of the upper surface of the pad;

forming an electroless barrier metal film, as a pad protection film, on said exposed upper surface of the pad, the barrier metal film having side surfaces abutting the passivation film on the upper surface of the pad; and

forming a solder precoat layer on a surface of said electroless barrier metal film, having a thickness so that an intermetallic compound layer having a bonded surface bonded substantially to the whole of the surface of said electroless barrier metal film is formed in said solder precoat layer in the vicinity of a boundary surface between said solder precoat film and said electroless barrier metal film.

13. The method according to claim 12, comprising forming the electroless barrier metal film directly on the exposed upper surface of the pad.

14. The method according to claim 12, wherein the pad comprises copper.

15. The method according to claim 12, comprising forming a solder bump on the solder precoat layer, wherein the intermetallic compound layer is formed within the solder bump.