Apparatus for electroless plating a contact pad

• US 20010052318A1
• Filed: 08/01/2001
• Published: 12/20/2001
• Est. Priority Date: 02/24/1999
• Status: Active Grant

• Current Assignee: Li Li, Tongbi Jiang
• Original Assignee: Li Li, Tongbi Jiang
• Inventors: Jiang, Tongbi, Li, Li
• Granted Patent: US 6,451,116 B2
• Time in Patent Office: Days
• US Class Current: 118/403
• CPC Class Codes: H01L 21/02052 Wet cleaning only H01L21/02085 takes precedence
• CPC Class Codes: H01L 21/288 from a liquid, e.g. electrolytic deposition
• CPC Class Codes: H01L 21/76826 by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76828 thermal treatment
• CPC Class Codes: H01L 21/76834 formation of thin insulating films on the sidewalls or on top of conductors H01L21/76831 takes precedence
• CPC Class Codes: H01L 21/76838 characterised by the formation and the after-treatment of the conductors etching for patterning the conductors H01L21/3213
• CPC Class Codes: H01L 21/7685 the layer covering a conductive structure H01L21/76849 takes precedence
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• 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 24/03 Manufacturing methods
• CPC Class Codes: H01L 24/05 of an individual bonding area
• 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 2924/01014 Silicon [Si]
• CPC Class Codes: H01L 2924/01016 Sulfur [S]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01075 Rhenium [Re]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/05042 : Si3N4
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/19043 : being a resistor
• CPC Class Codes: Y10S 134/902 : Semiconductor wafer

Abstract

A method and apparatus is disclosed for sequential processing of integrated circuits, particularly for conductively passivating a contact pad with a material which resists formation of resistive oxides. In particular, a tank is divided into three compartments, each holding a different solution: a lower compartment and two upper compartments divided by a barrier, which extends across and partway down the tank. The solutions have different densities and therefore separate into different layers. In the illustrated embodiment, integrated circuits with patterned contact pads are passed through one of the upper compartments, in which oxide is removed from the contact pads. Continuing downward into the lower compartment and laterally beneath the barrier, a protective layer is selectively formed on the insulating layer surrounding the contact pads. As the integrated circuits are moved upwardly into the second upper compartment, a conducting monomer selectively forms on the contact pads prior to any exposure to air. The integrated circuits can then be transferred to an ozone chamber where polymerization results in a conductive passivation layer on the contact pad.

Claims

1. An apparatus for sequential processing with a plurality of liquid solutions, the apparatus comprising a water-tight tank having an upper portion and a lower portion, the upper portion divided into at least a first side and a second side by a water-tight barrier, the lower portion open to and extending beneath both the first side and the second side, wherein the first side of the upper portion holds a first treatment fluid, the lower portion holds a second treatment fluid, and the second side of the upper portion holds a third treatment fluid, each of the first, second and third treatment fluids being different.

2. The apparatus of

claim 1

, wherein the first treatment fluid comprises a cleaning solution.

3. The apparatus of

claim 2

, wherein the cleaning solution comprises an oxide etchant.

4. The apparatus of

claim 2

, wherein the second treatment fluid comprises a siliconizing solution.

5. The apparatus of

claim 4

, wherein the siliconizing solution comprises dichloro-octamethyl-tetrasiloxane.

6. The apparatus of

claim 4

, wherein the third treatment fluid comprises a plating solution.

7. The apparatus of

claim 6

, wherein the plating solution comprises a conducting monomer

8. The apparatus of

claim 1

, wherein the apparatus further comprising an ozone chamber, wherein the second side of the upper portion communicates exclusively with the lower portion and the ozone chamber.

9. The apparatus of

claim 1

, wherein the tank comprises sidewalls formed of Teflon™

.

10. An apparatus for sequential in situ cleaning and formation of a conductive passivation layer on a conductive element in an integrated circuit, the apparatus comprising:

a tank;

a first liquid treatment phase within the tank, comprising a cleaning solution having a first density; and

a second liquid treatment phase within the tank, the second phase having a second density different from the first density, the second phase being immiscible and in direct contact with the first phase; and

a third liquid treatment phase having a third density different from the second density, the third phase being immiscible with the second phase and in direct contact therewith.

11. The apparatus of

claim 10

, wherein the first phase is aqueous and the second phase comprises an organic solvent.

12. The apparatus of

claim 10

, wherein the second phase is more dense than the first phase and extends thereunder.

13. The apparatus of

claim 10

, wherein the second phase selectively forms a protective layer over an insulating layer surrounding the conductive element and the third phase selectively forms a conducting material over the conductive element.

14. The apparatus of

claim 13

, wherein the conductive element comprises a bond pad for connecting the integrated circuit to an outside circuit.

15. An apparatus for sequential in situ cleaning and formation of a conductive passivation layer on a conductive element in an integrated circuit, the apparatus comprising:

a tank;

a first liquid treatment phase within the tank, comprising a cleaning solution having a first density;

a second liquid treatment phase within the tank, the second phase having a second density different from the first density, the second phase being immiscible and in direct contact with the first phase, wherein the second phase comprises an organic solvent; and

a third liquid treatment phase within the tank, the third phase having a third density different from the second density, the third phase being immiscible and in direct contact with the second phase, wherein the second phase comprises a plating solution.

16. The apparatus of

claim 15

, wherein the first phase is aqueous.