Classifications

• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D3/00—Electroplating: Baths therefor
  • C25D3/02—Electroplating: Baths therefor from solutions
  • C25D3/30—Electroplating: Baths therefor from solutions of tin
  • C25D3/32—Electroplating: Baths therefor from solutions of tin characterised by the organic bath constituents used
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D3/00—Electroplating: Baths therefor
  • C25D3/02—Electroplating: Baths therefor from solutions
  • C25D3/56—Electroplating: Baths therefor from solutions of alloys
  • C25D3/60—Electroplating: Baths therefor from solutions of alloys containing more than 50% by weight of tin
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D7/00—Electroplating characterised by the article coated
  • C25D7/12—Semiconductors
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D7/00—Electroplating characterised by the article coated
  • C25D7/12—Semiconductors
  • C25D7/123—Semiconductors first coated with a seed layer or a conductive layer

Definitions

• Exemplary compounds useful as the first grain refiner include, but are not limited to, cinnamic acid, cinnamaldehyde, benzylidene acetone, picolinic acid, pyridinedicarboxylic acid, pyridinecarboxaldehyde, pyridinedicarboxaldehyde, or mixtures thereof.
• Preferred first grain refiners include cinnamic acid, cinnamaldehyde, and benzylidene acetone.
• the first grain refiner is present in the plating baths of the invention in an amount of 0.0001 to 0.045 g/L.
• the first grain refiner is present in an amount of 0.0001 to 0.04 g/L, more preferably in an amount of 0.0001 to 0.035 g/L, and yet more preferably from 0.0001 to 0.03 g/L.
• Compounds useful as the first grain refiners are generally commercially available from a variety of sources and may be used as is or may be further purified.
• the second grain refiner is present in the plating baths of the invention in an amount of 0.005 to 0.75 g/L.
• the second grain refiner is present in an amount of 0.005 to 0.5 g/L, more preferably in an amount of 0.005 to 0.25 g/L, and yet more preferably from 0.01 to 0.25 g/L.
• Compounds useful as the second grain refiners are generally commercially available from a variety of sources and may be used as is or may be further purified.
• semiconductor substrates includes any substrate having one or more semiconductor layers or structures which include active or operable portions of semiconductor devices.
• semiconductor substrate is defined to mean any construction comprising semiconductive material, including but not limited to bulk semiconductive material such as a semiconductive wafer, either alone or in assemblies comprising other materials thereon, and semiconductive material layers, either alone or in assemblies comprising other materials.
• a semiconductor device refers to a semiconductor substrate upon which at least one microelectronic device has been or is being batch fabricated.
• Semiconductor wafers comprising a plurality of bonding features are electroplated by contacting the wafer with a plating bath of the present invention and applying a current density for a period of time to deposit a tin-containing layer on the plurality of bonding features.
• the semiconductor wafer functions as the cathode.
• the conductive interconnect bump pad may be one or more layers of a metal, composite metal or metal alloy typically formed by physical vapor deposition (PVD) such as sputtering.
• PVD physical vapor deposition
• Typical conductive bonding features comprise, without limitation, aluminum, copper, titanium nitride, and alloys thereof.
• Example 1 An electroplating composition for depositing pure tin was prepared by combining 75 g/L tin (from tin methanesulfonate), 140 g/L methanesulfuonic acid, 8.8 g/L of an ethoxylated beta-naphthol nonionic surfactant, 9.7 g/L of an ethoxylated bisphenol A nonionic surfactant, 0.0166 g/L of benzylidene acetone as the first grain refiner, 0.1 g/L of methacrylic acid as the second grain refiner, 1.5 g/L of alcohol solvent, 1 g/L of a commercial antioxidant, and DI water (balance). The pH of the composition was ⁇ 1.
• Electroplating was done until a mushroom shaped tin cap of 23 ⁇ m height was plated on top of copper pillars. Morphology of the resulting tin layer was inspected with a Hitachi S2460TM scanning electron microscope. The pure tin deposits were uniform, smooth, compact, and free of nodules.
• the resulting tin-silver solder bump deposit was flat and had a smooth morphology with a mean surface roughness of 150 nm as measured using a Leica DCM3D optical profilometer.
• the tin-silver solder deposit was reflowed using a Falcon 8500 tool (Sikama International, Inc.) having 5 heating and 2 cooling zones, using temperatures of 140/190/230/230/260° C, with a 30 second dwell time, and a conveyor rate of ca. 100 cm/min. and a nitrogen flow rate of 40 cubic feet/hour.
• the solder deposits were fluxed with Alpha 100-40 flux.
• the reflowed tin-silver deposit was evaluated using a Cougar microfocus X-ray system (YXLON International GmbH, Hamburg, Germany) and was found to be free of voids.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Electroplating And Plating Baths Therefor (AREA)
• Electroplating Methods And Accessories (AREA)

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• 2013
  • 2013-11-05 US US14/071,677 patent/US20150122661A1/en not_active Abandoned
• 2014
  • 2014-11-05 CN CN201410858388.9A patent/CN104674312A/zh active Pending
  • 2014-11-05 JP JP2014224805A patent/JP2015092021A/ja active Pending
  • 2014-11-05 KR KR1020140153138A patent/KR20150051926A/ko not_active Application Discontinuation
  • 2014-11-05 TW TW103138319A patent/TW201533278A/zh unknown
  • 2014-11-05 EP EP14191882.1A patent/EP2868775A3/fr not_active Withdrawn

Patent Citations (7)

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