Implantable microelectronic device and method of manufacture

• US 7,709,961 B2
• Filed: 10/25/2007
• Issued: 05/04/2010
• Est. Priority Date: 11/02/2005
• Status: Active Grant

• Current Assignee: Cortigent Incorporated
• Original Assignee: Second Sight Medical Products, Inc. (Vivani Medical, Inc.)
• Inventors: Greenberg, Robert J., Talbot, Neil Hamilton, Neysmith, Jordan Matthew, Ok, Jerry, Jiang, Honggang
• Primary Examiner(s): Smith; Zandra
• Assistant Examiner(s): Patton; Paul E
• Application Number:
  US11/924,486
• Publication Number:
  US 20080048330A1
• Time in Patent Office: 922 Days
• Field of Search: 257/690, 257/698, 257/701, 257/703, 257/729, 257/E23.01, 257/E23.011, 257E23116-E23118, 257E23124-E23126, 438/64, 438125-127
• US Class Current: 257/769
• CPC Class Codes: A61N 1/3754 Feedthroughs
• CPC Class Codes: H01L 2224/0345 Physical vapour deposition [PVD], e.g. evaporation, or sputtering
• CPC Class Codes: H01L 2224/0347 using a lift-off mask
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/05083 Three-layer arrangements
• CPC Class Codes: H01L 2224/05124 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/05147 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/05164 Palladium [Pd] as principal constituent
• CPC Class Codes: H01L 2224/05166 Titanium [Ti] as principal constituent
• CPC Class Codes: H01L 2224/05187 Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2224/05624 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/05647 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2224/13164 Palladium [Pd] as principal constituent
• CPC Class Codes: H01L 2224/13169 Platinum [Pt] as principal constituent
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48 of an individual wire connector
• CPC Class Codes: H01L 2224/85 using a wire connector
• CPC Class Codes: H01L 23/291 Oxides or nitrides or carbides, e.g. ceramics, glass
• CPC Class Codes: H01L 23/3107 : the device being completely enclosed
• CPC Class Codes: H01L 24/03 : Manufacturing methods
• CPC Class Codes: H01L 24/05 : of an individual bonding area
• CPC Class Codes: H01L 24/12 : Structure, shape, material or disposition of the bump connectors prior to the connecting process
• CPC Class Codes: H01L 24/85 : using a wire connector wire bonding in general B23K20/004
• 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 2924/00014 : 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 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/01015 : Phosphorus [P]
• CPC Class Codes: H01L 2924/01018 : Argon [Ar]
• CPC Class Codes: H01L 2924/01019 : Potassium [K]
• CPC Class Codes: H01L 2924/01022 : Titanium [Ti]
• CPC Class Codes: H01L 2924/01024 : Chromium [Cr]
• CPC Class Codes: H01L 2924/01027 : Cobalt [Co]
• CPC Class Codes: H01L 2924/01028 : Nickel [Ni]
• 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 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01077 : Iridium [Ir]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/04941 : TiN
• CPC Class Codes: H01L 2924/04953 : TaN
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/1433 : Application-specific integrated circuit [ASIC]
• CPC Class Codes: H01L 2924/207 : Diameter ranges
• CPC Class Codes: H01L 2924/351 : Thermal stress

Abstract

An implantable hermetically sealed microelectronic device and method of manufacture are disclosed. The microelectronic device of the present invention is hermetically encased in a insulator, such as alumina formed by ion bean assisted deposition (“IBAD”), with a stack of biocompatible conductive layers extending from a contact pad on the device to an aperture in the hermetic layer. In a preferred embodiment, one or more patterned titanium layers are formed over the device contact pad, and one or more platinum layers are formed over the titanium layers, such that the top surface of the upper platinum layer defines an external, biocompatible electrical contact for the device. Preferably, the bottom conductive layer is larger than the contact pad on the device, and a layer in the stack defines a shoulder.

Claims

1. A device, comprising:

a microelectronic device located on a silicon substrate, said microelectronic device having a conductive contact pad surrounded by electrically insulating material,

at least one patterned first metal layer formed on said contact pad and extending beyond the edge of said contact pad,

at least one patterned second metal layer formed over said first metal layer, said second metal layer having an exposed upper contact surface,

an electrically insulating material layer hermetically surrounding said microelectronic device and said patterned layers, said electrically insulating material layer having an aperture which exposes said upper contact surface.

2. The implantable device of claim 1 wherein the first metal layer comprises at least one patterned titanium layer.

3. The implantable device of claim 1 wherein the second layer comprises at least one patterned platinum layer.

4. The implantable device of claim 1 wherein said first layer defines a shoulder.

5. The device of claim 1, wherein said electrically insulating material is ceramic.

6. The device of claim 5, wherein said ceramic is alumina.

7. The device of claim 1, wherein said electrically insulating material is biocompatible.

8. The device of claim 1, wherein said aperture is filled with metal.

9. The device of claim 1, wherein said metal layer forms a shoulder over said contact pad.