Adhesion by plasma conditioning of semiconductor chip

• US 7,319,275 B2
• Filed: 02/01/2005
• Issued: 01/15/2008
• Est. Priority Date: 09/14/2001
• Status: Expired due to Fees

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Odegard, Charles, Yamunan, Vinu, Coffman, Phillip R., Murtuza, Masood, Cowens, Marvin W.
• Primary Examiner(s): Zarneke; David A.
• Application Number:
  US11/047,519
• Publication Number:
  US 20050161834A1
• Time in Patent Office: 1,078 Days
• Field of Search: 257/778, 257/789, 257/793, 257/795
• US Class Current: 257/778
• CPC Class Codes: H01L 21/563 Encapsulation of active face of flip-chip device, e.g. underfilling or underencapsulation of flip-chip, encapsulation preform on chip or mounting substrate
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/04042 Bonding areas specifically adapted for wire connectors, e.g. wirebond pads
• CPC Class Codes: H01L 2224/05022 the internal layer being at least partially embedded in the surface
• CPC Class Codes: H01L 2224/05027 the internal layer extending out of an opening
• CPC Class Codes: H01L 2224/05552 in top view
• CPC Class Codes: H01L 2224/05559 non conformal layer on a patterned surface
• CPC Class Codes: H01L 2224/05572 the external layer extending out of an opening
• CPC Class Codes: H01L 2224/05624 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/13006 Bump connector larger than the underlying bonding area, e.g. than the under bump metallisation [UBM]
• 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 2224/131 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 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 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48624 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/48724 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/73203 : Bump and layer connectors
• CPC Class Codes: H01L 2224/73204 : the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 23/3128 : the substrate having spherical bumps for external connection
• CPC Class Codes: H01L 23/3142 : Sealing arrangements between parts, e.g. adhesion promotors
• CPC Class Codes: H01L 23/4334 : Auxiliary members in encapsulations H01L23/49568 takes precedence
• 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 24/45 : of an individual wire 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 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01007 : Nitrogen [N]
• 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 2924/01023 : Vanadium [V]
• CPC Class Codes: H01L 2924/01028 : Nickel [Ni]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01032 : Germanium [Ge]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01049 : Indium [In]
• CPC Class Codes: H01L 2924/0105 : Tin [Sn]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/01087 : Francium [Fr]
• 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 2924/05042 : Si3N4
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/12044 : OLED
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15311 : being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/181 : Encapsulation

Abstract

A plasma conditioning method of improving the adhesion between an integrated circuit chip, having active and passive surfaces, the active surface polymer-coated and having a plurality of electrical coupling members, and an insulating underfill material. The method comprises the steps of positioning a wafer having a plurality of integrated circuits, including the coupling members, in a vacuum chamber of a plasma apparatus so that the polymer-coated surface faces the plasma source. Next, a plasma is initiated; the ion mean free path is controlled so that the ions reach the wafer surface with predetermined energy. The wafer surface is then exposed to the plasma for a length of time sufficient to roughen the polymer surface, clean the polymer surface from organic contamination and improve the surface affinity to adhesion. The adhesion ability of this surface to organic underfill material is thus enhanced.

Claims

1. A semiconductor device comprising:

an integrated circuit chip having active and passive surfaces, said active surface polymer-coated with a roughened surface opposing said active surface and having a plurality of electrical coupling members coupled to said active surface;

a substrate,

said chip assembled face-down onto said substrate, said coupling members forming a gap between said polymer coat and said substrate; and

polymeric underfill material filling said gap, said underfill material adhering to said polymer-coat and said substrate;

said adhesion of said underfill material being sufficiently strong so that a force applied externally to said semiconductor device breaks said substrate prior to or rather than breaking the interface between said underfill and said polymer-coat and/or said substrate.

2. The device according to claim 1 further comprising:

encapsulation material protecting said passive chip surface and at least a portion of said substrate not covered by said attached chip; and

solder balls attached to said substrate opposite to the attached chip and encapsulation material.

3. The device according to claim 1 wherein said semiconductor chip comprises silicon, silicon germanium, gallium arsenide, or any other semiconductor material used in electronic device production.

4. The device according to claim 1 wherein said polymer coat is made of polyimide (PIQ) or poly-benzoxasole (PBO) in the thickness range from about 2 to 8 μ

m.

5. The device according to claim 1 wherein said electrical coupling members are solder bumps selected from a group consisting of tin/silver, indium, tin/indium, tin/bismuth, tin-lead, conductive adhesives, and solder-coated spheres, and have a diameter from about 50 to 200 μ

m.

6. The device according to claim 1 wherein said electrical coupling members are bumps selected from a group consisting of gold bumps, copper bumps, copper/nickel/palladium bumps, and z-axis conductive epoxy.

7. The device according to claim 5 wherein said solder bumps have a center-to-center spacing between about 100 and 500 μ

m.

8. The device according to claim 1 wherein said underfill material is an epoxy filled with boron nitride or with aluminum nitride;

the epoxy is a bisphenol A with an anhydride cross-linking agent.

9. The device according to claim 1 wherein said substrate is made of organic material and is selected from a group consisting of polyimide film, FR-4, FR-5 and BT resin and may contain a plurality of electrically conductive interconnection lines, as well as strengthening fillers including a grid of glass fibers.

10. The device according to claim 2 wherein said encapsulation material is a molding compound.