Top layers of metal for high performance IC's

• US 6,620,728 B2
• Filed: 01/29/2002
• Issued: 09/16/2003
• Est. Priority Date: 12/21/1998
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Megic Corporation (Chipbond Technology Corporation)
• Inventors: Lin, Mou-Shiung
• Primary Examiner(s): Fourson, George
• Assistant Examiner(s): GARCIA, JOANNIE A
• Application Number:
  US10/058,259
• Publication Number:
  US 20020068441A1
• Time in Patent Office: 595 Days
• Field of Search: 438/637, 438/638, 438/FOR.355
• US Class Current: 438/637
• CPC Class Codes: H01L 21/768 Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
• 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 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 23/522 including external interconnections consisting of a multilayer structure of conductive and insulating layers inseparably formed on the semiconductor body
• CPC Class Codes: H01L 23/5222 Capacitive arrangements or effects of, or between wiring layers other capacitive arrangements H01L23/642
• CPC Class Codes: H01L 23/5223 Capacitor integral with wiring layers
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 23/5228 Resistive arrangements or effects of, or between, wiring layers other resistive arrangements H01L23/647
• CPC Class Codes: H01L 23/5286 Arrangements of power or ground buses
• CPC Class Codes: H01L 23/5329 Insulating materials
• CPC Class Codes: H01L 23/60 Protection against electrostatic charges or discharges, e.g. Faraday shields
• CPC Class Codes: H01L 27/0676 comprising combinations of diodes, or capacitors or resistors
• CPC Class Codes: H01L 27/08 including only semiconductor components of a single kind
• CPC Class Codes: H01L 28/10 Inductors
• CPC Class Codes: H01L 28/20 Resistors
• CPC Class Codes: H01L 2924/15174 in different layers of the multilayer substrate
• CPC Class Codes: H01L 2924/15184 in different layers of the multilayer substrate
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA

Abstract

A method of closely interconnecting integrated circuits contained within a semiconductor wafer to electrical circuits surrounding the semiconductor wafer. Electrical interconnects are held to a minimum in length by making efficient use of polyimide or polymer as an inter-metal dielectric thus enabling the integration of very small integrated circuits within a larger circuit environment at a minimum cost in electrical circuit performance.

Claims

1. A method for forming a top metallization system for high performance integrated circuits, comprising:

providing an integrated circuit comprising a plurality of devices formed in and on a semiconductor substrate, with an overlaying interconnecting metallization structure connected to said devices and comprising a plurality of first metal lines;

depositing a polymer insulating, separating layer over said semiconductor substrate;

forming openings through said polymer insulating, separating layer to expose upper metal portions of said interconnecting metallization structure;

forming said top metallization system in said openings and over said polymer insulating, separating layer, connected to said interconnecting metallization structure, wherein said top metallization system comprises a plurality of top metal lines, in one or more layers, having a width substantially greater than said first metal lines.

2. The method of claim 1 wherein said top metallization system comprises lines that are selected from the group consisting of signal lines, power buses and ground buses, or a combination thereof.

3. The method of claim 1 wherein said overlaying interconnecting metallization structure comprises electrical contact points whereby said contact points can comprise any appropriate contact material, such as but not limited to tungsten, copper (electroplated or electroless), aluminum, and polysilicon.

4. The method of claim 3 wherein a size of said contact points is within the range of approximately 0.3 um/to 5.0 um.

5. The method of claim 1 further comprising depositing a passivation layer over said interconnecting metallization structure.

6. The method of claim 5 wherein said passivation layer comprises Plasma Enhanced CVD (PECVD) oxide.

7. The method of claim 5 wherein said passivation layer comprises Plasma Enhanced CVD (PECVD) nitride.

8. The method of claim 1 wherein said polymer insulating, separating layer is selected from the group comprising polyimide and benzocyclobutene (BOB).

25. The method of claim 1 wherein said top metallization system comprises one or more layers of metal wherein each layer of metal is separated from adjacent layers of metal by thick insulator layers of polymer, wherein layers of metal that form said top metallization system are interconnected thereby forming a system of metal interconnect lines, wherein metal contacts and metal vias establish electrical contacts between layers within said top metallization system wherein said layers of metal comprises signal lines, ground lines or power lines, or any combination thereof.

9. A method for forming a top metallization system for high performance integrated circuits, comprising:

providing an integrated circuit comprising a plurality of devices formed in and on a semiconductor substrate, with an overlaying interconnecting metallization structure connected to said devices and comprising a plurality of fine-wire metal lines and with a passivation layer formed over said interconnecting fine-wire metallization structure;

depositing a polymer insulating, separating layer over said passivation layer that is substantially thicker than said passivation layer;

forming openings through said polymer insulating, separating layer to expose upper metal portions of said overlaying interconnecting metallization structure;

forming said top metallization system in said openings and over said polymer insulating, separating layer, connected to said overlaying interconnecting metallization structure, wherein said top metallization system comprises a plurality of top wide-metal lines, in one or more layers, having a width substantially greater than said fine-wire metal lines, and wherein said top metallization system is used to establish electrical interconnects between multiple points within said fine-wire interconnects.

10. The method of claim 9 wherein said top metallization system comprises signal lines that are substantially wider than lines in said interconnecting metallization structure.

11. The method of claim 9 wherein said top metallization system comprises power planes that are substantially wider than lines in said interconnecting metallization structure.

12. The method of claim 9 wherein said top metallization system comprises ground planes that are substantially wider than lines in said interconnecting metallization structure.

13. The method of claim 9 wherein said passivation layer comprises Plasma Enhanced CVD (PECVD) oxide.

14. The method of claim 9 wherein said passivation layer comprises Plasma Enhanced CVD (PECVD) nitride.

15. The method of claim 9 wherein said polymer insulating, separating layer comprises polyimide.

16. The method of claim 9 wherein said polymer insulating, separating layer comprises the polymer benzocyclobutene (BOB).

17. The method of claim 9 wherein said polymer insulating, separating layer is of a thickness after curing within a range of approximately 1.0 to 30 um.

18. The method of claim 9 wherein said polymer insulating, separating layer is spin-on coated and cured.

19. The method of claim 9 wherein said openings have an aspect ratio within a range of approximately 1 to 10.

20. The method of claim 9 wherein said metal contacts are selected from the group comprising sputtered aluminum, CVD tungsten, CVD copper, electroplated copper, electroless nickel and damascene metal filling.

21. The method of claim 9 wherein said openings through said polymer insulating, separating layer have sloping sides and wherein each of said openings are wider at their top.

22. The method of claim 9 thereby furthermore functionally and physically extending said top metallization system connected to said overlaying interconnecting metallization structure, wherein said top metallization system comprises a plurality of ground planes, in one or more layers, wherein furthermore said overlaying interconnecting metallization structure directly interconnects a multiplicity of ground wires said ground wires to be connected with fine-wire ground wires thereby functionally extending or connecting fine-wire ground wire metal interconnects with said wide-wire metal ground wire interconnects contained within said top metallization system thereby extending the fine-wire ground wires as contained within the overlaying interconnecting metallization structure with said top metallization system.

23. The method of claim 9 thereby furthermore functionally and physically extending said top metallization system connected to said overlaying interconnecting metallization structure, wherein said top metallization system comprises a plurality of signal planes, in one or more layers, wherein furthermore said overlaying interconnecting metallization structure directly interconnects a multiplicity of signal wires said signal wires to be connected with fine-wire signal wires thereby functionally extending or connecting fine-wire signal wire metal interconnects with said wide-wire metal signal wire interconnects contained within said top metallization system thereby extending fine-wire signal wires as contained within the overlaying interconnecting metallization structure with said top metallization system.

24. The method of claim 9 thereby furthermore functionally and physically extending said top metallization system connected to said overlaying interconnecting metallization structure, wherein said top metallization system comprises a plurality of power planes, in one or more layers, wherein furthermore said overlaying interconnecting metallization structure directly interconnects a multiplicity of power wires said power wires to be connected with fine-wire power wires thereby functionally extending or connecting fine-wire power wire metal interconnects with said wide-wire metal power wire interconnects contained within said top metallization system thereby extending fine-wire power wires as contained within an overlaying interconnecting metallization structure with said top metallization system.

26. A method for forming a top metallization system for high performance integrated circuits comprising:

providing an integrated circuit comprising a plurality of devices formed in and on a semiconductor substrate, with an overlaying interconnecting metallization structure connected to said devices and comprising a plurality of first metal lines in one or more layers, wherein intermetal dielectric layers are formed between said plurality of first metal lines and having a passivation layer formed over said interconnecting metallization structure;

depositing a polymer insulating, separating layer over said passivation layer that is substantially thicker than each of said intermetal dielectric layers;

forming openings through said polymer insulating, separating layer and said passivation layer to expose upper metal portions of said overlaying interconnecting metallization structure; and

forming said top metallization system in said openings and over said polymer insulating, separating layer, connected to said overlaying interconnecting metallization structure, wherein said top metallization system comprises a plurality of top metal lines, in one or more layers, each of said top metal lines having a width substantially greater than said first metal lines.

27. The method of claim 26 wherein said top metallization system further comprises one or more layers of metal whereby each layer of metal is separated from adjacent layers of metal by thick insulator layers of polymer, and wherein said thick insulator layers of polymer are substantially thicker than said intermetal dielectric layers.

29. The method of claim 27 wherein said thick insulator layers of polymer comprise an organic material, and wherein said intermetal dielectric layers comprise an inorganic material.

30. The method of claim 26 wherein said top metallization system is formed to provide fan-out capability, wherein a distance separating contact points in a top layer of said top metallization system is greater than a distance separating electrical contact points in said overlaying interconnecting metallization structure.

31. The method of claim 30 wherein said the number of said electrical contact points in said top metallization structure is larger than the number of said electrical contact points of said overlaying interconnecting metallization structure, by a substantial amount.

32. The method of claim 26 wherein said top metallization system is formed to provide relocation capability, wherein electrical contact points in a top layer of said top metallization system are connected to electrical contact points in said overlaying interconnecting metallization structure, wherein said relocation capability is provided by providing said electrical contact points in said top layer of said top metallization system in a different sequence than said electrical contact points in said overlaying interconnecting metallization structure.

33. The method of claim 26 wherein said top metallization system is formed to provide reduction capability, wherein electrical contact points in a top layer of said top metallization system are connected to electrical contact points, which are functionally equivalent to each other, in said overlaying interconnecting metallization structure, whereby the number of said electrical contact points in said top metallization system is less than the number of electrical contact points in said overlaying interconnecting metallization system.

35. The method of claim 26 wherein said integrated circuit comprising a plurality of devices formed in and on a semiconductor substrate, said overlaying interconnecting metallization structure connected to said devices, and said passivation layer, are manufactured in a sub-micron manufacturing facility, and wherein subsequent steps are performed in a less clean manufacturing facility, using less expensive manufacturing equipment than in said sub-micron manufacturing facility.

36. The method of claim 35 wherein said less clean manufacturing facility is a tens-micron manufacturing facility.

37. The method of claim 26 wherein said top metallization structure provides a means to standardize next level packaging.

38. The method of claim 37 wherein said next level packaging is Ball Grid Array (BGA) packaging.

39. The method of claim 26 wherein said top metallization structure provides means to simplify next level packaging.

40. The method of claim 26 further comprising forming solder balls on pads on a top layer of said top metallization structure, for connection to next level packaging.

41. The method of claim 26 further comprising bonding wires to pads on a top layer of said top metallization structure, for connection to next level packaging.

42. The method of claim 26 wherein openings between said top metal lines are wider than openings formed between said first metal lines in said interconnecting metallization structure.

28. A method for forming a top metallization system for high performance integrated circuits comprising:

providing an integrated circuit comprising a plurality of devices formed in and on a semiconductor substrate, with an overlaying interconnecting metallization structure connected to said devices and comprising a plurality of first metal lines in one or more layers, wherein intermetal dielectric layers are formed between said plurality of first metal lines;

providing a passivation layer over said interconnecting metallization structure;

depositing a polymer insulating, separating layer over said passivation layer that is substantially thicker than each of said intermetal dielectric layers;

forming openings through said polymer insulating, separating layer and said passivation layer to expose upper metal portions of said overlaying interconnecting metallization structure; and

forming said top metallization system in said openings and over said polymer insulating, separating layer, connected to said overlaying interconnecting metallization structure, wherein said top metallization system comprises a plurality of top metal lines, in one or more layers, each of said top metal lines having a thickness substantially greater than said first metal lines.

34. A method for forming a top metallization system for high performance integrated circuits comprising:

providing an integrated circuit comprising a plurality of devices formed in and on a semiconductor substrate, with an overlaying interconnecting metallization structure connected to said devices and comprising a plurality of first metal lines in one or more layers, wherein intermetal dielectric layers are formed between said plurality of first metal lines, and wherein said first metal lines are connected by first vias formed through said intermetal dielectric layers;

providing a passivation layer over said interconnecting metallization structure;

depositing a polymer insulating, separating layer over said passivation layer that is substantially thicker than each of said intermetal dielectric layers;

forming openings through said polymer insulating, separating layer and said passivation layer to expose upper metal portions of said overlaying interconnecting metallization structure, wherein said openings are substantially wider than said first vias in said intermetal dielectric layers; and

forming said top metallization system in said openings and over said polymer insulating, separating layer, connected to said overlaying interconnecting metallization structure, wherein said top metallization system comprises a plurality of top metal lines, in one or more layers.