Packaging of electronic chips with air-bridge structures

• US 20050285220A1
• Filed: 08/31/2005
• Published: 12/29/2005
• Est. Priority Date: 08/25/1999
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Farrar, Paul A.
• Granted Patent: US 7,387,912 B2
• Time in Patent Office: Days
• US Class Current: 257/522
• CPC Class Codes: H01L 21/7682 the dielectric comprising air gaps
• CPC Class Codes: H01L 23/20 gaseous at the normal operating temperature of the device
• CPC Class Codes: H01L 23/3677 Wire-like or pin-like cooling fins or heat sinks
• CPC Class Codes: H01L 23/4821 Bridge structure with air gap
• CPC Class Codes: H01L 23/5222 Capacitive arrangements or effects of, or between wiring layers other capacitive arrangements H01L23/642
• CPC Class Codes: H01L 23/5329 Insulating materials
• CPC Class Codes: H01L 23/66 High-frequency adaptations
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/1433 Application-specific integrated circuit [ASIC]
• CPC Class Codes: Y10S 438/977 Thinning or removal of substrate

Abstract

A circuit assembly for fabricating an air bridge structure and a method of fabricating an integrated circuit package capable of supporting a circuit assembly including an air bridge structure. A circuit assembly comprises an electronic chip and a conductive structure embedded in a plurality of materials having a plurality of vaporization temperatures. The plurality of materials is formed on the electronic chip and the conductive structure is coupled to the electronic chip. To fabricate the circuit assembly, a support structure, including interstices, is formed on an electronic chip. The interstices of the support structure are filled with a material having a vaporization temperature that is less than the vaporization temperature of the support structure. Conductive structures are embedded in the support structure and the material, and a connective structure is mounted on the support structure. Finally, the material is removed from the interstices by heating the circuit assembly.

Claims

1. A method of constructing an integrated circuit comprising:

fabricating a plurality of electronic devices on a substrate;

embedding a wiring structure in a plurality of materials having a plurality of vaporization temperatures, the plurality of materials is located on the substrate and the wiring structure interconnects the plurality of electronic devices;

mounting the integrated circuit on a packaging substrate; and

removing at least one of the plurality of materials after the integrated circuit is mounted on the packaging substrate.

2. The method of claim 1, further comprising:

attaching a C4 structure to the integrated circuit prior to mounting the integrated circuit on the packaging substrate.

3. The method of claim 2, wherein removing at least one of the plurality of materials after the integrated circuit is mounted on the packaging substrate comprises:

heating the integrated circuit.

4. The method of claim 3, wherein heating the integrated circuit comprises:

placing the integrated circuit in a furnace having an oxygen atmosphere heated to about 400 degrees centigrade.

5. A method of forming an air bridge structure comprising:

forming a support structure having a support structure vaporization temperature and having interstices on an electronic chip;

filling the interstices of the support structure with a fill material having a vaporization temperature that is less than the support structure vaporization temperature;

embedding a conductive structure in the support structure and the material;

mounting a connective structure on the support structure; and

removing the fill material.

6. The method of claim 5, wherein forming a support structure having a support structure vaporization temperature and having interstices on an electronic chip comprises:

depositing a layer of silicon dioxide on the electronic chip; and

etching the layer of silicon dioxide to form the support structure having interstices.

7. A method of forming an air bridge structure comprising:

forming a support structure having interstices on an electronic chip;

filling the interstices of the support structure with a fill material having a vaporization temperature that is less than the vaporization temperature of the support structure;

embedding a conductive structure in the fill material;

mounting a connective structure on the support structure; and

vaporizing the fill material.

8. The method of claim 7, wherein filling the interstices of the support structure with a material having a vaporization temperature that is less than the vaporization temperature of the support structure comprises:

depositing a layer of carbon on the electronic chip.

9. The method of claim 8, wherein depositing a layer of carbon on the electronic chip comprises:

sputtering the layer of carbon on the electronic chip.

10. The method of claim 9, further comprising:

planarizing the layer of carbon.

11. A method of forming an air bridge structure comprising:

forming a material layer on an electronic chip;

embedding a conductive structure and a conductive support structure in the material layer, the conductive structure is capable of electronically coupling to the electronic chip; and

removing the material layer.

12. The method of claim 11, wherein embedding a conductive structure and a conductive support structure in the material layer comprises:

etching the material layer to form a plurality of vertical wiring vias and a plurality of vertical support vias;

etching a wiring pattern in the material layer; and

applying a conductive material to the plurality of vertical wiring vias, the plurality of vertical support vias, and the wiring pattern.

13. The method of claim 12, wherein removing the material comprises:

vaporizing the material.

14. The method of claim 13, wherein vaporizing the material comprises:

processing the integrated circuit assembly in a furnace having an oxygen atmosphere at a temperature of approximately 400 degrees centigrade.

15. A method of forming an air bridge structure comprising:

forming a material layer on an electronic chip;

embedding a conductive structure and a conductive support structure in the material layer, the conductive structure is capable of being electronically coupled to the electronic chip;

mounting a connective structure on the support structure; and

removing the layer material.

16. The method of claim 15, further comprising:

attaching a heat sink to the electronic chip.

17. A method of packaging an integrated circuit comprising:

fabricating an integrated circuit structure including a conductive structure and a ribbed support structure embedded in a fill material;

mounting C4 pads on the integrated circuit structure;

mounting the integrated circuit structure on a substrate;

removing the fill material; and

backfilling with a gas and hermetically sealing the substrate.

18. The method of claim 17, wherein the gas is helium.

19. The method of claim 17, wherein the fill material is carbon.

20. The method of claim 17, wherein the fill material is a high temperature polymer.

21. The method of claim 17, wherein the high temperature polymer is polyimide.

22. The method of claim 17, where the structural material is a metal.

23. The method of claim 22, wherein the metal is copper.

24. The method of claim 17, wherein the structural material is SiO2.

25. The method of claim 17, wherein the structural material is Si3N4.