Memory system with conductive structures embedded in foamed insulator

• US 6,979,848 B2
• Filed: 06/24/2002
• Issued: 12/27/2005
• Est. Priority Date: 08/25/1999
• Status: Expired due to Fees

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Technology, Inc.
• Inventors: Farrar, Paul A.
• Primary Examiner(s): Abraham, Fetsum
• Application Number:
  US10/179,091
• Publication Number:
  US 20020175405A1
• Time in Patent Office: 1,282 Days
• Field of Search: 257296-310, 257758-760
• US Class Current: 257/296
• CPC Class Codes: H01L 21/02118 carbon based polymeric organic or inorganic material, e.g. polyimides, poly cyclobutene or PVC polymers per se C08G, photoresist per se G03F
• CPC Class Codes: H01L 21/02126 the material containing Si, O, and at least one of H, N, C, F, or other non-metal elements, e.g. SiOC, SiOC:H or SiONC
• CPC Class Codes: H01L 21/02282 liquid deposition, e.g. spin-coating, sol-gel techniques, spray coating
• CPC Class Codes: H01L 21/02337 treatment by exposure to a gas or vapour
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/31058 of organic layers
• CPC Class Codes: H01L 21/312 Organic layers, e.g. photoresist H01L21/3105, H01L21/32 take precedence; photoresists per se G03C
• CPC Class Codes: H01L 21/321 After treatment
• CPC Class Codes: H01L 21/7682 the dielectric comprising air gaps
• CPC Class Codes: H01L 23/5329 Insulating materials
• 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: H05K 1/024 Dielectric details, e.g. changing the dielectric material around a transmission line
• CPC Class Codes: H05K 1/0346 containing N

Abstract

A conductive system and a method of forming an insulator for use in the conductive system is disclosed. The conductive system comprises a foamed polymer layer on a substrate. The foamed polymer layer has a surface that is hydrophobic, and a plurality of conductive structures are embedded in the foamed polymer layer. An insulator is formed by forming a polymer layer having a thickness on a substrate. The polymer layer is foamed to form a foamed polymer layer having a surface and a foamed polymer layer thickness, which is greater than the polymer layer thickness. The surface of the foamed polymer layer is treated to make the surface hydrophobic.

Claims

1. A computer system comprising:

a processor;

a memory system coupled to the processor, the memory system is on a substrate and comprises a plurality of devices; and

an interconnect system comprising;

a foamed polymer layer having a plurality of cells, each cell having a cell size of less than about 0.1 microns, the foamed polymer layer on the substrate; and

a plurality of conductive structures embedded in the foamed polymer layer, and each of the plurality of conductive structures is capable of interconnecting at least two of the plurality of devices.

2. The computer system of claim 1, wherein the foamed polymer layer is parylene.

3. The computer system of claim 1, wherein the each of the plurality of conductive structures has a separation distance and the separation distance is less than about one micron.

4. A computer system comprising:

a processor; and

a memory device coupled to the processor, the memory device on a substrate, the memory device having a plurality of electronic devices coupled through an interconnect system the interconnect system including;

a foamed material layer having a surface that is hydrophobic; and

a plurality of conductive structures embedded in the foamed material layer.

5. The computer system of claim 4,wherein the foamed material layer is a foamed parylene layer.

6. The computer system of claim 4, wherein the foamed material layer has a dielectric constant between about 0.9 and about 1.8.

7. The computer system of claim 4, wherein the foamed material layer has a plurality of cells with an average cell size less than about 1 micron.

8. The computer system of claim 4, wherein the foamed material layer has a plurality of cells with an average cell size less than about 0.1 micron.

9. The computer system of claim 4, wherein the plurality of conductive structures has a separation distance and the foamed material layer has a plurality of cells with an average cell size less than the separation distance.

10. The computer system of claim 4, wherein the foamed material layer has a thickness that is about three times the thickness of an unfoamed material layer from which it is has been formed.

11. A computer system comprising:

a processor; and

a memory device coupled to the processor, the memory device on a substrate, the memory device having a plurality of electronic devices coupled through an interconnect system, the interconnect system including;

a foamed aerogel layer having a surface that is hydrophobic; and

a plurality of conductive structures embedded in the foamed aerogel layer.

12. The computer system of claim 11, wherein the foamed aerogel layer has a thickness between about 1.8 microns and about 2.4 microns.

13. The computer system of claim 11, wherein the conductive structures include a metal selected from a group consisting of silver, aluminum, gold, copper, and tungsten.

14. The computer system of claim 11, wherein the foamed aerogel layer has a thickness that is about three times the thickness of an unfoamed material layer from which it is has been formed.

15. A computer system comprising:

a processor; and

a memory device coupled to the processor, the memory device on a substrate, the memory device having a plurality of electronic devices coupled through an interconnect system, the interconnect system including;

a foamed polymer layer having a surface that is hydrophobic; and

a plurality of conductive structures embedded in the foamed polymer layer.

16. The computer system of claim 15, wherein the foamed polymer layer is a foamed fluro-polymer layer.

17. The computer system of claim 15, wherein the foamed polymer layer is a foamed polyimide layer.

18. The computer system of claim 15, wherein the foamed polymer layer is a foamed fluorinated polyimide layer.

19. The computer system of claim 15, wherein the foamed polymer layer is a foamed polymer layer containing silane.

20. A computer system comprising:

a processor; and

a memory device coupled to the processor, the memory device on a substrate, the memory device having a plurality of electronic devices coupled through an interconnect system, the interconnect system including;

a plurality of stacked foamed material layers on the substrate, each of the stacked foamed material layers having a surface that is hydrophobic; and

a plurality of conductive structures embedded in each of the plurality of foamed material layers.

21. The computer system of claim 20, wherein the foamed material layers are foamed polyimide layers.

22. The computer system of claim 20, wherein the foamed material layers are foamed aerogel layers.

23. The computer system of claim 20, wherein the foamed material layers are foamed polymer layers.

24. The computer system of claim 20, wherein the foamed material layers are foamed parylene layers.

25. The computer system of claim 20, wherein the foamed material layers have a dielectric constant between about 0.9 and about 1.8.

26. The computer system of claim 20, wherein the plurality of conductive structures have a separation distance and the foamed material layers have a plurality of cells with an average cell size less than the separation distance.

27. The computer system of claim 20, wherein the foamed material layers have a thickness that is about three times the thickness of each unfoamed material layer from which each foamed material layer has been formed.

28. A computer system comprising:

a processor; and

a memory device coupled to the processor, the memory device on a substrate, the memory device having a plurality of electronic devices coupled through an interconnect system, the interconnect system including;

an air-bridge structure coupling two of the electronic devices, the air-bridge structure having a surface that is hydrophobic.

29. The computer system of claim 28, wherein the air-bridge structure includes a metal selected from a group consisting of alloys of silver, aluminum, gold, copper, and tungsten.

30. The computer system of claim 28, wherein the air-bridge structure includes a metal selected from a group consisting of silver, aluminum, gold, copper, and tungsten.

31. A computer system comprising:

a processor; and

a memory device coupled to the processor, the memory device on a substrate, the memory device having a plurality of electronic devices coupled through an interconnect system the interconnect system including;

a foamed material layer having a surface that is hydrophobic; and

a plurality of conductive structures embedded in the foamed material layer;

the foamed material layer formed by exposing an unfoamed material layer to a supercritical fluid to form the material layer.

32. The computer system of claim 31, wherein the supercritical fluid is CO2.

33. The computer system of claim 31, wherein the unfoamed material layer is subjected to a low temperature bake before forming the foamed material layer.

34. The computer system of claim 31, wherein exposing an unfoamed material layer to a supercritical fluid further includes depressurizing at a rate such that the unfoamed material layer converts to the foamed material layer before substantial diffusion of the supercritical fluid out of the unfoamed material layer.

35. The computer system of claim 31, wherein the supercritical fluid is selected from a group consisting of NH3, NR3, ROH, H2O, CO2, N2O, He, Ne, Ar, HF, HCl, HBr, BCl3, Cl2, F2, O2, N2, CH4, C2H6, C3H8, C2H4, CO(OCH3)2, CF4, C2F4, CH3F, and C5H2F6O2.

36. A computer system comprising:

a processor; and

a memory device coupled to the processor, the memory device on a substrate, the memory device having a plurality of electronic devices coupled through an interconnect system, the interconnect system including;

a foamed material layer having a surface that is hydrophobic; and

a plurality of conductive structures embedded in the foamed material layer;

the surface of the foamed material layer formed hydrophobic by exposing the surface of the foamed material layer to a plurality of methane radicals.

37. The computer system of claim 36, wherein the plurality of methane radicals is formed by passing methane gas through a plasma.

38. The computer system of claim 36, wherein the plurality of methane radicals is formed by using a high frequency electric field.

39. The computer system of claim 36, wherein the foamed material layers are foamed polyimide layers.

40. The computer system of claim 36, wherein the foamed material layers are foamed parylene layers.

41. A computer system comprising:

a processor; and

a memory device coupled to the processor, the memory device on a substrate, the memory device having a plurality of electronic devices coupled through an interconnect system, the interconnect system including;

a foamed aerogel layer having a surface that is hydrophobic; and

a plurality of conductive structures embedded in the foamed aerogel layer;

the foamed aerogel layer having a hydrophobic surface being formed by exposing an unfoamed aerogel layer to a supercritical fluid to form the foamed aerogel layer, and exposing the surface of the foamed aerogel layer to a plurality of methane radicals.

42. The computer system of claim 41, wherein the supercritical fluid is CO2.

43. The computer system of claim 41, wherein the foamed aerogel layer has a plurality of cells with an average cell size less than about 1 micron.

44. The computer system of claim 41, wherein the plurality of methane radicals is formed by passing methane gas through a plasma.

45. A computer system comprising:

a processor; and

a memory device coupled to the processor, the memory device on a substrate, the memory device having a plurality of electronic devices coupled through an interconnect system, the interconnect system including;

an air-bridge structure coupling two of the electronic devices, the air-bridge structure having a surface that is hydrophobic;

the surface of the air-bridge structure formed hydrophobic by exposing the surface of the foamed material layer to a plurality of methane radicals.

46. The computer system of claim 45, wherein the plurality of methane radicals is formed by passing methane gas through a plasma.

47. The computer system of claim 45, wherein the plurality of methane radicals is formed by using a high frequency electric field.

48. The computer system of claim 45, wherein the air-bridge structure includes a metal selected from a group consisting of silver, aluminum, gold, copper, tungsten, and alloys of silver, aluminum, gold, copper, and tungsten.