Polymer sacrificial light absorbing structure and method

• US 20040157415A1
• Filed: 02/08/2003
• Published: 08/12/2004
• Est. Priority Date: 02/08/2003
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Goodner, Michael D.
• Granted Patent: US 6,876,017 B2
• Time in Patent Office: Days
• US Class Current: 438/496
• CPC Class Codes: H01L 21/76808 involving intermediate temporary filling with material
• CPC Class Codes: H01L 21/76835 Combinations of two or more different dielectric layers having a low dielectric constant H01L21/76832 takes precedence

Abstract

Method and structure for optimizing dual damascene patterning with polymeric dielectric materials are disclosed. Certain embodiments of the invention comprise polymeric sacrificial light absorbing materials (“polymer SLAM”) functionalized to have a controllable solubility switch wherein such polymeric materials have substantially the same etch rate as conventionally utilized polymeric dielectric materials, and subsequent to chemical modification of solubility-modifying protecting groups comprising the SLAM materials by thermal treatment or in-situ generation of an acid, such SLAM materials become soluble in weak bases, such as those conventionally utilized to remove materials in lithography treatments.

Claims

1. A microelectronic structure comprising:

a substrate layer;

a dielectric layer positioned adjacent the substrate layer, the dielectric layer comprising a dielectric polymer and defining a trench across the dielectric layer to the substrate layer; and

a SLAM layer substantially filling the trench, the SLAM layer comprising a SLAM polymer convertible to substantially the same solubility as the dielectric polymer.

2. The microelectronic structure of claim 1 wherein the dielectric polymer comprises a polymer from the list consisting of poly(norbornene), polyimide, polyarylene, poly(aryl ether), polystyrene, poly(p-phenylene), polyxylene, and cross-linked PMMA.

3. The microelectronic structure of claim 1 wherein the SLAM polymer comprises a polymer selected from the list consisting of poly(norbornene), polyimide, polyarylene, poly(aryl ether), polystyrene, poly(p-phenylene), polyxylene, and cross-linked PMMA.

4. The microelectronic structure of claim 1 wherein the SLAM polymer and dielectric polymer comprise substantially the same backbone.

5. The microelectronic structure of claim 1 wherein the SLAM polymer is functionalized with a protecting group.

6. The microelectronic structure of claim 5 wherein the protecting group comprises a compound selected from the list consisting of tert-butyl ester, tert-butoxycarbonate, adamantyl ester, adamantyl ether, adamantyl carbonate, alicyclic ester, alicyclic ether, alicyclic carbonate, alicyclic maleimide, alkyl ester, alkyl ether, alkyl carbonate, alkyl maleimide, aryl ester, aryl ether, aryl carbonate, aryl maleimide, ketal, and acetal.

7. The microelectronic structure of claim 1 wherein the SLAM polymer comprises a thermal acid generator.

8. The microelectronic structure of claim 1 wherein the SLAM polymer comprises a photo acid generator.

9. The microelectronic structure of claim 1 wherein the SLAM polymer formulation comprises a dye.

10. The microelectronic structure of claim 9 wherein the dye is a contained dye or a side group dye.

11. The microelectronic structure of claim 7 wherein the thermal acid generator is one selected from the list consisting of diaryl iodonium salts, sulfonate esters of oximes, sulfonate esters of benzyl alcohols, sulfonate esters of imides, N-allyl-N-dimethylanilinium hexafluoroantimonate salts, and N-crotyl-N-dimethylanilinium hexafluoroantimonate salts.

12. The microelectronic structure of claim 8 wherein the photo acid generator is one selected from the list consisting of diphenyl iodide hexafluorophosphate, diphenyl iodide hexafluoroarsenate, diphenyl iodide hexafluoroantimonate, diphenyl p-methoxyphenyl triflate, diphenyl p-tert-butylphenyl triflate, diphenyl p-isobutylphenyl triflate, diphenyl p-tert-butylphenyl triflate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroarsenate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium triflate, triphenylsulfonium nonafluorobutylsulfonate, diphenyliodonium heptadecafluorooctylsulphonate, and dibutylnaphthysulfonium triflate.

13. A method to form a microelectronic structure comprising:

forming a polymer dielectric layer adjacent a substrate layer;

forming a trench across the polymer dielectric layer to the substrate layer;

forming a polymer SLAM layer substantially filling the trench;

forming an enlarged trench across portions of the polymer dielectric layer and polymer SLAM layer, the enlarged trench having a bottom defined in part by the polymer SLAM layer and in part by the polymer dielectric layer; and

selectively removing the polymer SLAM layer.

14. The method of claim 13 wherein the bottom of the enlarged trench defines a substantially planar surface.

15. The method of claim 13 wherein selectively removing the polymer SLAM layer comprises converting the solubility of the polymer SLAM layer to a solubility substantially the same as that of the polymer dielectric layer.

16. The method of claim 15 wherein converting the solubility of the polymer SLAM comprises heating the polymer SLAM.

17. The method of claim 15 wherein converting the solubility of the polymer SLAM comprises irradiating the polymer SLAM.

18. The method of claim 16 wherein the polymer SLAM comprises a thermal acid generator.

19. The method of claim 18 wherein the polymer SLAM layer and the polymer dielectric layer comprise substantially the same polymer backbone.

20. The method of claim 17 wherein the polymer SLAM comprises a photo acid generator.

21. The method of claim 20 wherein the polymer SLAM layer and the polymer dielectric layer comprise substantially the same polymer backbone.

22. The method of claim 18 wherein the thermal acid generator comprises one selected from the grouping consisting of diaryl iodonium salts, sulfonate esters of oximes, sulfonate esters of benzyl alcohols, sulfonate esters of imides, N-allyl-N-dimethylanilinium hexafluoroantimonate salts, and N-crotyl-N-dimethylanilinium hexafluoroantimonate salts.

23. The method of claim 20 wherein the photo acid generator comprises one selected from the grouping consisting of diphenyl iodide hexafluorophosphate, diphenyl iodide hexafluoroarsenate, diphenyl iodide hexafluoroantimonate, diphenyl p-methoxyphenyl triflate, diphenyl p-tert-butylphenyl triflate, diphenyl p-isobutylphenyl triflate, diphenyl p-tert-butylphenyl triflate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroarsenate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium triflate, triphenylsulfonium nonafluorobutylsulfonate, diphenyliodonium heptadecafluorooctylsulphonate, and dibutylnaphthysulfonium triflate.

24. The method of claim 13 wherein the polymer dielectric layer comprises a polymer from the list consisting of poly(norbornene), polyimide, polyarylene, poly(aryl ether), polystyrene, poly(p-phenylene), polyxylene, and cross-linked PMMA.

25. The method of claim 13 wherein the polymer SLAM layer comprises a polymer selected from the list consisting of poly(norbornene), polyimide, polyarylene, poly(aryl ether), polystyrene, poly(p-phenylene), polyxylene, and cross-linked PMMA.

26. A polymer SLAM structure comprising:

a dielectric polymer having a polymeric backbone;

a dye; and

an acid catalyst for converting the solubility of the dielectric polymer.

27. The structure of claim 26 wherein the dielectric polymer comprises a polymer from the list consisting of poly(norbornene), polyimide, polyarylene, poly(aryl ether), polystyrene, poly(p-phenylene), polyxylene, and cross-linked PMMA.

28. The structure of claim 26 wherein the acid catalyst comprises a thermal acid generator.

29. The structure of claim 26 wherein the acid catalyst comprises a photo acid generator.

30. The structure of claim 28 wherein the thermal acid generator is one selected from the grouping consisting of diaryl iodonium salts, sulfonate esters of oximes, sulfonate esters of benzyl alcohols, sulfonate esters of imides, N-allyl-N-dimethylanilinium hexafluoroantimonate salts, and N-crotyl-N-dimethylanilinium hexafluoroantimonate salts.

31. The structure of claim 29 wherein the photo acid generator is one selected from the grouping consisting of diphenyl iodide hexafluorophosphate, diphenyl iodide hexafluoroarsenate, diphenyl iodide hexafluoroantimonate, diphenyl p-methoxyphenyl triflate, diphenyl p-tert-butylphenyl triflate, diphenyl p-isobutylphenyl triflate, diphenyl p-tert-butylphenyl triflate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroarsenate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium triflate, triphenylsulfonium nonafluorobutylsulfonate, diphenyliodonium heptadecafluorooctylsulphonate, and dibutylnaphthysulfonium triflate.