Polymer sacrificial light absorbing structure and method

• US 6,876,017 B2
• Filed: 02/08/2003
• Issued: 04/05/2005
• Est. Priority Date: 02/08/2003
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Goodner, Michael D.
• Primary Examiner(s): Dang, Phuc T.
• Application Number:
  US10/360,709
• Publication Number:
  US 20040157415A1
• Time in Patent Office: 787 Days
• Field of Search: 438/496, 438/504, 438/534, 438/562, 438/634, 438/796, 257/254, 257/276, 257/410, 257/522, 257/664, 257/750, 257/758
• US Class Current: 257/254
• 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 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 functionalized with a protecting group and convertible from a first solubility to a second solubility by removal of the protecting group from the SLAM polymer.

14. The microelectronic structure of claim 13 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.

15. The microelectronic structure of claim 13 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.

16. The microelectronic structure of claim 13 wherein the SLAM polymer and dielectric polymer comprise substantially the same backbone.

17. 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, the dielectric polymer having a first etch rate; and

a SLAM layer substantially filling the trench, the SLAM layer comprising a SLAM polymer with a second etch rate substantially matching the first etch rate, the SLAM polymer being convertible from a first solubility to a second solubility, the second solubility being substantially more soluble than the first solubility.

18. The microelectronic structure of claim 17 wherein the SLAM polymer is functionalized with a protecting group.

19. The microelectronic structure of claim 18 wherein the SLAM polymer is convertible from the first solubility to the second solubility by removal of the protecting group.

20. The microelectronic structure of claim 18 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.

21. The microelectronic structure of claim 17, wherein the first and second solubilities are solubitities in a weak basic solution.

22. The microelectronic structure of claim 21 wherein the dielectric polymer has a third solubility in the weak basic solution, the third solubility being substantially less soluble in the weak basic solution than the second solubility.

23. The microelectronic structure of claim 22, wherein the weak basic solution comprises a solution selected from the list consisting of tetramethyl ammonium hydroxide and potassium hydroxide.

24. The microelectronic structure of claim 22 wherein the first and second etch rates are etching rates during a dry etch process.