ORGANOMETALLIC SOLUTION BASED HIGH RESOLUTION PATTERNING COMPOSITIONS AND CORRESPONDING METHODS

• US 20160116839A1
• Filed: 10/22/2015
• Published: 04/28/2016
• Est. Priority Date: 10/23/2014
• Status: Active Grant

• Current Assignee: Inpria Corporation (JSR Corporation)
• Original Assignee: Inpria Corporation (JSR Corporation)
• Inventors: Meyers, Stephen T., Anderson, Jeremy T., Jiang, Kai, Keszler, Douglas A., Telecky, Alan J., Edson, Joseph Burton, Kocsis, Michael K., Cardineau, Brian J.
• Granted Patent: US 10,642,153 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G03F 7/0042 with inorganic or organometallic light-sensitive compounds not otherwise provided for, e.g. inorganic resists G03F7/075 takes precedence
• CPC Class Codes: G03F 7/0043 Chalcogenides; Silicon, germanium, arsenic or derivatives thereof; Metals, oxides or alloys thereof G03F7/0044 takes precedence
• CPC Class Codes: G03F 7/2004 characterised by the use of a particular light source, e.g. fluorescent lamps or deep UV light
• CPC Class Codes: G03F 7/32 Liquid compositions therefor, e.g. developers
• CPC Class Codes: G03F 7/322 Aqueous alkaline compositions
• CPC Class Codes: G03F 7/325 Non-aqueous compositions

Abstract

Organometallic radiation resist compositions are described based on tin ions with alkyl ligands. Some of the compositions have branched alkyl ligands to provide for improved patterning contrast while maintaining a high degree of solution stability. Blends of compounds with distinct alkyl ligands can provide further improvement in the patterning. High resolution patterning with a half-pitch of no more than 25 nm can be achieved with a line width roughness of no more than about 4.5 nm. Synthesis techniques have been developed that allow for the formation of alkyl tin oxide hydroxide compositions with very low metal contamination.

Claims

1. A coating solution comprising an organic solvent and a first organometallic compound represented by the formula RSnO_(3/2-x/2)(OH)_x where (0<

x<

3) with from about 0.0025M to about 1.5M tin in the solution, where R is an alkyl group or cycloalkyl group with 3-31 carbon atoms, where the alkyl or cycloalkyl group is bonded to the tin at a secondary or tertiary carbon atom.

2. The coating solution of claim 1 wherein the first organometallic compound comprises tert-butyl tin oxide hydroxide (R=—

C(CH₃)₃), iso-propyl tin oxide hydroxide (R=—

CH(CH₃)₂), tert-amyl tin oxide hydroxide (R=—

C(CH₂CH₃)(CH₃)₂) or mixtures thereof.

3. The coating solution of claim 1 further comprising a second organometallic compound distinct from the first organometallic compound and represented by the formula R′

SnO_(3/2-x/2)(OH)_x where (0<

x<

3) and R′

is a linear or branched alkyl or cycloalkyl group.

4. The coating solution of claim 1 wherein the organic solvent comprises an alcohol.

5. The coating solution of claim 1 having a viscosity from about 0.5 centipoises (cP) to about 150 cP and a tin concentration from about 0.01M to about 1.0M.

6. A coating solution comprising an organic solvent, a first organometallic compound represented by the formula RSnO_(3/2-x/2)(OH)_x where (0<

x<

3), where R is an alkyl group or cycloalkyl group with 3-31 carbon atoms, where the alkyl or cycloalkyl group is bonded to the tin at a secondary or tertiary carbon atom, and a second organometallic compound distinct from the first organometallic compound and represented by the formula R′

SnO_(3/2-x/2)(OH)_x where (0<

x<

3), where R′

is a linear or branched alkyl or cycloalkyl group and wherein R and R′

are not the same.

7. The coating solution of claim 6 wherein the first organometallic compound comprises tert-butyl tin oxide hydroxide (R=—

C(CH₃)₃), iso-propyl tin oxide hydroxide (R=—

CH(CH₃)₂), or tert-amyl tin oxide hydroxide (R=—

C(CH₂CH₃)(CH₃)₂).

8. The coating solution of claim 6 wherein R and R′

are each independently branched alkyl or cycloalkyl groups.

9. The coating solution of claim 6 wherein the second organometallic compound represents at least about 10 weight percent of the organometallic compounds in the coating solution.

10. The coating solution of claim 6 further comprising a third distinct organometallic compound represented by the formula R″

SnO_(3/2-x/2)(OH)_x where (0<

x<

3), where R″

is a linear or branched alkyl or cycloalkyl group wherein the third organometallic compound represents at least about 10 weight percent of the organometallic compounds in the coating solution.

11. The coating solution of claim 6 wherein the solvent comprises an alcohol and wherein the organometallic compounds result in a tin ion concentration from about 0.0025M to about 1.5M.

12. A method for patterning a film on a substrate, the method comprising:

exposing the film with EUV doses of no more than about 80 mJ/cm²; and

developing the film to form features at half-pitch no more than about 25 nm and linewidth roughness no more than about 5 nm.

13. The method of claim 12 wherein the EUV dose is from about 12 mJ/cm² to about 75 mJ/cm².

14. The method of claim 12 wherein the half-pitch is no more than about 18 nm.

15. The method of claim 12 wherein the organometallic film comprises a first organometallic compound represented by the formula RSnO_(3/2-x/2)(OH)_x where (0<

x<

3), where R is an alkyl group or cycloalkyl group with 3-31 carbon atoms, where the alkyl or cycloalkyl group is bonded to the tin at a secondary or tertiary carbon.

16. The method of claim 12 further comprising developing the film following exposure to form a negative image through the removal of unexposed portions of film.

17. The method of claim 12 further comprising developing the film following exposure to form a positive image through the removal of exposed portions of film.

18. A method for patterning an organometallic film on a substrate, the method comprising:

exposing the organometallic film to EUV radiation at a dose-to-gel value of no more than about 15 mJ/cm² to obtain a contrast of at least about 6.

19. A patterned structure comprising a substrate having a surface and a coating associated with the surface wherein at least portions of the coating are represented by the formulation (R)_zSnO_2-z/2-x/2 (OH)_x (0<

(x+z)<

4), where R is an alkyl group or cycloalkyl group with 3-31 carbon atoms, where the alkyl or cycloalkyl group is bonded to the tin at a secondary or tertiary carbon atom.

20. The patterned structure of claim 19 wherein z is less than about 1.

21. The patterned structure of claim 19 wherein z is less than about 1 and the ratio (2−

z/2−

x/2);

x is greater than about 1.

22. The patterned structure of claim 19 wherein the substrate comprises a polymer sheet, elemental silicon and/or a ceramic material.

23. The patterned structure of claim 19 wherein the coating has an average thickness of no more than about 50 nm.

24. The patterned structure of claim 19 wherein the coating forms a pattern at least a portion of which form features with a half-pitch of no more than about 25 nm.

25. A solution comprising a solvent and a compound represented by the formula RSnO_(3/2-x/2)(OH)_x where (0<

x<

3), where R is an alkyl, cycloalkyl or substituted alkyl moiety having from 1 to 31 carbon atoms, the solution having individual concentrations of contaminant metals of no more than about 1 ppm by weight.

26. The solution of claim 25 wherein R is an alkyl group or cycloalkyl group with 3-31 carbon atoms, where the alkyl or cycloalkyl group is bonded to the tin at a secondary or tertiary carbon atom.

27. The solution of claim 25 having concentrations of individual contaminant metals of no more than about 500 ppb by weight, wherein contaminant metals have a concentration of less than 100 ppm by weight.

28. The solution of claim 25 having concentrations of individual alkali and alkaline earth metals no more than about 100 ppb by weight.

29. A method for synthesizing a compound represented by the formula RSnOOH or RSnO_(3/2-x/2)(OH)_x (0<

x<

3), where R is an alkyl or cycloalkyl moiety having from 1 to 31 carbon atoms, the method comprising;

hydrolyzing a precursor composition having the formula RSnX₃, where X represents a halide atom (F, Cl, Br or I), or amido group(s), or combinations thereof wherein the hydrolysis is performed with sufficient water to effectuate the hydrolysis, wherein the hydrolysis product has individual concentrations of metals other than tin of no more than about 1 ppm by weight.

30. The method of claim 29 wherein the hydrolysis is performed with a quaternary ammonium hydroxide.

31. The method of claim 29 wherein the hydrolysis is performed in an organic solvent with sufficient water to effectuate the hydrolysis in a controlled reaction.

32. The method of claim 31 wherein the water is added to the organic solvent in a measured quantity.

33. The method of claim 31 wherein the water is absorbed form the ambient.