Patterned organometallic photoresists and methods of patterning

Patent metadata

Field	Value
Publication number	US-11480874-B2
Application number	US-201916654080-A
Country	US
Kind code	B2
Filing date	Oct 16, 2019
Priority date	Oct 17, 2018
Publication date	Oct 25, 2022
Grant date	Oct 25, 2022

Abstract

A rinse process is described for processing an initially patterned structure formed with an organometallic radiation sensitive material, in which the rinse process can remove portions of the composition remaining after pattern development to make the patterned structure more uniform such that a greater fraction of patterned structures can meet specifications. The radiation sensitive material can comprise alkyl tin oxide hydroxide compositions. The rinsing process can be effectively used to improve patterning of fine structures using extreme ultraviolet light.

First claim

What is claimed is:

1. A method for forming an adjusted patterned structure, the method comprising rinsing an initial patterned structure with a rinse solution to remove a portion of developed photoresist to control pattern dimensions and to form an adjusted patterned structure,
wherein the initial patterned structure was formed by (i) coating the surface of the substrate with an organometallic radiation sensitive resist material to form the radiation sensitive resist film, (ii) exposing the radiation sensitive resist film to patterned radiation to form an exposed film with exposed portions and unexposed portions, and (iii) contacting the exposed film with a developing solution to form a developed photoresist wherein either the exposed portions or the unexposed portions are selectively soluble in the developing solution.

2. The method of claim 1 wherein the rinse solution comprises aqueous quaternary ammonium hydroxide and the developing solution comprises an organic solvent.

3. The method of claim 1 wherein the developing solution comprises aqueous quaternary ammonium hydroxide and the rinse solution comprises an organic solvent.

4. The method of claim 1 wherein the rinse solution is about 0.5 to 30 weight percent aqueous tetramethyl ammonium hydroxide (TMAH).

5. The method of claim 1 wherein the organometallic radiation sensitive resist material comprises an alkyltin oxide hydroxide approximately represented by the formula R z SnO (2-z/2-x/2) (OH) x , where 0<x<3, 0<z≤2, x+z≤4, and R is a hydrocarbyl group forming a carbon bond with the tin atom.

6. The method of claim 1 wherein the organometallic radiation sensitive resist material comprises monoalkytin oxide hydroxide.

7. The method of claim 1 wherein the developing solution comprises a ketone.

8. The method of claim 1 wherein the developing solution comprises 2-heptanone.

9. The method of claim 1 wherein the substrate is a silicon wafer.

10. The method of claim 1 wherein the radiation sensitive resist film is exposed to extreme ultraviolet radiation at a dose of no more than about 100 mJ/cm 2 or with an electron beam at a dose no more than about 2 mC/cm 2 at 30 kV.

11. The method of claim 1 wherein the patterned structure has an initial dry thickness prior to the step of rinsing, and a final dry thickness after the step of rinsing, wherein the initial dry thickness is from about 1 nm to about 50 nm and the final dry thickness is from about 1 nm to about 50 nm.

12. The method of claim 1 wherein the rinse solution is about 0.5 to about 30 weight percent aqueous tetramethyl ammonium hydroxide, aqueous tetrapropylammonium hydroxide, aqueous tetrabutylammonium hydroxide, or combinations thereof.

13. The method of claim 1 wherein the initial patterned structure is rinsed with the rinsing solution for at least about one (1) second.

14. The method of claim 1 wherein a duration of rinsing and a concentration of the rinse solution are selected to produce a desired feature size of the patterned structure.

15. The method of claim 1 wherein the rinsing solution comprises tetramethylammonium hydroxide (TMAH), and wherein a space sizing and a pitch of the patterned radiation, duration of rinse, and a concentration of the TMAH in the solution are selected to produce a desired feature size and/or resolution of the adjusted patterned structure.

16. The method of claim 1 wherein the adjusted patterned structure has an average line-width roughness that is no more than about 5 nm.

17. The method of claim 1 further comprising:
either a step of A) depositing a material based on the adjusted patterned structure or B) etching the substrate based on the adjusted patterned structure; and
removing the adjusted patterned structure to form a processed substrate.

18. The method of claim 17 further comprising forming a subsequent patterned structure on the processed substrate.

19. The method of claim 1 further comprising forming the initial patterned structure wherein the developing solution comprises an organic solvent and wherein the rinse solution comprises a quaternary ammonium hydroxide.

20. The method of claim 1 wherein the rinsing step is performed using a puddle method wherein the rinsing solution is applied to the surface of the initial patterned structure and dried by spinning and/or blowing following a selected period of time.

21. The method of claim 1 wherein the radiation sensitive resist material comprises a monoalkyl tin oxide hydroxide.

22. The method of claim 21 wherein the radiation sensitive resist material is exposed to extreme ultraviolet radiation at a dose of no more than about 100 mJ/cm 2 , the initial dry thickness of the patterned structure is no more than about 50 nm, and wherein a duration of rinse and concentration of the rinsing solution are selected to produce a desired feature size and/or resolution of the patterned structure.

23. The method of claim 1 wherein the radiation sensitive resist material is suitable for either positive tone or negative tone development, and wherein if the initial pattern is formed using a developer to form a negative tone pattern, the rinse composition comprises a suitable composition to perform positive development of the radiation sensitive resist material, or if the initial pattern is formed with a developer to form a positive tone pattern, the rinse composition comprises a suitable composition to form a negative tone pattern.

Assignees

• Inpria Corp

Inventors

• Kocsis Michael
• De Schepper Peter
• Greer Michael
• Chang Shu-Hao

Classifications

• G03F7/405

  Treatment with inorganic or organometallic reagents after imagewise removal · CPC title

• G03F7/0042 Primary

  with inorganic or organometallic light-sensitive compounds not otherwise provided for, e.g. inorganic resists (G03F7/075 takes precedence) · CPC title

• G03F7/2004

  characterised by the use of a particular light source, e.g. fluorescent lamps or deep UV light · CPC title

• G03F7/322 Primary

  Aqueous alkaline compositions · CPC title

• G03F7/70033

  by plasma extreme ultraviolet [EUV] sources · CPC title