Dielectric tone inversion materials

Patent metadata

Field	Value
Publication number	US-9337033-B1
Application number	US-201514945456-A
Country	US
Kind code	B1
Filing date	Nov 19, 2015
Priority date	Oct 17, 2014
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

A process for patterning a hard mask material with line-space patterns below a 30 nm pitch and a 15 nm critical dimension by employing a spin-on titanium-silicon (TiSi) polymer or oligomer as a tone inversion material is provided. The spin-on TiSi material is spin-coated over a patterned OPL that includes a first pattern generated from a DSA based process. The spin-on TiSi material fill trenches within the patterned OPL to form a tone inverted pattern by removing the patterned OPL selective to the spin-on TiSi material. The inverted pattern is a complementary pattern to the first pattern, and is transferred into the underlying hard mask material by an anisotropic etch.

First claim

What is claimed is:

1. A process for patterning a hard mask material with line-space patterns below a 30 nm pitch and a 15 nm critical dimension by employing a spin-on titanium silicon (TiSi) material as a tone inversion material, comprising:
patterning an organic planarization (OPL) layer over a hard mask material with a line-space pattern below the 30 nm pitch and the 15 nm critical dimension;
formulating, filling, and overcoating the spin-on TiSi material into a patterned OPL layer;
etching back an excessive spin-on TiSi material, the excessive spin-on TiSi material overcoating the patterned OPL layer;
extracting the patterned OPL layer to achieve an inverted pattern; and
etching the inverted pattern into the hard mask material;
wherein:
the step of formulating, filling, and overcoating the spin-on TiSi material into the patterned OPL layer includes: (i) a first bake at an elevated temperature of 150 degrees Celsius for 60 seconds; and (ii) a second bake at an elevated temperature of 200 degrees Celsius for 60 seconds.

2. The process of claim 1 , wherein the patterned OPL layer has an OPL pattern that is transferred from a first pattern generated by a directed self assembly (DSA) process that is performed using one of a chemical epitaxy and a graphoepitaxy.

3. The process of claim 2 , wherein the OPL pattern is transferred from the first pattern by employing an O 2 -based plasma etching process selective to the spin-on TiSi material.

4. The process of claim 1 , wherein the filling and overcoating of the spin-on TiSi material into the patterned OPL layer is performed by a spin-coating process.

5. The process of claim 1 , wherein:
the spin-on TiSi material includes a silicon-containing recurring unit and a titanium-containing recurring unit; and
the spin-on TiSi material has a molecular weight in a range from 500 to 1500.

6. The process of claim 1 , wherein the hard mask material includes at least one of silicon nitride, silicon oxide, and silicon oxynitride.

7. The process of claim 1 , wherein the inverted pattern is complementary to the OPL pattern.

8. The process of claim 1 , wherein the inverted pattern is etched into the hard mask material using the inverted pattern as a mask by employing an etch process selective to the spin-on TiSi material.

9. The process of claim 8 , wherein the etch process includes at least a chlorine-based plasma etch process.

10. The process of claim 1 , wherein the spin-on TiSi material is a polymer or an oligomer having a polydispersity of less than 1.5.

11. The process of claim 10 , wherein the spin-on TiSi material is soluble in casting solvents having a close cup flash point greater than 35 degrees Celsius.

12. The process of claim 11 , wherein the solvents include: cyclohexanone and propylene glycol monomethyl ether acetate.

13. The process of claim 10 , wherein the spin-on TiSi material has twice the etch selectivity compared to a SiARC-like material.

14. The process of claim 1 , wherein the spin-on TiSi material is a spin-on TiSi oligomer.

15. The process of claim 1 , wherein a ratio of the numbers of repeat units of the silicon-containing unit with respect to the numbers of repeat units of the titanium-containing unit is in a range from 40:60 to 60:40.

Assignees

• IBM

Inventors

• Glodde Martin
• Huang Wu-Song
• Miyazoe Hiroyuki
• Sooriyakumaran Ratnam
• Tsai Hsinyu

Classifications

• H10P76/4085

  characterised by the processes involved to create the masks · CPC title

• H10P50/73

  using masks for insulating materials · CPC title

• H10P76/405 Primary

  characterised by their composition, e.g. multilayer masks · CPC title

• G03F7/0757

  Macromolecular compounds containing Si-O, Si-C or Si-N bonds (G03F7/0752 takes precedence) · CPC title

• H01L21/31138

  Electricity · mapped topic