EUV RESIST ETCH DURABILITY IMPROVEMENT AND PATTERN COLLAPSE MITIGATION

• US 20160109804A1
• Filed: 10/14/2015
• Published: 04/21/2016
• Est. Priority Date: 10/16/2014
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Huli, Lior
• Granted Patent: US 9,791,779 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G03F 7/0035 Multiple processes, e.g. applying a further resist layer on an already in a previously step, processed pattern or textured surface
• CPC Class Codes: G03F 7/32 Liquid compositions therefor, e.g. developers
• CPC Class Codes: G03F 7/40 Treatment after imagewise removal, e.g. baking
• CPC Class Codes: H01L 21/0271 comprising organic layers
• CPC Class Codes: H01L 21/0274 Photolithographic processes
• CPC Class Codes: H01L 21/0337 characterised by the process involved to create the mask, e.g. lift-off masks, sidewalls, or to modify the mask, e.g. pre-treatment, post-treatment

Abstract

A method for patterning a substrate is described. The patterning method includes receiving a first patterned layer overlying a material layer to be etched on a substrate, wherein the first patterned layer is composed of a resist material having (i) material properties that provide lithographic resolution of less than about 40 nanometers when exposed to extreme ultraviolet radiation lithography, and (ii) material properties that provide a nominal etch resistance to an etch process condition. The first patterned layer is over-coated with an image reversal material such that the image reversal material fills and covers the first patterned layer. The patterning method further includes removing an upper portion of the image reversal material such that top surfaces of the first patterned layer are exposed, and removing the first patterned layer such that the image reversal material remains resulting in a second patterned layer.

Claims

1. A method for patterning a substrate, the method comprising:

receiving a first patterned layer overlying a material layer to be etched on a substrate, the first patterned layer being composed of a resist material having (i) material properties that provide lithographic resolution of less than about 40 nanometers when exposed to extreme ultraviolet (EUV) radiation lithography, and (ii) material properties that provide a nominal etch resistance to an etch process condition selected to etch the material underlying the first patterned layer, wherein the first patterned layer is characterized by features having a height-to-width ratio of less than 1.5-to-1;

over-coating the first patterned layer with an image reversal material such that the image reversal material fills and covers the first patterned layer, wherein the image reversal material has material properties that provide an etch resistance to the etch process condition that exceeds the nominal etch resistance;

removing an upper portion of the image reversal material such that top surfaces of the first patterned layer are exposed; and

removing the first patterned layer such that the image reversal material remains resulting in a second patterned layer.

2. The method of claim 1, further comprising:

transferring the pattern of the second patterned layer into the material layer.

3. The method of claim 2, further comprising:

over-coating the patterned, material layer with a second image reversal material such that the second image reversal material fills and covers the patterned, material layer;

removing an upper portion of the second image reversal material such that top surfaces of the patterned, material layer are exposed; and

removing the patterned, material layer such that the second image reversal material remains resulting in a third patterned layer.

4. The method of claim 1, further comprising:

over-coating the second patterned layer with a second image reversal material such that the second image reversal material fills and covers the second patterned layer, wherein the second image reversal material has material properties that provide an etch resistance to the etch process condition that exceeds the nominal etch resistance;

removing an upper portion of the second image reversal material such that top surfaces of the second patterned layer are exposed; and

removing the second patterned layer such that the second image reversal material remains resulting in a third patterned layer.

5. The method of claim 4, further comprising:

transferring the pattern of the third patterned layer into the material layer.

6. The method of claim 1, wherein:

the first patterned layer comprises a high-speed resist, an extreme ultra-violet (EUV) resist, or an electron-beam resist.

7. The method of claim 6, wherein the EUV resist is a high-speed resist.

8. The method of claim 7 wherein the high-speed resist is a halfnium oxide-containing resist.

9. The method of claim 1, wherein:

the first patterned layer comprises a thermal freeze resist, an electromagnetic freeze resist, or a chemical freeze resist.

10. The method of claim 1, wherein:

the image reversal material is an organic or inorganic material.

11. The method of claim 1, wherein:

the image reversal material is a metal-containing material, a silicon-containing material, or a silicon anti-reflective coating (ARC) material.

12. The method of claim 1, wherein:

the image reversal material is a hard-cross linking material.

13. The method of claim 1, wherein:

the over-coating the first patterned layer includes an etch-back step or a stop and fill followed by an etch-back step.

14. The method of claim 13, wherein:

reversal agents for the image reversal material includes polymers with a residual develop-back capability.

15. The method of claim 13, wherein:

the reversal agents for the image reversal material includes oxide films processed with a chemical-mechanical planarization step or followed by an etch-back and a dry etch process.

16. The method of claim 13, wherein:

the image reversal material uses a non-resist material wherein an isotropic etch is performed to slim and etch-back the image reversal material.

17. The method of claim 1, wherein:

over-coating the first patterned layer includes a chemical trim overcoat where applied acid diffuses from a top down and changes solubility of the first patterned layer.

18. The method of claim 17, wherein:

the first patterned layer is baked so that the acid diffuses downwardly, resulting in the image reversal material having a top-down solubility profile.

19. The method of claim 1, wherein:

top surfaces of the first patterned layer are exposed following the overcoating of the first patterned layer.

20. The method of claim 1, wherein:

removing the first patterned layer is performed using a solvent vapor process, a chemical spin coating process, a resist developing process, a solvent spin coating process, a dry etch process or a wet etch process.

21. A method for patterning a substrate, the method comprising:

receiving a first patterned layer overlying a material layer to be etched on a substrate, the first patterned layer being composed of a resist material having (i) material properties that provide lithographic resolution of less than about 40 nanometers when exposed to extreme ultraviolet (EUV) radiation lithography, and (ii) material properties that provide a nominal etch resistance to an etch process condition selected to etch the material underlying the first patterned layer, wherein the first patterned layer is characterized by features having a height-to-width ratio of less than 1.5-to-1;

over-coating the first patterned layer with an image reversal material such that the image reversal material fills and covers the first patterned layer, wherein the image reversal material has material properties that provide an etch resistance to the etch process condition that exceeds the nominal etch resistance;

removing an upper portion of the image reversal material such that top surfaces of the first patterned layer are exposed;

removing the first patterned layer such that the image reversal material remains resulting in a second patterned layer; and

controlling one or more selected operating variables which are concurrently controlled during one or more operations including over-coating the first patterned layer with the image reversal material, removing the upper portion of the image reversal material, and/or removing the first patterned layer such that the image reversal material remains results in a second patterned layer, the controlling done in order to achieve patterning objectives.