Extensions of self-assembled structures to increased dimensions via a “bootstrap” self-templating method

• US 8,372,295 B2
• Filed: 04/20/2007
• Issued: 02/12/2013
• Est. Priority Date: 04/20/2007
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Millward, Dan B.
• Primary Examiner(s): ALANKO, ANITA KAREN
• Application Number:
  US11/738,169
• Publication Number:
  US 20080286659A1
• Time in Patent Office: 2,125 Days
• Field of Search: None
• US Class Current: 216/2
• CPC Class Codes: B81B 2203/0361 Tips, pillars
• CPC Class Codes: B81C 1/00031 Regular or irregular arrays of nanoscale structures, e.g. etch mask layer photomechanical, e.g. photolithographic, production of textured or patterned surfaces G03F7/00; lithographic processes for making patterned surfaces using printing and stamping G03F7/0002
• CPC Class Codes: B81C 2201/0149 Forming nanoscale microstructures using auto-arranging or self-assembling material
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: G03F 7/0002 Lithographic processes using patterning methods other than those involving the exposure to radiation, e.g. by stamping
• 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
• CPC Class Codes: H01L 21/3086 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
• CPC Class Codes: H01L 21/76879 by selective deposition of conductive material in the vias, e.g. selective C.V.D. on semiconductor material, plating plating on semiconductors in general H01L21/288
• CPC Class Codes: H01L 23/544 Marks applied to semiconductor devices or parts, e.g. registration marks, alignment structures, wafer maps test patterns for characterising or monitoring manufacturing processes H01L22/00
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: Y10T 428/24182 Inward from edge of web or sheet
• CPC Class Codes: Y10T 428/24612 Composite web or sheet

Abstract

Methods for fabricating sublithographic, nanoscale arrays of openings and linear microchannels utilizing self-assembling block copolymers, and films and devices formed from these methods are provided. Embodiments of the invention use a self-templating or multilayer approach to induce ordering of a self-assembling block copolymer film to an underlying base film to produce a multilayered film having an ordered array of nanostructures that can be removed to provide openings in the film which, in some embodiments, can be used as a template or mask to etch openings in an underlying material layer.

Claims

1. A method for fabricating a film comprising nanoscale microstructures, comprising:

forming a first film comprising a self-assembling block copolymer within a trench in a substrate, the trench having a floor, sidewalls, a width and a length;

annealing the first film to form a base layer comprising self-assembled polymer domains registered to the sidewalls and extending the length of the trench;

crosslinking polymer domains of the base layer;

forming a second film comprising a self-assembling block copolymer over the crosslinked base layer and over the substrate adjacent the trench, the second film having a thickness over the substrate insufficient for the second film to self-assemble to form ordered structures upon annealing;

annealing the second film within the trench and on the substrate to self-assemble the second film within the trench to form polymer domains registered to corresponding polymer domains of the base layer and the annealed film on the substrate outside the trench comprises non-ordered polymer material; and

crosslinking polymer domains of the second film.

2. The method of claim 1, further comprising:

forming a third film comprising a self-assembling block copolymer over the crosslinked second film;

annealing the third film to self-assemble the third film to form polymer domains registered to corresponding polymer domains of the second film; and

crosslinking polymer domains of the third film.

3. The method of claim 1, wherein the second film comprises perpendicularly-oriented, alternating lamellar domains of first and second polymer blocks registered to the annealed base film.

4. The method of claim 3, wherein the base layer comprises perpendicularly-oriented, alternating lamellar domains of the first and second polymer blocks.

6. The method of claim 1, wherein the base layer and the second film comprise perpendicularly-oriented cylinders of a first polymer domain extending through a matrix of a second polymer domain to the floor of the trench.

7. The method of claim 6, wherein the base layer comprises a single row of cylinders with a pitch distance between each cylinder of about L_o.

8. The method of claim 1, wherein the trench has a depth of about nL_o where n is 2 or greater, and the first film is formed from a lamellar-phase block copolymer.

9. The method of claim 1, wherein the trench has a depth of less than L_o, and the first film is formed from a cylindrical-phase block copolymer.

10. The method of claim 1, further comprising selectively removing one of the polymer domains to form a plurality of openings exposing the floor of the trench.

28. The method of claim 1, further comprising removing the non-ordered polymer material on the substrate outside the trench.

5. A method for fabricating a film comprising nanoscale microstructures, comprising:

forming a first film comprising a self-assembling block copolymer within a trench in a substrate, the trench having a preferential wetting floor, sidewalls, a width and a length;

annealing the first film to form a base film comprising lines of parallel-oriented half-cylinder polymer domains registered to the sidewalls and extending the length of the trench;

crosslinking polymer domains of the base film;

forming a second film comprising a self-assembling block copolymer over the crosslinked base layer and over the substrate adjacent the trench, the second film having a thickness over the substrate insufficient for the second film to self-assemble to form ordered structures upon annealing;

annealing the second film within the trench and on the substrate to form polymer domains registered to corresponding polymer domains of the base film within the trench, wherein the annealed second film on the substrate outside the trench comprises non-ordered polymer material; and

crosslinking polymer domains of the second film.

11. A method for fabricating a film comprising nanoscale microstructures, comprising:

forming a first film comprising a self-assembling block copolymer within a trench in a substrate, the trench having a floor, sidewalls, a width and a length;

annealing the first film to form a base layer comprising self-assembled polymer domains registered to the sidewalls and extending the length of the trench;

crosslinking polymer domains of the base layer;

forming a second film comprising a self-assembling block copolymer over the crosslinked base layer and over the substrate adjacent the trench, the second film having a thickness over the substrate insufficient for the second film to self-assemble to form ordered structures upon annealing;

annealing the second film within the trench and on the substrate to self-assemble the second film within the trench to form polymer domains registered to corresponding polymer domains of the base layer and the annealed second film on the substrate outside the trench comprises non-ordered polymer material;

crosslinking polymer domains of the second film;

removing non-ordered polymer material on the substrate outside the trench; and

repeating the acts of forming a second film, annealing the second film, crosslinking the second film, and removing non-ordered polymer material on the substrate outside the trench to form a multi-layered film comprising self-assembled polymer domains registered to underlying and corresponding polymer domains.

12. A method for fabricating a film comprising nanoscale microstructures, comprising:

forming a first film within a trench in a substrate, the first film comprising a block copolymer comprising first and second polymer blocks and capable of microphase separating and self-assembling upon annealing, the trench having a floor, sidewalls, a width, and a length;

annealing the first film to cause a microphase separation of the polymer blocks to form a base layer comprising self-assembled polymer domains registered to the sidewalls and extending the length of the trench;

crosslinking polymer domains of the base layer;

forming a second film over the crosslinked base layer and over the substrate adjacent the trench, the second film comprising a block copolymer comprising first and second polymer blocks and capable of microphase separating and self-assembling upon annealing, the second film having a thickness over the substrate insufficient to self-assemble to form ordered structures upon annealing;

annealing the second film within the trench and on the substrate to cause a microphase separation of the polymer blocks to form self-assembled polymer domains of the first polymer block and the second polymer block registered to the corresponding domains of the base layer within the trench, wherein the annealed second film on the substrate outside the trench comprises non-ordered polymer material; and

crosslinking polymer domains of the self-assembled second film.

13. A method for fabricating a film comprising nanoscale microstructures, comprising:

forming a first film comprising a lamellar-phase self-assembling block copolymer within a trench in a substrate, the trench having a floor, sidewalls, a width and a length;

annealing the first film to form a base layer comprising self-assembled lamellar polymer domains spanning the width and extending the length of the trench in a substantially parallel orientation to the sidewalls;

crosslinking polymer domains of the base layer;

forming a second film comprising a self-assembling lamellar-phase block copolymer over the crosslinked base layer and over the substrate adjacent the trench, the second film having a thickness over the substrate insufficient for the second film to self-assemble to form ordered structures upon annealing;

annealing the second film within the trench and on the substrate to self-assemble the second film within the trench to form lamellar polymer domains registered to corresponding lamellar polymer domains of the crosslinked base layer and the annealed second film on the substrate outside the trench comprises non-ordered polymer material; and

crosslinking polymer domains of the self-assembled second film.

14. The method of claim 13, wherein the sidewalls are preferentially wetting.

15. A method for fabricating a film comprising nanoscale microstructures, comprising:

forming a first film comprising a cylindrical-phase self-assembling block copolymer within a trench in a substrate, the trench having a width, a length, sidewalls, and a preferential wetting floor;

annealing the first film to form a base layer comprising lines of self-assembled half-cylinder polymer domains spanning the width, registered to the sidewalls and extending the length of the trench in a substantially parallel orientation to the sidewalls within a matrix of a second polymer domain;

crosslinking polymer domains of the base layer;

forming a second film comprising a self-assembling block copolymer over the crosslinked base layer and the substrate adjacent the trench, the second film having a thickness over the substrate insufficient for the second film to self-assemble to form ordered structures upon annealing;

annealing the second film within the trench and on the substrate to self-assemble the second film within the trench to form polymer domains registered to corresponding polymer domains of the base layer, and the annealed second film on the substrate outside the trench comprises non-ordered polymer material; and

crosslinking polymer domains of the self-assembled second film.

16. The method of claim 15, wherein the second film comprises a lamellar-phase self-assembling block copolymer, and the annealed second film comprises perpendicular-oriented lamellar phase polymer domains.

17. A method for fabricating a film comprising nanoscale microstructures, comprising:

forming a first film comprising a cylindrical-phase self-assembling block copolymer within a trench in a substrate, the trench having a width, a length, sidewalls and a trench floor;

annealing the first film to form a base layer comprising perpendicular-oriented cylinders of a first polymer domain within and extending through a matrix of a second polymer domain to the trench floor;

crosslinking polymer domains of the base layer;

forming a second film comprising a self-assembling block copolymer over the crosslinked base layer;

annealing the second film within the trench and on the substrate to self-assemble the second film to form polymer domains registered to corresponding polymer domains of the base layer within the trench and the annealed second film on the substrate outside the trench comprises non-ordered polymer material; and

crosslinking polymer domains of the self-assembled second film.

18. The method of claim 17, wherein the perpendicular-oriented cylinders extend the length of the trench in a single row.

19. The method of claim 17, wherein the perpendicular-oriented cylinders are in a hexagonal array.

20. A method for fabricating a film comprising nanoscale microstructures, comprising:

forming a first film comprising a cylindrical-phase block copolymer within a trench in a substrate, the trench having sidewalls, a floor, a width and a length;

annealing the first film to form a base layer comprising parallel lines of surface-exposed half-cylinder domains of a first polymer block in a matrix of a second polymer block, the half-cylinder domains registered to the sidewalls and extending the length of the trench, wherein a pitch distance between each half-cylinder domain is about L_o;

crosslinking polymer domains of the base layer;

forming a second film comprising a lamellar-phase block copolymer over the crosslinked base layer and over the substrate adjacent the trench, the second film having a thickness over the substrate insufficient for the second film to self-assemble to form ordered structures upon annealing;

annealing the second film within the trench and on the substrate to self-assemble the second film within the trench to form a single array of perpendicularly oriented, alternating lamellar domains of the first polymer block and the second polymer block registered to corresponding polymer domains of the base layer, and the film on the substrate outside the trench comprises non-ordered polymer material; and

crosslinking polymer domains of the self-assembled second film.

21. A method for fabricating a film comprising nanoscale microstructures, comprising:

forming a first film comprising a cylindrical-phase self-assembling block copolymer within a trench in a substrate, the trench having a width, a length, sidewalls, and a floor;

annealing the first film to form a base layer comprising self-assembled, perpendicular-oriented cylindrical polymer domains of a first polymer domain within and extending through a matrix of a second polymer domain to the trench floor, the self-assembled, perpendicular-oriented cylindrical polymer domains extending the length of the trench in a single array and a substantially parallel orientation to the sidewalls;

crosslinking polymer domains of the base layer;

forming a second film comprising a self-assembling cylindrical-phase block copolymer over the crosslinked base layer and over the substrate adjacent the trench, the second film having a thickness over the substrate insufficient for the second film to self-assemble to form ordered structures upon annealing;

annealing the second film within the trench and on the substrate to self-assemble the second film within the trench to form cylindrical polymer domains registered to corresponding polymer domains of the crosslinked, annealed base layer and the second film on the substrate outside the trench comprises non-ordered polymer material; and

crosslinking polymer domains of the self-assembled second film.

22. A method of etching a substrate, comprising:

forming an etch mask, comprising;

forming a first film comprising a self-assembling block copolymer within a trench in a substrate, the trench having a floor, sidewalls, a width and a length;

annealing the first film to form a base layer comprising self-assembled polymer domains registered to the sidewalls and extending the length of the trench;

crosslinking polymer domains of the base layer;

forming a second film comprising a self-assembling block copolymer over the crosslinked base layer and over the substrate adjacent the trench, the second film having a thickness over the substrate insufficient for the second film to self-assemble to form ordered structures upon annealing;

annealing the second film within the trench and on the substrate to self-assemble the second film within the trench to form polymer domains registered to corresponding polymer domains of the base layer and the second film on the substrate outside the trench comprises non-ordered polymer material;

crosslinking polymer domains of the self-assembled second film; and

selectively removing a first polymer domain to form an array of openings separated by a second polymer domain; and

etching a substrate through the array of openings.

23. The method of claim 22, wherein the openings have an aspect ratio of about 1:

2 to about 1;

20.

24. The method of claim 22, wherein the openings have a width of about 5-50 nm.

25. The method of claim 22, wherein the base layer and the second film comprise alternating, perpendicular-oriented lamellae of the first and second polymer domains, and selectively removing the first polymer domain forms a linear array of openings extending the length of the trench and parallel to the sidewalls.

26. A method of etching a substrate, comprising:

forming an etch mask, comprising;

forming a base film within a trench in a substrate, the trench having a floor, sidewalls, a width and a length, the base film comprising lines of parallel-oriented half-cylinders of a first polymer domain in a matrix of a second polymer domain, the parallel-oriented half-cylinder lines registered to the sidewalls and extending the length of the trench;

crosslinking the polymer domains of the base film;

forming a second film comprising a lamellar-phase block copolymer over the crosslinked base film and over the substrate adjacent the trench, the second film having a thickness over the substrate insufficient for the second film to self-assemble to form ordered structures upon annealing;

annealing the second film within the trench and on the substrate to self-assemble the second film within the trench to form lamellar domains registered to corresponding polymer domains of the base layer and the second film on the substrate outside the trench comprises non-ordered polymer material;

crosslinking polymer domains of the second film; and

selectively removing the lamellar domains of the second film and the underlying half-cylinders of the base layer to form a linear array of openings extending the length of the trench and parallel to the sidewalls; and

removing a portion of the matrix to extend the openings to expose the floor of the trench; and

etching the substrate through the openings.

27. A method of etching a substrate, comprising:

forming an etch mask, comprising;

forming a base film comprising a first block copolymer within a trench in a substrate, the trench having a floor, sidewalls, a width and a length, the base film comprising perpendicular-oriented cylinders of a first polymer domain in a matrix of a second polymer domain, the perpendicular-oriented cylinders extending through the matrix to the floor of the trench;

crosslinking polymer domains of the base film;

forming a second block copolymer film over the crosslinked base film and over the substrate adjacent the trench, the second block copolymer film having a thickness over the substrate insufficient for the second block copolymer film to self-assemble to form ordered structures upon annealing; and

annealing the second block copolymer film within the trench and on the substrate to self-assemble the second block copolymer film within the trench to form perpendicular-oriented cylinders of a first polymer domain registered to corresponding perpendicular-oriented cylinders of the base layer and the second block copolymer film on the substrate outside the trench comprises non-ordered polymer material;

crosslinking polymer domains of the second film; and

selectively removing the first polymer domain to form an array of cylindrical openings; and

etching a substrate through the array of cylindrical openings.