Spin-On Layer for Directed Self Assembly with Tunable Neutrality

Patent metadata

Field	Value
Publication number	US-2016276149-A1
Application number	US-201615068833-A
Country	US
Kind code	A1
Filing date	Mar 14, 2016
Priority date	Mar 17, 2015
Publication date	Sep 22, 2016
Grant date	—

Abstract

Techniques disclosed herein include methods for creating a directed self-assembly tunable neutral layer that works with multiple different block copolymer materials. Techniques herein can include depositing a neutral layer and then post-processing this neutral layer to tune its characteristics so that the neutral layer is compatible with a particular block copolymer scheme or schemes. Post-processing herein of such a neutral layer can modify a ratio of pi and sigma bonds in a given carbon film or other film to approximate a given self-assembly film that will be deposited on this neutral layer. Accordingly, a generic or single material can be used for a neutral layer and modified to match a given block copolymer to be deposited.

First claim

1 . A method for patterning a substrate, the method comprising:
depositing a tunable layer on a substrate, the tunable layer being an organic material having a first ratio of sigma bonds to pi bonds; identifying a mixture ratio of a first block copolymer to a second block copolymer that corresponds to a block copolymer mixture specified for deposition on the substrate; modifying the tunable layer, to result in a neutral layer, by increasing the first ratio of sigma bonds to pi bonds to a second ratio of sigma bonds to pi bonds, the second ratio of sigma bonds to pi bonds having a value that is equivalent to the mixture ratio of the first block copolymer to the second block copolymer; depositing the block copolymer mixture on the substrate; and causing phase-separation of the block copolymer mixture such that self-assembly of the block copolymer mixture occurs.

2 . The method of claim 1 , further comprising forming a relief pattern from the tunable layer subsequent to modifying the tunable layer and prior to depositing the block copolymer mixture on the substrate.

3 . The method of claim 1 , wherein depositing the tunab e ayer includes depositing the tunable layer on a relief pattern.

4 . The method of claim 1 , wherein sigma bonds are carbon single bonds, and wherein pi bonds are carbon double bonds.

5 . The method of claim 4 , wherein modifying the tunable layer includes increasing a number of pi bonds in the tunable layer.

6 . The method of claim 4 , wherein modifying the tunable layer includes increasing a ratio of sigma bonds to pi bonds in the tunable layer.

7 . The method of claim 1 , wherein modifying the tunable layer includes increasing cross-linking of the tunable layer by exposure to a flux of ballistic electrons or exposure to a patterned electron beam.

8 . The method of claim 1 , wherein modifying the tunable layer ncludes exposing the tunable layer to actinic radiation.

9 . The method of claim 8 , wherein exposing the tunable layer to actinic radiation includes exposing the tunable layer to light having a wavelength of 172 nanometers or 248 nanometers.

10 . The method of claim 1 , wherein the tunable layer includes thermal acid generators and wherein modifying the tunable layer includes executing a bake process that heats the tunable layer sufficient to generate acid from the thermal acid generators.

11 . The method of claim 1 , wherein the tunable layer comprises a polymethyl methacrylate film.

12 . The method of claim 1 , modifying the tunable layer includes altering a surface energy value of the tunable layer to match a surface energy value of the block copolymer mixture.

13 . The method of claim 1 , wherein the second ratio of sigma bonds to pi bonds results in self-assembly of lines from the phase-separation of the block copolymer mixture.

14 . The method of claim 1 , wherein the second ratio of sigma bonds to pi bonds results in self-assembly of cylinders from the phase-separation of the block copolymer mixture.

15 . A method for patterning a substrate, the method comprising:
depositing a tunable layer on a substrate, the tunable layer being a material having a surface energy with a modification potential; identifying a block copolymer mixture specified for deposition on the substrate; modifying the tunable layer by changing an initial surface energy value of the tunable layer to a modified surface energy value, modifying the tunable layer resulting in a neutral layer, the neutral layer having the modified surface energy value, the neutral layer enabling vertically-oriented structures to self-assemble from the block copolymer mixture specified for deposition on the substrate; depositing the block copolymer mixture on the substrate; and causing phase-separation of the block copolymer mixture such that self-assembly of the block copolymer mixture occurs on the neutral layer forming vertically-oriented structures.

16 . The method of claim 15 , wherein modifying the tunable layer includes executing a bond-changing surface treatment that is selected from the group consisting of exposure to actinic radiation, thermal exposure, exposure to plasma products, acid deposition, and exposure to a flux of ballistic electrons.

17 . A method for patterning a substrate, the method comprising:
receiving a substrate having a neutral layer positioned on one or more underlying layers, the neutral layer having an initial surface energy value, wherein the neutral layer has been deposited by spin-on deposition or vapor deposition; and executing a bond-changing surface treatment of the neutral layer such that an initial ratio of carbon sigma to pi bonds is modified to result in a predetermined ratio of carbon sigma to pi bonds of the neutral layer, the bond-changing surface treatment resulting in a modified surface energy value of the neutral layer that is different from the initial surface energy value, the modified surface energy value corresponding to a specified surface energy value that enables directed self-assembly of vertical structures from a specific block copolymer mixture.

18 . The method of claim 17 , wherein the bond-changing surface treatment is selected from the group consisting of exposure to electromagnetic radiation, thermal exposure, exposure to plasma products, acid deposition, and exposure to a flux of ballistic electrons.

19 . The method of claim 17 , wherein executing the bond-changing surface treatment generates acid within the neutral layer.

Assignees

• Tokyo Electron Ltd

Inventors

• Smith Jeffrey

Classifications

• H10P95/08

  Planarisation of organic insulating materials · CPC title

• H10P76/4085

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

• H10P76/20 Primary

  of masks comprising organic materials · CPC title

• H10P50/695

  characterised by the process involved to create the mask, e.g. lift-off masks or sidewalls or to modify the mask · CPC title

• H10P50/692

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