Lithographic mask layer

Patent metadata

Field	Value
Publication number	US-10824078-B2
Application number	US-201715813913-A
Country	US
Kind code	B2
Filing date	Nov 15, 2017
Priority date	Dec 15, 2016
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

An example embodiment relates to a method for making a mask layer. The method may include providing a patterned layer on a substrate, the patterned layer including at least a first set of lines of an organic material of a first nature, the lines having a line height, a first line width roughness, and being separated either by voids or by a material of a second nature. The method may further include infiltrating at least a top portion of the first set of lines with a metal or ceramic material. The method may further include removing the organic material by oxidative plasma etching, thereby forming a second set of lines of metal or ceramic material on the substrate, the second set of lines having a second line width roughness, smaller than the first line width roughness.

First claim

What is claimed is:

1. A method of making a mask layer, comprising:
providing a patterned layer on a substrate, the patterned layer comprising a first set of lines of an organic material of a first nature, wherein each line of the first set of lines has a line height, a first line width roughness, a first line edge roughness, and is separated by voids, the voids exposing a top surface of the substrate, the top surface of the substrate being such that no infiltrating by a metal or ceramic material can occur, wherein the top surface of the substrate is comprised of a layer formed by chemical vapor deposition, and wherein the top surface of the substrate comprises a first layer and wherein a second layer, underlying the first layer, comprises an amorphous material;
infiltrating at least a top portion of the first set of lines with the metal or ceramic material, the metal or ceramic material having an actual density in the infiltrated lines of the first set of lines; and
removing the organic material by oxidative plasma etching, wherein removing the organic material forms a second set of lines, wherein the second set of lines is formed of the metal or ceramic material and has a second line width roughness and a second line edge roughness, wherein the second line width roughness is at least 40% smaller than the first line width roughness and the second line edge roughness is at least 40% smaller than the first line edge roughness.

2. The method according to claim 1 , wherein the patterned layer is a block copolymer layer or a photoresist layer.

3. The method according to claim 2 , wherein the photoresist layer is an extreme ultraviolet lithography photoresist layer.

4. The method according to claim 2 , wherein the organic material of a first nature is made of one block of the block copolymer layer and wherein an organic material of a second nature is made of another block of the block copolymer layer.

5. The method according to claim 2 , wherein the organic material of a first nature is made of exposed photoresist and an organic material of a second nature is made of unexposed photoresist or wherein the organic material of a first nature is made of unexposed photoresist and the organic material of a second nature is made of exposed photoresist.

6. The method according to claim 1 , wherein the ceramic material is alumina.

7. The method according to claim 1 , wherein infiltrating at least the top portion of the first set of lines comprises a sequential infiltration synthesis.

8. The method according to claim 7 , wherein the sequential infiltration synthesis comprises:
exposing the first set of lines to a first precursor; and
exposing the first set of lines to a second precursor, wherein the sequential infiltration synthesis is repeated between 1 and 4 times.

9. The method according to claim 8 , wherein the first precursor is trimethylaluminum and wherein the second precursor is an oxidant.

10. The method according to claim 1 , wherein the oxidative plasma etching comprises exposure to a plasma of O 2 and one of Ar, N 2 , or He.

11. The method according to claim 10 , wherein each line of the first set of lines is separated by an organic material of a second nature and wherein infiltrating at least the top portion of the first set of lines is performed selectively on the first set of lines with respect to the organic material of a second nature.

12. The method according to claim 1 , wherein the top surface of the substrate is comprised of a hardmask layer of a material selected from SiOC, SiO 2 , SiON, SiN, TiN and AlN.

13. The method according to claim 1 , wherein the first layer and the second layer are separated by an adhesion layer.

14. The method according to claim 13 , wherein the amorphous material is amorphous carbon.

15. The method according to claim 1 , wherein infiltrating the at least the top portion of the first set of lines is performed so as to reduce distortions near a line interface.

Assignees

• Imec Vzw
• Univ Leuven Kath
• Univ Leuven Kath

Inventors

• Gronheid Roel
• Singh Arjun
• Knaepen Werner

Classifications

• G03F7/0002 Primary

  Lithographic processes using patterning methods other than those involving the exposure to radiation, e.g. by stamping · CPC title

• G03F7/094

  Multilayer resist systems, e.g. planarising layers · CPC title

• G03F7/38

  Treatment before imagewise removal, e.g. prebaking {(G03F7/265 takes precedence)} · CPC title

• G03F7/40 Primary

  Treatment after imagewise removal, e.g. baking · CPC title

• G03F7/405

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