Methods of forming patterns using photoresists

Patent metadata

Field	Value
Publication number	US-2016358778-A1
Application number	US-201615047659-A
Country	US
Kind code	A1
Filing date	Feb 19, 2016
Priority date	Jun 2, 2015
Publication date	Dec 8, 2016
Grant date	—

Abstract

In a method of forming a pattern, a lower coating layer and a photoresist layer are sequentially formed on an object layer. An exposure process may be performed such that the photoresist layer is divided into an exposed portion and a non-exposed portion. A portion of the lower coating layer overlapping or contacting the exposed portion is at least partially transformed into a polarity conversion portion that has a polarity substantially identical to that of the exposed portion. The non-exposed portion of the photoresist layer is selectively removed.

First claim

What is claimed is:

1 . A method of forming a pattern, the method comprising:
sequentially forming a lower coating layer and a photoresist layer on an object layer; performing an exposure process such that the photoresist layer is divided into an exposed portion and a non-exposed portion; transforming a portion of the lower coating layer overlapping or contacting the exposed portion at least partially into a polarity conversion portion that has a polarity substantially identical to that of the exposed portion; and selectively removing the non-exposed portion of the photoresist layer.

2 . The method of claim 1 , wherein the lower coating layer and the photoresist layer are initially hydrophilic.

3 . The method of claim 2 , wherein:
the photoresist layer is formed of a photoresist composition including a negative-tone photoresist polymer and a photoacid generator, and performing the exposure process includes converting a polarity of the exposed portion to be hydrophobic by an acid generated from the photoacid generator.

4 . The method of claim 3 , wherein the acid is diffused into the portion of the lower coating layer under the exposed portion to form the polarity conversion portion.

5 . The method of claim 4 , wherein the lower coating layer includes a polymer having a repeating unit to which a polarity conversion group is combined.

6 . The method of claim 5 , wherein transforming the portion of the lower coating layer includes inducing a dehydration reaction in the polarity conversion group by the acid diffused into the portion of the lower coating layer.

7 . The method of claim 6 , wherein:
the polarity conversion group includes a tertiary alcohol group, and a hydroxyl group included in the tertiary alcohol group is replaced with a double bond.

8 . The method of claim 7 , wherein the polarity conversion group includes an alicyclic hydrocarbon group or an aromatic hydrocarbon group which is combined with the tertiary alcohol group.

9 . The method of claim 1 , further comprising partially removing the object layer using the exposed portion as an etching mask.

10 . A method of forming a pattern, the method comprising:
forming a lower coating layer on an object layer, the lower coating layer including a polymer to which a polarity conversion group is combined; forming a photoresist layer on the lower coating layer; performing an exposure process on the photoresist layer such that the photoresist layer is divided into an exposed portion having a converted polarity and a non-exposed portion retaining a polarity thereof; inducing a dehydration reaction in the polarity conversion group included in a portion of the lower coating layer under the exposed portion; and removing the non-exposed portion of the photoresist layer.

11 . The method of claim 10 , wherein the lower coating layer includes a bottom of anti-reflection coating polymer and a polarity conversion polymer having a repeating unit to which the polarity conversion group is combined.

12 . The method of claim 11 , wherein the repeating unit is represented by Chemical Formula 1:

wherein, in Chemical Formula 1, R 1 is hydrogen or a C 1 -C 4 alkyl group,
R 2 is a divalent group selected from C 1 -C 6 alkylene, arylene, acrylate, carbonyl, oxy, ester, or a combination thereof,
R 3 is an alicyclic hydrocarbon group or an aromatic hydrocarbon group,
R 4 is a C 3 -C 10 branched alkylene group, and
n is an integer of 1 or 2.

13 . The method of claim 12 , wherein R 4 includes a tert-butyl group.

14 . The method of claim 10 , wherein the lower coating layer includes a bottom of anti-reflection coating polymer in which the polarity conversion group is incorporated.

15 . The method of claim 14 , wherein the bottom of anti-reflection coating polymer is represented by Chemical Formula 6:

wherein, in Chemical Formula 6, R 1 is hydrogen or a C 1 -C 4 alkyl group, R 3 is an alicyclic hydrocarbon group or an aromatic hydrocarbon group, R 4 is a C 3 -C 10 branched alkylene group,
R 6 includes sulfur, oxygen, or an amino group,
R 7 is a C 5 -C 10 alicyclic hydrocarbon group, a C 5 -C 10 aromatic hydrocarbon group, or a hetroring group containing sulfur or nitrogen,
R 8 is a hydroxyl group, an alkyl group combined with a hydroxyl group, or a thioether group combined with a hydroxyl group, and
n is an integer of 1 or 2.

16 . The method of claim 15 , wherein the bottom of anti-reflection coating polymer is represented by Chemical Formula 7 or Chemical Formula 8:

17 . The method of claim 10 , wherein:
inducing the dehydration reaction includes forming a polarity conversion portion at the portion of the lower coating layer under the exposed portion, and the polarity conversion portion and the exposed portion are hydrophobic.

18 . The method of claim 10 , wherein the exposed portion includes a double bond created by removal of a hydroxyl group through a dehydration reaction.

19 . A method of forming a pattern, the method comprising:
forming an isolation layer on a substrate such that an active pattern is defined by the isolation layer; sequentially forming a lower coating layer and a photoresist layer on the active pattern and the isolation layer; performing an exposure process such that the photoresist layer is divided into an exposed portion and a non-exposed portion; transforming a portion of the lower coating layer overlapping or contacting the exposed portion at least partially into a polarity conversion portion that has a polarity substantially identical to that of the exposed portion; selectively removing the non-exposed portion of the photoresist layer; and partially removing the active pattern using the exposed portion as an etching mask.

20 . The method of claim 19 , wherein the lower coating layer includes a polymer represented by Chemical Formula 3:

wherein, in Chemical Formula 3, R 1 is hydrogen or a C 1 -C 4 alkyl group,
R 2 is a divalent group selected from C 1 -C 6 alkylene, arylene, acrylate, carbonyl, oxy, ester, or a combination thereof,
R 3 is an alicyclic hydrocarbon group or an aromatic hydrocarbon group,
R 4 is a C 3 -C 10 branched alkylene group,
R 5 is a hydroxyl group, a C 1 -C 6 alkyl group or a C 1 -C 6 alkyl group combined with a hydroxyl group, and
n is an integer of 1 or 2.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Park Cheol-Hong
• Woo Sang-Yoon
• Koh Cha-Won
• Kim Hyun-Woo
• Park Sang-Min

Classifications

• H10P76/4088

  Processes for improving the resolution of the masks · CPC title

• H10P76/4085

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

• H10P76/4083

  characterised by their behaviours during the lithography processes, e.g. soluble masks or redeposited masks · CPC title

• H10P76/2043 Primary

  using an anti-reflective coating · CPC title

• H10P50/692

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