Pattern formation method

Patent metadata

Field	Value
Publication number	US-2026003261-A1
Application number	US-202519269777-A
Country	US
Kind code	A1
Filing date	Jul 15, 2025
Priority date	Jul 13, 2021
Publication date	Jan 1, 2026
Grant date	—

Abstract

A pattern formation method includes: forming a photosensitive hard mask made of a transition metal oxide film on a surface of a substrate; exposing the photosensitive hard mask to EUV light in a desired pattern; causing a state change in an exposed region by heat generated during exposure; and selectively removing either a region where the state change has occurred or a region where the state change has not occurred.

First claim

What is claimed is:

1 . A pattern formation method, comprising:
forming a photosensitive hard mask made of an inorganic material film on a surface of a substrate; forming a layer having a reducing action adjacent to the photosensitive hard mask; exposing the photosensitive hard mask to EUV light in a desired pattern; causing the inorganic material film to be reduced and changed in composition through a reaction between the inorganic material film and the layer having the reducing action in an exposed region by heat generated during exposure; and selectively removing either a region where the composition has changed or a region where the composition has not changed.

2 . The pattern formation method of claim 1 , wherein the inorganic material film is a transition metal oxide film.

3 . The pattern formation method of claim 2 , wherein a transition metal oxide constituting the transition metal oxide film is a tetravalent transition metal oxide.

4 . The pattern formation method of claim 3 , wherein the tetravalent transition metal oxide is HfO 2 or ZrO 2 .

5 . The pattern formation method of claim 4 , wherein the transition metal oxide film is an amorphous phase HfO 2 film, and the exposed region is configured to undergo a phase transition to a crystalline phase by being heated to a crystallization temperature or higher.

6 . The pattern formation method of claim 5 , wherein the selectively removing is performed by a dry etching or a wet etching.

7 . The pattern formation method of claim 6 , wherein a thickness t of the transition metal oxide film constituting the photosensitive hard mask is in a range of λ≤t≤3λ, where λ is an extinction length of the EUV light used for the exposure.

8 . The pattern formation method of claim 2 , wherein a transition metal oxide constituting the transition metal oxide film is a low-melting-point polyvalent oxide.

9 . The pattern formation method of claim 8 , wherein the low-melting-point polyvalent oxide is WO x , MoO x , or VO x .

10 . The pattern formation method of claim 9 , wherein the transition metal oxide film is an amorphous phase MoO x film or a crystalline phase MoO x film, the exposed region is heated to a crystallization temperature or higher to undergo a phase transition to a crystalline phase when the amorphous phase MoO x film is used, and the exposed region is heated to a temperature higher than a melting point thereof and rapidly cooled to undergo the phase transition to an amorphous phase when the crystalline phase MoO x film is used.

11 . The pattern formation method of claim 1 , wherein the selectively removing is performed by a dry etching or a wet etching.

12 . The pattern formation method of claim 1 , wherein a thickness t of the inorganic material film constituting the photosensitive hard mask is in a range of A≤t≤3λ, where 2 is an extinction length of the EUV light used for the exposure.

13 . A pattern formation method, comprising:
forming a photosensitive hard mask made of an inorganic material film on a surface of a substrate on which a film to be processed and a hard mask are formed; forming a layer having a reducing action adjacent to the photosensitive hard mask; exposing the photosensitive hard mask to EUV light in a desired pattern; causing the inorganic material film to be reduced and changed in composition through a reaction between the inorganic material film and the layer having the reducing action in an exposed region by heat generated during exposure; forming a first pattern on the photosensitive hard mask by selectively removing either a region where the composition has changed or a region where the composition has not changed; transferring the first pattern of the photosensitive hard mask to the hard mask; and forming a second pattern on the film to be processed by etching the film to be processed by using the hard mask to which the first pattern is transferred as a mask.

Assignees

• Tokyo Electron Ltd

Inventors

• Nakabayashi Hajime
• Yamaji Tomohito
• Yamada Kazuki
• Asako Ryuichi

Classifications

• H10P76/4085 Primary

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

• H10P76/405 Primary

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

• G03F7/11

  having cover layers or intermediate layers, e.g. subbing layers {(G03F7/091 - G03F7/093, B41N3/03 take precedence)} · CPC title

• G03F7/0042

  with inorganic or organometallic light-sensitive compounds not otherwise provided for, e.g. inorganic resists (G03F7/075 takes precedence) · CPC title

• G03F7/094

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