Method for forming pattern using photomask

• US 7,144,684 B2
• Filed: 12/21/2005
• Issued: 12/05/2006
• Est. Priority Date: 04/30/2002
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Misaka, Akio
• Primary Examiner(s): Young, Christopher G.
• Application Number:
  US11/312,349
• Publication Number:
  US 20060099523A1
• Time in Patent Office: 349 Days
• Field of Search: 430/5, 430/311, 430/322, 430/396
• US Class Current: 430/311
• CPC Class Codes: G03F 1/29 Rim PSM or outrigger PSM; Preparation thereof
• CPC Class Codes: G03F 1/32 Attenuating PSM [att-PSM], e.g. halftone PSM or PSM having semi-transparent phase shift portion,; Preparation thereof

Abstract

A photomask includes a semi-light-shielding portion having a light-shielding property, a light-transmitting portion surrounded by the semi-light-shielding portion and a peripheral portion positioned in a periphery of the light-transmitting portion on a transparent substrate. The semi-light-shielding portion and the light-transmitting portion transmit the exposure light in the same phase each other, whereas the peripheral portion transmits the exposure light in a phase opposite to that of the light-transmitting portion. A phase shift film that transmits the exposure light in a phase opposite to that of the peripheral portion is formed on the transparent substrate in the semi-light-shielding portion formation region.

Claims

1. A method for forming a pattern that uses a photomask, comprising the steps of:

forming a resist film on a substrate;

irradiating the resist film with exposure light via the photomask; and

developing the resist film irradiated with the exposure light so as to pattern the resist film,

wherein the photomask comprises on a transparent substrate;

a semi-light-shielding portion having a light-shielding property with respect to the exposure light;

a light-transmitting portion surrounded by the semi-light-shielding portion and having a light-transmitting property with respect to the exposure light; and

a peripheral portion surrounded by the semi-light-shielding portion and positioned in a periphery of the light-transmitting portion,

the semi-light-shielding portion and the light-transmitting portion transmit the exposure light in a same phase,

the peripheral portion transmits the exposure light in a phase opposite to that of the semi-light-shielding portion and the light-transmitting portion,

a phase shift film that has a transmittance that allows the exposure light to be transmitted partially and transmits the exposure light in a phase opposite to that of the peripheral portion is formed on the transparent substrate in a formation region for the semi-light-shielding portion, and

a surface of the transparent substrate in a formation region for the peripheral portion is exposed.

2. The method for forming a pattern according to claim 1,

wherein in the photomask, the transparent substrate in a formation region for the light-transmitting portion is dug down so as to have a thickness that transmits the exposure light in a phase opposite to that of the peripheral portion.

3. The method for forming a pattern according to claim 1,

wherein in the photomask, the phase shift film is a metal-containing oxide film.

4. The method for forming a pattern according to claim 1,

wherein in the photomask, the phase shift film comprises:

a transmittance adjusting film having a transmittance lower than that of the transparent substrate with respect to the exposure light, and

a phase adjusting film that is formed on the transmittance adjusting film and transmits the exposure light in a phase opposite to that of the peripheral portion.

5. The method for forming a pattern according to claim 4,

wherein in the photomask, the transmittance adjusting film is a thin film made of a metal or a metal alloy.

6. The method for forming a pattern according to claim 5,

wherein in the photomask, the transmittance adjusting film has a thickness of 30 nm or less.

7. The method for forming a pattern according to claim 4,

wherein in the photomask, the phase adjusting film is an oxide film.

8. The method for forming a pattern according to claim 4,

wherein in the photomask, the peripheral portion is disposed apart from the light-transmitting portion by a predetermined distance, and

only the transmittance adjusting film of the phase shift film is formed between the peripheral portion and the light-transmitting portion.

9. The method for forming a pattern according to claim 1,

wherein in the photomask, the peripheral portion is disposed so as to be in contact with the light-transmitting portion.

10. The method for forming a pattern according to claim 9,

wherein in the photomask, the peripheral portion is composed of a ring-shaped region which is in contact with a periphery of the light-transmitting portion.

11. The method for forming a pattern according to claim 9,

wherein in the photomask, the light-transmitting portion has a polygonal shape, and

the peripheral portion is composed of a plurality of rectangular regions, each region being in contact with each side of the light-transmitting portion.

12. The method for forming a pattern according to claim 1,

wherein in the photomask, the peripheral portion is disposed apart from the light-transmitting portion by a predetermined distance.

13. The method for forming a pattern according to claim 12,

wherein in the photomask, the peripheral portion is composed of a ring-shaped region, and

a part of the semi-light-shielding portion having a ring shape is interposed between the peripheral portion and the light-transmitting portion.

14. The method for forming a pattern according to claim 12,

wherein in the photomask, the light-transmitting portion has a polygonal shape,

the peripheral portion is composed of a plurality of rectangular regions, each region facing each side of the light-transmitting portion, and

a part of the semi-light-shielding portion is interposed between the peripheral portion and the light-transmitting portion.

15. The method for forming a pattern according to claim 1,

wherein in the photomask, the phase shift film comprises:

a phase adjusting film that transmits the exposure light in a phase opposite to that of the peripheral portion;

a transmittance adjusting film that is formed on the phase adjusting film and has a transmittance lower than that of the transparent substrate with respect to the exposure light; and

the phase adjusting film is also formed on the transparent substrate in a formation region for the light-transmitting portion.

16. The method for forming a pattern according to claim 15,

wherein in the photomask, the transmittance adjusting film is a thin film that is made of a metal or a metal alloy and transmits the exposure light in a same phase as that of peripheral portion.

17. The method for forming a pattern according to claim 16,

wherein in the photomask, the transmittance adjusting film has a thickness of 30 nm or less.

18. The method for forming a pattern according to claim 15,

wherein in the photomask, the phase adjusting film is an oxide film.

19. The method for forming a pattern according to claim 15,

wherein in the photomask, the peripheral portion is disposed so as to be in contact with the light-transmitting portion.

20. The method for forming a pattern according to claim 15,

wherein in the photomask, the peripheral portion is disposed apart from the light-transmitting portion by a predetermined distance.

21. The method for forming a pattern according to claim 1,

wherein in the photomask, a transmittance with respect to the exposure light of the phase shift film is 6% or more and 15% or less.

22. The method for forming a pattern according to claim 1,

wherein off-axis illumination is used in the step of irradiating the resist film with the exposure light.

23. A method for forming a pattern that uses a photomask, comprising the steps of:

forming a resist film on a substrate;

irradiating the resist film with exposure light via the photomask; and

developing the resist film irradiated with the exposure light so as to pattern the resist film,

wherein the photomask comprises on a transparent substrate;

a semi-light-shielding portion having a light-shielding property with respect to the exposure light;

a light-transmitting portion surrounded by the semi-light-shielding portion and having a light-transmitting property with respect to the exposure light; and

a peripheral portion surrounded by the semi-light-shielding portion and positioned in a periphery of the light-transmitting portion,

the semi-light-shielding portion and the light-transmitting portion transmit the exposure light in a same phase,

the peripheral portion transmits the exposure light in a phase opposite to that of the semi-light-shielding portion and the light-transmitting portion,

a phase shift film that has a transmittance that allows the exposure light to be transmitted partially and transmits the exposure light in a phase opposite to that of the peripheral portion is formed on the transparent substrate in a formation region for the semi-light-shielding portion, and

the peripheral portion is disposed apart from the light-transmitting portion by a predetermined distance.

24. The method for forming a pattern according to claim 23,

wherein in the photomask, the transparent substrate in a formation region for the light-transmitting portion is dug down so as to have a thickness that transmits the exposure light in a phase opposite to that of the peripheral portion.

25. The method for forming a pattern according to claim 23,

wherein in the photomask, the peripheral portion is composed of a ring-shaped region, and

a part of the semi-light-shielding portion having a ring shape is interposed between the peripheral portion and the light-transmitting portion.

26. The method for forming a pattern according to claim 23,

wherein in the photomask, the light-transmitting portion has a polygonal shape,

the peripheral portion is composed of a plurality of rectangular regions, each region facing each side of the light-transmitting portion, and

a part of the semi-light-shielding portion is interposed between the peripheral portion and the light-transmitting portion.

27. The method for forming a pattern according to claim 23,

wherein in the photomask, the phase shift film comprises:

a transmittance adjusting film having a transmittance lower than that of the transparent substrate with respect to the exposure light;

a phase adjusting film that is formed on the transmittance adjusting film and transmits the exposure light in a phase opposite to that of the peripheral portion; and

the transmittance adjusting film is also formed on the transparent substrate in a formation region for the peripheral portion.

28. The method for forming a pattern according to claim 27,

wherein in the photomask, the transmittance adjusting film is made of a metal or a metal alloy and transmits the exposure light in a same phase as that of peripheral portion.

29. The method for forming a pattern according to claim 28,

wherein in the photomask, the transmittance adjusting film has a thickness of 30 nm or less.

30. The method for forming a pattern according to claim 27,

wherein in the photomask, the phase adjusting film is an oxide film.

31. The method for forming a pattern according to claim 23,

wherein in the photomask, a transmittance with respect to the exposure light of the phase shift film is 6% or more and 15% or less.

32. The method for forming a pattern according to claim 23,

wherein off-axis illumination is used in the step of irradiating the resist film with the exposure light.

33. A method for forming a pattern that uses a photomask, comprising the steps of:

forming a resist film on a substrate;

irradiating the resist film with exposure light via the photomask; and

developing the resist film irradiated with the exposure light so as to pattern the resist film,

wherein the photomask comprises on a transparent substrate;

a semi-light-shielding portion having a light-shielding property with respect to the exposure light;

a light-transmitting portion surrounded by the semi-light-shielding portion and having a light-transmitting property with respect to the exposure light; and

a peripheral portion surrounded by the semi-light-shielding portion and positioned in a periphery of the light-transmitting portion,

the light-transmitting portion has a polygonal shape,

the peripheral portion is composed of a plurality of rectangular regions, each region facing each side of the light-transmitting portion,

the semi-light-shielding portion and the light-transmitting portion transmit the exposure light in a same phase,

the peripheral portion transmits the exposure light in a phase opposite to that of the semi-light-shielding portion and the light-transmitting portion, and

a phase shift film that has a transmittance that allows the exposure light to be transmitted partially and transmits the exposure light in a phase opposite to that of the peripheral portion is formed on the transparent substrate in a formation region for the semi-light-shielding portion,

the phase shift film comprises;

a transmittance adjusting film having a transmittance lower than that of the transparent substrate with respect to the exposure light; and

a phase adjusting film that is formed on the transmittance adjusting film and transmits the exposure light in a phase opposite to that of the peripheral portion, and

the transmittance adjusting film is also formed on the transparent substrate in a formation region for the peripheral portion.

34. The method for forming a pattern according to claim 33,

wherein in the photomask, the transparent substrate in a formation region for the light-transmitting portion is dug down so as to have a thickness that transmits the exposure light in a phase opposite to that of the peripheral portion.

35. The method for forming a pattern according to claim 33,

wherein in the photomask, the peripheral portion is disposed so as to be in contact with the light-transmitting portion.

36. The method for forming a pattern according to claim 33,

wherein in the photomask, a transmittance with respect to the exposure light of the phase shift film is 6% or more and 15% or less.

37. The method for forming a pattern according to claim 33,

wherein off-axis illumination is used in the step of irradiating the resist film with the exposure light.