Photomask, method for producing the same, and method for forming pattern using the photomask

• US 7,504,186 B2
• Filed: 06/27/2007
• Issued: 03/17/2009
• Est. Priority Date: 04/30/2002
• Status: Expired due to Fees

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Misaka, Akio
• Primary Examiner(s): Young; Christopher G
• Application Number:
  US11/819,367
• Publication Number:
  US 20070254219A1
• Time in Patent Office: 629 Days
• Field of Search: 430/5, 430/311, 430/322, 430/396
• US Class Current: 430/5
• 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 has a semi-light-shielding portion having a light-shielding property and a light-transmitting portion surrounded by the semi-light-shielding portion, and a peripheral portion positioned in the periphery of the light-transmitting portion. The semi-light-shielding portion and the light-transmitting portion transmit exposure light in the same phase, whereas the peripheral portion transmits exposure light in a phase opposite to that of the light-transmitting portion.

Claims

1. A photomask comprising on a transparent substrate:

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

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

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

wherein 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

the transparent substrate in a formation region for the peripheral portion is dug down such that a thickness thereof is such an extent that the exposure light is transmitted in a phase opposite to that of the light-transmitting portion.

2. The photomask according to claim 1,

wherein a semi-light-shielding film that has a transmittance that allows the exposure light to be transmitted partially and transmits the exposure light in a same phase as that of the light-transmitting portion is formed on the transparent substrate in the semi-light-shielding portion.

3. The photomask according to claim 1,

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

4. The photomask according to claim 1,

wherein the peripheral portion is spaced apart from the light-transmitting portion, and

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

5. The photomask according to claim 1,

wherein a transmittance of the semi-light-shielding portion with respect to the exposure light is 6% or more and 15% or less.

6. The photomask according to claim 1, wherein the peripheral portion is formed of a ring-shaped region disposed in the periphery of the light-transmitting portion.

7. The photomask according to claim 1, wherein a part of the semi-light-shielding portion in a ring shape is interposed between the peripheral portion and the light-transmitting portion.

8. The photomask according to claim 6, wherein a part of the semi-light-shielding portion in a ring shape is interposed between the peripheral portion and the light-transmitting portion.

9. The photomask according to claim 1, wherein the peripheral portion transmits the exposure light with a phase difference of (150+360×

n) degrees or not and (210+360×

n) degrees or less (where n is an integer) with respect to the light-transmitting portion.

10. The photomask according to claim 1, wherein the semi-light-shielding film is a thin film made of a metal or a metal alloy.

11. The photomask according to claim 10, wherein the thin film has a thickness of 30 nm or less.

12. The photomask according to claim 10, wherein the metal is Zr, Cr, Ta, Mo or Ti.

13. The photomask according to claim 10, wherein the metal alloy is a Ta-Cr alloy, a Zr-Si alloy, a Mo-Si alloy, or a Ti-Si alloy.

14. The photomask according to claim 1, wherein the transparent substrate is made of quartz.

15. The photomask according to claim 1, wherein the peripheral portion is disposed to be in contact with the light-transmitting portion.