Optical proximity correction

• US 6,541,167 B2
• Filed: 04/24/2001
• Issued: 04/01/2003
• Est. Priority Date: 05/01/2000
• Status: Expired due to Term

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Masktools Netherlands B.V. (ASML Holding NV)
• Inventors: Chen, Jang Fung, Petersen, John S.
• Primary Examiner(s): Rosasco, S.
• Application Number:
  US09/840,307
• Publication Number:
  US 20020001758A1
• Time in Patent Office: 707 Days
• Field of Search: 430/5, 430/322, 716/19, 716/20, 716/21, 250/492.2, 250/492.22
• US Class Current: 430/5
• CPC Class Codes: G03F 1/26 Phase shift masks [PSM]; PSM blanks; 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
• CPC Class Codes: G03F 7/70125 Use of illumination settings tailored to particular mask patterns details of setting means G03F7/70091
• CPC Class Codes: G03F 7/70283 Mask effects on the imaging process
• CPC Class Codes: G03F 7/70441 Optical proximity correction [OPC]
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]

Abstract

Method for utilizing halftoning structures to manipulate the relative magnitudes of diffraction orders to ultimately construct the desired projected-image. At the resolution limit of the mask maker, this is especially useful for converting strongly shifted, no-0^th-diffraction-order, equal-line-and-space chromeless phase edges to weak phase-shifters that have some 0^th order. Halftoning creates an imbalance in the electric field between the shifted regions, and therefore results in the introduction of the 0^th diffraction order.

Claims

1. A device manufacturing method comprising the steps of:

(a) providing a substrate that is at least partially covered by a layer of radiation-sensitive material;

(b) providing a projection beam of radiation using a radiation system;

(c) using a pattern on a mask to endow the projection beam with a pattern in its cross-section;

(d) projecting the patterned beam of radiation onto a target portion of the layer of radiation-sensitive material,

wherein, in step (c);

use is made of a phase-shifting mask comprising at least one unattentuated, halftoned, phase-shift feature;

the mask is off-axis illuminated by the radiation system.

2. A device manufactured using a method according to claim 1.

3. A device manufacturing method comprising the steps of:

(a) providing a substrate that is at least partially covered by a layer of radiation-sensitive material;

(b) providing a projection beam of radiation using a radiation system;

(c) using a pattern on a mask to endow the projection beam with a pattern in its cross-section;

(d) projecting the patterned beam of radiation onto a target portion of the layer of radiation-sensitive material,

wherein, in step (c);

use is made of a phase-shifting mask comprising at least one feature, wherein said at least one feature includes halftoned, phase-shifted, transparent features; and

the mask is off-axis illuminated by the radiation system.

4. A device manufactured using a method according to claim 3.

5. A computer program product for controlling a computer comprising a recording medium readable by the computer, means recorded on the recording medium for directing the computer to generate at least one file corresponding to a phase shifting mask capable of transferring an image including 0^th diffraction order and ±

1^st diffraction orders, onto a material, said generation of said file comprising the step of;

generating a phase-shifting mask comprising at least one unattenuated, halftoned, phase-shift feature;

said phase-shifting mask being utilized in conjunction with off-axis illumination such that radiation traverses said mask and impinges on said material.

6. A computer program product for controlling a computer comprising a recording medium readable by the computer, means recorded on the recording medium for directing the computer to generate at least one file corresponding to a phase shifting mask capable of transferring an image, including 0^th diffraction order and ±

1^st diffraction orders, onto a material, said generation of said file comprising the step of;

generating a phase-shifting mask comprising at least one feature, wherein said at least one feature includes halftoned, phase-shifted, transparent features; and

said phase-shifting mask being utilized with off-axis illumination such that radiation passes through said mask onto said material.

7. The computer program product of claim 6, wherein said at least one feature further includes semi-transparent features.

8. The computer program product of claim 6, wherein said at least one feature further includes opaque features.

9. A computer program product for controlling a computer comprising a recording medium readable by the computer, means recorded on the recording medium for directing the computer to generate at least one file corresponding to a mask capable of transferring an image onto a material, said generation of said file comprising the step of:

generating a phase-shifting mask comprising at least two unattenuated, halftoned, phase-shift features having a width w, said features separated by a width substantially equal to w,

wherein said mask provides an image including 0^th diffraction order and ±

1^st diffraction orders, when illuminated.

10. The computer program of claim 9, wherein a focus-exposure process window for maintaining a predetermined resist line-width sizing of said mask is substantially common to an attenuated, phase-shift mask of a similar pitch.

11. A computer program product for controlling a computer comprising a recording medium readable by the computer, means recorded on the recording medium for directing the computer to generate at least one file corresponding to a mask capable of transferring an image onto a material, said generation of said file comprising the step of:

generating a phase-shifting mask comprising at least two halftoned, phase-shifted, transparent features having a width w, said features separated by a width substantially equal to w,

wherein said mask provides an image including 0^th diffraction order and ±

1^st diffraction orders, when illuminated.

12. The computer program of claim 11, wherein said at least two features further include semi-transparent features.

13. The computer program of claim 11, wherein said at least two features further include opaque features.

14. The computer program of claim 11, wherein a focus-exposure process window for maintaining a predetermined resist line-width sizing of said mask is substantially common to an attenuated, phase-shift mask of a similar pitch.