Method of correcting pattern data for drawing photomask to overcome proximity effects

• US 5,792,581 A
• Filed: 07/23/1996
• Issued: 08/11/1998
• Est. Priority Date: 08/01/1995
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Ohnuma, Hidetoshi
• Primary Examiner(s): Young, Christopher G.
• Application Number:
  US08/681,524
• Time in Patent Office: 749 Days
• Field of Search: 430/5, 430/30, 430/296
• US Class Current: 430/30
• CPC Class Codes: G03F 1/36 Masks having proximity correction features; Preparation thereof, e.g. optical proximity correction [OPC] design processes
• CPC Class Codes: G03F 7/70441 Optical proximity correction [OPC]
• CPC Class Codes: Y10S 430/143 Electron beam

Abstract

A correcting method and a correcting apparatus which consider a proximity effect when drawing a pattern of a photomask by an energy beam such as an electron beam or a light proximity effect when performing exposure by using a photomask and obtaining a transfer pattern and can correct the pattern data so that the finally obtained transfer pattern becomes close to the designed pattern even if they occur. Where there is another pattern at the periphery of a pattern in a certain mesh at a center which is subjected to mesh registration, it is decided that a mutual proximity effect will occur at the time of drawing, only a part of the patterns in which it can be considered that the mutual proximity effect will occur are subdivided, and the dosage amount data at drawing are assigned to individual subdivided patterns. Where there is not another pattern at the periphery, it is decided that the self proximity effect will occur at the time of drawing, the peripheral portions of the pattern in which it can be considered that the self proximity effect will occur are subdivided, and the dosage amount data at drawing are assigned to individual subdivided patterns.

Claims

1. A method of correcting pattern data for drawing a photomask comprising the steps of:

preparing mesh-registered pattern data by dividing a design pattern into meshes having a size within a scattering range of an energy beam emitted when drawing an image and registering the pattern encompassed by the mesh;

determining whether or not another pattern is registered in the periphery of the pattern registered for the mesh by designating a center for the mesh and searching inside the mesh and the mesh periphery; and

correcting for mutual proximity effect when a periphery pattern is detected in said determining step and said detected periphery pattern is determined to cause mutual proximity effect at the time of drawing, said correcting step including subdividing only parts of the pattern causing the mutual proximity effect and assigning dosage amount data to the respective subdivided patterns to be used in drawing said image.

2. A method of correcting pattern data for drawing a photomask comprising the steps of:

preparing mesh-registered pattern data by dividing a design pattern into meshes having a size within a scattering range of an energy beam emitted when drawing an image and registering the pattern encompassed by the mesh;

determining whether or not another pattern is registered in the periphery of the pattern registered for the mesh by designating a center for the mesh and searching inside the mesh and the mesh periphery; and

correcting for self proximity effect when no periphery pattern is detected in said determining step and self proximity effect is determined to occur at the time of drawing, said correcting step including subdividing only parts of the pattern causing the self proximity effect and assigning dosage amount data to the respective subdivided patterns to be used in drawing said image.

3. A method of correcting pattern data for drawing a photomask comprising the steps of:

preparing mesh-registered pattern data by dividing a design pattern into meshes having a size within a range of light proximity effect at the time of exposure in transferring an image of the photomask onto a substrate and registering the pattern encompassed by the mesh;

determining whether or not another pattern is registered in the periphery of the pattern registered for the mesh by designating a center for the mesh and searching inside the mesh and the mesh periphery and

correcting for mutual proximity effect when a periphery pattern is detected in said determining step and said detected periphery pattern is determined to cause mutual light proximity effect at the time of exposure, said correcting step including subdividing only parts of the pattern causing the mutual light proximity effect and moving the edges of the subdivided patterns so that the image becomes closer to the design pattern.

4. A method of correcting pattern data for drawing a photomask comprising the steps of:

preparing mesh-registered pattern data by dividing a design pattern into meshes having a size within a range of light proximity effect at the time of exposure in transferring an image of the photomask onto a substrate and registering the pattern encompassed by the mesh;

determining whether or not another pattern is registered in the periphery of the pattern registered for the mesh by designating a center for the mesh and searching inside the mesh and the mesh periphery; and

correcting for self proximity effect when no periphery pattern is detected in said determining step and self light proximity effect is determined to occur at the time of exposure, said correcting step including subdividing peripheral portions of the pattern in which the self light proximity effect is determined to occur and moving the edges of the subdivided patterns so that the image becomes closer to the design pattern.