PATTERN GENERATION METHOD AND CHARGED PARTICLE BEAM WRITING APPARATUS

Information

  • Patent Application
  • 20070192757
  • Publication Number
    20070192757
  • Date Filed
    February 05, 2007
    18 years ago
  • Date Published
    August 16, 2007
    17 years ago
Abstract
A pattern generation method includes changing a dimension of a pattern included in each mesh-like region of a plurality of mesh-like regions by using an area of the pattern and a total sum of lengths of circumferential sides of the pattern included in each mesh-like region to correct a dimension error of the pattern, wherein the dimension error being caused by loading effects and the plurality of mesh-like regions being virtually divided from a pattern forming region of a target object, and generating a pattern of the dimension changed on the target object.
Description

BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 is a diagram showing an example of a design pattern formed in a first embodiment;



FIG. 2 is a diagram showing an example of a writing pattern obtained when the design pattern in FIG. 1 is written;



FIG. 3 is a conceptual diagram for explaining a mesh region in the first embodiment;



FIG. 4 is a graph showing an example of an iterative calculation result in the first embodiment;



FIG. 5 is a diagram showing an example of a pattern formed in a second embodiment;



FIG. 6 is a diagram for explaining an area of a pattern reduced in the second embodiment;



FIG. 7 is a diagram for explaining an area error generated at an apex of the pattern according to the second embodiment;



FIG. 8 is a diagram showing an example of a pattern for measuring a correction error in the second embodiment;



FIG. 9 is a graph showing an example of a correction accuracy obtained when only an area is considered;



FIG. 10 is a graph showing an example of a correction accuracy obtained when solutions are calculated in cases 1 and 2 according to the second embodiment;



FIG. 11 is a graph showing an example of a correction accuracy obtained when a solution is found in case 3 according to the second embodiment;



FIG. 12 shows a main part of a flow chart in a writing method according to a fourth embodiment;



FIG. 13 is a conceptual diagram showing an example of a main configuration of a writing apparatus according to the fourth embodiment;



FIG. 14 is a diagram for explaining an example of a method to derive a correlative CD (η, BaseDose) between proximity effect correction coefficients and base doses of the beam with respect to a correction line width dimension CD according to the fourth embodiment;



FIGS. 15A and 15B are graphs of line widths with respect to proximity effect correction coefficients at the base dose of the beam in the fourth embodiment;



FIG. 16 is a graph showing a change of a line width CD, i.e., a correlative CD (η, BaseDose) of a correction line width dimension when proximity effect correction coefficients and base doses of the beam are changed along a correlative continuous line subjected to interpolation on the basis of combinations between optimum proximity effect correction coefficients and base doses of the beam about the standard proximity effect correction coefficient η0, the standard base dose BaseDose0 of the beam, and a line width obtained at this time in the fourth embodiment;



FIG. 17 is a conceptual diagram for explaining an operation of a conventional variable-shaped electron beam photolithography apparatus;



FIG. 18 is a diagram showing an example of a design pattern;



FIG. 19 is a diagram showing an example of a writing pattern obtained when the design pattern in FIG. 18 is written; and



FIG. 20 is a conceptual diagram for explaining a line width of an actually completed pattern after etching when writing is performed at the dimension in FIG. 19.


Claims
  • 1. A pattern generation method comprising: changing a dimension of a pattern included in each mesh-like region of a plurality of mesh-like regions by using an area of the pattern and a total sum of lengths of circumferential sides of the pattern included in each mesh-like region to correct a dimension error of the pattern, wherein the dimension error being caused by loading effects and the plurality of mesh-like regions being virtually divided from a pattern forming region of a target object; andgenerating a pattern of the dimension changed on the target object.
  • 2. The pattern generation method according to claim 1, further comprising: iteratively calculating an amount of pattern dimension correction until the dimension error of the pattern falls within a predetermined range by using the area of the pattern and the total sum of lengths of the circumferential sides of the pattern;wherein the change is performed on the basis of the calculated amount of pattern dimension correction.
  • 3. The pattern generation method according to claim 1, further comprising: calculating an amount of pattern dimension correction obtained by modulating a variation in pattern dimension generated in the pattern due to loading effects by using the total sum of sides of the pattern;wherein the change is performed on the basis of the amount of pattern dimension correction.
  • 4. The pattern generation method according to claim 3, wherein the amount of pattern dimension correction is modulated by using a constant of apex such that an area of apex parts of the pattern is calculated by multiplying the constant by a square of the amount of pattern dimension correction.
  • 5. The pattern generation method according to claim 1, further comprising: calculating a first amount of pattern dimension correction obtained by modulating a variation in pattern dimension generated in the pattern due to loading effect by using the total sum of sides of the pattern; anditeratively calculating a second amount of pattern dimension correction until the dimension error of the pattern falls within a predetermined range on the basis of the first amount of pattern dimension correction;wherein the change is performed on the basis of the second amount of pattern dimension correction.
  • 6. A pattern generation method comprising: changing a exposure dose of a charged particle beam by using an area of a pattern included in each mesh-like region of a plurality of mesh-like regions and a total sum of lengths of circumferential sides of the pattern to correct a dimension error of the pattern, wherein the dimension error being caused by loading effects and the plurality of mesh-like regions being virtually divided from a pattern forming region of a target object; andirradiating a charged particle beam at the exposure dose changed to form the pattern on the target object.
  • 7. The pattern generation method according to claim 6, further comprising: iteratively calculating an amount of pattern dimension correction until the dimension error of the pattern falls within a predetermined range by using the area of the pattern and the total sum of lengths of the circumferential sides of the pattern;wherein the change is performed on the basis of the calculated amount of pattern dimension correction.
  • 8. The pattern generation method according to claim 6, further comprising: calculating an amount of pattern dimension correction obtained by modulating a variation in pattern dimension generated in the pattern due to loading effects by using the total sum of sides of the pattern;wherein the change is performed on the basis of the amount of pattern dimension correction.
  • 9. The pattern generation method according to claim 8, wherein the amount of pattern dimension correction is modulated by using a constant of apex such that an area of apex parts of the pattern is calculated by multiplying the constant by a square of the amount of pattern dimension correction.
  • 10. The pattern generation method according to claim 6, further comprising: calculating a first amount of pattern dimension correction obtained by modulating a variation in pattern dimension generated in the pattern due to loading effect by using the total sum of sides of the pattern; anditeratively calculating a second amount of pattern dimension correction until the dimension error of the pattern falls within a predetermined range on the basis of the first amount of pattern dimension correction;wherein the change is performed on the basis of the second amount of pattern dimension correction.
  • 11. A charged particle beam writing apparatus comprising: a correcting unit configured to correct a exposure dose of a charged particle beam by using an area of a pattern included in each mesh-like region of a plurality of mesh-like regions and a total sum of lengths of circumferential sides of the pattern, wherein the plurality of mesh-like regions being virtually divided from a pattern forming region of a target object; anda pattern writing unit configured to write the pattern onto the target object by irradiating the charged particle beam at the corrected exposure dose.
Priority Claims (2)
Number Date Country Kind
2006-036640 Feb 2006 JP national
2006-263817 Sep 2006 JP national