Photomask having a blind region including periodical clear portions

Patent metadata

Field	Value
Publication number	US-9417517-B2
Application number	US-201414300416-A
Country	US
Kind code	B2
Filing date	Jun 10, 2014
Priority date	Jun 27, 2013
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

A photo mask includes a plurality of dark patterns disposed on a transparent substrate, a first region, a shield region, and a second region. The first region includes the dark patterns that are disposed with a wider space than a first distance. The shield region is adjacent to the first region on the transparent substrate and is filled with the dark pattern. The second region is faced to the first region across the shield region and includes the dark patterns that are disposed with a narrower space than a second distance. The second distance is narrower than ninety percent of the first distance.

First claim

What is claimed is:

1. A photo mask comprising:
a plurality of dark patterns disposed on a transparent substrate;
a first region including the dark patterns that are disposed with a wider space than a first distance;
a shield region, adjacent to the first region on the transparent substrate, being filled with the dark pattern; and
a second region, faced to the first region across the shield region, including the dark patterns that are disposed with a narrow space than a second distance,
wherein the second distance is narrower than ninety percent of the first distance.

2. The photo mask according to claim 1 , wherein each of the dark patterns in the second region, has a line shape extending in a first direction with a first width, and arranged periodically with the narrower space in a second direction that intersects the first direction.

3. The photo mask according to claim 1 , further comprising:
a first pitch defined by a total of the first width and the second distance, wherein the second distance ranges from forty percent to sixty percent of the first pitch.

4. The photo mask according to claim 1 , wherein the second distance is defined by a narrower width of a clear rectangle pattern surrounded by the dark pattern.

5. The photo mask according to claim 4 , wherein a plurality of the clear rectangle patterns are arrayed periodically so as to fill in the second region.

6. The photo mask according to claim 5 , wherein a total area of the plurality of the clear rectangle patterns occupies from forty percent to sixty percent within the area of the second region.

7. The photo mask according to claim 1 , wherein a distance between the first region and the second region facing each other across the shield region, ranges from four micrometers to twenty micrometers.

8. The photo mask according to claim 1 , wherein the transparent substrate is quartz having a transmittance to a designed wavelength of light more than eighty-five percent.

9. A photo mask comprising:
a transparent substrate including first, second, and third regions, the third region adjacent to the first region, the first and the second regions facing each other across the third region;
first dark patterns that are arranged with a first pitch in the first region;
second dark patterns that are arranged with a second pitch in the second region; and
a third dark pattern filling in the third region,
wherein the second pitch is narrower than ninety percent of the first pitch.

10. The photo mask according to claim 9 , wherein each of the first, the second, and the third dark patterns is a partial transmittance layer.

11. The photo mask according to claim 10 , wherein the partial transmittance layer has a transmittance less than ten percent to a designed wavelength of light.

12. The photo mask according to claim 11 , wherein the second dark patterns are non-resolution patterns to the designed wavelength of light.

13. A photo mask comprising:
a first region including a plurality of first clear portions having a minimum size;
a dark region surrounding the first region; and
a second region surrounding the dark region and including a plurality of second clear portions having a maximum size that is smaller than ninety percent of at least the minimum size.

14. The photo mask according to claim 13 , wherein each of the plurality of second cleat portions has a line shape.

15. The photo mask according to claim 13 , further comprising a dark portion in the second region, wherein each of the plurality of second clear portions has a rectangle shape that is surrounded with the dark portion.

16. The photo mask according to claim 14 , further comprising a dark portion in the second region, wherein the plurality of second clear portions are arranged periodically so as to form a tripe pattern with the dark portion.

17. The photo mask according to claim 15 , wherein the plurality of second clear portions are arranged in an array.

18. The photo mask according to claim 13 , wherein a total area of the plurality of second clear portions occupies from forty present to sixty present within the area of the second region.

19. The photo mask according to claim 13 , further comprising a transparent substrate including the first region, the dirk region, and the second region.

20. The photo mask according to claim 13 , wherein the first region faces to the second region across the dark region.

Assignees

• Micron Technology Inc

Inventors

• Kato Katsuya

Classifications

• G03F1/38 Primary

  Masks having auxiliary features, e.g. special coatings or marks for alignment or testing; Preparation thereof · CPC title

• G03F1/50

  Mask blanks not covered by G03F1/20 - G03F1/34; Preparation thereof · CPC title