Mask having balance pattern and method of patterning photoresist using the same

Abstract

A method and mask having balance patterns for reducing and/or preventing chemical flare from occurring in a photoresist between a first mask region and a second mask region. Balance patterns formed on the mask may have a desired and/or predetermined pitch and may be regularly arranged. If the pitch of the balance patterns is equal to or smaller than a threshold value, the balance patterns may not allow the patterns to be transferred onto a photoresist. In addition, the photoresist corresponding to the balance patterns may be either completely removed or completely remain depending on the duty of the balance patterns.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of the invention will be apparent by considering the following detailed description of example embodiments of the present invention in conjunction with the accompanying drawings. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.

FIGS. 1A to 1C are cross-sectional views for explaining chemical flare and correspond to a case in which a wafer has a low EAR.

FIGS. 2A to 2C are cross-sectional views for explaining chemical flare and correspond to a case in which a wafer has a high EAR.

FIGS. 3A to 3C are plan views of mask patterns in accordance with an example embodiment of the present invention.

FIGS. 4A and 4B are cross-sectional views for explaining an operation of balance patterns illustrated in FIGS. 3A to 3C in accordance with an example embodiment of the present invention.

FIGS. 5A and 5B are cross-sectional views for explaining an operation of balance patterns illustrated in FIGS. 3A to 3C in accordance with an example embodiment of the present invention.

FIG. 6 is a graph showing the intensity of light irradiated onto a photoresist while changing a duty of balance patterns in accordance with an example embodiment of the present invention.

FIGS. 7A to 7C are plan views of masks in accordance with an example embodiment of the present invention.

FIGS. 8A to 8C are plan views of masks in accordance with an example embodiment of the present invention.

Claims

1. A mask comprising: a first mask region having a plurality of dense patterns and transferring the dense patterns; anda second mask region disposed around the first mask region and having balance patterns with a pitch smaller than a pitch of the plurality of dense patterns of the first mask region and a duty determining if a photoresist is removed or remains.

2. The mask according to claim 1, wherein the balance patterns are arranged with a pitch equal to or smaller than a first threshold value, and the first threshold value corresponds to the following equation:

3. The mask according to claim 2, wherein if the duty of the balance patterns is equal to or smaller than a second threshold value, the photoresist is removed; andif the duty of the balance patterns exceeds the second threshold value, the photoresist remains.

4. The mask according to claim 3, wherein the second threshold value is a duty value corresponding to a cutting level of light intensity at which the photoresist starts to be removed by exposure.

5. The mask according to claim 1, wherein the balance patterns are line & space type.

6. The mask according to claim 1, wherein the balance patterns have contact shapes.

7. The mask according to claim 1, wherein the balance patterns have pillar shapes.

8. A mask comprising: a first mask region having a plurality of dense patterns and transferring the dense patterns; anda second mask region having balance patterns arranged around the first mask region with a pitch adjusted to inhibit a rapid chemical imbalance from occurring in a photoresist region between the first mask region and the second mask region.

9. The mask according to claim 8, wherein the pitch of the balance patterns corresponds to the following equation:

10. The mask according to claim 9, wherein the balance patterns have a duty adjusted to remove or leave behind the photoresist corresponding to the second mask region.

11. The mask according to claim 10, wherein if the duty of the balance patterns is equal to or smaller than a threshold value, the photoresist is removed; andif the duty of the balance patterns exceeds the threshold value, the photoresist remains.

12. The mask according to claim 11, wherein the threshold value is a duty value corresponding to a cutting level that is light intensity at which the photoresist starts to be removed by exposure.

13. The mask according to claim 8, wherein the balance patterns are line & space type.

14. The mask according to claim 8, wherein the balance patterns have contact shapes.

15. The mask according to claim 8, wherein the balance patterns have pillar shapes.

16. A method of patterning a photoresist using a mask, comprising: carrying out an exposure process on a wafer on which the photoresist is coated using the mask, the mask having a first mask region with a plurality of dense patterns and a second mask region with balance patterns regularly arranged around the first mask region; andpatterning the photoresist of a first wafer region corresponding to the first mask region on the exposed wafer,wherein the balance patterns inhibit a rapid chemical imbalance from occurring at a boundary between the first and second wafer regions based on a pitch of the balance patterns and the photoresist in the second region remains or is removed based on a duty of the balance patterns.

17. The method according to claim 16, further comprising: setting the pitch of the balance patterns according to the following equation:

18. The method according to claim 17, further comprising: adjusting a duty of the balance patterns to control if the photoresist in the second region is completely removed or remains.

19. The method according to claim 18, further comprising: removing the photoresist in the second region if a duty of the balance patterns is equal to or smaller than a threshold value; andleaving behind the photoresist in the second region if the duty of the balance patters is greater than the threshold value.

20. The method according to claim 19, wherein the threshold value is a duty value corresponding to a cutting level that is light intensity from which the photoresist starts to be removed by exposure.