Cylindrical reticle system, exposure apparatus and exposure method

Patent metadata

Field	Value
Publication number	US-9323163-B2
Application number	US-201314029939-A
Country	US
Kind code	B2
Filing date	Sep 18, 2013
Priority date	Mar 5, 2013
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

A cylindrical reticle system is provided for performing a unidirectional scan-exposure. The cylindrical reticle system includes a base and a center shaft fixed a one side of the base. The cylindrical reticle system also includes a first bearing fixed at the end of the center shaft near to the base and a second bearing fixed at the other end of the center shaft far from the base. Further, the cylindrical reticle system includes a cylindrical reticle having an imaging region and two non-imaging regions at both end of the imaging region.

First claim

What is claimed is:

1. A cylindrical reticle system, comprising:
a center shaft fixed a one side of a base;
a first bearing fixed at the end of the center shaft near to the base;
a second bearing fixed at the other end of the center shaft far from the base; and
a cylindrical reticle,
wherein:
the first bearing and the second bearing have a bearing outer ring, a bearing inner ring, and rolling elements between the bearing outer ring and the bearing inner ring, respectively;
the first bearing and the second bearing further include: first gripping holders for generating a pressure on an inner surface of non-imaging regions of the cylindrical reticle to harness the cylindrical reticle on the bearing outer rings tightly;
the bearing inner rings of the first bearing and the second bearing are fixed on the center shaft;
the cylindrical reticle is a hollow cylinder; and
the cylindrical reticle harnesses on the bearing outer rings of the first bearing and the second bearing.

2. The cylindrical reticle system according to claim 1 , wherein:
the cylindrical reticle has a middle imaging region and two non-imaging regions at both end of the middle imaging region.

3. The cylindrical reticle system according to claim 1 , wherein:
the center shaft is a hollow tube; and
an illuminator box is placed inside the center shaft.

4. The cylindrical reticle system according to claim 3 , wherein:
the center shaft has an optical slit at bottom;
the optical slit is parallel to the center axis of the center shaft; and
light emitting from the illuminator box passes through the optical slit, and projects on the imaging region of the cylindrical reticle.

5. The cylindrical reticle system according to claim 4 , wherein:
a length of the optical slit is equal to a length of the imaging area of the cylindrical reticle; and
the length of the optical slit is in a range of approximately 1 μm˜20 μm.

6. The cylindrical reticle system according to claim 4 , wherein:
an optical lens system with cylindrical surface is between the cylindrical reticle and an optical projection unit to correct a focus plane of the light from the optical slit to match the curvature of the cylindrical reticle.

7. The cylindrical reticle system according to claim 1 , wherein:
the cylindrical reticle have larger cylinder diameter with reticle patterns magnified in a rotation direction such that the circumference is equal to one stepping period along the Y-direction, or the regular scan direction.

8. The cylindrical reticle system according to claim 1 , further including:
a first drive unit connecting with the first bearing and/or second bearing to drive the first bearing and the second bearing to rotate around the center shaft.

9. The cylindrical reticle system according to claim 1 , further including
a second drive unit for installing and uninstalling the cylindrical reticle on the bearing outer rings of the first bearing the second bearing.

10. The cylindrical reticle system according claim 1 , further including:
reticle pre-alignment sensors fixed on a reticle stage frame; and
reticle alignment sensors on wafer stages.

11. A cylindrical reticle system, comprising:
a base;
a center shaft fixed at one side of the base;
a first bearing fixed on the end of the center shaft near to the base;
a second bearing on the other end of the center shaft far from the base; and
a cylindrical reticle,
wherein:
the first bearing and the second bearing have a bearing outer ring, a bearing inner ring, and rolling elements between the bearing outer ring and the bearing inner ring, respectively;
the bearing inner rings of the first bearing and the second bearing are fixed on the center shaft;
sides of the bearing outer rings of the first bearing and the second bearing facing to each other have groves;
the second bearing is a detachable bearing;
a third drive unit is connected with the second bearing;
the third drive unit is used to fix the second bearing on the center shaft, and/or remove the second bearing from the center shaft; and
the cylindrical reticle is clamped in the groves.

12. The cylindrical reticle system according to claim 11 , wherein:
the cylindrical reticle has a middle imaging region and non-imaging regions at both ends of the imaging region.

13. The cylindrical reticle system according to claim 12 , wherein:
the imaging region has a plurality of the reticle alignment marks.

14. The cylindrical reticle system according claim 13 , wherein:
a number of the reticle alignment marks is at least 3 groups.

15. The cylindrical reticle system according to claim 11 , wherein:
the bearing outer rings of the first bearing and the second bearing have second gripping holders; and
the second gripping holders generate pressure on the outer surface on the non-imaging area of the cylindrical reticle to fix the cylindrical reticle on the center shaft when the non-imaging regions are clamped in the groves of the bearing outer rings of the first bearing and the second bearing.

16. A method for using a cylindrical reticle system, comprising:
installing cylindrical reticle into a cylindrical reticle stage of the cylindrical reticle system, the cylindrical reticle system comprising:
a center shaft fixed at one side of a base; a first bearing fixed on the end of the center shaft near to the base; and a second bearing on the other end of the center shaft far from the base, wherein:
the first bearing and the second bearing have a bearing outer ring, a bearing inner ring, and rolling elements between the bearing outer ring and the bearing inner ring, respectively; the bearing inner rings of the first bearing and the second bearing are fixed on the center shaft; sides of the bearing outer rings of the first bearing and the second bearing facing to each other have groves; the bearing outer rings of the first bearing and the second bearing have second gripping holders; the second gripping holders generate pressure on an outer surface on non-imaging area of the cylindrical reticle to fix the cylindrical reticle on the center shaft when the non-imaging regions are clamped in the groves of the bearing outer rings of the first bearing and the second bearing; and the cylindrical reticle is clamped in the groves;

detecting reticle alignment marks, loading and rotating status of the cylindrical reticle using reticle pre-alignment sensors;
obtaining a position relationship between the cylindrical reticle and a wafer stage; and
performing a unidirectional exposure.

17. The method according to claim 16 , wherein the obtaining a position relationship between the cylindrical reticle and a wafer stage further includes:
detecting reticle alignment marks on the cylindrical reticle using the reticle alignment sensors with different heights.

18. The method according to claim 16 , wherein performing an exposure further includes:
passing light through an optical slit of the cylindrical reticle;
rotating the cylindrical reticle around a center shaft; and
performing a unidirectional scan using a wafer stage loaded with a wafer.

Assignees

• Semiconductor Mfg Int Shanghai

Inventors

• Wu Qiang
• Gu Yiming

Classifications

• G03F7/70741 Primary

  Handling masks outside exposure position, e.g. reticle libraries · CPC title