Reticle inspection and purging method and tool

Patent metadata

Field	Value
Publication number	US-12596301-B2
Application number	US-202318173287-A
Country	US
Kind code	B2
Filing date	Feb 23, 2023
Priority date	Sep 23, 2022
Publication date	Apr 7, 2026
Grant date	Apr 7, 2026

Abstract

A reticle inspection and purging method comprises following steps. A first reticle is moved from a first load port of a lithography tool to a reticle inspection tool located outside the lithography tool. The first reticle is inspected using the reticle inspection tool located outside the lithography tool. Whether the first reticle is acceptable for exposure is determined based on the inspection result. In response the determination determines that the first reticle is not acceptable for exposure, the first reticle is purged.

First claim

What is claimed is:

1 . A method, comprising:
moving, by using a robot arm, a first reticle from a first load port of a lithography tool to a reticle inspection tool located outside the lithography tool, wherein the robot arm comprises an inner fork, an outer fork, and an anti-collision bar, wherein the inner fork has a first prong and a second prong and the outer fork has a third prong and a fourth prong, wherein the first and second prongs are between the third and fourth prongs, and the anti-collision bar connects the third and fourth prongs and has a top surface higher than top surfaces of the first and second prongs; inspecting the first reticle using the reticle inspection tool located outside the lithography tool; determining whether the first reticle is acceptable for exposure based on a result of inspecting the first reticle; and in response the determination determines that the first reticle is not acceptable for exposure, purging the first reticle using a gas knife to remove contaminants from the first reticle.

2 . The method of claim 1 , further comprising:
moving a second reticle from a second load port of the lithography tool to an exposure tool; and performing an exposure process on the second reticle during inspecting the first reticle.

3 . The method of claim 2 , wherein moving the first reticle from the first load port to the reticle inspection tool is performed using a first robot arm, and moving the second reticle from the second load port to the exposure tool is performed using a second robot arm.

4 . The method of claim 3 , wherein the first robot arm is located outside the lithography tool, and the second robot arm is located inside the lithography tool.

5 . The method of claim 1 , further comprising:
prior to inspecting the first reticle, calibrating a horizontal relative position of the first reticle with respect to a camera of the reticle inspection tool.

6 . The method of claim 1 , further comprising:
prior to inspecting the first reticle, calibrating a vertical relative position of the first reticle with respect to a camera of the reticle inspection tool.

7 . The method of claim 1 , further comprising:
prior to inspecting the first reticle, calibrating an orientation of the first reticle with respect to a camera of the reticle inspection tool.

8 . The method of claim 1 , wherein inspecting the first reticle comprises capturing an image of the first reticle by using a camera of the reticle inspection tool.

9 . The method of claim 8 , wherein determining whether the first reticle is acceptable for exposure comprises:
determining whether a size of an identified particle in the captured image of the first reticle exceeds a particle size threshold.

10 . The method of claim 8 , wherein determining whether the first reticle is acceptable for exposure comprises:
determining whether an identified particle count in the captured image of the first reticle exceeds a particle count threshold.

11 . The method of claim 1 , further comprising:
after purging the first reticle, inspecting the first reticle using the reticle inspection tool again.

12 . The method of claim 1 , wherein the robot arm further comprises a crash sensor disposed on one of the third and fourth prongs of the outer fork.

13 . A method, comprising:
moving, by using a first robot arm, a first reticle from a first load port of a lithography tool to a reticle inspection tool, wherein the first robot arm comprises an inner fork, an outer fork, and an anti-collision bar, wherein the inner fork has a first prong and a second prong and the outer fork has a third prong and a fourth prong, wherein the first and second prongs are between the third and fourth prongs, and the anti-collision bar connects the third and fourth prongs and has a top surface higher than top surfaces of the first and second prongs; moving, by using a second robot arm, a second reticle from a second load port of the lithography tool to an exposure tool of the lithography tool; inspecting the first reticle using the reticle inspection tool; and during inspecting the first reticle using the reticle inspection tool, performing an exposure process on the second reticle using the exposure tool to transfer a pattern onto a semiconductor substrate.

14 . The method of claim 13 , wherein the reticle inspection tool is outside the lithography tool.

15 . The method of claim 13 , further comprising:
after inspecting the first reticle, determining whether a particle on the first reticle has a size exceeding a size threshold; and when the determination determines that the size of the particle exceeds the size threshold, purging the first reticle.

16 . The method of claim 15 , wherein purging the first reticle is performed automatedly using a gas knife.

17 . The method of claim 13 , further comprising:
after inspecting the first reticle, determining whether a particle count on the first reticle exceeds a count threshold; and when the determination determines that the particle count exceeds the count threshold, purging the first reticle.

18 . The method of claim 17 , wherein purging the first reticle is performed automatedly using a gas knife.

19 . A tool comprising:
a reticle inspection tool outside a lithography tool; a reticle purging tool outside the lithography tool, the reticle purging tool comprising a gas knife; a robot arm having a range of motion sufficient to transfer a reticle between a load port of the lithography tool and the reticle inspection tool, and also sufficient to transfer the reticle between the reticle inspection tool and the reticle purging tool, wherein the robot arm comprises an inner fork, an outer fork, and an anti-collision bar, wherein the inner fork has a first prong and a second prong and the outer fork has a third prong and a fourth prong, wherein the first and second prongs are between the third and fourth prongs, and the anti-collision bar connects the third and fourth prongs and has a top surface higher than top surfaces of the first and second prongs; an image analyzer configured to determine whether a reticle image captured by the reticle inspection tool has an unacceptable particle condition; and a purging controller programmed to activate the gas knife of the reticle purging tool to blow particles away from the reticle, in response to a determination of the image analyzer determines that the reticle image has an unacceptable particle condition.

20 . The tool of claim 18 , further comprising:
a crash sensor disposed on one of the third and fourth prongs of the outer fork.

Assignees

• Taiwan Semiconductor Mfg Company Ltd
• Tsmc China Company Ltd

Inventors

• Zhou Xianhui
• Wang Lei
• Zhang Zihao
• Xu Huiming

Classifications

• G03F7/70741

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

• G03F7/70925

  Cleaning, i.e. actively freeing apparatus from pollutants, e.g. using plasma cleaning · CPC title

• G03F1/82

  Auxiliary processes, e.g. cleaning or inspecting · CPC title

• G03F1/84 Primary

  Inspecting · CPC title