Method for determining a position of a structure element on a mask and microscope for carrying out the method

Patent metadata

Field	Value
Publication number	US-10089733-B2
Application number	US-201615281760-A
Country	US
Kind code	B2
Filing date	Sep 30, 2016
Priority date	Sep 30, 2015
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

A method and a microscope for determining a position of a structure element on a mask are provide. The method comprises predefining a region on the mask which comprises at least the structure element; determining a phase image of the region, wherein the phase image comprises in a spatially resolved manner the phase of the imaging of the mask by the illumination radiation; and determining the position of the structure element within the phase image.

First claim

What is claimed is:

1. A method for determining a position of a structure element on a mask, comprising the following steps:
predefining a region on the mask which comprises at least the structure element,
determining a phase image of the region, wherein the phase image comprises in a spatially resolved manner the phase of the imaging of the mask by the illumination radiation, and
determining the position of the structure element within the phase image;
wherein, for determining the phase image, at least two aerial images of the region of the mask are recorded, wherein the at least two aerial images are recorded under diversified conditions determining the positioning error of the structure element as distance of the position of the structure element from a set point position of the structure element in the phase image.

2. The method according to claim 1 , comprising the following step:
determining the setpoint position of a structure element from the position of the structure element within a simulated phase image of the region of the mask.

3. The method according to claim 1 , comprising the following steps:
determining a first position of a first structure element within the phase image,
determining a second position of the first structure element within an intensity image,
determining the deviation of the first position from the second position, and
correcting a third phase image of a second structure element by the determined deviation.

4. The method according to claim 1 , wherein the diversifications can be described by mathematical models.

5. The method according to claim 1 , wherein the diversification is effected by the recording of the at least two aerial images in parallel planes spaced apart from one another.

6. The method according to claim 1 , wherein the recording of one of the aerial images is effected in the best focal plane.

7. The method according to claim 1 , wherein the diversification is effected by a spatial frequency filtering in the pupil plane of the imaging beam path of the imaging.

8. The method according to claim 1 , wherein the diversification is effected by the recording of the at least two aerial images with different illumination directions.

9. The method according to claim 1 , wherein determining the phase image is effected by recording an image of the region by use of a phase contrast microscopy.

10. A microscope comprising:
an imaging optical unit for recording an aerial image of a predefined region on a mask which comprises at least a structure element,
a detector for recording the aerial image, and
an image processing device configured to carry out the following steps:
predefining a region on the mask which comprises at least the structure element,
determining a phase image of the region, wherein the phase image comprises in a spatially resolved manner the phase of the imaging of the mask by the illumination radiation, and
determining the position of the structure element within the phase image,
wherein, for determining the phase image, at least two aerial images of the region of the mask are recorded, wherein the at least two aerial images are recorded under diversified conditions determining the positioning error of the structure element as distance of the position of the structure element from a set point position of the structure element in the phase image,

wherein aerial images recorded by the microscope are used.

11. The microscope of claim 10 in which the diversifications can be described by mathematical models.

12. The microscope of claim 10 in which the diversification is effected by the recording of the at least two aerial images in parallel planes spaced apart from one another.

13. The microscope of claim 10 in which the recording of one of the aerial images is effected in the best focal plane.

14. The microscope of claim 10 in which the diversification is effected by a spatial frequency filtering in the pupil plane of the imaging beam path of the imaging.

15. The microscope of claim 10 in which the diversification is effected by the recording of the at least two aerial images with different illumination directions.

16. The microscope of claim 10 in which determining the first phase image is effected by recording an image of the region by use of a phase contrast microscopy.

17. The microscope of claim 10 in which the image processing device is configured to carry out the following step: determining the setpoint position of a structure element from the position of the structure element within a simulated phase image of the region of the mask.

18. The microscope of claim 10 in which the image processing device is configured to carry out the following steps:
determining a first position of a first structure element within the phase image,
determining a second position of the first structure element within an intensity image,
determining the deviation of the first position from the second position, and
correcting a third phase image of a second structure element by the determined deviation.

19. A microscope comprising:
an imaging optical unit for recording a phase image of a predefined region on a mask which comprises at least a structure element,
a detector for recording the phase image,
an image processing device configured to carry out the following steps:
predefining a region on the mask which comprises at least the structure element,
determining a phase image of the region, wherein the phase image comprises in a spatially resolved manner the phase of the imaging of the mask by the illumination radiation, and
determining the position of the structure element within the phase image,
wherein, for determining the phase image, at least two aerial images of the region of the mask are recorded, wherein the at least two aerial images are recorded under diversified conditions determining the positioning error of the structure element as distance of the position of the structure element from a set point position of the structure element in the phase image,

wherein phase images recorded by the microscope are used.

20. The microscope of claim 19 in which the diversifications can be described by mathematical models.

21. The microscope of claim 19 in which the diversification is effected by the recording of the at least two aerial images in parallel planes spaced apart from one another.

22. The microscope of claim 19 in which the recording of one of the aerial images is effected in the best focal plane.

23. The microscope of claim 19 in which the diversification is effected by a spatial frequency filtering in the pupil plane of the imaging beam path of the imaging.

24. The microscope of claim 19 in which the diversification is effected by the recording of the at least two aerial images with different illumination directions.

25. The microscope of claim 19 in which determining the first phase image is effected by recording an image of the region by use of a phase contrast microscopy.

26. The microscope of claim 19 in which the image processing device is configured to carry out the following step: determining the setpoint position of a structure element from the position of the structure element within a simulated phase image of the region of the mask.

27. The microscope of claim 19 in which the image processing device is configured to carry out the following steps:
determining a first po

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Seidel Dirk

Classifications

• G06T2207/30141

  Printed circuit board [PCB] · CPC title

• G06T7/0004 Primary

  Industrial image inspection · CPC title

• G06T2207/10056

  Microscopic image · CPC title

• G03F1/84

  Inspecting · CPC title

• G06T2207/30148

  Semiconductor; IC; Wafer · CPC title