Optical system for transferring original structure portions of a lithography mask, projection optical unit for imaging an object field in which at least one original structure portion of the lithography mask is arrangeable, and lithography mask

Patent metadata

Field	Value
Publication number	US-11137688-B2
Application number	US-202017092978-A
Country	US
Kind code	B2
Filing date	Nov 9, 2020
Priority date	May 9, 2018
Publication date	Oct 5, 2021
Grant date	Oct 5, 2021

Abstract

An optical system transfers original structure portions (13) of a lithography mask (10), which have an x/y-aspect ratio of greater than 4:1, and are aligned on the lithography mask, separated respectively by separating portions (14) that carry no structures to be imaged. The optical system transfers the original structure portions onto image portions (31) of a substrate (26). Each of the original structure portions is transferred to a separate image portion. The image portions onto which the original structure portions are transferred are arranged in a line next to one another. An associated projection optical unit may have an anamorphic embodiment with different imaging scales for two mutually perpendicular field coordinates specifically, one that is reducing for one of the field coordinates and the other is magnifying for the other field coordinates.

First claim

What is claimed is:

1. Optical system for transferring original structure portions of a lithography mask comprising a plurality of the original structure portions to be imaged and separating portions,
wherein the original structure portions are arranged in a line next to one another and are separated from one another by the separating portions, which do not carry any structures to be imaged,
wherein the original structure portions have a first extent in a first dimension (x) and a second extent in a second dimension (y) that extends perpendicularly to the first dimension (x), wherein an aspect ratio (x/y) of the first and the second extents is greater than 4:1,
wherein a transfer onto image portions of a substrate with a diameter (d) comprises imaging an object field, in which at least one of the original structure portions of the lithography mask is arrangeable, into an image field, in which at least one of the image portions of the substrate is arrangeable, and
wherein the optical system is embodied such that
an image of each of the original structure portions is transferred to a separate image portion and wherein the image portions onto which the images of the original structure portions are transferred are arranged in a line next to one another,
a totality of the original structure portions on the lithography mask produce a totality of the image portions during the transfer, wherein the totality of the image portions have an overall length (D y ) in one direction (y) that is greater than half (d/2) the diameter (d) of the substrate.

2. The optical system of claim 1 , wherein the transfer onto the image portions of the substrate comprises a reduction in the first dimension and a magnification in the second dimension.

3. The optical system of claim 2 , wherein the magnification in the absolute value range is between 1.5 and 5.

4. The optical system of claim 2 , wherein the reduction in the absolute value range is between ⅛ and ⅓.

5. Projection optical unit for projection lithography for imaging an object field, in which at least one original structure portion of a lithography mask is arrangeable, into an image field, in which at least one image portion of a substrate is arrangeable,
wherein the projection optical unit has an anamorphic embodiment with different imaging scales (β x , β y ) for two mutually perpendicular field coordinates (x, y), and
wherein the projection optical unit is embodied such that one of the imaging scales (β x ) is reducing for one of the field coordinates (x) and the other of the imaging scales (β y ) is magnifying for the other of the field coordinates (y).

6. Projection optical unit according to claim 5 , wherein the magnifying imaging scale (β y ) in the absolute value range is between 1.5 and 5.

7. Projection optical unit according to claim 5 , wherein the reducing imaging scale (β x ) in the absolute value range is between ⅛ and ⅓.

8. Optical system comprising a projection optical unit according to claim 5 .

9. Optical system comprising a projection optical unit according to claim 5 .

10. Optical system according to claim 9 , comprising:
a mask holder arranged to hold the lithography mask, and to displace in an object displacement direction (y) in response to a mask displacement drive,
a substrate holder arranged to hold the substrate and to displace along the object displacement direction (y) in a manner synchronized to the mask displacement drive in response to a substrate displacement drive.

11. Optical system according to claim 10 , wherein the field coordinate for which the projection optical unit has a magnifying embodiment coincides with the object displacement direction (y).

12. Optical system according to claim 11 , comprising an illumination optical unit for illuminating the object field with illumination light of a light source.

13. Optical system according to claim 11 , further comprising a light source for the illumination light.

14. Projection exposure apparatus comprising an optical system according to claim 13 .

15. Method for producing a structured component, comprising:
providing a reticle provided with a structure and a wafer provided with a light-sensitive layer,
projecting the structure on the reticle onto the light-sensitive layer of the wafer with the projection exposure apparatus according to claim 14 ,
producing a microstructure or nanostructure on the wafer.

16. Lithography mask comprising a plurality of original structure portions to be imaged, which are arranged in a line respectively next to one another and are separated from one another by a plurality of separating portions that carry no structures to be imaged, wherein the original structure portions have a first extent in a first dimension (x) and a second extent in a second dimension (y) that extends perpendicularly to the first dimension (x), and wherein an aspect ratio (x/y) of the first and the second extents is greater than 4:1.

17. The lithography mask of claim 11 , wherein the plurality of original structure portions are configured to be imaged with a reduction in the first dimension and a magnification in the second dimension.

18. The lithography mask of claim 17 , wherein the magnification in the absolute value range is between 1.5 and 5.

19. The lithography mask of claim 17 , wherein the reduction in the absolute value range is between ⅛ and ⅓.

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Patra Michael
• Ruoff Johannes

Classifications

• G03F7/70216

  Mask projection systems · CPC title

• G03F7/70233

  Optical aspects of catoptric systems, i.e. comprising only reflective elements, e.g. extreme ultraviolet [EUV] projection systems · CPC title

• G03F1/24

  Reflection masks; Preparation thereof · CPC title

• G02B13/08

  Anamorphotic objectives · CPC title

• G03F7/70225 Primary

  Optical aspects of catadioptric systems, i.e. comprising reflective and refractive elements · CPC title