Lithography projection objective

Patent metadata

Field	Value
Publication number	US-11899181-B2
Application number	US-201917419967-A
Country	US
Kind code	B2
Filing date	Dec 30, 2019
Priority date	Dec 30, 2018
Publication date	Feb 13, 2024
Grant date	Feb 13, 2024

Abstract

Provided a lithography projection objective includes: first lens group, second lens group, third lens group, fourth lens group, and fifth lens group, wherein first lens group, second lens group, third lens group, fourth lens group, and fifth lens group are sequentially arranged along an optical axis; first lens group and third lens group each has negative optical power, second lens group and fourth lens group each has positive optical power, fifth lens group has optical power of 0, sum optical power of first lens group, second lens group, third lens group, fourth lens group, and fifth lens group is 0; lithography projection objective further includes diaphragm; and first lens group, third lens group, and fourth lens group each comprises aspheric lenses, one aspheric lens thereof includes an aspherical surface; and a number of aspheric lenses is greater than or equal to 4 and less than or equal to 8.

First claim

What is claimed is:

1. A lithography projection objective, comprising: a first lens group, a second lens group, a third lens group, a fourth lens group, and a fifth lens group, wherein the first lens group, the second lens group, the third lens group, the fourth lens group, and the fifth lens group are sequentially arranged along an optical axis; the first lens group and the third lens group each has a negative optical power, the second lens group and the fourth lens group each has a positive optical power, the fifth lens group has an optical power of 0, a sum optical power of the first lens group, the second lens group, the third lens group, the fourth lens group, and the fifth lens group is 0; the lithography projection objective further comprises an aperture stop; and
the first lens group, the third lens group, and the fourth lens group each comprises aspheric lenses, one aspheric lens of the aspheric lenses comprises an aspherical surface, and a number of the aspheric lenses is greater than or equal to 4 and less than or equal to 8.

2. The lithography projection objective of claim 1 , wherein,
an aspheric deviation degree of each the aspheric lenses in the first lens group and the third lens group is less than 0.5 mm; and an aspheric deviation degree of at least one aspheric lens in the fourth lens group is greater than or equal to 0.5 mm; or,
an aspheric deviation degree of each the aspheric lenses in the first lens group and the fourth lens group is less than 0.5 mm, and an aspheric deviation degree of at least one aspheric lens in the third lens group is greater than or equal to 0.5 mm;
wherein an aspheric deviation degree of an aspheric lens is an axial distance between an aspheric surface of the aspheric lens and a best-fitting spherical surface.

3. The lithography projection objective of claim 1 , wherein at least one lens in the fourth lens group has a negative optical power.

4. The lithography projection objective of claim 1 , wherein at least one lens in the first lens group has a positive optical power.

5. The lithography projection objective of claim 4 , wherein the second lens group comprises a plurality of lenses each having a positive optical power; an optical power value of the lenses having a positive optical power in the first lens group is smaller than an optical power value of any lens in the second lens group.

6. The lithography projection objective of claim 1 , wherein the first lens group and the third lens group each comprises a meniscus lens.

7. The lithography projection objective of claim 6 , wherein the first lens group and the fourth lens group comprise at least two meniscus lenses in total.

8. The lithography projection objective of claim 1 , wherein the third lens group comprises at least two aspherical lenses.

9. The lithography projection objective of claim 1 , wherein the aperture stop is located between two adjacent lenses in the fourth lens group.

10. The lithography projection objective of claim 1 , wherein:
the first lens group comprises three lenses, and two lenses among the three lenses of the first lens group are aspherical lenses;
the second lens group comprises four lenses;
the third lens group comprises three lenses, and two lenses among the three lenses of the third lens group are aspherical lenses;
the fourth lens group comprises seven lenses, and three or four lenses among the seven lenses of the fourth lens group are aspherical lenses; and
the fifth lens group comprises two lenses.

11. The lithography projection objective of claim 1 , wherein a light incident surface of any lens in the fifth lens group and a light emitting surface of any lens in the fifth lens group are plane.

12. The lithography projection objective of claim 1 , wherein the first lens group comprises an anamorphic lens compensator, the anamorphic lens compensator is a lens in the first lens group, a range of an aperture-thickness ratio of the anamorphic lens compensator is 9 to 10, and the aperture-thickness ratio is a ratio of a maximum aperture of a lens to a thickness of a lens; and
an effective aperture of a first surface of the anamorphic lens compensator is ϕ 1 , and an effective aperture of a second surface of the anamorphic lens compensator is ϕ 2 , wherein the second surface of the anamorphic lens compensator is located between the first surface of the anamorphic lens compensator and the second lens group, and ϕ 2 −ϕ 1 >20 mm.

13. The lithography projection objective of claim 1 , wherein light emitted by an argon fluoride (ArF) excimer laser and light emitted by a krypton fluoride (KrF) excimer laser are applicable to the lithography projection objective.

14. The lithography projection objective of claim 1 , wherein a maximum image-side numerical aperture of the lithography projection objective is 0.82.

15. The lithography projection objective of claim 1 , wherein an object-image conjugate distance of the lithography projection objective is less than or equal to 1100 mm.

Assignees

• Shanghai Micro Electronics Equipment Group Co Ltd

Inventors

• Guo Yinzhang

Classifications

• G02B13/0045 Primary

  having five or more lenses · CPC title

• G02B9/60

  having five components only · CPC title

• G03F7/70241 Primary

  Optical aspects of refractive lens systems, i.e. comprising only refractive elements · CPC title

• G02B13/18 Primary

  with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration {(G02B13/002 takes precedence)} · CPC title

• G03F7/20

  Exposure; Apparatus therefor (photographic printing apparatus for making copies G03B27/00) · CPC title