System correction from long timescales

Patent metadata

Field	Value
Publication number	US-9829800-B2
Application number	US-201414573126-A
Country	US
Kind code	B2
Filing date	Dec 17, 2014
Priority date	Jul 20, 2012
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

Aberrations of a projection lens for microlithography can be subdivided into two classes: a first class of aberrations, which are distinguished by virtue of the fact that their future size increases by a non-negligible value after a constant time duration, independently of their current size, and a second class of aberrations, which, after reaching a threshold, only increase by a negligible value after each further time duration. An adjustment method is proposed, which adjusts these two classes of aberrations in parallel in time with one another.

First claim

The invention claimed is:

1. A method of adjusting a microlithographic projection exposure apparatus comprising a projection lens, the method comprising:
performing a first partial adjustment which comprises:
prescribing a first temporal adjustment duration t 1 ;
establishing a first aberration b 1 of the projection lens;
adjusting b 1 during t 1 ; and

performing a second partial adjustment which comprises:
prescribing a second temporal adjustment duration t 2 ,
establishing a second aberration b 2 of the projection lens,
adjusting b 2 during t 2 ,

wherein:
t 1 <t 2 ;
b 1 changes more quickly than b 2 during t 2 ;
b 1 and b 2 are scalar aberrations;
b 1 has a lower waviness than b 2 ; and
the first partial adjustment is performed in parallel with the second partial adjustment.

2. The method of claim 1 , comprising performing the first partial adjustment repeatedly while performing the second partial adjustment.

3. The method of claim 2 , wherein:
the projection exposure apparatus comprises a plurality of manipulators comprising one or more manipulators of a first class of manipulators and one or more manipulators of a second class of manipulators;
the one or more manipulators in the first class of manipulators are quicker manipulators than the one or more manipulators in the second class of manipulators; and
the method comprises:
using the one or more manipulators of the first class of manipulators during the first partial adjustment; and
using one or more manipulators of a class of the second manipulators of the manipulators during the second partial adjustment.

4. The method of claim 3 , comprising using equivalent manipulators in terms of design during the first and second partial adjustments.

5. The method of claim 4 , comprising using equivalent thermal manipulators in terms of design during the first and second partial adjustments.

6. The method of claim 5 , comprising using a manipulator with a greater accuracy setting during the second partial adjustment than during the first partial adjustment.

7. The method of claim 1 , wherein t 1 <100 milliseconds, and t 2 is at least twice t 1 .

8. The method of claim 1 , comprising:
using a first algorithm to determine manipulator travel for the first partial adjustment; and
using a second algorithm to determine manipulator travel for the second partial adjustment,
wherein the first algorithm has a quicker run time than the second algorithm.

9. The method of claim 1 , comprising:
using a first algorithm to determine manipulator travel for the first partial adjustment; and
using a second algorithm to determine manipulator travel for the second partial adjustment,
wherein the first algorithm has a lower accuracy than the second algorithm.

10. The method of claim 1 , using a measurement to establish at least one aberration selected from the group consisting of b 1 and b 2 .

11. The method of claim 1 , using a prediction based on a prediction model to establish at least one aberration selected from the group consisting of b 1 and b 2 .

12. The method of claim 11 , comprising adjusting b 1 repeatedly while adjusting b 2 .

13. The method of claim 12 , wherein:
the projection exposure apparatus comprises a plurality of manipulators comprising one or more manipulators of a first class of manipulators and one or more manipulators of a second class of manipulators;
the one or more manipulators in the first class of manipulators are quicker manipulators than the one or more manipulators in the second class of manipulators; and
the method comprises:
using the one or more manipulators of the first class of manipulators while adjusting b 1 ; and
using one or more manipulators of a class of the second manipulators of the manipulators while adjusting b 2 .

14. The method of claim 13 , wherein t 1 <100 milliseconds, and t 2 is at least twice t 1 .

15. A method, comprising:
adjusting a first aberration b 1 of a projection lens of a microlithographic projection exposure apparatus during a first temporal adjustment duration t 1 ; and
simultaneously adjusting a second aberration b 2 of the projection lens of the microlithographic projection exposure apparatus during a second temporal adjustment duration t 2 ,
wherein:
t 1 <t 2 ;
during t 2 , b 1 changes more quickly than b 2 ;
the method comprises:
using a first algorithm to determine manipulator travel for adjusting b 1 ; and
using a second algorithm to determine manipulator travel for adjusting b 2 ; and

the first algorithm has a quicker run time than the second algorithm, and/or the first algorithm has a lower accuracy than the second algorithm.

16. The method of claim 15 , using a measurement to establish at least one aberration selected from the group consisting of b 1 and b 2 , and/or using a prediction based on a prediction model to establish at least one aberration selected from the group consisting of b 1 and b 2 .

17. A method of adjusting a microlithographic projection exposure apparatus comprising a projection lens, the method comprising:
performing a first partial adjustment which comprises:
prescribing a first temporal adjustment duration t 1 ;
establishing a first aberration b 1 of the projection lens;
adjusting b 1 during t 1 ; and

performing a second partial adjustment which comprises:
prescribing a second temporal adjustment duration t 2 ,
establishing a second aberration b 2 of the projection lens,
adjusting b 2 during t 2 ,

wherein:
t 1 <t 2 ;
b 1 changes more quickly than b 2 during t 2 ;
the first partial adjustment is performed in parallel with the second partial adjustment; and
the method comprises using equivalent manipulators in terms of design during the first and second partial adjustments.

18. A method of adjusting a microlithographic projection exposure apparatus comprising a projection lens, the method comprising:
performing a first partial adjustment which comprises:
prescribing a first temporal adjustment duration t 1 ;
establishing a first aberration b 1 of the projection lens;
adjusting b 1 during t 1 ; and

performing a second partial adjustment which comprises:
prescribing a second temporal adjustment duration t 2 ,
establishing a second aberration b 2 of the projection lens,
adjusting b 2 during t 2 ,

wherein:
t 1 <t 2 ;
b 1 changes more quickly than b 2 during t 2 ;
the first partial adjustment is performed in parallel with the second partial adjustment;
the method comprises:
using a first algorithm to determine manipulator travel for the first partial adjustment; and
using a second algorithm to determine manipulator travel for the second partial adjustment; and

the first algorithm has a quicker run time than the second algorithm, and/or the first algorithm has a lower accuracy than the second algorithm.

19. The method of claim 18 , wherein the first algorithm has a quicker run time than the second algorithm.

20. The method of claim 18 , wherein the first algorithm has a lower accuracy than the second algorithm.

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Bittner Boris
• Wabra Norbert
• Von Hodenberg Martin
• Schneider Sonja
• Schoemer Ricarda
• Mack Ruediger

Classifications

• G03F7/70258 Primary

  Projection system adjustments, e.g. adjustments during exposure or alignment during assembly of projection system · CPC title

• G03F7/706 Primary

  Aberration measurement · CPC title

• G02B27/0043

  in projection exposure systems, e.g. microlithographic systems · CPC title

• G03F7/70891

  Temperature · CPC title

• G02B27/0068

  having means for controlling the degree of correction, e.g. using phase modulators, movable elements (controlling the phase of light using moving or deformable elements G02B26/06) · CPC title