Multi-electrode stack arrangement

Patent metadata

Field	Value
Publication number	US-9355751-B2
Application number	US-201414541238-A
Country	US
Kind code	B2
Filing date	Nov 14, 2014
Priority date	Nov 14, 2013
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

The invention relates to an electrode stack ( 70 ) comprising stacked electrodes ( 71 - 80 ) for manipulating a charged particle beam along an optical axis (A). Each electrode comprises an electrode body with an aperture for the charged particle beam. The electrode bodies are mutually spaced and the electrode apertures are coaxially aligned along the optical axis. The electrode stack comprises electrically insulating spacing structures ( 89 ) between each pair of adjacent electrodes for positioning the electrodes ( 71 - 80 ) at predetermined mutual distances along the axial direction (Z). A first electrode and a second electrode each comprise an electrode body with one or more support portions ( 86 ), wherein each support portion is configured to accommodate at least one spacing structure ( 89 ). The electrode stack has at least one clamping member ( 91 - 91 c ) configured to hold the support portions ( 86 ) of the first and second electrodes, as well as the intermediate spacing structure ( 89 ) together.

First claim

The invention claimed is:

1. An electrode stack, in particular a collimator electrode stack, wherein the electrode stack comprises:
a plurality of stacked electrodes for manipulating a charged particle beam along an optical axis, wherein each electrode comprises an electrode body with an electrode aperture for permitting passage of the charged particle beam, wherein the electrode bodies are mutually spaced along an axial direction that is substantially parallel with the optical axis, and wherein the electrode apertures are coaxially aligned along the optical axis, and
spacing structures essentially consisting of an electrically insulating material, and arranged between each pair of adjacent electrodes for positioning the electrodes at predetermined mutual distances along the axial direction;
wherein a first electrode and a second electrode each comprise an electrode body with one or more support portions, wherein each support portion is configured to accommodate at least one spacing structure,
wherein the electrode stack is formed with at least one clamping member that is configured for holding together the respective support portions of the first and second electrodes, with the at least one spacing structure located in between.

2. The electrode stack according to claim 1 , wherein the electrode body of the first electrode and/or the second electrode has a disk shape or an oblate ring shape.

3. The electrode stack according to claim 1 , wherein at least one of the first and second electrodes comprises three support portions along a radially outward perimeter of the electrode body, wherein the three support portions jointly support a weight of the electrode body.

4. The electrode stack according to claim 3 , wherein the support potions are sufficiently rigid to prevent deflection of the support portions with respect to the electrode body along the axial direction.

5. The electrode stack according to claim 3 , wherein the electrode support portions of adjacent electrodes and interposed spacing structures are axially aligned to define a support column parallel with the axial direction.

6. The electrode stack according to claim 5 , wherein each support column is connected with a respective clamping member, for holding the support portions and interposed spacing structures together.

7. The electrode stack according to claim 3 , wherein a support portion is connected in a radially movable manner to the electrode body of the corresponding electrode by means of an electrode support member.

8. The electrode stack according to claim 7 , wherein the electrode support member is provided along the outward electrode perimeter, thereby defining a thermal expansion space between the electrode support portion and the outer electrode perimeter.

9. The electrode stack according to claim 7 , wherein the electrode support member comprises a movable elongated arm that is connected at a first end to the outer electrode perimeter and connected with a second end to a corresponding electrode support portion.

10. The electrode stack according to claim 9 , wherein the movable elongated arm comprises an flexible arm narrowing that allows deflection of the corresponding electrode support portion with respect to the electrode body in a radial-angular plane, while preventing deflection of the corresponding electrode support portion with respect to the electrode body in the axial direction.

11. The electrode stack according to claim 10 , wherein the flexible arm narrowing is included on at least one end portion of the movable elongated arm.

12. The electrode stack according to claim 9 , wherein the movable elongated arm extends substantially along the angular direction, and wherein the thermal expansion space forms a slot that extends substantially along the angular direction.

13. The electrode stack according to claim 5 , wherein the support portions and the spacing structures of a corresponding support column comprise axially aligned through holes, wherein the through holes jointly define a void that accommodates a corresponding clamping member, and wherein the clamping member is pre-tensioned to exert a compression force on the support column parallel with the axial direction.

14. The electrode stack according to claim 13 , wherein an inner diameter of a through hole in a support portion and/or a spacing structure is substantially larger than an outer diameter of the clamping member.

15. The electrode stack according to claim 14 , wherein a difference in the inner diameter of the through hole and the outer diameter of the clamping member leaves open a radial void for providing electrical insulation between the clamping member on the one hand and the support portion and/or spacing structure on the other hand.

16. The electrode stack according to claim 1 , wherein, viewed along the axial direction, a thickness of the electrode body of the first electrode and/or the second electrode is in the order of magnitude of an inter-electrode distance between the first electrode and the second electrode.

17. A charged particle beam generator, comprising:
a beam source for generating a charged particle beam along an optical axis;
an electrode stack with stack support system according to claim 1 ;

wherein the first electrode is provided at an upstream end of the electrode stack and the beam source is provided upstream of the first electrode, and
wherein the beam source and the electrode apertures of the electrodes are coaxially aligned along the optical axis.

18. The charged particle beam generator according to claim 17 , adapted for operation as a particle beam collimator, in particular wherein the charged particle beam generator is configured for applying a electric potential difference between a first electrode and a second electrode, and a further electric potential difference between the second electrode and a third electrode, wherein the further electric potential difference is larger than the electric potential difference.

19. The charged particle beam generator according to claim 18 , wherein at least the third electrode is provided with a cooling conduit for conducting a cooling liquid.

20. The charged particle beam generator according to claim 17 , comprising:
a generator vacuum chamber for accommodating the electrode stack, wherein the generator vacuum chamber comprises chamber apertures adapted for passing through protruding support portions of the stack support system, to allow the protruding support portions to establish a separate support connection outside of the generator vacuum chamber and with respect to the external reference frame, and
gaskets, wherein each gasket is adapted to seal a void between a respective chamber aperture and a corresponding protruding support portion.

21. The charged particle beam generator according to claim 17 , formed as a beam generator module, wherein the beam generator vacuum chamber is insertable into, supportable by, and removable from a carrier frame provided inside a vacuum chamber of a charged particle lithography system.

22. The charged particle beam generator according to claim 17 , comprising:
a source chamber located on an upstream end of the electrode stack, and adapted for accommodating the beam source on an inside thereof, and
source chamber support members for directly supporting the source chamber onto the stack support system.

23. A charged particle lithography system for processing a target, the system comprising:
a vacuu

Assignees

• Mapper Lithography Ip Bv

Inventors

• Urbanus Willem Henk
• Wieland Marco Jan-Jaco

Classifications

• H01J37/3177

  Multi-beam, e.g. fly's eye, comb probe · CPC title

• H01J37/3007

  Electron or ion-optical systems · CPC title

• G21K1/02 Primary

  using diaphragms, collimators · CPC title

• H01J2237/0216

  Means for avoiding or correcting vibration effects · CPC title

• H01J2237/1825

  Evacuating means · CPC title