Back to results
US 2014/0151571 A1Published application
Charged particle beam lens and exposure apparatus using the same
AssigneeCanon Kabushiki Kaisha
InventorsTakahisa Kato, Yutaka Setomoto
Life of this patent
Estimating the term…
Abstract
In a charged particle beam lens according to the present invention, the orientations of through-holes formed in electrodes and precision of forming the through-holes are determined in accordance with the degree of influences of the surfaces of the electrodes on the aberration of the lens.
Claims12
An electrostatic charged particle beam lens comprising:
- a first flat plate including a first surface having a normal line extending in a direction of an optical axis and a second surface opposite to the first surface;
- a second flat plate including a third surface facing the second surface and a fourth surface opposite to the third surface;
- and
- a third flat plate including a fifth surface facing the fourth surface and a sixth surface opposite to the third surface,
- wherein the first flat plate has a first through-hole extending therethrough from the first surface to the second surface,
- wherein the second flat plate has a second through-hole extending therethrough from the third surface to the fourth surface,
- wherein the third flat plate has a third through-hole extending therethrough from the fifth surface to the sixth surface,
- wherein the first through-hole, the second through-hole, and the third through-hole are arranged so that a charged particle beam is allowed to successively pass therethrough, and
- wherein, when an opening cross section is defined as a cross section of one of the through-holes taken along a plane perpendicular to the optical axis and an incircle and a circumcircle are respectively defined as two concentric circles having a smaller radius and a larger radius between which the opening cross section is disposed and having the smallest difference in the radii, a difference in the radii of the incircle and the circumcircle of the opening cross section at each of the first surface and the sixth surface is larger than a difference in the radii of the incircle and the circumcircle of the opening cross section at each of the second surface, the third surface, the fourth surface, and the fifth surface.
6 more elements
An electrostatic charged particle beam lens comprising:
- a first flat plate including a first surface having a normal line extending in a direction of an optical axis and a second surface opposite to the first surface;
- a second flat plate including a third surface facing the second surface and a fourth surface opposite to the third surface;
- and
- a third flat plate including a fifth surface facing the fourth surface and a sixth surface opposite to the third surface,
- wherein the first flat plate has a first through-hole extending therethrough from the first surface to the second surface,
- wherein the second flat plate has a second through-hole extending therethrough from the third surface to the fourth surface,
- wherein the third flat plate has a third through-hole extending therethrough from the fifth surface to the sixth surface,
- wherein the first through-hole, the second through-hole, and the third through-hole are arranged so that a charged particle beam is allowed to successively pass therethrough, and
- wherein, when an opening cross section is defined as a cross section of one of the through-holes taken along a plane perpendicular to the optical axis, a value of circularity of the opening cross section at each of the first surface and the sixth surface is larger than a value of circularity of the opening cross section at each of the second surface, the third surface, the fourth surface, and the fifth surface.
6 more elements
Dependencies are inferred from the claim text.