US 7,605,378 B2 · Charged-particle beam system

Abstract

There is disclosed a charged-particle beam system equipped with a higher-order aberration corrector capable of correcting fifth-order spherical aberration and third-order chromatic aberration such that the primary trajectory of an electron beam is not affected by the strength of a transfer lens. The corrector is so adjusted that the image point of the corrector is located at a position shifted a distance of L0 from the principal plane of an objective lens toward the electron source. The transfer lens is so disposed that the position of the principal plane is coincident with the image point of the corrector. Therefore, the primary trajectory of the electron beam passes through the center of the transfer lens. Consequently, the primary trajectory is not affected by the strength of the transfer lens.

Claims15

Dependent claims

A charged-particle beam system comprising:

a source of a beam of charged particles;
an objective lens;
an aberration corrector for correcting third-order spherical aberration, the aberration corrector being mounted between the source of the beam and the objective lens, the aberration corrector defining an image point;
and
a transfer lens for correcting fifth-order spherical aberration and third-order chromatic aberration, the transfer lens being so placed that a principal plane of the transfer lens is located at the image point of the aberration corrector.

2 more elements

Dependencies are inferred from the claim text.

Charged-particle beam system

Life of this patent

Charged-particle beam system

Life of this patent

Abstract

Claims15