Patent ID: 7763866

Claim:
A charged particle beam device for inspecting or structuring a specimen comprising: a charged particle beam source to generate a charged particle beam; a focussing lens to focus the charged particle beam onto the specimen; and an aperture system for defining an aperture for the charged particle beam, the aperture system comprising: a first member to block a first portion of the charged particle beam between the charged particle beam source and the focussing lens; a second member to block a second portion of the charged particle beam between the charged particle beam source and the focussing lens; first means for moving the first member to adjust a size of a blocked first portion of the charged particle beam; second means for moving the second member independently of the first member, wherein the first member and the second member have a respective first edge and a second edge capable of defining a respective first boundary and a second boundary of the aperture, the first edge is a first lateral edge and the second edge is a second lateral edge, and the first means and second means for moving the members are each capable of moving the respective member independently in two orthogonal directions; a third, a fourth, a fifth, a sixth, a seventh or an eighth members to selectively block respective third, fourth, fifth, sixth, seventh or eighth portions of the charged particle beam between the charged particle beam source and the focussing lens; and a third, a fourth, a fifth, a sixth, a seventh or an eighth means for moving the respective third, fourth, fifth, sixth, seventh or eighth members to adjust sizes of the blocked respective third, fourth, fifth, sixth, seventh or eighth portions of the charged particle beam between the charged particle beam independently.