| 摘要 |
A charged particle beam apparatus and a method are provided. The apparatus comprises a charged particle emitter (1) located within a gun chamber (11), the gun chamber being adapted to encompass a first pressure; at least one further vacuum chamber adapted to encompass a second pressure between one order and four orders of magnitude higher than the first pressure; a first aperture unit (102; 202, 402; 602; 702; 802); comprising at least a first aperture opening and a molecule blocking area; a second aperture unit (104; 204, 214) comprising a second aperture opening. Thereby, the first aperture unit and/or the second aperture unit is a differential pressure aperture separating two independently evacuateable vacuum chambers and being adapted for maintaining a pressure difference of at least two orders of magnitude and the emitter, the molecule blocking area (706; 806) and the second aperture opening are positioned to be on a straight line. |
