Patent ID: 6710340
Filing Date: 2004-03-23
Classification: H01J

Abstract:
A scanning electron microscope having an inner polepiece, an outer polepiece, an objective lens forming a magnetic lens field leaking onto a surface of a specimen located under lower end surfaces of the polepieces, the objective lens acting to focus an electron beam onto the specimen, a first opening formed in the inner polepiece and located above the lower end surface of the inner polepiece, and a secondary electron detector mounted outside the inner polepiece to detect secondary electrons passed through the first opening,wherein a negative voltage is applied to the specimen to produce a decelerating electric field near the surface of the specimen to decelerate the electron beam, wherein there is provided a conversion electrode on which secondary electrons emitted from the specimen impinge, the conversion electrode being mounted around an electron beam passage inside the objective lens, and wherein secondary electrons emitted from said conversion electrode are guided via said first opening to said secondary electron detector and detected.