Patent ID: 8921784
Filing Date: 2014-12-30
Classification: H01J

Abstract:
1. A scanning electron microscope for observing a sample by irradiating the sample with an electron beam emitted from an electron source and focused by condenser lenses, and detecting secondary electrons or backscattered electrons from the sample, comprising: a Wehnelt electrode or an anode electrode adapted to change an accelerating voltage; and an objective aperture adapted to regulate the electron beam, wherein the condenser lenses comprise both an electromagnetic coil-type condenser lens and a permanent magnet-type condenser lens, the permanent magnet-type condenser lens is arranged in the scanning electron microscope to focus the electron beam emitted from the electron source, the electromagnetic coil-type condenser lens is arranged in the scanning electron microscope after the permanent magnet-type condenser lens to focus the electron beam focused by the permanent magnet-type condenser lens, and the electromagnetic coil-type condenser lens is adapted to be controlled to change a position in an up/down direction of a cross-over created between the electromagnetic coil-type condenser lens and an objective lens, to adjust a spot size on the sample, and to adjust a probe current.