Patent ID: 9595416
Date: 2017-03-14
CPC Classifications: H01J

Claim:
1. A transmission electron microscope comprising: an electron beam source producing an electron beam; an illumination lens system for causing the electron beam from the electron beam source to impinge on a sample; a sample stage for holding the sample thereon; a first objective lens having an upper polepiece and a lower polepiece located on opposite sides of the sample, the upper and lower polepieces cooperating to produce a magnetic field; a second objective lens disposed behind the first objective lens; an imaging lens system disposed behind the second objective lens; and a controller for controlling the first objective lens and the second objective lens, wherein the controller is configured or programmed to perform an operation for controlling the second objective lens to construct a transmission electron microscope image of the sample from the electron beam transmitted through the sample, and wherein the controller is further configured or programmed to perform an operation for controlling the first objective lens according to imaging conditions to produce a magnetic field that cancels out stray magnetic fields at a position where the sample is placed, and wherein, during said operation for producing a magnetic field that cancels out said stray magnetic fields, the excitation current of said first objective lens is found, using a function indicating a relation between the excitation current of said imaging lens system and the excitation current of said first objective lens for canceling out the stray magnetic fields.