Electron microscope and sample observation method

Abstract

This invention provides an electron microscope that can reduce the decrease in secondary electron detection efficiency even when the sample is tilted. [Solution] The electron microscope 100 includes an electron source 10 that emits an electron beam, an electromagnetic field superimposed objective lens 20 in which an accelerating tube 240 is incorporated inside a magnetic field lens 22, a correction electrode 50 positioned between the accelerating tube 240 and the sample S, and a sample stage 30 that supports the sample S in a tiltable manner. A positive voltage is applied to the accelerating tube 240, a negative voltage is applied to the correction electrode 50, and the potential on the optical axis A between the correction electrode 50 and the sample S is greater than or equal to the potential of the sample S.

Claims

1. An electron source that emits an electron beam, An electromagnetic field superimposed objective lens in which an accelerating tube is incorporated inside the magnetic field lens, A correction electrode is placed between the accelerating tube and the sample, A sample stage that supports the aforementioned sample in a tiltable manner, Includes, A positive voltage is applied to the acceleration tube. A negative voltage is applied to the correction electrode. An electron microscope in which the potential on the optical axis between the correction electrode and the sample is greater than or equal to the potential of the sample.

2. In claim 1, An electron microscope in which the size of the correction electrode along the optical axis is smaller than the inner diameter of the correction electrode.

3. In claim 1 or 2, A correction power supply that applies a negative voltage to the correction electrode, A sample power supply that applies a negative voltage to the sample, Includes, The correction power supply applies a voltage to the correction electrode based on the voltage applied to the sample by the sample power supply in an electron microscope.

4. In claim 1 or 2, The aforementioned electromagnetic field superimposed objective lens is, A coil that generates a magnetic field, Upper and lower electrodes made of magnetic material, It has, The correction electrode is made of a magnetic material, An electron microscope in which the correction electrode is connected to the lower electrode via an insulating portion.

5. In claim 1, An electron microscope including a detector for detecting secondary electrons emitted from the sample and drawn into the electromagnetic field superimposed objective lens.

6. A sample stage that supports the sample in a tiltable manner, An electron source that emits an electron beam, An electromagnetic field superimposed objective lens in which an accelerating tube is incorporated inside the magnetic field lens, A correction electrode is placed between the accelerating tube and the sample, A method for observing a sample using an electron microscope, including, A step of operating the optical system including the electromagnetic field superimposed objective lens and the correction electrode, The process of tilting the sample, The process involves irradiating the sample with an electron beam to obtain an electron microscope image, Includes, In the process of operating the optical system, By applying a positive voltage to the accelerating tube and a negative voltage to the correction electrode, the electron beam is accelerated by the accelerating tube, and the electron beam is decelerated by the decelerating electric field formed between the accelerating tube and the sample. A method for observing a sample, comprising making the potential on the optical axis between the correction electrode and the sample greater than or equal to the potential of the sample.

7. In claim 6, This includes a step of changing the inclination angle of the sample, A sample observation method that keeps the voltage applied to the correction electrode constant even when the tilt angle of the sample is changed.

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