Scanning electron microscope
AssigneeHitachi, Ltd.
InventorsHideo Todokoro, Makoto Ezumi
Life of this patent
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Abstract
A scanning microscope is provided for producing a scan image at high spatial resolution and in a low acceleration voltage area. An acceleration tube is located in an electron beam path of an objective lens for applying a post-acceleration voltage of the primary electron beam. The application of an overlapping voltage onto a sample allows a retarding electric field against the primary electron beam to be formed between the acceleration tube and the sample. The secondary electrons generated from the sample and the secondary signals such as reflected electrons are extracted into the acceleration tube through the effect of an electric field (retarding electric field) immediately before the sample. The signals are detected by secondary signal detectors located upwardly than the acceleration tube.
Claims31
A scanning microscope for producing an image of a sample and having an electron source, scanning deflectors for scanning a primary electron beam fired from said electron source onto said sample, an objective lens for converging said primary electron beam, an electron detector for detecting electrons formed from said sample, wherein:
- a conductive target plate having an aperture for passing said primary electron beam is located between said objective lens and said electron source, and
- a deflecting electrode for deflecting said electrons is located between said objective lens and said target plate.
A scanning microscope for producing an image of a sample and having an electron source, scanning deflectors for scanning a primary electron beam fired from said electron source onto said sample, an objective lens for converging said primary electron beam, and an electron detectors for detecting a electrons generated from said sample, comprising:
- at least two electron detectors provided between said electron source and said sample;
- a first target plate located between said electron source and said two electron detectors and having aperture for passing through said primary electron beam;
- and
- at least two-staged deflecting electrode for deflecting electrons is provided to each of said two electron detectors.
Dependencies are inferred from the claim text.