Method and apparatus for imaging a specimen using low profile electron detector for charged particle beam imaging apparatus including electrostatic mirrors

Abstract

A charged particle beam method and apparatus use a primary electron beam to irradiate a specimen so as to induce the specimen to emit secondary and backscattered electrons carrying information about topographic and material structure of the specimen, respectively. The specimen may be an article to be inspected. The electrons emitted by the specimen are deflected in the electric field of an electron mirror and detected using an electron detector of the apparatus. The electron mirror permits the detection of the secondary electrons traveling close to the optical axis of the apparatus and corrects the aberrations of the secondary electrons. In addition, the electron mirror accelerates the electrons improving the detection efficiency of the electron detector and enhancing the time-of-flight dispersion characteristics of the secondary electron collection. A second electron mirror can be provided to further control the direction of the electron's landing on the surface of the electron detector.

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