Abstract

3-dimensional observation on the atomic arrangement and atomic species in a thin-film specimen as well as conventional electron microscope observations is carried out at high speed and accuracy by an electron microscope which measures electrons emitted at high angle from the specimen. For that purpose, the present invention provides a scanning transmission electron microscope having an electron detection device comprising a scintillator converting electrons detected thereby to photons, a photoconductive-film converting photons from the scintillator detected thereby to c.a. 1000 times as many electron-hole pairs as these photons (i.d. avalanche multiplication), an electron gun emitting an electron beam toward the photoconductive-film to detect the holes generated therein, and electron deflector electrodes deflecting the electron beam on the photoconductive-film. Avalanche multiplication in the photoconductive-film amplifies the signal of these photons at so high signal-to-noise ratio that the electron microscope in this invention can detect such weak electrons as emitted at high angle from the specimen at high sensitivity and resolution. Therefore this invention enables a scanning transmission electron microscope to obtain for example 3-dimensional image of point defects and impurity elements existing in joint interfaces and contacts in a ULSI device rapidly and accurately.

Other References

• Ultramicroscopy, "Filtered Dark-Field and Pure Z-Contrast: Two Novel Imaging Modes in a Scanning Transmission Electron Microscope", M. Haider, 1989, North-Holland, Amsterdam
• Fiber Optically Coupled TV System, Model 622S