| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 1989: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1988: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Research Abstract |
Cathodoluminescence (CL) detection system combined with transmission electron microscope (TEM) can realize a higher spatial resolution than that combined with scanning electron microscope (SEM), and has an advantage to obtain the crystallographic informations from transmission electron micrographic images simultaneously. However, the TEM/CL system has some difficulty in getting a sufficient intensity from thin specimens and also in preparing specimens without any damages for luminescence centers. In this project we planned to produce a new type of CL detection system combined with Reflection electron microscope (REM). In the REM technique, an electron beam is incident onto a specimen surface by a small glancing angle, and a REM is observed. A CL spectrum from the observed region can be detected simultaneously using the REM/CL system. The system can be reconstructed from the existed TEM/CL system by changing the light-collection part and by producing a special sample holder for REM. We examined two types of light-collection. One is to use a lens which directly collects light emitted from a specimen surface, and another is to use an ellipsoidal mirror with proper setting of the specimen in the holder. Both have their own advantage and disadvantage in collection efficiency, polarization conservation of light, etc. The system was applied to the observation of GaAs-AlGaAs single quantum well structure, and the irregularity of the interface was revealed in the REM image. When the ellipsoidal mirror was set below the specimen holder, the light, which is different from CL, was detected from the transparent insulator specimen such as mica and quartz. It was found that the light is Cherenkov radiation, and its dependences on the accelerating voltage and specimen thickness were studied. In addition, transition radiation was observed from metals and semiconductorspecimens, and their properties are now under examination.
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