A new image contrast is reported for LSIs covered with an insulator film in a low accelerating voltage scanning electron microscope. The surface region above the conducting lines is often observed brighter than that without conducting lines. This contrast is quasi-stationarily observed contrary to well-known capacitive-coupled voltage contrast, and is called static capacitance contrast. The optimum irradiation conditions for the maximum image contrast is studied and its mechanism is discussed.

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Cell marking is widely used to examine cell development and differentiation in developmental biology. We developed a new method for localizing cell markers in a semi-thin epoxy section with scanning electron microscopy. Cultured fibroblasts ingesting carbon particles were autologously transplanted into a rabbit transparent ear chamber, 6 mm in diameter and 100 microm in depth. Eight days after the transplantation, tissues in the chamber were fixed and embedded in epoxy resin. Semi-thin sections were cut and stained with toluidine blue. Fibroblasts in connective tissues which contained black spots were observed with a light microscope. These sections were subsequently ion-etched with an ion-coater and coated with platinum. The same fibroblasts were then visualized by secondary electron imaging using a scanning electron microscope. A nucleus with nuclear envelope, nuclear pores, a nucleolus and heterochromatin, mitochondria with cristae and rough endoplasmic reticulum were observed in the fibroblasts. The black spots in the fibroblasts were identified as bright bodies with the scanning electron microscope. The bright bodies were found to be a lump of tiny particles less than 100 nm in diameter. In order to analyse such particles with energy dispersive X-ray microanalysis, ion-etched sections were coated with carbon. X-ray energy spectrometry clearly demonstrated that these were carbon particles, which had been endocytosed by the fibroblast. This suggests that scanning electron microscopy combined with energy dispersive X-ray microanalysis is useful for detecting carbon particles in the cytoplasm at an ultrastructural level in semi-thin epoxy sections subsequent to ion etching and that this method may be applicable to other cell markers, such as gold particles to track cells in the field of cell development and cell differentiation.

Both scanning electron microscopy and a liquid toner method have been carried out on an identical uncoated b plate of triglycine sulfate (TGS), to clarify the correspondence between the polarities of ferroelectric 180° domains and the contrast of their secondary electron images (SEI). It has been found that the contrast between the ends of adjacent 180° domains is reversed in a toner pattern, as well as in an SEI, between two temperature regions above and below the aging temperature Ta. This is attributed to the change in the sign of the total surface charge density σt at Ta, which consists of spontaneous polarization Ps and true charge density σn on the ends of adjacent domains. The magnitude of σn, which exactly neutralizes Ps at Ta, remains almost unchanged while the magnitude of Ps increases with decreasing temperature. Negatively charged toner particles are adsorbed on the end with σt≳0 of each domain, which corresponds to the (+) domain of Ps≳0 below Ta and the (−) domain of Ps<0 above Ta. It has been determined, on the basis of the above sign of Ps, that the end with σt<0 of each domain is observed to be bright in the SEI, which corresponds to the (−) domain below Ta and the (+) domain above Ta. Electric fields generated both inside and outside the TGS plate can contribute to the secondary electron emission from the end with σt<0 of each 180° domain.

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