Hitachi, Ltd.

Syobu Saito

Yoshio Sakitani

Akimitsu Okura

Motohide Ukiana

In a field emission scanning type electron microscope which varies widely a primary electron beam acceleration voltage, a width of the primary electron beam is thinly focused by a large acceleration voltage when the beam passes through the focusing lens. The AC variation caused due to the gases near an electron source is included in the primary electron beam current. The variation of the primary electron beam which spreads near an objective lens after it has passed through the focusing lens is detected by a detector near the objective lens. The secondary electron beam emitted from a specimen is detected by a scintillator to produce a scanning measurement signal. When the acceleration voltage is large, the scanning measurement signal is divided by an output signal of a detector near the objective lens. When the acceleration voltage is small, the measurement signal is divided by an output signal of a detector near the focusing lens. This selection may be performed by means for selecting on the basis of a ratio R (=(acceleration voltage V.sub.0)/(lead-out voltage V.sub.1) to be obtained from the high voltage source apparatus. Alternatively there may be provided comparator means for comparing the AC variations of the two signals which are obtained by dividing a scanning measurement signal by the signals of both detectors and selector means for applying the smaller signal to a display.

Scanning type electron microscope

A specimen holder holding a frozen specimen is adapted to engage the opened end of a recess in a specimen support, such that the frozen specimen is exposed to the inside of the recess. The mutually engaging specimen holder and the specimen support are shifted to a specimen chamber. In the specimen chamber, the specimen holder is separated from the specimen support and is received by a specimen receiving chamber. The specimen holder received by the specimen receiving member can be moved together with the latter to a specimen treating chamber. Cooling means for cooling the specimen receiving member is unitarily secured to the specimen receiving member, so as to be moved together with the specimen receiving member.

Device for shifting frozen specimen, for use in scanning type electron

In a sample analysis apparatus, a sample to be analyzed is irradiated by the electron beam from an electron gun, and the information obtained from the sample and characteristic of the sample is detected for the analysis of the sample. The electron gun and the sample are placed respectively in an electron gun chamber and in a sample chamber. An intermediate chamber is located between the electron gun chamber and the sample chamber. That portion of the sample chamber which contains the sample is protuberant into the intermediate chamber. The intermediate chamber is evacuated to a degree of vacuum higher than the sample chamber but lower than the electron gun chamber.

Growing community of inventors

Ibaraki, Japan

Syobu Saito