Thin-film phase plate, phase-contrast electron microscope using same, and method of preventing charging of phase plate

摘要

An antistatic phase plate for use in a phase-contrast electron microscope. The phase plate is made of a thin film held on the objective aperture of the microscope for shifting the phases of incident and scattered electron waves by a uniform amount. The thin film is a conductive amorphous material typified by amorphous carbon and amorphous gold or a composite of such conductive amorphous materials. A genuinely circular, microscopic electron passage hole is formed in the center of the opening in the objective aperture. Alternatively, a genuinely circular amorphous material is deposited on the center of the opening in the objective aperture to delay the phase of electron waves by &pgr;.