Bayer Aktiengesellschaft

Ernst Leitz Wetzlar Gmbh

Hommelwerke Gmbh

Klaus Dransfeld

Knut Heitmann

Ulrich Fischer

Peter Guethner

An acoustic scanning microscope uses damping of a resonant acoustic oscillator and an acoustic near-field effect. In a preferred embodiment, a 32 KHz tuning fork serving as an acoustic oscillator with a 50 nm point achieves a vertical resolution of 5 nm and a horizontal resolution of 50 nm in the case of a minimum distance of approximately 50 nm. Frequency or amplitude variation of the resonant acoustic oscillator can be used. The acoustic near-field effect is dependent on the coupling medium, e.g., air, and the pressure, e.g., normal pressure.

Acoustic screen scan microscope for the examination of an object in the

The information recorded in the data carrier in the form of a locally variable electric polarization is scanned and selected by means of an electron beam. For this purpose, the secondary electrons produced on the surface of the data carrier are used. The data carrier is simultaneously either periodically heated by radiating electromagnetic waves or charged with ultrasonics. Potential fluctuations of equal frequency thereby arise on the surface of the data carrier dependent on local polarization, which fluctuations result in a modulation of the secondary electrons. The secondary electron flow thus receives information via the polarization conditions stored in the data carrier. To recover this information, the secondary electron flow is frequency-selectively amplified and electronically evaluated according to amount and/or phase. A polyvinylidene flouride film (PVDF) is preferably used as data carrier.

Process for reading-out information from electrically polarizable data

Polar structures in microscopic object areas, such as, for example, electric or magnetic dipoles, can be locally selectively detected with high resolution if either resonant ultrasonic waves are induced in the object area by a locally effective high-frequency field and are detected by means of a focused acoustic lens arrangement, or electric or magnetic high-frequency oscillations are induced in the object area by focused ultrasonic waves and are detected by an appropriate receiver. By comparing the phases and/or amplitudes of the induced and of the detected waves, these provide information on the existence and the direction of the dipoles. Existing dipole alignments can be made energetically unstable by a critical direct-current electric or magnetic field and locally selectively reversed by the focused ultrasonic beam.

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Ermatingen, Switzerland

Klaus Dransfeld