Ultrasonic imaging in scanning electron microscopy

A new type of microscopy is described here which uses a focused, modulated electron beam to generate ultrasonic waves at the front surface of a specimen and a piezoelectric transducer to detect these waves at the rear surface. The transducer output is used to form a scanned, magnified image of the specimen. A unique feature of this technique is that image contrast comes primarily from spatial variations in thermal and elastic properties. Images of integrated circuits have been obtained with ∼4 μm resolution. In thin film specimens 0.1 μm resolution should be possible. © 1980 Nature Publishing Group.