Fraunhofer-gesellschaft Zur Foerderung Der Angewandten Forschung E.v.

Other

Walter Arnold

Ute Rabe

Michael Reinstädtler

Kerstin Meder

Kerstin Schwarz

Andrzej Kulik

A device for oscillation excitation of a leaf spring, which is fastened on one side in an atomic force microscope (AFM) and comprises semiconductor material, which has no piezoelectric properties, a free end to which a tip is attached, which is brought into contact with a sample surface to be examined. The present invention has the leaf spring connected at least sectionally to a metal layer to form a Schottky contact, and an electrical voltage or field source is provided, which generates an electrical AC voltage a vicinity or area of the Schottky contact.

Device for oscillation excitation of an elastic bar fastened on one side in an atomic force microscope

A method is described for determining a dopant concentration on a surface and/or in layer region lying close to the surface of a semiconductor sample using an atomic force microscope, whose leaf-spring tip is brought into contact with the semiconductor sample, forming a Schottky barrier, wherein an electric alternating potential is applied between the spring-leaf tip and the semiconductor sample in the region of the Schottky barrier in such a way that a space charge region inside the semiconductor sample defining the three-dimensional extension of the Schottky barrier is excited and begins to oscillate within the confines of its spatial extension, said oscillations are transmitted to the leaf-spring, are detected and form the basis for determining the dopant concentration.

Method for determining a dopant concentration in a semiconductor sample

A method for exciting free torsional vibrations a spring cantilever, which is clamped in on one side and has a longitudinal extension, of an atomic force microscope (AFM) is disclosed. The invention provides

Method and device for the contactless excitation of torsional vibrations in a one-sidedly clamped-in spring cantilever of an atomic force microscope

A method for examining a surface of a sample is described using an atomic force scanning microscope (AFM) comprising a cantilever with a longitudinal extension along which a measuring tip is disposed, which is selectively arranged relative to the sample surface by a means for driving and whose spatial position is detected using a sensor unit. Vibration excitation is conducted at excitation amplitudes which produce inside the cantilever torsional amplitudes with maximum values which form a largely (substantively) constant plateau value despite increasing excitation amplitudes and the resonance spectra, in a range of maximum values of the torsional amplitudes, a widening of the resonance spectrum which is determinable by a plateau width. The resonance spectra, preferably the plateau value, the plateau width and/or the gradient of the respective resonance spectra are used for examining the sample.

Method for determining tribological properties of a sample surface using a scanning microscope (sem) and associated scanning microscope

An ultrasonic microscope for acquiring data from internal regions of a sample body is provided. The ultrasonic microscope includes an ultrasonic transmitter for providing a point source of ultrasonic waves for input-coupling into a sample body at a point in proportion to the dimensions of the sample body. Ultrasonically-induced excursions of a receiving tip can be detected with atomic resolution by using an ultrasonic detector that measures with high sensitivity resolution. The ultrasonic transmitter and the ultrasonic detector may be positioned relative to one another such that the ultrasonic detector can adopt several receiving positions for each transmitting position of the ultrasonic transmitter. A measurement data signal from the ultrasonic detector is stored and processed in a central processor. An image generator within the central processor uses a tomographic algorithm to reconstruct an image of at least one area inside the sample body from the measurement data.

Ultrasonic microscope for imaging the internal regions of a sample body

An acoustic microscope allowing both the topography and the elasticity of a sample to be measured at the same time. To this end the displacement of a cantilever with a tip is measured by the deflection of a laser beam. In order to measure the topography, the average deviation of the tip is held constant by a regulation circuit. The regulation circuit consists of a split-photodiode which supplies a neutral signal to the output of a normalizing amplifier which delivers a neutral value. Deviations from this neutral signal are compensated by a z-electrode of a piezocrystal. The elastic properties of the sample are measured by coupling ultrasound into the sample by means of a transducer and the high-frequency displacements of the cantilever with the tip are detected by a second detection device that consists of knife-edge detector and a fast photodiode. The detection device may also consist of a heterodyne time-of-flight interferometer or a capacitive detection scheme.

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Saarbrücken, Germany

Walter Arnold