Siemens Aktiengesellschaft

Hans P Feuerbaum

Johann Otto

Gerald Tobolka

For quantitative potential measurement of surface-wave filters, an alternating voltage with amplitude U.sub.E.sbsb.i is connected to an input transducer of the surface-wave filter. At a local region for measurement on the filter, an alternating voltage of amplitude U.sub.P arises. For each such measuring location, the voltage U.sub.P is compared to a nominal value and if it deviates therefrom, this deviation is utilized to control an amplitude of the input voltage U.sub.E.sbsb.i so as to maintain the voltage U.sub.P substantially constant. For the various measurement locations, the changes of the input voltage U.sub.E.sbsb.i are analyzed and a local attenuation factor for each measured region in the filter may be determined. By knowing a frequency of the driving alternating voltage, conclusions can be drawn concerning specific characteristics of the filter.

Method and arrangement for quantitative potential measurements on

The invention relates to a device for contact free potential measurements of integrated circuits by means of measuring the energy of the secondary electrons released at the measuring location. One collector electrode 16 and one opposing field electrode 18 are arranged in succession at a predetermined distance from the measuring point with the electrodes 16 and 18 being formed as grid electrodes and arranged parallel to the flat surface of the circuit being tested. The secondary electrons are intercepted by a scintillator where their energy can be measured and the device makes it possible to have contact free potential measurements on paths of integrated circuit wafers.

Device for contact-free potential measurements

A method and apparatus for the contact-free potential measurement at an electronic component using an electron beam wherein a predetermined potential is applied to the measuring point and the output voltage of a controlled gain amplifier is set to a predetermined reference value U.sub.S by means of controlling a photomultiplier voltage U.sub.PM and the photomultiplier voltage U.sub.PM is maintained constant. The measuring voltage U.sub.M is then determined from the difference of the voltages U.sub.R -U.sub.S between the control unit output voltage U.sub.R and the index value voltage U.sub.S. The method and apparatus allow the quantitative potential measurement to be made on the conducting paths of an integrated circuit without utilizing manual adjustments.

Apparatus and method for contact-free potential measurements of an

A scanning electron microscope with an electron optical column and a sample chamber for a test sample disposed therein in a vacuum, in which the sample holder forms, directly or indirectly, an hermetic seal for the sample chamber. The electron-optical column is preferably suspended underneath the sample chamber, and the sample holder or its base form a cover for the sample chamber permitting simple and troublefree contact with the sample. Use of the electron microscope for the testing of integrated circuits is disclosed.

Scanning electron microscope

A method for electronically imaging the potential distribution in an electronic component such as an integrated circuit in which the phase of the pulses of the primary electron beam is shifted by a time delay with respect to the potential distribution in the component with a multiple of the frequency of the line deflection of the primary electron beam on the component and a frequency synchronous therewith chosen as the frequency of the time delay.

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Munich, Germany

Hans P Feuerbaum