Current Imaging (fault localization)

In principle, Current Imaging is similar to methods such as 'pico Amp imaging' or other conductive AFM techniques.

In contrast to those methods, Current Imaging is quick and easy. A probe tip is simply landed on the sample surface or in very close proximity (tunneling contact) and subsequently a scan pattern is executed.

Various configurations of voltage source and current sink are possible, such as:

  • the probe tip is biased and a second tip is used as the current sink
  • the probe tip is biased and the sample is used as the current sink
  • the sample is biased and the scanning probe is used as the current sink
  • alternatively the tip can be stationary while the sample is used to scan the area of interest...

With the help of a high performance amplifier, the resulting map of the sample's current response to the voltage bias at each point of the scan is obtained.

These current maps can be used to locate defects such as leakages, shorts, or opens.

This simple approach is only possible using the highly stable MM4 micromanipulators which are deployed on the Prober Shuttles.