Field of Expertise: Advanced Material Science

EBIC measurements on biased samples
Martin Faccinelli
15:00 - 17:00 Thursday 23 October 2014 Rechbauerstrasse 12, HSII

Electron Beam Induced Current (EBIC) is one type of signal which can be used inside a Scanning Electron Microscope (SEM) to create a 2D image of a microscopic structure. In contrast to the secondary electron signal which is usually used to get topographic information of a sample, EBIC is used to visualize pn-, or Schottky junctions. If charge carriers are generated in proximity to such a junction, they are separated by the built-in electric field. If both sides of this junction are electrically contacted, the electric current generated by this process can be detected. The maximum signal is measured if charge carriers are generated directly in the space charge region. If a diode is reversed biased, the width of the space charge region at the pn-junction is increased. The reverse bias causes a leakage current which is often orders of magnitudes higher than the EBIC signal. Still, EBIC measurements on biased diodes are possible if a Lock-In Technique is used.