Characterisation of dopants distribution using electron holography and FIB-based lift-off preparation

Electron holography, a special method based on TEM is capable of visualizing the dopant distribution in a structured semiconductor by detection of differences in the inner electrostatic potential. There are some special requirements on sample preparation for successful application, which can be fulfilled by Focussed Ion Beam technique in combination with mechanical and chemical treatments. The application of Lift-Out-technique in a Dual-Beam tool allows target preparation under very restricted circumstances. Results show the feasibility of the method for p-channel FET as well as for n-channel FET. There are hopeful chances for a quantitative treatment.