Electron holography of biased semiconductor junctions
ABSTRACT: A two-contact TEM biasing holder has been designed and constructed for use in the Cambridge Philips CM300 FEGTEM. A silicon semiconductor device has been examined using off-axis electron holography under a reverse bias of 0 to 3 V. Reconstructed differential phase images reveal changes in the electrostatic potential with varying reverse bias. Examination of a Si device without bias using off-axis electron holography has also been performed, indicating a phase change of 2.8 radians across the p-n junction. This corresponds to a built-in voltage of 0.85 V, close to the expected value demonstrating the truly quantitative nature of electron holography.