In situ electron holographic analysis of biased Si n+ -p junctions

The two-dimensional electrostatic potential distribution across Si n+ -p junctions over a range of positive and negative biasing conditions has been studied in situ using off-axis electron holography. A sample holder with a movable probe as the electrode was used to bias focused-ion-beam-milled membranes during hologram acquisition. Reverse biasing of the junction resulted in an increase in potential across the junction, whereas the junction potential decreased with forward bias and eventually completely disappeared. The trends of the experimental results matched reasonably well with computer simulations.