Device structures on porous silicon studied by scanning electron microscopy in the electron-beam current mode

Contacts metal/porous silicon and p/n device structures on porous silicon were studied by scanning electron microscopy in the electron-beam-induced current mode. It is shown that the drift processes are dominant in operation of porous silicon-based devices. We present the theoretical analysis of electron-beam-induced current measurements and estimate such important parameters of device structures as: the width of the space-charge region (several microns), charge state density in the space-charge region (1014–1015 cm−3), and electron drift length (up to 10−3 cm). The spatial distribution of the electric field in space-charge region was derived. The possibility of studying the influence of porous silicon/crystalline silicon interfaces on operation of porous silicon-based devices has been illustrated.