DEVICE STRUCTURES ON POROUS SILICON STUDIED BY SCANNING ELECTRON-MICROSCOPY IN THE ELECTRON-BEAM CURRENT-MODE

Contacts metal/porous silicon and pill device structures on porous sil icon were studied by scanning electron microscopy in the electron-beam -induced current mode. It is shown that the drift processes are domina nt in operation of porous silicon-based devices. We present the theore tical analysis of electron-beam-induced current measurements and estim ate such important parameters of device structures as: the width of th e space-charge region (several microns), charge state density in the s pace-charge region (10(14)-10(15) cm(-3)), and electron drift length ( up to 10(-3) cm). The spatial distribution of the electric field in sp ace-charge region was derived. The possibility of studying the influen ce of porous silicon/crystalline silicon interfaces on operation of po rous silicon-based devices has been illustrated. (C) 1996 American Ins titute of Physics.