In search of a hole inversion layer in Pd/MoOx/Si diodes through I- v characterization using dedicated ring-shaped test structures

Palladium (Pd) capped molybdenum-oxide (MoOx) thin films deposited bye-beam evaporation on p- and n-type silicon (Si) substrates were investigated employing dedicated ring-shaped test structures. The results show diode characteristics on n-type Si with a high rectification of ~108 and a low leakage current of ~10-11 A and an ohmic contact on p-type Si, as expected from the reported high workfunction of MoOx. Reports in the literature that an inversion layer of holes should be present at the MoOx/n-Si interface were investigated via various DC electrical measurements on lateral test structures, but no indication of any sianificant inversion was found.