On the SiSiO<inf>2</inf> interface roughness in VLSIMOS structures

The microroughness of the SiO2 interfaces in VLSIMOS devices is studied considering a statistical distribution of local oxide thicknesses at an appropriated superficial scale. The influence of this microroughness on the Fowler‐Nordheim (F‐N) conduction is analyzed in detail. The current in the F‐N regime is found to flow concentrated in small regions of the total area of the rough oxide layer. The F‐N plot is found to deviate from linearity in the low‐electric‐field region. Quantum oscillations in the F‐N plot of structures containing very thin and rough oxides are theoretically explained after having reinterpreted the SiOx interfacial transition layer in terms of the microroughness and assuming a chemically abrupt local interface. Copyright © 1988 WILEY‐VCH Verlag GmbH & Co. KGaA