ELECTRICAL CHARACTERIZATION OF M/I/M STRUCTURES INCORPORATING THIN-LAYERS OF 22-TRICOSENOIC ACID DEPOSITED ON NOBLE-METAL BASE ELECTRODES

New techniques for fabricating Ag/LB/Mg structures have been developed which yield structures having insulating properties in the absence of metal oxide layer. This has allowed an original study of the conduction processes through multilayers of 22-tricosenoic acid down to a thickness of only a bilayer of this material. The room temperature conductance G was found to be independent of frequency from 0.001 to 0.1 Hz, but changed to a G(omega) varies as f0.7dependence for higher frequency signals from 10 to 105Hz. The low- and high-bias results showed a change in the conduction mechanism with change in layer thickness, associated with possible differences in the LB structure between the first and subsequently deposited monolayers. The high-bias results for greater than six monolayers showed that the logarithm of the current was proportional to the square root of the voltage, characteristic of a Schottky or Poole-Frenkel mechanism. Assuming a Schottky mechanism to describe this dependence the height of the insulating barrier was calculated to be 1.06+or-0.04 V. © 1990 IOP Publication Ltd.