| Abstract
| - Thin films (20−150 nm thickness) of poly(o-anthranilic acid) with various doping levels were prepared on siliconsubstrates with deposited indium tin oxide, and their topography and current−voltage (I−V) characteristics werequantitatively investigated using current-sensing atomic force microscopy with a platinum-coated tip. The films werefound to have a surface morphology like that of orange peel, with a periodic modulation and a surface roughness.The films exhibited nonuniform current flows and I−V characteristics that depended on the doping level as well ason the film thickness. Films with a high doping level were found to exhibit Zener diode switching behavior, whereasthe films with a very low doping level (or that were dedoped) exhibited no current flow at all, and so are insulators.Interestingly, self-doped films (which are at an intermediate doping level) were found to have a novel electricalbistability, i.e., a switching characteristic like that of Schottky diodes, and increasingly insulating characteristics asthe film thickness was increased. The films with thickness ≤62 nm, which exhibited this novel and stable electricalbistability, can potentially be used in the fabrication of high-density, stable, high-performance digital nonvolatilememory devices based only on transistors. The measured current images and I−V characteristics indicate that theelectrical switching and bistability of the films are governed by local filament formation and charge traps.
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