Construction and Electrical Characterization of 0.9 nm Tall Channels Made via Pyryl Phosphonic Acid (PYPA) Self-assembly

Molecular self-assembly can yield well-defined systems for charge carrier transport for the construction of a variety of devices such as field effect transistors and biosensors. In this paper, we present a simple method to construct a nano conductive channel by exploiting self-assembly of pyryl phosphonic acid (PYPA) molecules. By spincoating an ethanolic solution of PYPA on a silicon dioxide surface, we were able to form a conductive channel between a pair of pre-patterned Cr/Au electrodes. We used X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) to characterize the PYPA self-assembled film. We then measured the current-voltage curves and current-temperature curves of the fabricated devices. By utilizing the specific reaction between the phosphoric acid moiety and silicon dioxide surface, we provide a straightforward method to integrate the nanometer size conduction channel with the complementary metal oxide semiconductor (CMOS) integrated circuits in a one-step post-process procedure.