The Characterization of Silicon-Based Molecular Devices

Abstract

Abstract. In order to realize molecular electronic (ME) technology, an intermediate integration with more traditional silicon-based technologies will likely be required. However, there has been little effort to develop the metrology needed to enable the fabrication and characterization of CMOS-compatible ME devices. In this work, we used two different characterization techniques to evaluate the potential of molecular electronic device materials with increased CMOS-compatibility.The first technique was the electrical characterization of a simple prototypical molecular electronic device structure fabricated on a silicon substrate with a (111) crystalline orientation. To compare these electrical results with the structure of the molecular monolayers (which is critical to confirm that the molecules are playing a role in charge transport), a novel backside incident FTIR technique (the second technique) was used to spectroscopically characterize the molecular monolayers under a full top-metallization. The combination of these two characterization techniques showed that silver top contacts, unlike gold top contacts, do not penetrate and displace the molecular monolayer. We then fabricated and electrically characterized a prototypical molecular electronic device structure using the silicon orientation that is traditionally used for CMOS devices (Si (100)). Assembly on Si (100) can enable integrated ME-CMOS structures that allow on-chip characterization of molecular devices and is a major step on the route to hybrid molecular-CMOS circuitry.