The Characterization of Silicon-Based Molecular Devices

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.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...