| About this Abstract |
| Meeting |
2011 Electronic Materials Conference
|
| Symposium
|
2011 Electronic Materials Conference
|
| Presentation Title |
NN1, Au-Molecule-GaAs Devices with Graphene Barrier Layer |
| Author(s) |
Patrick D. Carpenter, Ting-Fung Chung, David B. Janes, Yong P. Chen |
| On-Site Speaker (Planned) |
David B. Janes |
| Abstract Scope |
Molecular electronics has offered many solutions to current semiconductor fabrication issues. The atomic size and versatile functionality of the molecules allow for the fabrication of electric switching devices, high-density memory devices, or chemical/biological sensors. These interesting properties have been realized through the fabrication of molecular devices in metal-molecule-metal (MMM) and metal-molecule-semiconductor (MMS) configurations. While these devices have proven to be interesting test beds for molecular devices, there are still issues associated with top contact metallization of the molecular layer. Electrical characteristics can be greatly affected by evaporated metal, creating metal shorts in the molecular devices or dislodging the molecules from the substrate. A previous study was conducted to determine the most effective metal deposition technique to prevent metal penetration [4]. A low energy, thermal metal deposition method was determined as the most effective method; however there was still indication that there remained a relatively small amount of metal penetration. In this study, a single layer of graphene was inserted between the top metal contact and the molecular layer in a MMS device. The graphene layer was grown by chemical vapor deposition and transferred to the device substrate. Metal-graphene-molecule-GaAs devices were fabricated for spectroscopic analysis and electrical characterization. Fourier transform infrared spectroscopy (FTIR) was used to determine survivability of the molecules from the chemical processing and the top layer metallization. Sharp peaks in the IR spectra, both before and after metallization of the molecule-GaAs samples, indicate that a well ordered monolayer is present. A slight deformation of the molecular layer after metallization is apparent, indicated by shifts and tail broadening of the molecular peaks. Current-voltage (<I>I-V</I>) data shows that there is a 10x increase in the conductance of the metal-graphene-GaAs device versus a comparable metal-GaAs device, indicating a change in the electrostatic barrier height due to the addition of the graphene layer. The metal-graphene-molecule-GaAs devices display another order of magnitude increase in conductivity. This increase in conductivity is consistent with prior results for MMS devices fabricated using low-penetration metallization techniques. Based on these results graphene appears to be an effective interlayer for blocking metal penetration in molecular devices.. |
| Proceedings Inclusion? |
Undecided |