AVS 53rd International Symposium
    Electronic Materials and Processing Friday Sessions
       Session EM-FrM

Paper EM-FrM8
Fabrication of Semiconductor-Molecule-Semiconductor (SMS) Devices

Friday, November 17, 2006, 10:20 am, Room 2001

Session: Molecular Electronics
Presenter: A. Mahapatro, Purdue University
Authors: A. Mahapatro, Purdue University
M. Martinez, Purdue University
P. Carpenter, Purdue University
A.D. Scott, Purdue University
A. Yulius, Yale University
J. Woodall, Purdue University
D.B. Janes, Purdue University
Correspondent: Click to Email
Molecular electronic devices have typically been fabricated using metal-molecule-metal (MMM) configurations. Recently, several studies involving semiconductor-molecule-metal (SMM) junctions have been reported, motivated by the prospects of realizing covalent bonds to one contact and exploiting the semiconductor states in device properties. The MMM and SMM junctions are the commonly used device structures for studying the electrical behavior of single/few molecules. While the SMM structures address some of the problems with reliability of MMM structures, there is still the possibility of metal penetration through the molecular layer during deposition or device operation. This study illustrates a technique to fabricate large area molecular devices in a semiconductor-molecule-semiconductor (SMS) configuration by depositing a pre-formed semiconductor island (InAs) onto a molecular self-assembled monolayer (SAM) which has been formed on another semiconductor substrate (GaAs). Micron-scale InAs islands with Au top contact layers are formed on a sacrificial substrate and transferred onto the SAM-coated GaAs substrate. Identical topography of the grains on the surface of the settled islands and freshly prepared Au surfaces, confirm that the InAs side of the island is in contact with the SAM-coated GaAs surface. In order to verify that thiol-based bonds are possible on InAs (for the top contact), we have also developed SAMS of short thiol molecules on InAs surfaces. The resulting SAMs were characterized through X-ray photoemission spectroscopy. Electrical conduction has been measured for p@super +@GaAs/xylyl-dithiol/InAs structures of 100-400 µm@super 2@ contact areas. This study demonstrates that molecular devices can be realized using exclusively semiconductor contacts.