Fabrication and characterization of metal-molecule-silicon devices

Metal-molecule-silicon (MMSi) devices have been fabricated, electrically characterized, and analyzed. Molecular layers were grafted to n and p+ silicon by electrochemical reduction of para-substituted aryl-diazonium salts and characterized using standard surface analysis techniques; MMSi devices were then fabricated using traditional silicon (Si) processing methods combined with this surface modification. The measured current-voltage characteristics were strongly dependent on both substrate type and molecular head group. The device behavior was analyzed using a qualitative model considering semiconductor depletion effects and molecular dipole moments and frontier orbital energies.