Leakage Current and Defect Analysis of Schottky Diodes on Molecular Monolayer-doped Silicon

The molecular monolayer doping technique, as an alternative doping technique of conventional ion implantation, has been extensively investigated in recent years. It provides promising solutions to the challenges of the state-of-art metal-oxide-semiconductor field effect transistors (MOSFET) by enabling accuracy at atomic scale and conformal doping for three dimensional (3D) devices. In this paper, we investigated the leakage current and related defects of Schottky diodes fabricated on molecular monolayer-doped silicon. We found that the device leakage current went up 1000 times in comparison with the device fabricated on blank silicon substrate. In the subsequent deep level transient spectroscopy (DLTS) and minority carrier transient spectroscopy (MCTS) measurements, we detected carbon-related majority carrier traps in phosphorus doped silicon and oxygen-related majority carrier traps and carbon-related minority carrier traps in boron doped silicon. These defects increase the leakage current and degrade the device performance by deactivating dopants and increasing the generation-recombination (G-R) rate.