Investigation of current transport in Galfenol based Schottky diodes

Abstract

We demonstrate for the first time Galfenol (FeGa) alloy in a ferromagnetic/semiconductor Schottky diode configuration with n-Si substrates. Electrical properties have been studied using current vs. voltage (I-V) and capacitance vs. voltage (C-V) measurements. The Schottky contact was fabricated by depositing a thin layer of FeGa onto n-Si substrates by radio frequency magnetron sputtering. Diode parameters in accordance with thermionic emission theory, such as ideality factor, barrier height and series resistance were extracted from the forward bias semi logarithmic I-V graph and were found to be 2.57, 0.76 eV and 43.25 kΩ respectively at room temperature. The corresponding values when calculated from dV/d(ln(I)) vs. I plot and Cheung functions were found to be 2.28, 0.74 eV and 43.2 kΩ respectively. Barrier height obtained using C-V measurement was found to be 0.77 eV which is close to the other two measurements. The increase in ideality factor and barrier height can be attributed to formation of a native interfacial oxide layer and inhomogeneity in barrier formation. Mixed type of conduction has been inferred from double logarithmic plots. Rectifying nature of the contact has been investigated by using the diode in half-wave rectifier configuration, testing the promise of a working Galfenol based device.