The Effect of Doping Concentration of Si on the Nature of Barrier of Co2MnSi/MgO/n-Si Junctions

In this work, we have presented the electrical characteristic of Co2MnSi/MgO/n-Si junctions as a function of the doping concentration of Si. Films were fabricated by dc sputtering and post annealed at 400 degrees C for 1 h without breaking the vacuum. The Co2MnSi/MgO/n-Si junctions exhibited diode like characteristics at low doping concentration 10(16)/cc. This can be attributed due to oxide charges or interface traps close to the silicon interface, which causes the bend bending and forms the large extended depletion region. The junction characteristic was found to change with the increase of doping concentration and became symmetric at doping concentration of 10(19)/cc. Therefore, with the same thickness of MgO barrier, the junction characteristic was changed from Schottky to symmetric tunneling with the doping density of Si. The origin of the change of junction characteristic might be due to the change of the depletion width with the doping density.