Electrical Characteristics of Samarium Oxynitride Thin Film on Silicon-Based MOS Device

In this work, metal-oxide-semiconductor (MOS) properties of oxynitrided Sm film on Si in nitrous oxide environment were investigated and trap-assisted tunneling mechanism through the oxide were quantitatively analysed. The effects of oxynitridation temperatures on the capacitance-voltage and leakage current density-electrical field behaviours were reported. It was revealed that sample oxynitrided at 700°C demonstrated dielectric contant of 13 and the highest electrical breakdown field of 4 MV/cm at the lowest leakage current density of 10-7 A/cm
²
. This is attributed to the thinnest effective interfacial layers between the oxynitride and the semiconductor, with the lowest effective oxide charge, interface trap density, and total interface trap density. The Fowler-Nordheim tunneling mechanism has been investigated for all samples and the highest value of barrier height extracted between the conduction band edges of oxide and semiconductor was 6.33 eV. This type of oxide could be act as an alternative gate dielectric on Si-based MOS device.