Low-frequency noise characterization of amorphous InGaZnO thin-film transistors with double-stack Ga₂O₃/SiO₂ dielectric

This letter reports the fabrication and characterization of amorphous indium zinc oxide (a-IGZO) thin-film transistors (TFTs) with a double-stack Ga₂O₃/SiO₂ dielectric. The low-frequency noise characteristics of the devices are studied. With the double-stack Ga ₂O₃/SiO₂ dielectric, the leakage current of the TFTs is reduced and good transfer characteristics are obtained. Based on the carrier fluctuation model, the interface trap densities of a-IGZO TFTs with various SiO₂ thicknesses are evaluated. The trap density is found to decrease with increasing SiO₂ thickness. The results indicate that an SiO₂ interlayer with a moderate thickness can effectively suppress defects at the insulator/channel interface.