Solution-processed Pb0.8Ba0.2ZrO3 as a gate dielectric for low-voltage metal-oxide thin-film transistor

Abstract

A solution-processed low-voltage metal-oxide thin-film transistor (TFT) is fabricated by using ferroelectric perovskite structure barium zirconate (PBZ) as gate dielectric. This PBZ thin film is deposited on heavily doped Si substrate (p++-Si) by low-cost sol-gel process followed by annealing at 830 °C. The thin film is characterized by XRD, UV-Vis absorption spectroscopy and atomic force microscopy (AFM) that reveals fully oxidized PBZ thin film is highly crystalline in nature with high optical transparency in visible region that exhibited a lower roughness of 4.6 nm. Solution-processed indium zinc oxide (IZO) has been used as a channel semiconductor for bottom-gate top-contact TFT. The fabricated device require < 5 V operating voltage to saturate with high drain current which is very beneficial for low-power electronics because of its low operating voltage with respect to convention SiO2 gate dielectric device that required ~ 40 V operating voltage. This typical TFT shows an excellent electron mobility of 4.5 cm2 V−1 s−1 with on/off ratio 5 × 103 and subthreshold swing 0.35 V/decade.