The bottom-gate structure ZnO based thin film transistors(ZnO-TFTs) using Bi1.5Zn1.0Nb1.5O7(BZN)thin films as gate insulator were fabricated on Pt/SiO2/Si substrate by radio frequency magnetic sputtering.We investigated the effect of annealing temperature at 300,400,and 500 ℃ on the performance of BZN thin films and ZnO-TFTs.XRD measurement confirmed that BZN thin films were amorphous in nature.BZN thin films annealed at 400 ℃ obtain the high capacitance density of 249 nF/cm2,high dielectric constant of 71,and low leakage current density of 10-7 A/cm2 on/off current ratio and field effect mobility of ZnO-TFTs annealed at 400 ℃are approximately one order of magnitude and two times,respectively higher than that of ZnO-TFTs annealed at300 ℃.When the annealing temperature is 400 ℃,the electrical performance of ZnO-TFTs is enhanced remarkably.Devices obtain a low sub-threshold swing of 470 mV/dec and surface states density of 3.21 × 1012cm-2.
The bottom-gate structure ZnO based thin film transistors (ZnO-TFTs) using Bi1.5Zn1.0Nb1.507 (BZN) thin films as gate insulator were fabricated on Pt/SiO2/Si substrate by radio frequency magnetic sputtering. We investigated the effect of annealing temperature at 300, 400, and 500℃ on the performance of BZN thin films and ZnO-TFTs. XRD measurement confirmed that BZN thin films were amorphous in nature. BZN thin films annealed at 400℃ obtain the high capacitance density of 249 nF/cm2, high dielectric constant of 71, and low leakage current density of 10^-7 A/cm2 ordoff current ratio and field effect mobility of ZnO-TFTs annealed at 400℃ are approximately one order of magnitude and two times, respectively higher than that of ZnO-TFTs annealed at 300℃. When the annealing temperature is 400℃, the electrical performance of ZnO-TFTs is enhanced remarkably. Devices obtain a low sub-threshold swing of 470 mV/dec and surface states density of 3.21×10^12cm^-2.