Effect of annealing temperature of Bi_1.5Zn_1.0Nb_1.5O₇ gate insulator on performance of ZnO based thin film transistors

【摘要】 The bottom-gate structure ZnO based thin film transistors（ZnO-TFTs） using Bi_1.5Zn_1.0Nb_1.5O₇（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.更多还原

【Abstract】 The bottom-gate structure ZnO based thin film transistors（ZnO-TFTs） using Bi_1.5Zn_1.0Nb_1.5O₇（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.更多还原