Search

Abstract: We report on the dielectric properties and leakage current characteristics of 3 mol% Mn-doped Ba0.6Sr0.4TiO3 (BST) thin films post-annealed up to 600 °C following room temperature deposition. The suitability of 3 mol% Mn-doped BST films as gate insulators for low voltage ZnO thin film transistors (TFTs) is investigated. The dielectric constant of 3 mol% Mn-doped BST films increased from 24 at in-situ deposition up to 260 at an annealing temperature of 600 °C due to increased crystallinity and the formation of perovskite phase. The measured leakage current density of 3 mol% Mn-doped BST films remained on the order of 5×10−9 to 10−8 A/cm2 without further reduction as the annealing temperature increased, thereby demonstrating significant improvement in the leakage current characteristics of in-situ grown Mn-doped BST films as compared to that (5×10−4 A/cm2 at 5 V) of pure BST films. All room temperature processed ZnO–TFTs using a 3 mol% Mn-doped BST gate insulator exhibited a field effect mobility of 1.0 cm2/Vs and low voltage device performance of less than 7 V. [Copyright &y& Elsevier]

The authors report on the influence of Mg acceptor doping on the markedly reduced leakage current characteristics (<5×10-8 A/cm2 at 2 MV/cm) of Ba0.6Sr0.4TiO3 thin films. The suitability of room temperature deposited Mg-doped Ba0.6Sr0.4TiO3 films as gate insulators for low-voltage ZnO thin-film transistors (TFTs) (<6 V) was investigated. All room temperature processed ZnO-TFTs on plastic substrates exhibited a high field-effect mobility of 16.3 cm2/V s and a current on/off ratio of 6.4×104. The threshold voltage and subthreshold swing were 2.8 V and 400 mV/decade, respectively. [ABSTRACT FROM AUTHOR]

The authors report on the role of MgO capping layers in notably reducing leakage currents and improving mobility in ZnO thin film transistors (TFTs) utilizing compatible high-k Bi1.5Zn1.0Nb1.5O7 (BZN) gate insulators. All room temperature processed ZnO based TFTs with stacked MgO/BZN gate insulator exhibited a much enhanced field effect mobility of 5.4 cm2/V s with excellent saturation characteristics as compared to that (μFE=1.13 cm2/V s) of ZnO based TFTs with BZN gate insulator. This work demonstrates the suitability of MgO/BZN stacked gate insulators in the fabrication of low voltage ZnO based TFTs on plastic substrates. [ABSTRACT FROM AUTHOR]