Abstract
Tantalum pentoxide (Ta2O5) is a candidate for use in metal-insulator-metal capacitors in switching devices for active-matrix liquid-crystal displays. High quality Ta2O5 thin films were obtained by using an anodizing method. Rutherford backscattering spectroscopy, transmission electron microscope observations, auger electron spectroscopy, ellipsometry measurements, and electrical measurements, such as current-voltage (I - V) measurements were performed to investigate Ta2O5 films and their reliability and indicated that the obtained TaOx thin films were reliable Ta2O5 films for the applications. Physical and electrical measurements revealed that the Ta2O5 films had excellent properties: refractive indices of 2.1-2.2, a reasonable breakdown field (5 MV/cm) and low leakage currents (<10-7 A/cm2 at 2 MV/cm). We applied novel process technologies which postannealed whole thin-film diode elements, instead of conventional annealing, to the fabrication. The postannealing process reduced the asymmetry and improved the symmetry of the I-V characteristics. Furthermore, in this paper, we discuss the effects of top-electrode metals and annealing conditions. The conduction mechanism of the leakage current and the symmetry characteristics related to the Schottky emission and Poole-Frankel effect are also discussed using the results of electrical measurements and conduction barrier theory.
Original language | English |
---|---|
Pages (from-to) | 686-691 |
Number of pages | 6 |
Journal | Journal of the Korean Physical Society |
Volume | 39 |
Issue number | 4 SUPPL. Part 1 |
State | Published - Oct 2001 |