Effect of Oxygen Partial Pressure on the Structural and Electrical Properties of DC Sputtered (Ta_2O_5)_(0.85)(TiO_2)_(0.15) Thin Films on Si

摘要

Thin films of (Ta_2O_5)_(0.85)(TiO_2)_(0.15)) were deposited on p-Si (100) by DC reactive magnetron sputtering at various oxygen partial pressures in the range 3×10~(-2) - 9×10~(-2) Pa and annealed in air for 1 hour at 700°C. The structural properties of the (Ta_2O_5)_(0.85)(TiO_2)_(0.15) films were studied and the electrical properties of Al/(Ta_2O_5)_(0.85)(TiO_2)_(0.15) gate stacks formed on p-Si substrates were systematically investigated. The leakage current density of the films deposited at 3×10~(-2) Pa was 6.97×10~(-6) A/cm~2 (at a gate bias voltage of 1.5 V) and it was decreased to 1.75×10~(-8) A/cm~2 with the increase of oxygen partial pressure to 9×10~(-2) Pa. The current conduction mechanism of the (Ta_2O_5)_(0.85)(TiO_2)_(0.15) films was analyzed and compared with mechanisms of Poole-Frenkel and Schottky emissions.