Effects of interracial oxide layer for the Ta₂O₅ capacitor after high-temperature annealing

Thin Ta₂O₅ films were prepared by low-pressure chemical vapor deposition (LPCVD) and subsequently annealed in O₂ ambient at various temperatures. It was found that the leakage current of the Ta₂O₅/SiO_x capacitor was controlled by the Ta₂O₅ layer when the annealing temperature was lower than 700°C. On the other hand, the leakage current was controlled by the interracial oxide layer when the annealing temperature was higher than 700°C. It was also found that we could achieve an equivalent thin oxide thickness and a small leakage current at the same time from the Ta₂O₅/SiO_x capacitor with a suitable thermal annealing treatment.