摘要
For TaN/HfO2/TaN capacitors, thermal annealing or plasma treatment is conducted after HfO2 deposition. Rapid thermal annealing or furnace thermal annealing at 400 °C can improve the leakage current but worsens the voltage linearity of capacitance. A capacitor with adequate NH 3 plasma treatment can have a lower leakage current and a better voltage linearity property compared with the control sample. Atomic force microscopy (AFM) data indicate that the roughness of thermalannealed or plasma-treated HfO2 film is related to the voltage linearity property for the capacitor. In addition to thermally induced stress, the oxygen atoms diffuse through the HfO2 film and then oxidize the bottom TaN electrode, leading to a rougher interface during O2 thermal annealing. Because of nitrogen atom diffusion into HfO2 film and a less damaged surface, the quality of the TaN/HfO2 interface and HfO2 film can be improved, which leads to better analog characteristics. © 2008 The Japan Society of Applied Physics.