Filling performance and electrical characteristics of Al2O3 films deposited by atomic layer deposition for through-silicon via applications

We have evaluated the conformality and electrical properties of Al2O3 films deposited by atomic layer deposition at temperatures below 300 °C for through-silicon via (TSV) applications. Al2O3 films were able to be conformally deposited on the scallops of 50-μm-wide, 100-μm-deep TSV at the temperature range between 200 and 300 °C. The median breakdown fields of the metal-insulator-metal device with 30-nm-thick Al2O3 layer were above 6 MV/cm for the films deposited at 250 and 300 °C, while that at 200 °C was inferior due to residual carbon impurities in the oxide layer.