Engineering structure and properties of hafnium oxide films by atomic layer deposition temperature

HfO2 films were atomic layer deposited from HfCl4 and H2O on Si(100) in the temperature range of 300-600 °C. At low temperatures, films grow faster and are structurally more disordered, compared to films grown at high temperatures. At high temperatures, the films are better crystallized, but grow slower and contain grain boundaries extending from substrate to gate electrode. Film growth rate and capacitance of HfO2 dielectric layers was improved by depositing stacked structures with polycrystalline films of higher purity at 600 °C on thin HfO2 sublayer grown on Si at 300 °C.