Effect of selected atomic layer deposition parameters on the structure and dielectric properties of hafnium oxide films

Hf O 2 films were atomic layer deposited from HfCl4 and H2O on Si(100) in the temperature range of 226–750°C. The films consisted of dominantly the monoclinic polymorph. Elastic recoil detection analysis revealed high residual chlorine and hydrogen contents (2–5at.%) in the films grown below 300–350°C. The content of residual hydrogen and chlorine monotonously decreased with increasing growth temperature. The effective permittivity insignificantly depended on the growth temperature and water partial pressure. Capacitance-voltage curves exhibited marked hysteresis especially in the films grown at 400–450°C, and demonstrated enhanced distortions likely due to the increased trap densities in the films grown at 700–750°C. Changes in water pressure led to some changes in the extent of crystallization, but did not induce any clear changes in the capacitance of the dielectric layer.