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

摘要

HfO2 films were atomic layer deposited from HfCl4 and H2O on Si(100) in the temperature range of 226-750 degreesC. The films consisted of dominantly the monoclinic polymorph. Elastic recoil detection analysis revealed high residual chlorine and hydrogen contents (2-5 at. %) in the films grown below 300-350 degreesC. 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 degreesC, and demonstrated enhanced distortions likely due to the increased trap densities in the films grown at 700-750 degreesC. 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. (C) 2004 American Institute of Physics.