The influence of process parameters and pulse ratio of precursors on the characteristics of La1 − x Al x O3 films deposited by atomic layer deposition

Abstract

The influence of processing parameters of aluminum oxide (Al 2 O 3) and lanthanum oxide (La 2 O 3) gate dielectric is investigated. Trimethylaluminum (TMA) and tris(isopropylcyclopentadienyl) lanthanum [La(iPrCp) 3 ] were used as precursors separately, and H 2 O was used as oxidant. The ultra-thin La 1 − x Al x O 3 gate dielectric films are deposited on p-type silicon substrates by atom layer deposition (ALD) for different pulse ratios of precursors. Effects of different La/Al precursor pulse ratios on the physical properties and electrical characteristics of La 1 − x Al x O 3 films are studied. The preliminary testing results indicate that the increase of La precursor pulse can improve the characteristics of film, which has significant effects on the dielectric constant, equivalent oxide thickness (EOT), electrical properties, and stability of film.