Growth characteristics and electrical properties of La2O3 gate oxides grown by thermal and plasma-enhanced atomic layer deposition

Abstract We comparatively investigated thermal and plasma-enhanced atomic layer deposition (T-ALD and PE-ALD, respectively) of lanthanium oxide (La 2 O 3 ) films using tris(isopropyl-cyclopentadienyl)lanthanum [La(iPrCp) 3 ] as a La precursor. H 2 O and O 2 plasma were used as reactants for T-ALD and PE-ALD La 2 O 3 , respectively. Both of the processes exhibited ALD mode growth with good self-saturation behavior and produced pure La 2 O 3 films. However, PE-ALD La 2 O 3 showed higher growth rate and dielectric constant value than those of T-ALD La 2 O 3 . In addition, lower leakage current density and interface state density were observed for PE-ALD La 2 O 3 , compared to those of the T-ALD La 2 O 3 . These experimental results indicate that the PE-ALD La 2 O 3 process using La(iPrCp) 3 precursor can be one of the viable options applicable into future microelectronic industry.