US Patent 7250367 Deposition methods using heteroleptic precursors

An ALD method includes exposing a substrate to a first precursor including a plurality of different ligands, chemisorbing a precursor monolayer on the substrate, and reacting a second precursor with the precursor monolayer to yield a product monolayer. A surface reactive ligand exhibits a chemisorption affinity that exceeds the chemisorption affinity exhibited by a gas reactive ligand. Another deposition method includes exposing a substrate to a precursor containing an amino and/or imino ligand and a halide ligand and depositing a layer. The precursor exhibits a volatility that exceeds the volatility with a halide ligand taking the place of each amino and/or imino ligand. The precursor exhibits a thermal stability that exceeds the thermal stability with an amino and/or imino ligand taking the place of each halide ligand. The layer may exhibit less halogen content than with a halide ligand taking the place of each amino and/or imino ligand.