Synthesis of New Heteroleptic Indium Complexes as Potential Precursors for Indium Oxide Thin Films

Abstract

New heteroleptic indium complexes, i. e., [MeIn(mdpa)(tmhd)] 2 (2), [MeIn(mdpa)(acac)] 2 (3), [MeIn(edpa)(tmhd)] 2 (4), and [MeIn (edpa)(acac)] 2 (5), with three different ligands, bearing N-alkoxy carboxamide and β-diketonate were designed and synthesized as indium precursors for indium oxide thin films by atomic layer deposition (ALD) using [Me 2 In(edpa)] 2 and [Me 2 In(mdpa)] 2 (1) as starting materials. The resulting complexes were characterized by NMR and FT-IR spectroscopy, elemental analysis (EA), thermogravimetric analysis (TGA), and single crystal X-ray diffraction. TGA curves of all the complexes showed clear single-step weight losses, with low residual masses of 7-13 %. Among them, complex 5 was volatile and thermally stable, and thus, it can be used as potential indium precursor for indium oxide-based thin films.