Preparation of copper and copper oxide films by metal-organic chemical vapour deposition using β-ketoiminato complexes

Abstract

Two β-ketoiminato complexes of copper (II), namely bis-(acetylacetone)ethylenediiminato-copper(II) ( 1) and [4-[ N′-dimethylethylamino)- N-iminato]-pentan-2-one](acetano)copper( II) ( 2) were investigated as precursors for the growth of metallic copper films by metal-organic chemical vapour deposition (MOCVD). Evaporation experiments showed a rather low volatility compared with β-diketonato compounds as Cu(acac), Cu(dpm) 2 and Cu(tfa) 2 and Cu(hfa) 2. The more volatile complex 1 was used in MOCVD experiments in a horizontal quartz reactor using a graphite susceptor covered with copper or copper oxide. Thin films (thickness, 0.1–0.7 μm) were grown on quartz, sappire, Si[100], MgO[100] and Al. The kinetic dependence of the growth rate on partial pressure of 1 and the reaction gas hydrogen is discussed. Single-phase films or mixtures of metallic copper and copper oxide could be identified by X-ray diffraction. Scanning Auger microscopy yielded a rather high level (about 6 at.%) of carbon and no nitrogen (1 at.% or less) in the films.