Charge trapping behavior in organic–inorganic alloy films grown by molecular layer deposition from trimethylaluminum, p-phenylenediamine and water

Abstract

Organic–inorganic hybrid or alloy films have great potential as a functional material because they have structural flexibility owing to the presence of an organic moiety. Here organic–inorganic hybrid films were grown by molecular layer deposition (MLD) by using trimethylaluminum and p-phenylenediamine. Although the hybrid films could be grown via the self-limiting growth mechanism of MLD, the hybrid films were severely air sensitive. The stability problem of the hybrid films could be solved by alloying the hybrid layer with Al₂O₃ layers. The alloy films, which were grown by repeating supercycles with one subcycle for the hybrid layer and four subcycles for the Al₂O₃ layers, showed excellent dielectric properties: a leakage current density of ∼2.3 × 10⁻⁸ A cm⁻² at 1 MV cm⁻¹; a dielectric breakdown field at ∼2.9 MV cm⁻¹; and a dielectric constant of ∼6.2. Interestingly, charge trapping behavior was clearly observed in the alloy film. The charge trapping ability of the alloy film was verified with a charge trapping memory capacitor in which the alloy film was inserted as a charge trapping layer.