Metal−Organic Chemical Vapor Deposition of Indium Selenide Thin Films

Abstract

Indium selenide (InSe) thin films have been grown at 230−420 °C by low-pressure metal−organic chemical vapor deposition (MOCVD) using the single-source precursors [(tBu)2In(μ-SetBu)]2 and [(Me2EtC)In(μ3-Se)]4. Characterization of the films by energy-dispersive X-ray analysis (EDX) showed those grown from [(tBu)2In(μ-SetBu)]2 to be indium rich, while those grown from [(Me2EtC)In(μ3-Se)]4 are stoichiometric InSe. Transmission electron microscopy (TEM) indicates that the film morphology and crystallinity are highly dependent on the precursor and the deposition temperature. At low temperatures <330 °C ball-like morphologies are observed, while deposition at 350−370 °C results in highly crystalline textured films. Use of [(tBu)In(μ3-Se)]4 as the precursor at 320−420 °C results in indium metal films. The relationship between the precursor's structure and the film's morphology and chemical composition are discussed. The efficacy of the single-source precursor approach is considered with respect to elemental composition, phase formation, and film morphology.