Chemical vapor deposition of zinc gallate using a novel single precursor

Abstract
A novel single precursor, bis(dimethylgallium-di-µ-isopropoxo)zinc which contains zinc, gallium, and oxygen in the 1 : 2 : 4 ratio, has been developed for the chemical vapor deposition of zinc gallate, ZnGa₂O₄, a prospective low voltage phosphor material for field emission display (FED). The precursor is a solid at room temperature and has a low melting point and a reasonably high vapor pressure when heated at about 50 °C. It was characterized by X-ray photoelectron spectroscopy (XPS) in its frozen state and by X-ray crystallography. In the low pressure chemical vapor deposition (LPCVD) reaction, the precursor is thought to undergo β-hydrogen elimination and partial dissociation producing a film that is a mixture of zinc gallate, gallium oxide, and zinc oxide. In the film, zinc gallate is the dominant phase and the amount of zinc oxide is minimal. The films deposited were characterized by XPS, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Possible mechanisms of the CVD reaction have been discussed to explain the peculiarities of the film composition.