MOCVD Fabrication of Magnesium Fluoride Films: Effects of Deposition Parameters on Structure and Morphology

Abstract

AbstractMagnesium fluoride (MgF2) films are fabricated via low pressure metal‐organic (MO)CVD on glass or quartz substrates from the novel single‐source precursor Mg(hfa)2 · 2H2O · 2diglyme. The nature and quality of films are scrutinized depending on relevant operational parameters, namely the deposition temperature, the precursor vaporization rate, and finally the flow of the oxygen reacting gas. Grazing incidence X‐ray diffraction (GIXRD) data point to the formation of crystalline MgF2 films. Scanning electron microscope (SEM) images indicate very homogeneous surfaces with grain dimensions dependent upon operational conditions, while energy dispersive X‐ray (EDX) analyses point to the absence of any C or O contaminants. Smooth and homogeneous surfaces can be obtained upon deposition under high oxygen flow. The MgF2 film deposited on glass at 400 °C under optimized conditions shows a ∼80% transmittance in the range 300 − 800 nm. The high crystalline and optical quality of the MgF2 films, deposited using mild deposition temperatures (< 450 °C) still confirms MOCVD as a versatile and competitive deposition technique.