The effect of substrate temperature on the oxidation behavior of erbium thick films

The effect of substrate temperature on the oxidation behavior of erbium thick films, fabricated by electron-beam vapor deposition (EBVD), was investigated by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The erbium thick film is black when it is deposited at substrate temperature below 450 °C and turns gray at higher substrate temperature in a vacuum pressure of approximately 1.5 × 10−6 Torr, which indicates that the thickness of erbium oxide layer formed on the surface of erbium films increases with the decreasing substrate temperature. XPS depth profile results demonstrate that the thickness of the surface erbium oxide layer of erbium film deposited at substrate temperature of 550 and 350 °C are about 50 and 75 nm, respectively. The thicker oxide layer at lower substrate temperatures may be attributed to grain size and the dynamic vacuum condition around the substrates. Other possible factors involved in the oxidation behavior are also discussed.

► Substrate temperature effect on oxidation behavior of erbium film was investigated.
► Color of erbium films change from black to gray with increasing temperatures.
► Thickness of erbium oxide layer increases with decreasing substrate temperatures.
► Oxidation behavior of erbium film is attributed to vacuum condition and grain size.