The thermal stability and electrical properties of LaErO₃films as high-kgate dielectrics

Lanthanum erbium oxide thin films have been deposited on an Si (1 0 0) wafer by using the pulsed laser deposition technique. The thermal and electrical properties of LaErO 3 films were investigated by x-ray diffraction, x-ray photoelectron spectroscopy and high resolution transmission electron microscopy. Capacitance measurements reveal good C – V curves with an equivalent oxide thickness of 1.4 nm and little hysteresis. Transmission electron microscopic images reveal that the 6.5 nm LaErO 3 film shows a thin interfacial layer even after being annealed in N 2 at 700 °C for 30 s. X-ray photoelectron spectroscopic spectra indicate that little SiO 2 was formed at the interface during the deposition of LaErO 3 films. The measured thermal and electrical properties of the thin film suggest that the LaErO 3 film should be a promising candidate for future high- k gate dielectrics.