Gadolinium scandate by high-pressure sputtering for future generations of high-k dielectrics

Abstract

Gd-rich gadolinium scandate (Gd2-xScxO3) was deposited by high-pressure sputtering on (100) silicon by alternating the deposition of lower than 0.5 nm thick films of its binary components: Sc2O3 and Gd2O3. The formation of the ternary oxide was observed after the thermal treatments, with a high increase in the effective permittivity of the dielectric (up to 21). The silicon diffuses into the Gd2-xScxO3 films, which show an amorphous character. After the annealing no interfacial silicon oxide is present. CHF-VG curves indicated low hysteresis (55 mV) and a density of interfacial defects of 6e11 eV-1 cm-2.