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

Abstract

Gd-rich gadolinium scandate (Gd2–xScxO3) was deposited by high-pressure sputtering on (1 0 0) silicon by alternating the deposition of <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 6 × 1011 eV–1 cm–2.