Dysprosium scandate thin films as an alternate amorphous gate oxide prepared by metal-organic chemical vapor deposition

Abstract

Dysprosium scandate (DyScO3) thin films were deposited on Si substrates using metal-organic chemical vapor deposition. Individual source precursors of Dy and Sc were used and deposition temperatures ranged from 480to700°C. Films were amorphous with low root mean square roughness (⩽2Å) and were stable up to 1050°C annealing. Electrical characterization yielded C-V curves with negligible hysteresis (<10mV), high dielectric constant (∼22), and low leakage currents. The electrical properties of the DyScO3∕SiOx∕Si stacks were stable up to 800°C for films on native oxide; however, this limit increased to 900°C for films on special chemically grown oxide, suggesting further improvement with proper diffusion barrier.