Optimization of electrical characteristics of TiO2-incorporated HfO2 n-type doped gallium arsenide metal oxide semiconductor capacitor with silicon interface passivation layer

Structural approach of TiO2-incorporated HfO2 multimetal dielectric n-type doped gallium arsenide (n-GaAs) metal oxide semiconductor capacitors and their electrical characteristics are investigated. Top TiO2 with bottom HfO2 bilayer dielectric shows excellent C-V characteristics and the lowest hysteresis. Scaling down of this TiO2∕HfO2 dielectric results in substantial reduction in hysteresis and equivalent oxide thickness compared to HfO2 dielectric. Reduced hysteresis is believed to be due to lower trap density of TiO2 than HfO2.