Characteristics of hafnium silicate as gate dielectric in n-GaN capacitors were investigated. The Hf0.57Si0.43O x , Hf0.64Si0.36O x and HfO2 films exhibited high dielectric constants of 15.4, 15.9, and 17.6, respectively. The Hf0.57Si0.43O x and Hf0.64Si0.36O x films, which had an amorphous structure, showed superior properties, including a minimal flatband voltage (V fb) hysteresis (≤70 mV) and a small V fb shift (≤-0.45 V), as well as a low interface state density (∼4 × 1011 cm-2 eV-1 at -0.4 eV from conduction band), and a high breakdown electric field (≥8.6 MV cm-1) compared to those of a polycrystalline HfO2 film.
ASJC Scopus subject areas
- Physics and Astronomy(all)