Characteristics of hafnium silicate as gate dielectric in n-GaN capacitors were investigated. The Hf 0.57 Si 0.43 O x , Hf 0.64 Si 0.36 O x and HfO 2 films exhibited high dielectric constants of 15.4, 15.9, and 17.6, respectively. The Hf 0.57 Si 0.43 O x and Hf 0.64 Si 0.36 O 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 × 10 11 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 HfO 2 film.
ASJC Scopus subject areas
- Physics and Astronomy(all)