HfOx, and HfOxNygate dielectrics are fabricated by sputtering in oxygen- and nitrogen-containing ambient, respectively, followed by postdeposition annealing in N2ambient at 700°C. The material characteristics of the dielectric layers are investigated by glancing incident angle X-ray diffraction (GIAXRD), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). GIAXRD analysis indicates that both HfOxand HfOxNyfilms are amorphous, as deposited and after annealing. Nevertheless, formation of a nitrogen self-doped interfacial layer (IL) in the as-sputtered HfOx-Ny, dielectric stack is resolved by XPS and HRTEM, which leads to its superiority in lessening the thickness of IL over the HfOxsystem. Regarding the electrical property, the HfOxNydielectric layer is superior to HfOxin reducing the leakage current and it exhibits a very narrow capacitance-voltage hysteresis loop (ΔVhysteresis= 10 mV). The influence of the nitrogen self-doped IL on the electrical performance of the gate stack is discussed.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry