Point defect chemistry in amorphous HfO2: Density functional theory calculations

Neutral and charged native point defects in amorphous HfO2 were studied using first-principles computations. Thermodynamically, positively charged O vacancies and negatively charged Hf vacancies are the most probable point defects over a large atomic and electronic chemical-potential range. Moreover, of all point defects, the positively charged O vacancy is the one with the lowest migration barrier. Hence, this point defect is identified as the most dangerous one in amorphous HfO2 within the context of high-K gate dielectric applications in microelectronics.