DC-stress-induced Degradation of Analog Characteristics in HfxAl(1-x)O MIM Capacitors

Time-dependent capacitance-density (CD) increase and linearity degradations of HfAlO-MIM capacitors by constant voltage stress were demonstrated for the first time. It was found that extrapolated CD increase after 10 years strongly depends on Al concentration in HfAlO dielectric. Accordingly, Al concentration of more than 14 at.% is required to keep CD increase below 1%. It was also found that the CD increase and linearity degradations (temperature and frequency) originate from the dielectric-loss increase and that the relationships between these parameters quantitatively agree with Gevers' model.