Charge trapping and degradation of HfO2/SiO2 MOS gate stacks observed with enhanced CAFM

In this letter, a prototype of conductive atomic force microscope with enhanced electrical performance has been used to separately investigate the effect of the electrical stress on the SiO2 and the HfO2 layers of a high-kappa gate stack. Charge trapping in HfO2 native defects and degradation of both layers have been observed, depending on the stress level.