Spatial distributions of trapping centers in HfO₂/SiO₂ gate stack

An analysis methodology for charge pumping (CP) measurements was developed and applied to extract spatial distributions of traps in SiO₂HfO₂ gate stacks. This analysis indicates that the traps accessible by CP measurements in the frequency range down to a few kilohertz are located primarily within the SiO₂ layer and HfO₂ SiO₂ interface region. The trap density in the SiO₂ layer increases closer to the high-κ dielectric, while the trap spatial profile as a function of the distance from the high-κ film was found to be dependent on high-κ film characteristics. These results point to interactions with the high-κ dielectric as a cause of trap generation in the interfacial SiO₂ layer.