Abstract
A major reliability concern in modern high-k field effect transistors (FETs) resembles the defect density distribution within the hafnium oxide layer as well as its interaction with the interfacial oxide layer. For a deeper understanding of the distribution of charged traps both energetically as well as spatially, it is essential to upgrade from a two level charge pumping scheme to a three level scheme. Through variation in pulse width and amplitude of a subsequent second level pulse, defect energy and location can be extracted inside the gate stack, which is important to understand the overall reliability impact of these traps onto the device properties.