Charge trapping studies on ultrathin ZrO ₂ and HfO ₂ high-k dielectrics grown by room temperature ultraviolet ozone oxidation

Abstract

The charge trapping behavior of ultrathin ZrO 2 and HfO 2 dielectrics grown by the ultraviolet ozone oxidation (UVO) method was studied. The dependence of charge trapping behavior on top gate electrode process was discussed. Charge trapping studies were performed by injecting varying levels of charge into the dielectrics and measuring the shift in flatband as a function of time. The results show that the electrical properties depends on gate electrode processing, with in situ sputtered platinum (Pt) gate stacks showing less charge trapping compared to ex situ processed gates.