High-k materials and their response to gamma ray radiation

Abstract

The radiation response of four different high-k materials has been investigated by irradiating them using a 979 MBq Cs137 γ-ray source and a dose absorption rate of 0.71rad(Si)∕s. Acceptorlike electron traps and donorlike traps were observed in HfO2 and ZrO2 metal-oxide-semiconductor capacitors originating from radiation-induced defects. A lower density of donor-like traps were created in LaAlO3 and NdAlO3 capacitors, but both electron and hole trapping play a role in shifting the flat band voltage. The radiation hardness of the LaAlO3 and NdAlO3 thin films is similar to thermal SiO2 but better than the HfO2 and ZrO2.