Defects Generation under Constant Voltage Stress in La2O3/HfO2 Gate Stacks Grown on Ge Substrates

Abstract

We report on the defect generation under constant voltage stress in La2O3/HfO2 gate stacks grown on Germanium (001) substrates by molecular beam deposition utilizing a stress and sense technique. A voltage range from 0.5V up to 2.4V was used for the measurements. At low applied gate voltages, the stress induced current decrease could be explained by a field lowering model due to charge trapping, while at higher voltages the generation of shallow traps in the Lanthanum oxide layer becomes more important.