Maxwell-Wagner Instabilities and Defects Generation during CVS in REO-HfO2 Gate Stacks Grown on Germanium Based MOS Devices

Abstract

The Current Instabilities and defects generation during constant voltage stress (CVS) in REO-HfO2 gate stacks grown on Ge (001) substrates by molecular beam deposition are extensively studied, and we report. Due to the different conductivities of the dielectrics in gate stacks charge accumulates at the interface of bilayer and results in current decay, and this behavior can be explained by the simultaneous effects of the Maxwell-Wagner instability and dielectric relaxation. However under CVS conditions new defects are created which is evident from 'Border traps' analysis.