Investigation of HfAlO Trapping Layer with Various Al Contents by Variable Temperature Kelvin Probe Force Microscopy

Abstract

In order to explore the charge storage and loss characteristics of HfAlO charge trapping layer, Kelvin probe force microscopy (KFM) technology was applied. HfAlO trapping layer was deposited by an atom layer deposition (ALD) system with the precursors Hf[N(C2H5) CH3]4 (TEMAH), Al(CH3)3 (TMA) and H2O as source materials. Comparing with HfO2 trapping layer, the trap density of the HfAlO sample was significantly increased. And the data retention abilities were improved with the increased Al contents. The effective electron trap energies were extracted, by variable temperature KFM measurement. The results demonstrate that the trap energies of HfO2 layer increase with Al doping.