Electrical Properties and Charge Transport in the Pd/Al2O3/InGaAs MOS Structure

Abstract

The paper presents the results of a study focused on electrical properties and determination of transport mechanism through dielectric layer in Pd/Al2O3/In0.53Ga0.47As/InP MOS system. We found the current to be governed by Fowler-Nordheim tunneling in case of electron injection from the metal electrode for all dielectric thicknesses and of injection from the semiconductor for 10 nm Al2O3 thickness. The potential barrier for electrons at the metal-dielectric interface equals to 2.40±0.10 eV. The conduction band offset at the dielectric-semiconductor interface equals to 2.50±0.06 eV. The optimal value for Al2O3 oxide thickness among the MOS structures under study is proposed to be 10 nm. Increase of the Al2O3 thickness results in increase of fixed positive charge in the dielectric and probably extension of transition layer between the dielectric and semiconductor.