Annealing effects of in-depth profile and band discontinuity in TiN/LaO/HfSiO/SiO2/Si gate stack structure studied by angle-resolved photoemission spectroscopy from backside

Abstract

We have investigated annealing effects on in-depth profile and band discontinuity for a metal gate/high-k gate stack structure on a Si substrate using backside angle-resolved photoemission spectroscopy with synchrotron radiation. In-depth profiles analyzed from angle-resolved photoemission spectroscopy show that La atoms diffuse through the HfSiO layer and reach interfacial SiO2 layers by rapid thermal annealing. Chemical shift of Si 2p core-level spectra suggests that there are changes in the band discontinuity at the high-k/SiO2 interface, which is well related to the Vth shift based on the interface dipole model.