(Invited) XPS Study on Chemical Bonding States of high-κ/high-μ Gate Stacks for Advanced CMOS

Abstract

The paper reviews the two topics on the non-destructive characterization of high-k/high-mobility gate stacks using the hard X-ray(7.94 keV) photoemission spectroscopy. The first topic is the change in the compositional depth profiles and the chemical bonding states of HfO2/Si-cap/strained-Ge/Si0.5Ge0.5/Si(100) laminating structures. The second topic is the influence of HF, (NH4)2S and HMDS treatments on In0.53Ga0.47As surface, La2O3 interlayer insertion on the chemical bonding states at high-k/In0.53Ga0.47As interface. Analyses of Ge 2p, Si 1s and Hf 3d spectra show that the strained-Ge layer is oxidized during the deposition of HfO2 in the case of 1-nm-thick Si cap layer and that strained-Ge layer is not oxidized in the case of 3 and 5-nm-thick Si cap layer. A critical Si thickness is also extracted. Analyses of measured spectra show that the oxidation of In0.53Ga0.47As is suppressed by La2O3 interlayer insertion ant that (NH4)2S treatment can suppress the oxidation of In0.53Ga0.47As surface.