Application of Synchrotron X-ray Diffraction Methods to Gate Stacks of Advanced MOS Devices

Abstract

We demonstrate two topics of the application of synchrotron X-ray diffraction methods to thin films used in gate stack structures. One is related to the structural change in the interfacial SiO2 layer between the high-k dielectric layer and the Si substrate. It is shown that O2 molecules dissociate into O atoms during diffusion through the HfO2 layer and these O atoms destroy the ordered SiO2 in the interfacial layer. The other is the characterization of strained Si wafers using a synchrotron X-ray microbeam diffraction and topography. The nonuniformity in micro- and centimeter scales is shown for the SiGe layer of the strained Si wafers.