Oxygen K near‐edge spectra of amorphous silicon suboxides

Abstract

SUMMARY Chemical disorder in silicon suboxides has been modelled by constructing several small atomic clusters which were used as input for multiple scattering calculations of the energy‐loss near‐edge structure at the oxygen K‐edge. A redistribution of intensity at the O K‐edge is observed as the number of second neighbour oxygen atoms is reduced. Since photoelectrons scattered by second neighbours of oxygen (at least) contribute to the spectra, O K‐edge data provide valuable structural information, additional to that obtained from the Si L23‐edge, which appears to be restricted to the local coordination shell. Comparison with the experimental O K‐edge for a‐SiOx (O < × < 2), prepared by oxidation of amorphous Si, suggests that the material consists of an intimate mixture of a wide range of Si sites with varying proportions of oxygen and silicon in the first neighbour shell.

Characterization of hafnium oxide grown on silicon by atomic layer deposition: Interface structure

“…Oxygen K-edge spectra from the deposited film show double peaks characteristic of stoichiometric bulk HfO 2 [33], similar to that obtained previously and reported for pure HfO 2 [34]. EELS spectra obtained at the interfacial layer show the fine structure to be mostly that of silicon oxide [35], further corroborating our earlier findings that silicate structure is not present at our deposition conditions. Fig.…”

Direct observation of site-specific valence electronic structure at theSiO2∕Siinterface

“…This is consistent with the previous results [8]. According to the theoretical studies by Wallis et al, the oxygen K-edge of the intermediate states in the amorphous silicon shifts to lower energy as the oxidation number of the adjacent silicon atoms decreases [17]. Thus, we assigned the absorption edges at 530 and 531.5 eV to an O atom bonding to Si 1+ and Si 3+ at the interface, respectively (hereafter, we denote O atom bonding to Si 1+ and Si 3+ at the interface as P1 and P3, respectively).…”

A new analytical method for characterising the bonding environment at rough interfaces in high-k gate stacks using electron energy loss spectroscopy

“…Recall from sections 4.3-4.4 that evidence was found for a silicon oxynitride layer at the TiN/ poly-Si interface. The ELNES changes at the TiN/ poly-Si interface in figure 11 are consistent with experimental measurements and multiple scattering simulations of the O-K edge from sub-stoichiometric silicon oxides [33]. Replacement of some of the oxygen atoms with nitrogen as well as the possibility of silicon dangling bonds within the silicon oxynitride layer could therefore explain the changes to the O-K edges observed in figure 11.…”