Oxidation states in scanning-probe-induced Si3N4 to SiOx conversion studied by scanning photoemission microscopy

Abstract

The biased conductive probe of an atomic force microscope can induce local oxidation in ambience for converting silicon nitride films to silicon oxides with high reaction rate. Spatially resolved photoemission analysis with submicron resolution has been utilized to study the oxidation states of converted silicon oxide patterns in comparison with the surrounding Si3N4 layer. The core level shift of the Si 2p photoelectron peak and the spectral features in the valence band reveal a complete conversion of silicon nitride to silicon oxide at a bias voltage of 10 V, with no remaining nitrogen left. The major oxide is SiO2. The observed oxidation states of Si4+, Si3+, and Si2+ show a gradient depth distribution indicating excess silicon in the layer.

Zone-Plate-Based Scanning Photoelectron Microscopy at Srrc: Performance and Applications

“…However, no remaining nitrogen incorporated in the film as indicated by the absence of N 1s and N 2s signals (see Ref. 15 and the valence band spectrum in Fig. 4) could be observed.…”

“…at lower photon energy. 15 We conclude that those chemical states are due to intermediate oxidation produced during the nitride conversion and located in the layer with gradient depth distribution. However, no remaining nitrogen incorporated in the film as indicated by the absence of N 1s and N 2s signals (see Ref.…”

On the scaling issues and high-κ replacement of ultrathin gate dielectrics for nanoscale MOS transistors

“…Oxynitride prepared by NH 3 nitridation would introduce a large amount of traps because of the hydrogen incorporation and the amount of nitrogen incorporation at high temperature (>1000°C) is still too low (<5%) [70,71,[85][86][87] to improve the j value. With the advantages of low hydrogen content and the selflimited low growth rate, N 2 O oxide permits a better control of film thickness and slightly increases the resistance to boron diffusion [88][89][90][91][92][93][94][95][96][97][98][99][100][101][102][103][104][105].…”

Scanning Photoelectron Microscopy for the Characterization of Novel Nanomaterials

“…It is a detailed PES analysis of selected areas where the SPEM images show particularly interesting features. With the advantage of photon energy tunability of an SR light source, by changing photon energy and the aids of numerical data deconvolution, different chemical moieties and their relative depths can be resolved [38]. µ-XPS spectra from uniform areas can also be taken while scanning the sample [39], which decreases the photon exposure per surface area.…”

“…However, the demand on new SPEM systems will essentially depend on the scientific merit. The already existing systems have recently been applied to investigate the local electronic structure of various semiconductor nanostructures, such as GaN nanowires [42], ZnO nanorods [43,44], AlN nanotips [45], and focused-laser-treated CNTs [36], and the atomic force microscopy (AFM)-induced formation of silicon oxide pad [38,46] or silicon carbide nanowires [47]. Other studies included the dynamics of surface chemical processes on catalytic transition metal surfaces [48,49], the defect formation in organic light-emitting devices [50], the spatial chemical inhomogeneity of ferromagnetic semiconductors [51], and the band alignment of the in situ cleaved InN/GaN heterostructure [52].…”