Second-harmonic intensity and phase spectroscopy as a sensitive method to probe the space-charge field in Si(100) covered with charged dielectrics

Abstract

Second-harmonic intensity and phase spectroscopy as a sensitive method top robe the space-charge field in Si(100) covered with canged dielectrics.

Influence of the spatial extent of the space-charge region in c-Si on the electric-field-induced second-harmonic-generation effect

“…Further confirmation of the phase shift in the EFISH contribution can be found in our earlier work [32]. In that work a similar trend in the phase was observed; however, at the time of writing the trend in the EFISH phase was not expected, and it was not interpreted further.…”

“…As expected, the Schottky model (M2) is only valid for strong SCRs, and the interface-only The trend for a positive SCR is similar to that of a negative SCR with an offset of πrad. The CP phase factor determined in this work for a series of samples by combined SHG phase and intensity spectroscopic measurements are included in the figure (triangles) as well as the data set published by Terlinden et al, simultaneously analyzing a large set of intensity-only spectra (squares) [32]. No data points are available in for positive fixed charge because the few thin films that exhibit a large positive fixed charge such as SiN x also generate bulk SHG, complicating the interpretation of the spectra.…”

“…The complementary nature of the phase and intensity measurements enhances the sensitivity to changes in the phase and should suffice to detect a shift of 0.1π rad. For a detailed description of the setup and an evaluation of its sensitivity, see the SI and Terlinden et al [32].…”

“…The parameterized model M3p strikes a good balance: it is hardly more complex than the interface-only model (M1) but yields significantly more accurate results. It can readily be adopted in the excitonic models typically used to fit SHG spectra [4,5,29,31,32,44,[46][47][48][49][50].…”

“…The charge density and polarity of the fixed charges can be probed by SHG via the EFISH effect in a contactless and virtually sample-preparationfree fashion [4,17,[29][30][31]. This makes SHG particularly well suited as a diagnostic for in situ studies of (buried) interfaces and the characterization of built-in charges in an early stage before a fully functioning electrically device has been realized [29,32]. These capabilities set SHG apart from other approaches such as capacitance-voltage (CV) measurements.…”