Quantitative profiling of SiGe/Si superlattices by time‐of‐flight secondary ion mass spectrometry: the advantages of the extended Full Spectrum protocol

Abstract

The abundance of work on SiGe-based devices demonstrates the importance of the compositional characterization of such materials. However, Secondary Ion Mass Spectrometry (SIMS) characterization of SiGe layers often suffers from matrix effects due to the non-linear variation of ionization yields with Ge content. Several solutions have been proposed in order to overcome this problem, each having its own limitations such as a restricted germanium concentration range, or a weak sensitivity to dopants or impurities. Here, we studied the improvements brought by an alternative protocol: the extended Full Spectrum protocol, which states proportionality between the composition of the secondary ion beam and that of the actual material. Previous studies on this protocol showed that it was extremely precise and reproducible for Ge quantification in a permanent regime, because of minimized matrix effects. In this study we thus investigated its accuracy for the simultaneous quantitative depth profiling of both matrix elements (Si, Ge) and impurities (B, C or P) in strained SiGe/Si superlattices by comparing results with those from more classic protocols. The profiles provided by the extended Full Spectrum protocol were found to be accurate, and to exhibit better properties than classic protocols in terms of signal/noise ratio and signal stability, along with a slight enhancement in depth resolution.

Study of magnetic iron nitride thin films deposited by high power impulse magnetron sputtering

“…In general, exact calculation of RSF is a tedious process due to involved matrix effects, but in the simplest case of two elements RSF can be calculated by using a reference sample with known concentration. [23,52] Using equation 1 we measured N at.% both for HiPIMS and dc-MS samples. Figure 7 shows the observed variation of nitrogen concentration with increasing R N2 .…”

Low temperature boron and phosphorous doped SiGe for recessed and raised sources and drains

“…Si and Ge quantification was performed using the extended Full Spectrum protocol detailed in Ref. [28].…”

Atomic spectrometry update. Industrial analysis: metals, chemicals and advanced materials

“…327,328 As discussed previously, matrix effects can limit the usefulness of SIMS measurements and therefore many workers use the measurement of MCs 2+ secondary ions, which enables the Ge concentration to be quantified in a Si 1Àx Ge x type material over the range 0.05 # x # 0.85. 327,328 As discussed previously, matrix effects can limit the usefulness of SIMS measurements and therefore many workers use the measurement of MCs 2+ secondary ions, which enables the Ge concentration to be quantified in a Si 1Àx Ge x type material over the range 0.05 # x # 0.85.…”