Each crystal structure has its own phonon modes, which appear in the Raman spectrum of Raman scattering. In the case of silicon, phonon modes associated with the diamond structure of silicon can be detected. In a Raman spectrum, the position of the lines, their intensity, and the width of the lines are usually measured. Raman spectroscopy is a powerful tool for studying crystalline materials at the molecular level, and its application in the study of semiconductors and nanomaterials provides important information about their structure and properties. In this study, the spectra of two types of silicon were analyzed: n-Si and p-Si, as well as their doped analogues n-Si and p-Si. The obtained Raman imaging results demonstrated spatially varying nanocrystallinity and microcrystallinity of the samples. The n-Si and p-Si spectra indicate the appearance of a Raman band at 525 cm-1 with a shift of -5 cm-1 and +5 cm-1, respectively, relative to the position of the silicon substrate peak, indicating the presence of tensile strain in the materials. The absence of other impurity peaks indicates the high purity of the n-Si and p-Si samples. The holmium doped Si material exhibits additional peaks in the Raman spectra, which is attributed to the presence of vacancies and defects in the newly formed Si-Ho compositions. The results of the analysis of the spectra indicate the influence of doping silicon with holmium on its structure and properties, forming new bonds and defects.

The characteristics of silicon MIS structures with ytterbium impurity are studied using non-stationary capacitance spectroscopy of deep levels. It is established that the presence of ytterbium atoms in the bulk of the silicon substrate leads to a shift in the capacitance-voltage characteristics towards positive bias voltages and a decrease in the density Nss of the surface states of the MIS structures. It is shown that this effect depends on the concentration of ytterbium atoms in the silicon substrate of the studied structures. In MIS structures based on Si, one deep level with an ionization energy Ec-0.32 eV is detected.

In this study, we investigated silicon samples doped with gadolinium using two different methods: incorporation during growth and diffusion treatment at elevated temperatures. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) were used to analyze the surface microstructure and impurity atom distribution, while Raman spectroscopy revealed characteristic phonon mode shifts induced by gadolinium doping. It was found that doping during growth results in a more uniform structure with fewer large defects, although localized regions enriched in carbon and oxygen remain. In contrast, diffusion doping leads to the formation of pronounced inhomogeneities, indicating significant dislocation formation and structural defects due to lattice parameter mismatches. The results demonstrate the influence of the doping method on the silicon surface state, elastic stress distribution, and the emergence of new vibrational modes, which can be utilized for the targeted modification of material properties in spintronic, optoelectronic, and sensor devices.

A comprehensive investigation of thermally induced phase transformations in the silicon-manganese (Si–Mn) system was conducted. The study utilized X-ray diffraction (XRD), Raman spectroscopy (including chemical Raman mapping), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM–EDS), deep-level transient spectroscopy (DLTS), and thermodynamic CALPHAD modeling. The sequence of transformations has been reliably reconstructed as follows: (i) interstitial incorporation of Mn and partial amorphization of the near-surface Si layer; (ii) nucleation and growth of MnSi (B20 structure, P2₁3); (iii) stabilization of the higher silicide phase Mn₄Si₇ under Si-rich conditions; (iv) at T ≫ 900 °C, a partial reverse transformation to MnSi. DLTS analysis revealed three electrically active deep-level centers with activation energies of Eс–0.53 eV, Eс–0.43 eV, and Eс–0.20 eV (σn ≈ 10⁻¹⁶–10⁻¹⁵ cm²), which correlate with the MnSi → Mn₄Si₇ transition and interface traps at the “silicide/Si” boundary. CALPHAD modeling confirmed negative Gibbs free energies of formation (ΔGf) and identified thermodynamic stability windows for MnSi (600–750 °C) and Mn₄Si₇ (800–950 °C). The resulting process map provides the technological parameters for synthesizing CMOS-compatible Si–Mn structures.