In this work, structural changes arising from the doping of p-type silicon (KDB-48, ρ=48 Ω·cm) single crystals with neodymium (Nd) atoms by thermal diffusion were studied using Raman spectroscopy. Samples were diffused in vacuum quartz ampoules at 1300o C for 10 hours and prepared by rapid cooling. Raman spectra were measured at room temperature using a spectrometer equipped with a 785 nm laser. In the initial and control samples, TA (127, 183 cm-1 ), LA (311/315 cm-1 ), TO/LO (523.9 cm-1), and second-order optical (952 cm-1) phonon modes were identified. After thermal treatment, the phase composition did not change, but the intensities of all modes increased due to structural ordering (LA mode by +71.1%). In the neodymium-diffused sample, fundamentally different changes were observed: the appearance of new peaks at 288, 398, 478, and 672 cm1 confirms the formation of Nd2O3 and Nd-Si (silicide) phases. The high intensity of the TO phonon peak at 520 cm-1 (7882 a.u.) and its shift to lower frequency (Δν =-3.9 cm-1) indicate a high degree of crystallinity and reduced mechanical stress in the diffused layer. The results confirm that neodymium significantly alters the structural and vibrational properties of silicon by forming new phases.