In this paper, we followed the formation sequences of the different manganese silicides by performing simple annealing at different temperatures of the deposited manganese (Mn) on silicon (Si) substrate. Phase change and transition temperatures have been reported. In situ x-ray diffraction (XRD) is used in two different chambers and the results obtained are presented in 3D figures. The surface roughness is first obtained by atomic force microscopy (AFM) and then by scanning electron microscopy (SEM) characterization. The latter is also used for the detection of the different superimposed layers after the formation of the different silicides obtained in the solid phase reaction (SPR). Focus ion beam (FIB) cuts were used to analyze the different layers obtained during silicide formation at these temperatures. In this study, we have obtained Mn15Si26 for high temperatures (above 850°C). Finally, an epitaxy of HMS (Mn15Si26) is obtained at high temperatures with a simple annealing process.