Ion-beam synthesis of the crystalline Ge phase in SiO$_{x}$N$_{y}$ films upon annealing under high pressure

The nucleation of the crystalline Ge phase in SiO$_{x}$N$_{y}$ films implanted with Ge$^+$ ions with the energy 55 keV to doses of 2.1 $\times$ 10$^{15}$–1.7 $\times$ 10$^{16}$ cm$^{-2}$ and then annealed at a temperature of $T_a$ = 800–1300$^{\circ}$C under pressures of 1 bar and 1–12 kbar is studied. From analysis of the Raman spectra, it is concluded that amorphous Ge precipitates increase in size upon hydrostatic compression at a temperature of 1000$^{\circ}$C. Raman scattering at optical phonons localized in Ge nanocrystals is observed only after annealing of the samples with the highest content of implanted atoms at a temperature of 1300$^{\circ}$C. In the photoluminescence spectra, a peak is observed at the wavelength $\sim$730 nm. The peak is considered to be the manifestation of the quantum-confinement effect in nanocrystals $\sim$3 nm in size.