Fabrication of Si1-xGex Alloy on Silicon by Ge-Ion-Implantation and Short-Time-Annealing

In our contribution we present the fabrication of Si1-xGex alloy by ion-implantation and millisecond flash lamp annealing. The 100 keV Ge ions at the fluence of 10×1016, 5×1016, and 3×1016 cm-2 were implanted into monocrystalline (100)-oriented Si wafers covered by 50 nm thermal oxide. In the consequence, the 50 nm amorphous Ge rich Si layers were obtained. The recrystallization of the implanted layers and the Si1-xGex alloying were accomplished by flash lamp annealing with the pulse duration of 20 ms. Flash lamp treatment at high energy densities leads to local melting of the Ge-rich silicon layer. Then the recrystallization takes place due to the millisecond range liquid phase epitaxy. Formation of the high quality monocrystalline Si1-xGex layer was confirmed by the μ-Raman spectroscopy, the Rutherford backscattering channeling and cross-sectional transmission electron microscopy investigation. The μ-Raman spectra reveal three phonon modes located at around 293, 404, and 432 cm-1 corresponding to the Ge-Ge, Si-Ge and Si-Si in the Si1-xGex alloy vibrational modes, respectively. Due to much higher carrier mobility in the Si1-xGex layers than in silicon such system can be used for the fabrication of advanced microelectronic devices.