Erbium silicidation on SiGe for advanced MOS application

Ti capping has been found to be beneficial on Er(Si1−yGey)2 formation in Ti/Er/Si1−xGex system. In the case of the system without Ti cap, the sample was oxidized at temperature as low as 300 °C and Er2SiO5 was found to be the predominant phase at all annealing temperatures. On the other hand, for Ti/Er/Si1−xGex samples, no Er2O3 was formed and the predominant phase found after annealing at higher temperature was Er(Si1−yGey)2 resulting in a lower sheet resistance than those without Ti cap. In addition, Ti capping has also improved the surface morphology of the sample by reducing the pyramid-like defects which were found in Er/Si1−xGex samples especially after annealing at 600 °C.