Thermally treated Ge crystallites embedded inside PS with Si capping layer for potential photonics application

In this work a very low cost and conventional technique was used to prepare Ge nano/microstructures by means of filling the material inside porous silicon (PS) using thermal evaporator. PS was prepared by anodization of Si wafer in ethanoic hydrofluoric acid (HF).The Ge layer was deposited onto the PS by thermal evaporation.Subsequent annealing at 650°C and 750 C for 30 mins were done to drive in the Ge inside PS structure.Structural analysis of the samples was performed using energy dispersive X-ray analysis (EDX),scanning electron microscopy (SEM),X-ray diffraction (XRD)and Raman spectroscopy. The process was completed by inter- digitated Ni metal deposition using thermal evaporator followed by post metal annealing of 400°C for 10 mins to form Metal-Semiconductor-Metal (MSM) structure. Raman spectrum showed that a good crystalline structure of the Ge can be produced inside the silicon pores. Finally current-voltage (I-V) measurement of the Si/Ge/PS MSM photodetector was carried out to show potential application in photonics.