Effect of SiGe thickness on crystallisation and electrical properties of sputtered silicon film in Si/SiGe/insulator structure

Layered structures Si/SiGe were deposited on silicon oxide by RF sputtering system and were furnace crystallised at a temperature of 550°C. The effect of SiGe seeding layer thickness on crystallisation and electrical properties of the top silicon film was studied for SiGe films with thicknesses of 11, 22 and 45 nm. Crystallisation process was characterised by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Doping of stacked structures by phosphorous and boron was investigated through measurement of sheet resistance and Hall mobility. In the scope of investigated thickness ranges, 11 nm thick seeding layer showed the best performance. It is effective in reducing the crystallisation time of the top silicon film, while providing improved morphological and electrical properties of the stacked structure.