THE ELECTRICAL ASSESSMENT OF SI1-XGEX SI HETEROSTRUCTURES/

A comprehensive electrical characterisation of the SiGe/Si heterostruc tures has been performed in the wide temperature range (10-270 K). For this study die structures fabricated by the ion implantation techniqu e at three different substrate temperatures (room temperature, 150 C a nd 450 C) have been used. The presence and parameters of shallow and d eep levels and the diode performance were studied as a function of the substrate temperature. The sample implanted at 450 C shows the best d iode operation reflecting the higher quality of the surface silicon la yer as compared to RT- and 150 C-implanted samples. For the first time the cryogenic TSCR technique has been applied to this system which ma kes it possible to investigate strain in the silicon layer due to SiGe layer formation.