OPTICAL PROPERTIES OF SB DOPED GE FILM ON SILICON SUBSTRATE BY MOLECULAR BEAM EPITAXY TECHNIQUE

Abstract

To enhance the photoluminescence effeciency of the Ge film, we can apply a tensile strain or n doping in the Ge epilayers for modifying it’s energy band gap structure. In this work, we combine both electron doping method from Sb source and inducing a tensile strain in Ge films. Sb doped Ge grown on Si(100) substrate by molecular beam epitaxy technique. The dependence of photoluminescence intensity on the substrate temperature in the range of 130-240oC and on the Sb source temperature from 240 to 300oC are investigated. The active electron concentration obtained up to 2.5x1019cm-3. The tensile strain level in the Sb-doped Ge epilayers is twice larger than that of the P-doped Ge films using GaP solid source or PH3 gas precursor. These results are significant in the realization of the Si based photoelectronic devices which are compatible with mainstream CMOS technology.