Growth of single crystalline GePb film on Ge substrate by magnetron sputtering epitaxy

This paper reports the synthesis of single-crystalline GePb alloy films on a Ge(100) substrate by magnetron sputter epitaxy. The as-grown GePb alloy films possess high crystalline quality and no dislocations, as revealed by X-ray diffractometry, transmission electron microscopy. The Pb composition of the GePb alloy was about 0.4% at the growth temperature of 250 °C and it decreased with increasing substrate temperature up to 400 °C. The thermal stability of the GePb alloy was studied using Raman spectra and atomic force microscopy (AFM)results, and it was observed that Pb segregated from the GePb alloy above 400 °C. The successful growth of single-crystal GePb lays the foundation for future GePb device fabrication.