AUTHOR=Mosleh Aboozar , Alher Murtadha A. , Cousar Larry C. , Du Wei , Ghetmiri Seyed Amir , Pham Thach , Grant Joshua M. , Sun Greg , Soref Richard A. , Li Baohua , Naseem Hameed A. , Yu Shui-Qing 

TITLE=Direct Growth of Ge1−xSnx Films on Si Using a Cold-Wall Ultra-High Vacuum Chemical-Vapor-Deposition System

JOURNAL=Frontiers in Materials

VOLUME=2

YEAR=2015

URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2015.00030

DOI=10.3389/fmats.2015.00030

ISSN=2296-8016

ABSTRACT=<p>Germanium–tin alloys were grown directly on Si substrate at low temperatures using a cold-wall ultra-high vacuum chemical-vapor-deposition system. Epitaxial growth was achieved by adopting commercial gas precursors of germane and stannic chloride without any carrier gases. The X-ray diffraction analysis showed the incorporation of Sn and that the Ge<sub>1−</sub><italic><sub>x</sub></italic>Sn<italic><sub>x</sub></italic> films are fully epitaxial and strain relaxed. Tin incorporation in the Ge matrix was found to vary from 1 to 7%. The scanning electron microscopy images and energy-dispersive X-ray spectra maps show uniform Sn incorporation and continuous film growth. Investigation of deposition parameters shows that at high flow rates of stannic chloride the films were etched due to the production of HCl. The photoluminescence study shows the reduction of band-gap from 0.8 to 0.55 eV as a result of Sn incorporation.</p>