Understanding Epitaxial Growth of Phase-Change Materials through Studies of the Local Structure

Abstract

Ge₂Sb₂Te₅ (GST) thin films were grown epitaxially on (001)- and (111)-oriented substrates with control of the growth surface temperature obtained by in-situ quadrupole mass spectrometry (QMS). X-ray absorption near edge spectra (XANES) obtained on samples prepared on different substrate orientations and with different surface temperature were compared. The results show that the Ge₂Sb₂Te₅ layers grown on (111) surfaces show a more pronounced rhombohedral distortion as compared to layers grown on (001)-oriented surfaces.