Segregation and trapping of erbium during silicon molecular beam epitaxy

Erbium surface segregation is observed during growth of Er-doped Si by molecular beam epitaxy on Si~100! at 600 °C. Once a critical Er surface areal density of 2310 Er/cm is reached, enhanced Er trapping is observed, possibly due to the formation of silicide precipitates. Er segregation on Si~100! is fully avoided when growth is performed in an oxygen background pressure of ; 10 mbar, due to the formation of Er-O complexes. No Er segregation is observed on Si~111!, which is attributed to the formation of epitaxial Er3Si5 precipitates. © 1995 American Institute of Physics.