Impurity related interface effects in GSMBE grown InP

The authors have found a highly conductive n-type interface layer between semi-insulating InP substrate and undoped InP layer grown by gas source molecular beam epitaxy. Due to this interfacial layer the measured Hall mobilities at 300 K and 77 K are underestimated and carrier concentration is overestimated. The secondary ion mass spectrometry depth profiles reveal an accumulation of silicon and carbon at the interface. The samples were grown on differently pretreated substrates. It seems that silicon and carbon contaminations originate from the exposure to air during the loading to the growth chamber.<>